Conference 7.286::home_work

    I had a problem like that many years ago.  It turned out that the
    neutral line was open at the service feed somewhere.  Thus many
    appliances had 220 across them and many had 0.  This kind of situation
    is extremely dangerous (fire hazard, etc. etc.).  If you have an
    open neutral and your ground connection is VERY good, nothing much
    happens.  If the ground is bad or becomes bad, things go to hell
    in a handbasket fast.

    I just thought I'd throw a few comments out to maybe draw some
    discussion about this one...
    
    My first reaction to this one is to think that the problem is really
    at your neighbors house (the one whose water line was disconnected
    when you had your problems).  There is no reason that I can think
    of that there should be a potential difference between his water
    line and the water main (the shock the workman got and the sparks
    when reconnecting). My theory is that the neighbor's water line
    is shorted to a hot wire somewhere in his house. This of course
    is not a "dead short" but probably a nick in a wire causing a 
    high resistance connection. Since ground and neutral are tied together
    in the service panel, their ground and neutral being tied to a hot
    lead essentially ties your ground and neutral to the same hot lead
    (giving you a zero reading on one side and 190 on the other)because
    your ground is tied to their ground via the water lines.
    
    just a couple of questions:
    
    Are there any more houses that are serviced from the same transformer
    that you are?
    Did anyone else have any electronic stuff get damaged?
    
    Joe

       We are also having some water work done on our street. Last
    week our neighbors had the fire dept. there because they smelt
    smoke and the lights were flickering. After invesigating,  the
    Mass. electric company said that the water dept.  disconnected
    their ground wire from the water meter which caused an electrical
    surge. From what they told me... a few of thier wires got fried
    and the water dept. is liable.

The problem has been solved (I hope)!  (.1) had the answer.

The electric company came by my house yesterday morning to install recording
meters on my main service panel.  While they were there, they checked the main
circuit breaker box and discovered that the neutral connection was very loose.
This service panel had supposedly been "checked" by the town electrician and an
electrician I had called. 

The electric company also checked the connections at my meter and decided that
the neutral there was also bad.  This had been discovered the first time they
were at my house and said it probably was not the cause of the problem but I
should have my electrician fix it.  My electrician looked at it but had to
order the appropriate parts so he did not fix it.  (The wire is aluminum, going
into the box, and the wire exiting from the box and going into my house is
copper. The wires are joined in the meter box with a device which clamps each
piece and serves as a connection.  The correct procedure is to apply a special
paste (Penetrox?) on the wires to prevent corrosion.  This was not done 17 years
ago when the house was built.) 

The electric company removed both wires from the very corroded clamp and the
wire hidden under the clamp was in very poor condition.  They cleaned the wires
with a stiff metal brush and then created a fairly solid, but temporary, jump
between them.  The jump apparently violates electrical codes for permanent
connections but they are allowed to make them for emergencies.  They are also
not supposed to fix any connections belonging to the customer (rather the
customer's electrician is supposed to do this under their direction); however
this can be waved in an emergency if the customer is willing to assume any
liability (which I was).  I still have to get my electrician to make a
permanent connection with the proper clamp. 

We went back into my house and started the dryer which no longer caused the
lights to dim on start-up.  They explained to me that the dimming was
previously caused by the dryer motor (at 110) rather than the dryer heater
resistance (at 220). The "definitive" test they suggested is to run the washing
machine in spin cycle; this worked fine with no lights dimming.  They came back
this morning to remove their recording meters and everything appeared fine.
                 

In summary, I have probably had this problem for the five years I lived in the
house.  The dynamite blasts for the sewer construction most likely caused
vibrations that made a loose connection(s) much worse.  As I understand it, the
grounding load is supposed to be distributed 50-50 between the neutral at the
service panel and the water pipe ground;  my corroded/loose neutral connections
threw this into a very unbalanced (20-80?) state.  Since I was the only
one in the neighborhood to suffer any damage, the disconnection-reconnection
of my neighbor's ground appears to have further upset this condition but
did not harm his appliances (his lights don't dim so his neutral is probably
fine).  Note:  dimming lights don't automatically mean you have a poor neutral,
it is also a function of the service rating and distance from the transformer.
Since I have 200 amp service and the transformer is in front of my house,
dimming lights did, in fact, indicate a problem.

The connection at my circuit breakers is something I could check every couple
of years; however, how often do you remove your electric meter to check
the connections there?  This problem would not be recognized until you ran into
a problem like mine, or worse yet, a fire.

I also feel that the electric company really did a super job in helping me.
The connections behind the meter and at my service panel are legally my
responsibility, not theirs.  They could have just diagnosed a potential
problem and come back after I had fixed it.  

I think I'll log off and plug in the rest of my appliances.  Ready Kilowatt
and Mr. Light Bulb are my friends, once again! 

mike

    I have a basic electrical question.
                              
    What is the proper way to wire a light when I want two switches able to
    control it? I know this is frequently done -- for instance at the
    top and bottom of a stairway. You can turn on the light at the bottom
    and turn it off at the top, etc.              
               
               
                              ------------
    --------                  |  light   |          --------     
    |switch|                  |__________|          |swtich|           
    --------                                        --------        
                                                         
                                                    
    ---------                                       
    | power |                                       
    | panel |                                       
    --------                                        

I have done simple wiring before, but this one eludes me!
    
    Thanks for the help.
    
    VCS

                               14/3
       ,----------------------------------------------.
       |                      ------------            |
    --------                  |  light   |          --------     
    |switch| 3-way            |__________|          |swtich| 3-way          
    --------                        |               --------        
       |                            `-----------------'                    
       | - 14/2                              14/2              
    ---------                                       
    | power |                                       
    | panel |                                       
    --------                                        

    The logic looks like this:

    |     14/2    |          14/3           |             14/2

    white---------*-------------------------*--------------------------*----.
                                                                            |
                                                                          load
                  ,-*--------black-------*-.                                |
    black------*-'                          `-*--------black-----------*----'
                    *---------red--------*

    The light is on. If either of the two switches is moved to the red wire,
    the circuit is broken. To relight the light, either that switch must be
    moved back to the black, or the other switch moved to the red.

    
                                o-----(Black)--o
    Power  (Black)-----------o                    o-----(black)---LIGHT
                                o------(Red)---o
           (White)------------------------------------------------FIXT
    
    (Tough to draw switches).  You need single pole double throw switches.
    
    The left end of the left-hand switch, and the right end of the
    right-hand switch as shown above go to the terminal labeled "COMMON"
    on each switch.    
                       

    You can also add more switches, as shown below:

    white---*--------------------------*-------------------------*---------
                (B)                (A)   (C)
         (A) ,-*--------black-------*-. ,-*--------black-------*
    black-*-'   (C)                (B) X (D)                      ,-*--black
               *---------red--------*-' `-*---------red--------*-'

           3-way                     4-way                      3-way

    The "3-way" and "4-way" should probably be translated into "3-pole"
    and "4-pole". A nornal light switch has two poles, which are either
    connected or not. A 3-way (3-pole) switch has three connections, and the
    input connection (A) is always connected to one of the output connections
    (B or C). The 4-way (4-pole) has four connections; in one position, the
    connections are (A-D) and (B-C), and in the other position, the connections
    are (A-C) and (B-D).

    More 4-way switches can be added to the above circuit, as long as they are
    between the 3-ways. I've used the three-switch setup, with the first switch
    at the bottom of the stairs, the second at the top, and the third at the
    other end of the upstairs hallway - I have yet to see a situation that calls
    for more than three.
    

    Thanks for the information. I'm all set now!
    
    VCS

Mass Hardware in Acton carries a wonderful little book with all
the wiring help you could ever want.  It's called something like
"Electrical wiring for Home and Farm Simplified".  The book
claims to conform to the latest national wiring standards and is
in it's 37th edition.  For $2.95 you can't go wrong...

R.

    The real question is FINDING 4-POLE switches!!! Try it. I have yet
    to
    find a retailer that carries it IN STOCK!
    
    Mark
    

                That's the sort of thing that you go to your local
        electrical supply house for.
                
                /s/     Bob

     Spag's has (had) four pole switches, as so does Maynard Supply
    on Rt.62.
    					Kenny
    

re: .5

The book's title is "Wiring Simplified".
It's in its 37th edition.

R.

    I bought a 4-pole switch at Spag's last week ($6.50 or so).  I had
    to ask at the Electrical Department (they kept them in the back).

By the way, for ease of wiring, you always need a 14-3 wire between the two 
switches, but you can run the power into either switch box or the light box, 
and if you run the power into a switch box you can run the 14-2 wire to the 
light from either switch box.  For example, if you run the power to the light:

   Switch							 Switch
 +-------+		     		  		       +--------+
 |	 |		     	White	 		       |        |
 |     o-+-----------------------------------------------------+-o      |
 |  o    |                       Red                           |    o   |
 |  |  o-+-----------------------------------------------------+-o  |   |
 |  |    |			Black			       |    |   |
 |  |  ,-+-----------------------------------------------------+----'   |
 |  |  | |						       |        |
 +--+--+-+		      +---------+		       +--------+
    |  | 	Black	      |         | Black
    |  `----------------------+---------+-------- Power in
    `-------------------------+---,  ,--+-------- 
		White	      |   |  |  | White
			      +---+--+--+
				  |  |
				 Light

With a few minutes and a piece of paper it's easy to figure out the other 
variations.  Also, note that if you are using 14-3 wire, the circuit should 
only be a 15 amp circuit (which most lighting circuits are).  If it's on a 20 
amp circuit, you should use 12 guage wire.

Paul

Here's the variation for the author's problem (light between the switches).
'W/tape'  means White wire with a band of black electrician's tape at both
ends (to signal that this is a 'hot' wire)



                 B
    B        o----------------------------------------------o
----------o      R                                             o-----|
             o----------------------------------------------o        |
    W            W                              W/tape               |
-------------o-------------------|   |-------------------------------|
                                 |   |
                               W |   | B
                                 light

    
    Now the next question is: "Where do you add a dimmer to any of the
    above circuits and do they have 3-way dimmers?"
    
    John
    

As the author of .0:
    
    Thanks for all the help on the wiring. I put in the 14-3 and the
    swtiches -- and it works!
    
    PROBLEM:                                          
                                                      
    Even though I put the fluorescent lights on a separate circuit, they
    dim when other appliances in the house come on. Why?
                                                      
    This is a 2 year old house. Originally, the basement had standard
    incandescent lights on a circuit with the freezer and other appliances.
    These lights (as well as others which may or may not have been on the
    same circuit) dimmed when some of the appliances started. So, I ran a
    new circuit -- complete with a new 15amp circuit breaker to make sure
    the new fluorescent lights would not dim. But they do. 
                                                         
                           Any ideas on what is wrong?   
                                                         
    

    re .13
    
    Yes, 3-way dimmers are available, in most department stores (and
    surely Spag's). You put a single dimmer at either end of the
    run of switches. Unfortunately, you can only control the brightness
    from that end.

Just a piece of info for those of you who have to control/dim lights from
several locations for convenience.  I use BSR x10 modules in my house and
with control consoles located in strategic locations I can control circuits
anywhere in the house.  Its especially nice at night in a multi-story
house to hit the all-off button and all my lights go off - or in an emergency
you can hit all on and all the lights come on.  The original reason I got them
was so my wife could turn the outside floods on from the upstairs master
bedroom.  Now were addicted - we can control the whole house from anywhere.
Additionally I have a timer module so I can have any ligths come on at
any time for security or other reasons - like coming home to a house with
some lights on when you drive home in the dark.

As for dimming.  Putting devices on a separate service is not necessarily
going to eliminate such a problem.  It depends on what your house wiring
and service back at the box looks like.  When a large appliance goes
on (one with motors) a large surge current can and does cause a momentary
voltage drop coming into the house.  This voltage drop can and does get
reflected on house branch circuits especially if the devices on these
circuits are very voltage sensitive.

    RE: -.1
    
>    It depends on what your house wiring and service back at the box
>    looks like.  
    
Can you elaborate on this? This is a new house and I assumed it had
adequate service.    
    
>    This voltage drop can and does get reflected on house branch circuits 
>    especially if the devices on these circuits are very voltage sensitive.


1. Are fluorescent light fixtures "very voltage sensitive"?
2. Are lights on a dimmer switch which have been turned down to a low output
   level "very voltage sensitive"?

    
    Do you know of any "cure" for the situation?
    
                       Thanks, VCS

    re .16- the BSR system 10
    
    I agree they are a real great gadget. I didnt buy one because they
    were a bit expensive. Last year DAK- a catalog company that sells
    electronic stuff was selling the controller for $9.90, plus a couple
    bucks shipping. They had the simple controller and the fancy
    programmable timer controller and several of the optional device
    controllers all at similar savings. I just got a catalog from them
    a couple weeks ago and noted they still had them listed. Unfortunately
    I threw the catalog out so I cant give you an exact address or current
    price.
    
    

    If you are having a dimming effect on one circuit when an appliance
    on a TOTALLY different circuit is switched on... then you have
    feeder problems.
    
    	1. Check overall box loading. If you approach the box limit
    		for appliances ACTUALLY in use, then you ned more 
    		AMPS from the street. (Not usually the case as boxes
    		are typically calculated properly by a good electrician.)
    		If you DO NEED more amps from the street... look out!
    		the power company gets real picky about what they can
    		and can not do, and what it will cost YOU to upgrade!
    

    	2. Have a qualified electrician check the MAIN feeder connections.
    		If you have a dimming effect, power is being lost
    		somewhere. If the connections are faulty, the actual
    		joint will take some power (and heat up in the process!)
    
    mark
    

    
    Let me add to the recommendations for the BSR units. I use them
    to control several lights/appliances in my house. They are getting
    cheaper too. BTW, Radio Shack and Sears sell them under their brand
    names. Usually one of them is having a sale (plus DAK). Sears seems
    to be the only one who makes a three way wall switch unit.
    
    							Mark
    

    RE: .17
    >    1. Are fluorescent light fixtures "very voltage sensitive"?
           
    I have several (like six or seven) fluorescent lights in my shop,
    a few of which were VERY cheap ones ($9.00 each or something like that).
    Those lights are VERY VOLTAGE SENSITIVE. The better lights (in the
    range of $20 each) do not show the problem nearly as much.  My drill
    press and band saw are on the light circuit as they have lights
    on them I always forget to turn off.  Everytime I start the drill
    press, the cheap light just about go out - well, a slight exaggeration,
    but they do dim quite a lot.  The good ones hardly blink.  It probably
    depends on the quality of the ballast used.  I also have on in my
    organ that is "All solid state", which I guess means that it doesn't
    have a ballast in it and it hums like hell. A little 60hz noise
    I can deal with but this too much!
    
    -Bob 

    
>    It depends on what your house wiring and service back at the box
>    looks like.  
    
> Can you elaborate on this? This is a new house and I assumed it had
> adequate service.    
    
I suppose I should ask exactly what is going on which causes your lights
to dim.  Large motor devices (like well pumps) draw large surge currents
momentarily so a voltage drop can be seen especially if you are at the
end of the line from where the power source is for your house (power
source being the reduction tranformer).  To give an example an RA disk
drive can suck 36 amps at 120 volts.  Usually the dimming would/should
be very momentary.  What's the service into your house, how far from
distribution tranformer?

-peter

    RE: -1
    
    The service is 100amp, and I do not know how far I am from a
    distribution transformer. I am not in a development, nor at the
    end of a street, so I would guess that there is a transformer within
    a reasonable distance.
    
    As for what is going on, the lights have done a momentary dimming when:
                                                  
   1 This morning I know that the furnace was on (FHA-oil) as well as
     the water heater (Elect).                    
                                                  
   2 Last night I know that the furnace and hot water heater were off,
     and the refrigerator kicked in.
             
   3 Night before last (furnance & water heater off) when the large
     upright freezer kicked in the lights dimmed momentarily and then 
     flickered for several minutes.
    
    
    Based on all the information I have received thus far, I would guess
    that the problem is caused by: 

    a. The cheapness of my lights (Channel $10)
    b. The 100amp service my house was wired with
    
   Any other thoughts?
    
    Thanks
    VCS                            
     

>    a. The cheapness of my lights (Channel $10)
    
>   Any other thoughts?

Forget the flourescents for the moment.  What do the incandescents show.
If you can hang an incandescent off the same circuit this will give a
much more reliable indication (visually) of what's happening.  The light
from the incandescent will reflect better the volatage fluctuation.  If it
dims momentarily (we're talking less than 1/2 second here - and the dimming
is just) then I should think this would be ok.  If its much longer or much
dimmer then the service box, feed and branch circuits bear a little closer
inspection.  Closer inspection means looking at the mechanical connections
making sure everything is tight can clean.  How old are the circuit breakers?
Maybe one is old and is not giving good connection.  Turn them on and off
several times to cause contact wiping.  Next step would be to look at
actual current draw and voltages.  This would require an amp probe and
voltmeter.  

-peter

    
     

    I too say forget the 'cheapness' of the lights. That should NOT
    be an issue.
    
    One trick I learned is as follows: (This MUST be done with caution)
    
    Using a standard AC voltmeter, press one probe into the main feeder
    line. (there should be 3 wires coming into your house which produce
    basically two separate 'legs' for your breaker box.)
    Determine which appliances turning on cause the problem and find
    the breaker that is supplying it.
    Press firmly one voltmeter probe into the FEEDER lead at the TOP
    of the first connection to the box. (Wire is probably 1/2" in diameter
    so look for that on the TOP of the box. Press into WIRE not after
    connection point!)
    Press the other probe into the BREAKER screw connection feeding
    the leg in question.
    If the appliance kicks on, you should see VERY little voltage
    present if everything is ok. (actually ideally ZERO, but in reality
    a breaker will take a few volts in the element within it)
    
    IF THE VOLTAGE IS ANYTHING MORE THAN A FEW VOLTS... check connections,
    check breakers, check wires that have been nicked, etc.
    
    
    Mark
    
    (BE CAUTIOUS IF YOU DO THIS!!! LOTSA AMPS IN THAT BOX!)
    
    

    Your problem sounds very familiar to me. I had the flickering lights
    problem for quite some time before isolating it. I suspected the
    power company was causing it due to the time of day I noticed it,
    early AM. I thought maybe they were throwing some big switches or
    something as the demand increased.
    
    I checked with some neighbors as to whether they were experiencing
    any of this, of course they weren't, so then I got real curious
    and worried about my electric service.
    
    I isolated the problem by waiting until the flickering came up again
    and went down to the service panel, took off the cover and just
    looked and listened.
    
    What I found was the connection from the main to the circuits was
    loose on one leg and the flickering lights was caused by the arcing
    across the on again off again gap. 
    
    The solution was simple, VERY CAREFULLY, WITH ONE HAND IN YOUR POCKET,
    WEARING RUBBER SOLED SHOES, reach in with a screw drive and tighten
    the screw.
    
    Loose electrical connections can/will cause fires. God knows how
    long this problem existed in my house, it's 40 years old.
    
    Careful and happy hunting,
    
    -boB

    A new (Cape-style) house with unfinished 2nd floor & basement...
    
    I am about to embark on wiring the upstairs.  My thought was to
    use 12/2 wiring for plugs/lights.  However, when I examined the
    wiring left by the builder for the connections to the power box
    (in basement) he used 14/2.
    
    	Question - which alternative is recommended ?
    
    		1. continue 14/2 usage.
    		2. install at junction/connection 12/2.
    		3. reroute 12/2 to the box in basement.
    
    Also, I had hoped to run a separate circuit to the bathroom but
    only two circuits are terminated to the 2nd floor.  Should I -
    
    		1. connect ground-fault plug to the 1st floor plug,
    		   or install a second circuit.
    		2. split the bathroom between the two circuits.
    		3. is it worth the effort to drop a third line to the
    		   power box.
    
    Any input would be appreciated; I'm not very confident in this area...
    
    Dwight
 
    

    Two circuits are enough for the upstairs of a normal-sized cape,
    and 14/2 is sufficient, unless you're planning to put a shop or
    a 5-kw. ham transmitter up there.
    
    Put the bathroom at the end of one circuit. Place a GFCI/outlet
    unit in the first box, then wire the rest of the bathroom (including
    light and switch) from the LOAD side of the unit. That way, the
    entire bathroom is protected, and only the bathroom.
    
    Use the two circuits so that if one trips, you can still find your
    way to the stairs with light from the other (eg, you might want
    to supply the hallway light from one circuit, and put an outlet
    in the hallway from the other circuit, into which you can plug a
    night/emergency light).
    
    To keep voltage drops to a minimum, use the screw connections on
    the sides of outlets, and not the slip-in connections on the back.
    
    For more home wiring hints, see "Home Wiring Simplified" (or something
    like that, available in electrical dept. at Spag's), or hardcover
    books from Readers Digest and Home and Garden, available at libraries
    and book stores.

In general, 14 gauge wire is used for 15 amp circuits and 12 gauge wire is used 
for 20 amp circuits.  If by any chance the 14/2 wire is attached to a 20 amp 
breaker, you should probably change the breaker to 15 amp, since I believe that 
it's a fire hazard to send 20 amps through 15 gauge wire.

Which you decide to use depends on the size of the circuit, but whichever way 
you go, match the wire to the breaker.

Paul

    First, .-1 is right:   the 14-gauge wire is for 15-amp max.   If
    you continue from the drop your builder left you with 12 gauge,
    think of the 14 gauge as a fuse (that is, don't do it).   The maximum
    capacity of the circuit is the smallest capacity item on it - that
    is normally the circuit breaker.   If you run a 20-amp breaker,
    to 14-gauge wire, and then continue with 12 gauge wire, you've got
    a 15 amp circuit, and a good chance of a fire.   DON'T DO IT.  
    It may also be against code (the code generally "makes sense" and
    this doesn't make sense.)
    
    The recommendation about the GFCI is also correct.   You can get
    the GFCI outlets at almost any hardware store, and I'm sure Spags
    has them too.   If you have a dedicated breaker in your panel, and
    you can "find" that circuit, then there is ample capacity to handle
    one more bathroom (those circuits handle the kitchen (most likely
    some but not all, probably the ones around the kitchen counter) and
    the other bath.   If you can't locate the circuit from upstairs
    (I couldn't, it was too far away), the outlet-style ones will be
    enough.   Also, my inspector exempted the bathroom lights from the
    GFCI protection.   Also note that connecting the convenience outlet
    on a medicine cabinet is against the code.   They are generally
    two-wire outlets and thus can't be connected to the GFCI to give
    the right protection.

    Another recommendation:   Do get a permit and have it inspected.
    I had to have my inspection before I put up ANY insulation - all
    wires must be visible.   And, use insulated staples.   The books
    mentioned earlier describe the maximum number of wires you can have
    in any single outlet box or junction box - adhere to them.   Make
    sure you don't cross your hot/ground (keep the black wire connected
    to the black wire throughout) as the final inspection (hot wire
    test) will insure that the polarity is correct on all outlets. 
    They will also test the GFCI, and you must tell the inspector what
    outlets are on the load side of any outlet-type GFCI  protector.

    Another point: Do *not* use a GFCI circuit breaker at the box. 
    My electrician says they are expensive, often fail to work right
    out of the box, and are not worth the trouble.  Use the outlet type--
    they only cost $10-15 and can be used to protect a number of outlets
    in a chain.
    
    Alex

Are you sure on that $10-$15 price tag?  I bought one at Spags 5 years 
ago for $20 and felt like I got a bargain because everywhere else wanted 
over $30!  Have prices on something finally come down?

-mark

    
    re .6
    
    Yes, GFCI outlet devices have come down quite a bit in price. The
    one I bought at Spag's eight years ago cost me $27, and now I can
    find them for $10 on sale in department stores (even Sears stocks
    them at $16). They are a much better buy than the panel GFCI breakers,
    and seem to be much less prone to lightning suicide.
    
    re .3
    
    Assuming that the electrician knew his job, there is a 15-amp breaker
    at the other end of each 14/2 wire that he ran to the second floor.
    Extending the circuit with 12/2 does not violate any code in that
    case, as the circuit is still protected in accordance with its
    weakest link. For long-haul circuits, it sometimes makes sense to
    use a heavier wire than minimum to decrease line voltage drop. However,
    I would not classify a normal circuit in a two story house as long
    haul, and in any event running 12/2 for the second half would not
    gain enough in reduced line loss to justify the cost in materials
    and decreased wire counts in the boxes.

    	I have a question about something that was mentioned in .1.
    
    	Is it better to attach the wire to the sides of the outlet,
    instead of the quick connects? If so, Why and What are the benefits?
    
    	I've always used the quick connects and not have have any problems
    but maybe I should start using the sides. I guess quick connect
    = Easier + Me taking the easy route..
    
    				Thanks
    

The problem with the quick connects is that the point of contact to the wire is 
quite small.  There are (I think) two metal plates angled together like a V, 
and the wire slips between them, with the V preventing the wire from being 
pulled back out.  The only point of contact is where these plates hit the wire, 
and that's usually with only an edge of the plate:

			\ \   | |   / /
			 \ \  | |  / /
			  \ \ | | / /
			   \ \| |/ /
			    \/| |\/
			      |_|

This is at least an order of magnitude smaller than the contact area of a screw 
terminal.  I know of at least one case where the connection in a quick connect 
has failed altogether.  If you think of a large circuit, the current must go 
through a series of these to get to the last outlet, and this can cause a 
significant voltage drop.  It might not be much of a loss to use the quick 
connects on the last outlet, but terminating outlets are easy to wire anyway.

It takes a little longer, but I always use the screw terminals.

Paul

    
    .9 was on the money. I have traced a multitude of wiring problems
    to use of the slip-in connects (not in MY house, of course ;-).

re: quick connection stories

I had 2 intermittent open circuits because of them.  I think that
quick connections exist so that contractors don't have to pay
electricians to do the job right.

__Never__ use quick connections with Aluminum wire!!!

R.

    While you are in the planning stages for the wiring, you may
    want to plan for a future room air conditioner.  If there is a 
    window where you think you may install an air conditioner, you
    may want to run a separate circuit to an outlet below that window
    so that the AC will have its own circuit.
    
    Mark
    

    RE: .11
    
>   __Never__ use quick connections with Aluminum wire!!!

    This may be true with fixture for CU wire (which should NEVER be used
    with AL wire anyway), but AL fixtures have just that type of
    connections - to keep constant pressure on the wire. The problem with
    AL wire is that as it oxidizes, it gets smaller in diameter.  With a
    screw connection, this can lead to a loose and hence dangerous
    connection.  The 'quick type connection' keeps constant pressure on the
    wire as it gradually gets (minutely) smaller. 
    
    Just thought you'd like to know.
    
    -Bob
                                                 

    The same electrician who told me never to use quick-connects also
    told me to avoid wiring through outlets.  That is instead of using
    the receptacle to splice the circuit like so:


          -----------------------      ---------------------------
            S              _____ \    / _____                        
            o             / __  \_@__@_/ __  \         to other      
            u             |    o            o|          outlets      
            r             \ --  /-@--@-\ --  /                       
            c              ----- /    \ -----
            e                   /      \
          ---------------------/        \------------------------

    Do it this way:

                                splice
          ----------------------\---------------------------------
            S              _____ \      _____                        
            o             / __  \_@__@_/ __  \          to other
            u             |    o            o|           outlets
            r             \ --  /-@--@-\ --  /
            c              ----- /      -----
            e                   /
          ---------------------/---------------------------------

    The reasons are:
	- If ANY screw works loose in the wire-thru method, you get problems
	  all the way down the line (no, the gremlins don't loosen them,
	  you do when you're wallpapering or whatever).

	- Those little break-off bars between the screws don't have to
	  carry the current for the whole circuit.

    SInce I just had my final inspection done on my wiring heres
    my two cents worth. On several of my outlets I used a type
    that you could insert from the back then by tighting the
    screw on the side the wire was clamped to the outlet. It
    met code but the inspector wasn't pleased. The reason was
    that there was more bending of the wire when the outlet
    was pushed into the box when it was inserted from the back 
    then when put on the screw on the side. 
    
    Adding a little thought to that one could see that with straight
    push in there could be more pressure put on the contact points
    causing the wire to pull out. The other is that if one did
    not push the wire in far enough or the wire started pulling
    out there will be some bare wire showing. This could cause
    a intermitten short.
    
    dave
    

    re .14
    
    First, I find your drawing a little confusing.  What do you mean
    be source.  Wouldn't it be better to label it like so?
    
    
               black                            black
          -----------------------      ---------------------------
                           _____ \    / _____                        
                          / __  \_@__@_/ __  \                       
                          |    o            o|                       
                          \ --  /-@--@-\ --  /                       
                           ----- /    \ -----
               white            /      \        white
          ---------------------/        \------------------------
    
    Is thre any reason to go through the house and make the changes
    in the wiring your friend suggested?  Finally, should the splice
    go to of the live screws on the outlet or is the power drop over
    one of the tabs inconsequential and it's only when power passes
    through several tabs that the loss becomes noticeable.
    
                                                August G. Reinig

    Is there any way to tell whether an existing panel breaker has a
    GFCI? 

    					Val 
    					(also doing bathroom wiring)

I believe the panel breakers have the same test feature as the outlets 
(you're supposed to push test once a month to see if the ground fault 
portion is working properly).  I believe that the affected outlets 
would be labeled as well.  GFCI breakers are rare in most houses.  Due 
to cost and reliability, most builders opt for the single-outlet types.

	I have a GFCI breaker.  It's as you described.
    

    I've recently 'liberated' a motor from a dishwasher we replaced.
     I'd like to use this motor for something, since it does work OK.
    (I'll probably get something like a belt sander or lathe from AMT,
    they sell their tools without motors).  Anyway, this motor was wired
    to a 110V line, and has 4 wires coming from it - black, white, yellow,
    and red.  My question, for you electrical types, is how would I
    wire this up to a standard 3-prong plug so I can use it?  Thanks
    in advance for any help.
    
    -Mark LePage
    

    Before you decide to use it for anything check out the HP of the
    motor. A lot of diskwasher motors are less then 1/4 HP. If it
    is, junk it. Its not worth using. Also some of them are two speed.
    
    dave

    Most (all?) dishwasher motors are bi-directional.  One direction pumps
    the water through the spray arms, the other pumps it out the drain. 
    
    -joet

    The point in .1 (horespower rating) is one I had forgotten about.
    I took a look at it last night, but can't find any h/p rating on
    the plate with the other standard info.  The motor will certainly
    need to produce 1/2 h/p or more, so maybe this 'project' isn't worth
    it.  An underpowered tool probably wouldn't be much good.
    

    The saga continues.  After some good replies to my questions on
    kitchen subfloors, etc. I am well on my way to a new kitchen.  As
    part of the "package", the installer is putting in the exhaust vent
    from the stove to the outside.  When he got to the wall he encountered
    a stud (just about dead center) and a wire.  Jogging around the
    stud would have been difficult because of lack of room, so he cut
    it.  I guess I can live without one stud.  Anyway, the wire is a
    different story.  He notched the end of one of the vent pieces and
    slid it over the wire. Now I have a wire running through the exhaust
    vent.  Is this legal?  Will the wire deteriorate?  Should a conduit
    surround the wire as it passes through?
    
    
    Chris

    I had the same problem, except that I AM doing it myself.  I boxed
    in the area which will contain the vent and rerouted the wire. 
    I can't see how it would or could be legal to have the wire run
    through the vent area.  There should at least be a grommet over
    the wire at each edge of the vent to protect it from chafing on
    the edge of the sheet metal.  (Just my $.02 worth)
    
    bb

    I wonder it it's breaking some obscure code? When wiring is
    specifically installed in ductwork (using the ductwork as a convenient
    wiring route), the wire must be encased in a metal conduit, or it
    must be certified as low-smoke-creating (in case it starts to burn).
    Certainly the spirit of the code is not being violated in ypur case
    (since the duct only vents to the outside) but you may be inviting a
    future technicality hangup.
    
    The point about possible chafing is also well taken.

In this case, who cares about code?  It is certainly not unheard of to have all 
the grease that accumulates in the vent catch fire.  That's why they have to be 
metal.  Aside from the fact that such a fire would quickly remove any 
insulation from the wires, it can also escape into the wall cavity through the 
hole that the jerk cut in the vent.  It's plain unsafe, code or not.

Tell him, in no uncertain terms, that his solution is completely unacceptable, 
that he has to buy a new vent to replace the one he cut, and he has to either 
move the vent or the wire.

Paul

    Have to agree.....

    The National Electrical Code has a good deal to say about wires
    passing through hazardous and harsh environments.  (I would certainly
    consider an oven/range vent to be a harsh environment.)  To comply
    with the current code, it is usually necessary to use special cable
    and/or supply conduit for the cable to run in.
    
    From your description of what was done, I would say that the work
    was in violation of the electrical code.  (It might also be useful
    to indicate who did this, so that other of us will know to stay
    clear.)
    
    I would also second the suggestion that you get the installer to
    fix the problem correctly.  You should probably also consider
    with-holding payment until this problem is fixed.  IT IS MOST CERTAINLY
    A DANGEROUS SITUATION.
    
    - Mark
    
    BTW:  I had the pleasure of reading through all 600 some odd pages
    of the 1984 code (1987 version isn't out yet) when I installed a
    new service panel in my house.  (I went from a 100 amp fuse panel
    to a 200 amp breaker panel.)

    
    
    	    I agree.  Common sense should tell you, you are
    	asking for trouble.  I usually do my own work when
    	possible, simply because I sleep better at night know-
    	ing it's done right.  In your case, I wouldn't get
    	much sleep!
    					/Derrick

I agree with the preceding replies; the installation as stands doesn't 
sound safe, and almost certainly doesn't meet code.  If you need a specific 
code reference, ask for it here and we code-hounds can have a race!

If your contractor doesn't want to fix it, get the town building inspector 
and/or wiring inspector involved.

Of course, depending on how your contract is worded, you may have to pay 
some extra money to have the wire re-routed properly.  The question is 
whether the contractor should have reasonably expected to find a wire with 
insufficient slack in that wall; it may be a judgement call.

But one reason to pay a pro is so he can take this type of risk, and so 
you're sure everything is done safely and to code.  Don't settle for 
anything less.

    Well, all's well that...
    
    I confronted the installer and told him that the installation was
    sleazeball.  He agreed and we worked on a solution.  No hard feelings
    although I wish he would have filled me in before he made a decision.
    
    We traced the wire and found that it serviced the washer/dryer.
    What's strange is that the wire is dedicated (I did an exhaustive
    test of all plugs/switches in the house) yet runs up to the second
    floor, down through the kitchen wall into the basement and mounts
    on the foundation wall.  After we convinced ourselves that this
    was strange and that the line was indeed dedicated, we clipped the
    wire.  I'll run a new one downstairs on the floor joists.
    
    This is why I like to do things myself.  Unfortunately things like
    family, work, time constraints and lack of experience force me to depend on
    "professionals".  I do go home every night though, look over the
    work and say "Is that the way I would have done it?"
    
    Thanks for your replies.
    
    Chris

    re: .5
    
    The 1987 NEC is out; I have a copy at home.  As mentioned in a
    previous note, the cost is around $37.  However, I found that it
    is available in loose-leaf for $24.50.
    
    
    Mark
    

After installing a fluorescent light fixture in my kitchen, I noticed a warning
on the box just as I was throwing it away. It essentially says:

WARNING - DANGER OF FIRE.  Most homes built before 1985 have wiring rated at
60 degrees C. Consult qualified electrician before installing.

Needless to say, my house is older than that. If there is a real problem,
selling these units for installation in existing homes is ludicrous. 
There does not appear to be any temperature marking on the house wiring.
I have since seen other fluorescent fixtures for sale with the same warning
on the box. 

What's going on here? Are these things really a fire hazard or are the warnings
the result of an over zealous consumer protection agency run by Ralph Nader? 


- Rich

    wild bill's answer is correct. The wire insulation now requires
    the higher temperature. Fiberglas or teflon insulated falls under
    the newer code. The fix is to be sure that all wiring *within the
    fixture* have the higher temperature rating 90 degree C (which is
    almost at boiling temperature).
    
    /cal, an ex electrician who found wiring was too shocking.
    

We are moving into a place which may need some electrical work - I'm 
looking for opinions on what does/doesn't NEED to be fixed, and what 
can be done by a DIY'er as opposed to a licensed electrician.  The 
situation is:

House is 26 years old.  Has old style fuses (round screw-in, large 
'automobile' type), appears prior owner did some DIY work in the 
fusebox.  ALL outlets are 2-prong.  No outlets in bathrooms (excepting 
1 in the light fixture over the mirror, in SOME bathrooms).  
Fusebox has 100A coming in, but only 60A service.  (Note: my wife uses 
1300W hair dryer in the bathroom, and we want to add central A/C)

The EE in me says that the 'RIGHT' things to do are:

	1) replace/update fusebox, put in 100A service and breakers.
	2) put new service to bathrooms, with GFI
	3) put 3 prong outlets everywhere.

Is this all luxury, or a good idea (it does cost $$)?

We also want to:

	4) put ceiling fixture boxes in 5 rooms
	5) hang a fan from the cathedral ceiling in the living room (can I do 
	   this with ZIP cord?)
	6) (maybe) wire external spotlights over garage, out back, etc
	
Is this DIY or 'electrician' stuff?
				thanx	/j

    You might consider putting in 200 amp service if you are going to
    re-wire.  The incremental cost is insignificant compared to wanting
    to do it later when you get the  arc welder for the garage or some
    such.  The key word here is RE-WIRE.  To go from 2 prong to 3 prong
    outlets may mean rewiring the entire house from 2 wire to 3.  Can
    be  done but fishing wires through existing construction can be
    painful and the least time consuming.
    
    If you don't put in 200 amp service consider an oversize panel (i.e.
    200 amp box) and use a 100 amp main breaker.  Change is then minimal.

    Just re-read the original note.  In Mass.  90 per cent of what you
    want to do MUST be done by licensed electrician.  If you have the
    knowledge or can get a friend to help, you could have an electrician
    do the main panel and all the hookups.  See if you can strike a
    deal with him (or her) that you fish all the wiring.  Most electricians
    would be willing to do this I expect cause it's a real pain in the
    whatsis.  It's also very time consuming therefore $$$$$$.  You gots
    to talk nice though.  I once heard of a guy who told the electrician
    that he'd hook up the main panel after the electrician had strung
    all the wires figuring he'd save himself a day's labor fee.  What
    the heck all the wires are just dangling there waiting to be dressed
    and just 'plugged' into the panel.  Well talk to a frien whose wired
    houses and he'll tell you that wiring the house is the dog work
    and hooking up the panel is the 'gravy'.  Well I don't know how
    the guy was stupid enough to turn his back on the electrician, msut
    have been picking up his tools or something but when he went to
    hook up the panel there were no longer any labels on any of the
    wires and most if not all were just a tad SHORT.
    
    Moral, when you make a deal with the contractor make an honest one.
    What the heck, you expect him to have integrity. 

>        Just re-read the original note.  In Mass.  90 per cent of what you
>    want to do MUST be done by licensed electrician. 

    You can do your own wiring in Mass.  You don't need a licensed
    electrician for any of it.
    
    If your town requires you to have a licensed electrician take out
    the electrical permit, then that's probably because your town's
    wiring inspector is a licensed electrician and is doing this as
    a favor to all the electricians in your area.  What town is this?
    

Thanks for all the good comments so far......some additional info

I had an electrician look at the job, he tells me that the 3rd wire is 
available at all the outlets, just need new sockets.

The town is Sudbury, MA

Extra question:  What do you suppose an electrician should charge for 
all this, his pre-estimate guess was $1000 - $1500

    
    GOSH!  Your original note sounds EXACTLY like what we are facing.
    Our house is 34 years old, 60amp service, no grounded outlets, old
    fabric wrapped wiring, etc...
    
    The estimates that one electrician gave us (another is coming tonight):
    
    Upgrade from 60amp to 100  -- $700
    Upgrade from 60amp to 150  -- $870
    Upgrade from 60amp to 200  -- $1100  <-- We're thinking about putting
                                             in a hottub.  (Oh by the
                                             way we are in California,
                                             Bay Area.)
    
    To ground an existing outlet -- $60 each  <-- We aren't fortunate enough
                                                  to have the third wire there.
    
    To "clean-up" (work done by the previous owner not to code) -- $200
    
    Install bathroom GFI outlets -- $100 each
    
    Install bathroom fan -- $250 (depending on which fan we choose to
                                  use).
    
    My husband also wants to do some of the work himself.  He wants
    to rewire the whole house!  I don't think it's necessary.  I sure
    will be interested in the future replys to this note.
    
    -Gina
    

    Ditto on .6 .  If you have a specific location where a grounded
    outlet makes sense (the garage, maybe) think about getting that
    done.  But the whole house? Not worth the money or trouble.
    A GFI in the bathroom is nice, but the slightest bit of common
    sense (don't stand in the shower while you unplug the heater with
    wet hands) is just as good.  I might upgrade the service entrance 
    to 100 amps with breakers (200 amp if you have or plan on getting
    LOTS of appliances) and let it go at that.  The wiring you have is 
    probably perfectly safe, as is.  If/when you discover a real need
    for additional circuits or grounding, get that done.  
    

    When I checked on changing my house in Littleton, Ma. from 60 to
    100 amps, I was told that the code required that the entire house
    be brought up to current code standards if the main service equipment
    was changed.  Are you prepared to re-do the entire house to current
    code?  (your code may vary... check with the town.)
    
    Also, to change an outlet to a GFI is only about a $10 part (on
    sale) and isn't much different than just replacing an outlet.  Of
    course, the GFI requires a grounded circuit to the box it is going
    into.
    
    Jim D.

BTW: Mass codes require all new outlets in bathrooms to be GFI

re .4, Sudbury:  I heard a rumor that Sudbury is one of the most
restrictive towns around, and requires ALL electrical work to be done by a
licensed electrician.  Note that this is a rumor only; please double-check 
before you base any decisions on this information!

The Maynard wiring inspector told me that legally I wasn't supposed to do 
any electrical work, but that he realized I would probably do it whether he 
approved or not, so he might as well issue me a permit and perform 
inspections.  I said "Yes, sir!", and didn't ask him to quote chapter and
verse. 

re .0:

I agree with the other replies:  it doesn't sound like any of your proposed 
work is critically necessary.  Do fuses blow often?  Do the lights dim when 
you plug in the iron?

You're extremely lucky to have grounded wiring in place.  Is it in good 
condition?

Start by making a circuit map of the house.  Find out which circuit serves 
each outlet, fixture, and appliance.  You can determine a lot by tracing
the wires through the basement, but verify your work by disconnecting the
circuits one-by-one.  Then figure the normal and worst-case wattage load
for each circuit. 

If there are unused circuits (fuse sockets) in the fuse panel, or if the
existing circuits have excess capacity, you may not need a new panel. 
There's nothing inherently inferior or unsafe about fuses; they're just
less convenient than circuit breakers. 

> 1300W hair dryer in the bathroom, and we want to add central A/C

A dedicated circuit with GCFI will handle this hair dryer just fine.
Consider gas A/C?

>	1) replace/update fusebox, put in 100A service and breakers.
>	2) put new service to bathrooms, with GFI
>	3) put 3 prong outlets everywhere.
>
>Is this all luxury, or a good idea (it does cost $$)?

Except to power the A/C, about which I know nothing (I'm originally from
the Washington, DC area; New England summers still don't seem hot to me), 
sounds like luxury.  Given that you have grounded wiring, 3-prong outlets
are easy and DIY if you're reasonably careful, but I'd still install
3-prong only where specifically needed.

>	4) put ceiling fixture boxes in 5 rooms

Now you're talking ceiling demolition/repair or serious fishing or both.  
Unless, of course, there's an unfinished attic above.  If you want wall
switch too, see the first sentence.

>	5) hang a fan from the cathedral ceiling in the living room (can I do 
>	   this with ZIP cord?)

I'm not sure what you're talking about, but zip cord doesn't sound kosher.  
A ceiling fan needs strong mechanical support, usually a metal rod through 
which the wiring runs.

>	6) (maybe) wire external spotlights over garage, out back, etc

Worthwhile, probably DIY, perhaps top priority for all this stuff.  Parts
suitable for outdoor use are relatively expensive, and you may again be
looking at some serious fishing and/or demolition/repair.

    re .12   I agree with you that it should have been done right; however,
    when was the last time you attached the wire pigtail or tab from
    a 3 - 2 adapter to the center screw on the outlet?  (if the outlet
    box isn't grounded, even doing that doesn't give you a grounded
    outlet)  

    RE: .12
    
    I am doing exactly that in my house.  First, the old 2 prong outlets
    have been painted over (why do people do this???) and second, a
    lot of the outlets are just worn out and don't hold the plug like
    they should.  Oh, and third, do they sell 2 prong outlets anymore?
    I can't recall seeing any.  I've got plenty to do already, so rewiring
    the entire house just doesn't come close to the top of the list.

    I know this is the "right" way but I just can't see it.  Should
    I label the outlets "NOT GROUNDED".  As a previous note suggested,
    I'm not sure I really need grounded outlets except in the kitchen
    and bath (which I intend to re-wire).
    
    Phil

>    Should I label the outlets "NOT GROUNDED"?

A rhetorical question, I assume. Who wants to have little labels on every 
outlet?  What I suppose you could do, if you were really worried about it, would
be to buy a length of 1/8" metal rod, cut off a bunch of 1/2" pieces, and shove 
them into the ground plug holes.  That would prevent anyone from inserting a 
3-prong plug, and it doesn't detract from the look of it.  Of course, if you 
sell the house, the poor sap who buys it won't know anything about it until he 
tries to use a 3-prong plug.  Due to Murphy's law, this person will not have a 
3-to-2 prong adapter, and this will occur at 10:05 on a Friday evening when he
absolutely needs to use this tool to finish some job on the guest room, and 
relatives are coming first thing in the morning.  Still, I suppose it's better 
than letting him plug it in thinking it's grounded and getting a nasty 
surprise.  But I can just see the reply to note 147: "You'll never believe what 
the jerk who owned my house did! ...."

Paul

      Are you sure there is no connection to the ground of the fuse box?
    If you have armored cable (BX) then the outer metal jacket should
    make a connection between the fuse box and the outlet box. If you
    have Romex it should have a ground wire that is connected to the
    fuse box and the outlet box. I suppose there may be some very old
    wiring that is 2 conductor with absolutly no ground, but this should
    be very rare. Knob-and-Tubing wiring does not have any ground, but you
    would only find this in VERY old houses (75+ years).
    
     If you have armored cable, a simple pigtail from the new outlet
    to a screw in the outlet box should give you the ground you need.
    
    					Kenny

    
    	There IS stuff called two wire romex.  It isn't armored cable
    and contains no ground wire.  It is vintage 1930's.  My house is 
    full of the stuff (except in my shiny new kitchen :^) ).  Yes I 
    also have knob and tube wiring, except I've replaced the knobs with 
    junction boxes.  The stuff still looks and works fine, so I'm in
    no hurry to replace it.  History of wiring tours will be given upon
    request. 

    Two wire Romex is not at all rare. It was the only kind in use
    from sometime in the 30's until I think late 50's or maybe even
    the 60's. Even in the 60's two wire was still being used in some
    cases.            
    

Re: .14

In Massachusetts, you can buy and use two-prong outlets only as
replacements for existing non-grounded service.  So, yes, remove
your painted and worn outlets and install unpainted equivalents. 

Hmm ... why is the paint stuck so tightly while the lamp won't
stay plugged in due to gravity? 

    
    Upon doing some rewiring in my 65 year old 2-family I also found
    some electrocution kits. :^)   (3rd terminal not grounded)
    
    An easy way to check to see if the 3rd terminal is grounded is to
    put a voltage checker(light) between ground and one of the other terminals.
    
    I woundn't bother to replace all your 2 prongers with 3's either,
    execpt maybe the kitchen (fridge, microwave, or any number of
    modern appliances). I would say that mine are about half and half
    right now.
    
    I'm planning in putting in an outdoor outlet too, I'll get plenty
    of use out of it, mostly when trimming the hedges. Also for electric
    starting snow blowers, or any other work outside needing a power
    tool.                                   
    
    I guess the previous owner strung an extension cord out a window.
    Not for me!  You might want to also.
                
    The wiring schematics for older houses will be quite strange too,
    as was mine.  You'll probably find that each room has one of it's
    outlets tied together on one circuit.  In other words you may have
    to unscrew 2 or 3 fuses to completely shut down power to a room.
    When they upgraded the electrical system, they didn't bother to
    consolidate one room on one circuit, just added wiring to what was
    already there.  Nothing wrong with this, just a little inconvenient
    until you've generated the schematic for your house.
                                                                   
    My unit has a 100 amp service, which serves my needs fine.  The rental
    unit has a 60 amp service, but is only using 30 amps of it, there
    are two empty fuse sockets in the fuse panel.  I plan on tapping
    these to add some outlets to the rental.  They've blown a fuse once,
    when they had their hair curler on at the same time as they pushed
    down on the toaster.  (that's what they said)  I put a slo-blo fuse
    in there and haven't had a problem since.  But this is an indication that
    the electrical system in the rental needs some upgrading.
    I feel that 60 amp is good enough for an apartment but for an entire
    house, maybe not.
    
    Steve
    
    
    Back in the horse and buggy days each room
    was lucky if there was one outlet in it, and some times the whole
    house ran off two 20 amp fuses!  There weren't too may appliances
    on the market then

    The "original" wiring in my house (built around 1950) is all 2 wire,
    non-shielded romex (cloth covered).  I'm pretty sure this includes
    all kitchen, bathroom and exterior lighting circuits.  Some new wiring
    was added in the basement for what used to be an apartment.  This is 
    3-wore romex.  There must be at least 6-7 sub-panels clustered around
    the main panel (there's one there somewhere).  I'm pretty sure it's
    60-amp service.
    
    I'm planning on upgrading the service to 100-amp and replacing the
    thousands of fused, subpanels with breakers.  When I redo the bathroom
    and kitchen, I'll run new, GFI 12-2 circuits.
    
    Is there anything else I should consider doing?  My detached garage
    is fed from a single line run from the house.  Should there be any
    special considerations for this circuit?  Has anybody out there
    actually replaced their 2-wire romex with 3-wire throughout
    the house?  Is it difficult?  Is it worth it?  I'm pretty close
    to re-wiring the whole house anyway.

    Phil

    Outlets in the garage (as well as outside) should be GFI protected
    as well. You don't want to zap your self when to step in a puddle
    while you're using the electric buffer on your car! :-)
    
    Charly

    re: .21
    
    I've redone a few circuits in my house from 2-wire to 2-wire w/ground.
    Since you don't have to "fish", it's really less than half the work
    of adding a new outlet in old construction. 
    
    You have to twist and tape the old and the new together and basically
    just pull the old stuff out. Make sure that it's solid wire and not
    going through a junction box somewhere.  
    
    A little detective work and it'll be OK. 

    -joet
    
    P.S. 14 gauge pulls a hell of a lot easier than 12.

    re .23
    
    That's great unless the old wiring is stapled to the studs like
    it is in mine.  You 'throw away' the old and put in new.  I'm told
    that this is code in my area to do this (Nashua, NH circa 1969).
    
    Fortunately I'm only making some minor changes, nothing major.
    It just goes against the grain to know that wire is lurking in the
    walls going to waste.

    re: .24
    
>    That's great unless the old wiring is stapled to the studs like it is
>    in mine.
 
    Pull REAL hard?
    
    -joet

	I'm bringing power out to a new porch via a circuit that now powers one
upstairs bathroom outlet.  I plan on putting a GFI in the bathroom and then
running 14-2 from there to the porch outlets and lights i.e

	 L--|--|
	 ---|--|--o-----------------o-----------
	|   |  |_______________________  	|
	|   |  |		       | 	|
	|   |  L-----\ 	PORCH	       L 	|
	0   / /	      \			       /0
	|  / /	       \     _________________/	|
	| | /		\   /			|
	 -s-s--------------o--------------------------------------------
	|		Bath. Outlet					|
	|			HOUSE					|

There will be two legs coming off the bathroom outlet box.  One leg will go to
the GFI and from there to the first outlet on the right and then continue
around to power all the other outlets.  The other leg will go to the inside 
porch lights and associated switch leg.  Off the left light I want to bring 
power to some outside lights and put those on a separate switch.

Before I go through and do all this I want to make sure there is nothing wrong 
with my circuit plan.  So, can any of you electrical types that are more 
familiar with wiring then I am see anything wrong?  

Thanks,

George

    It is generally a good idea to have at least one light on a separate
    circuit.  Having everything on one circuit has the potential for
    creating a dangerous situation.  If you should happen to trip a
    breaker/blow a fuse, you could be left in the dark; which will give
    you lots to bang into.
    
    Also, you might run into a problem with the size of the wire currently
    serving the bathroom.  I would not be at all surprised to find it
    as 14-2.  Supplying another room off that could lead to problem.
    
    A general rule that I use when running new circuits is to use nothing
    smaller than 12-2 for outlets, and usually 14-2 for lights.
    
    - Mark

Would it be legal to just run a new ground wire through whatever route was
convenient?  I don't have this problem, because my house is only 6 years old,
but in reading this stuff, it dawned on me that replacing all the wiring seems
like a lot of work compared to just running a ground wire.  Dropping a 14
guage single wire (bare or insulated) from the attic or into the basement
might be an easy spot upgrade if it ran to a legal ground.  Since the wire
is sitting at ground, it would be pretty hard to make it dangerous.  
Or is this a no no for some reason?

> < Note 873.14 by WELFAR::PGRANSEWICZ >
>
>    I know this is the "right" way but I just can't see it.  Should
>    I label the outlets "NOT GROUNDED".  As a previous note suggested,
>    I'm not sure I really need grounded outlets except in the kitchen
>    and bath (which I intend to re-wire).

A nit, but an important one:  according to code and modern practice, you 
not only need grounded outlets in kitchens and baths (and basement, and 
outdoors), but those grounded outlets also need GFCI protection.

>    ...do they sell 2 prong outlets anymore?
>    I can't recall seeing any.  

They're hard to come by new.  They should be readily available from 
renovation and rewiring projects, though.


re .-1

> Would it be legal to just run a new ground wire through whatever route was
> convenient?  

The code has some specific requirements for supporting and insulating
single conductors, but I can't remember if they apply to the ground wire.  
On the one hand, what you're proposing is weird and nonstandard, and 
therefore not a good idea; on the other hand, if it does improve the safety
of your wiring, and you probably wouldn't have gone to the trouble of a 
more drastic safety improvement, then it's better than nothing.

Note that you need to connect all of the ground wires to the service panel, 
rather than finding a convenient water pipe or other local ground.  I'm not 
sure exactly what "ground loops" are, but I know they're bad!

    ok, let's see what the NEC has to say about all this...
    
    Do you only need grounded outlets in the bath and kitchen?

    	210-7(a)  Receptacles installed on 15- and 20- ampere branch 
    	circuits shall be of the grounding type.
    	  Exception: Nongrounding-type receptacles installed in
    	accordance with 210-7(d), Exception.

    Can you leave them ungrounded?
    
    	210-7(b)  Receptacles and cord connectors having grounding 
    	contacts shall be effectively grounded.
    	  Exception: Ground-fault circuit-interrupter replacement
    	receptacles installed as permitted by section 210-7(d),
    	Exception.
        
    so, what do I replace my two-conductor outlets with?    
    
    	210-7(d)  Grounding-type receptacles shall be used as replacements
    	for existing nongrounding types and shall be connected to a
    	grounding conductor installed in accordance with [210-7] (c)
    	above.
    	  Exception: Where a grounding means does not exist in the 
    	receptacle enclosure either a nongrounding or ground-fault
    	circuit-interrupter type of receptacle shall be used. A
    	grounding conductor shall not be connected from the
    	ground-fault circuit-interrupter type receptacle to any outlet
    	supplied from the ground-fault circuit-interrupter type 
    	receptacle.

    [this "shall not be connected", I believe, deals with wire-
    through GFI connections downstream..]
    
    ...tek
    
    
    

    I recently moved into a new (actually 7 year old) house.  The wiring
    is interesting because almost every light is controlled from 2
    switches, for convenience I suppose.  The previous owners took their
    dining room celing fixture with them and I want to hook up my new
    one.  I have installed numerous celing lights in the past and have
    never had any problems until now.  The dining room light is controlled
    by 2 switches; one is a dimmer and the other is a regular on/off
    switch.  The ceiling box has three sets of wires feeding into it.
    Each set of wires has a black, white, and a copper ground.  The
    3 copper grounds are all twisted together, but all the other wires
    were just left hanging.  The fixture that I want to install has
    2 wires, 1 black and 1 white.  HERE IS THE PROBLEM: I tried to install
    the fixture by connecting all the white wires together (the 3 from
    the ceiling box and the one from the fixture), and then connecting
    all the black wires together.  I left the ground wires twisted together
    and tucked them up into the box. The result is that the circuit
    breaker switches off the first time I use the wall switch.
    
    WHAT AM I DOING WRONG???   GAWD, I FEEL SO STUPID!!!
    
    The wife really wants this light working this weekend, so any help
    would be greatly appreciated.

You did cover each connection?  With the wire nut?  With 
the black electrical tape?  

If the wires were just twisted together and jammed into the box, 
they could short against each other and even against the box 
itself.  (We have been there!)

    
    The first thing to do is disconnect the wires you connected, get paper
    and pencil, pull out the switches in question, and try to make a
    diagram of the circuit. An AC voltmeter or circuit testing light will
    help in this endeavor. An alternative would be to ask the previous owner.
    
    No red wires, eh? Guess the installer didn't go the normal route,
    using 14/3 cable to provide the extra conductor needed for such
    a circuit.
    
    Two normal variations of the circuit are shown below. (The switches
    can be either dimmers or toggle - circuit is still the same.)
    
             switch           switch            light
               ,*-----red------*.
    black----*'                  `*----black-----*
                *----black-----*                  \
                                                  / (load)
    white-----*-----------------*----------------*

    
             switch           light            switch
               ,*-----red-------*----------------*.
    black----*'                                    `*-.
                *----black------*----------------*    |
                                                      |
    white-----*---------------*   *-------------------'
                               \ /
                              (load)

    I can't come up with a variation, using an extra 14/2 to replace
    the red conductor from the 14/3, that puts three cables in the light
    box. Perhaps the results of your circuit testing will help.
    
    You shouldn't feel stupid - the problem is that you're not placing
    the blame on the correct party (see the ever popular "Why did they
    ever do that?" note in this conference).

I bet I know what is going on.  You have three two-conductor wires coming into
the light box.  One is the power coming in from the circuit box.  Another is 
the power going out, continuing on to another light on the same circuit.  And 
the third is going out to the remote switches.  There is a 3-conductor wire 
connecting one switch with the other.  That means that one of the switch boxes 
has the other end of the two conductor wire going out from the light and the 
three conductor wire going to the other switch, and the other switch box has 
just the three conductor wire.  A diagram will probably help:

			+---------------+
		Black	|		|  Black
Power in   -------------+---         ---+----------  Power out
from		White	|		|  White     to other 
Panel	   -------------+---	     ---+----------  lights
			|      | |	|
			+------+-+------+
			      W| |B
			       | |
			   +---+-+---+		+---------+
			   |   | |   |  Black	|	  |
			   |   | +---+----------+-------+ |
			   |   |     |  Red	|	| |
			   |   |  ---+----------+---\   | |
			   |   +-    |  White	|    ---+ |
			   |     \---+----------+---	  |
			   |         |		|	  |
			   +---------+		+---------+

Thus it makes sense that the breaker trips when you hit the switch, because you 
are directly connecting the black and white wires.  What you want to do is 
this:  First, wire all three of the black wires together, but don't include the 
black wire from the light, just the three black wires coming in.  By doing 
that, you connect the power in with the power out, and you provide power to thw 
switch.  Next figure out which of the three wires is the one going to the 
switch.  It might help to find out which of the switch boxes has the wire 
coming in.  Then, connect the white wires of the OTHER two wires with the white 
wire of the light.  Again here, you're connecting power in with power out, and
you're tying in the neutral end of the light with the circuit.  All you should 
have left at this point is the white wire from the switch and the black wire on 
the light.  Hook these together, and you're done.  

BTW, you might be able to tell which is the switch if the white wire has a 
piece of black electrical tape wrapped around it, which indicates that it is 
really carrying current.  If it's not there, you might do that yourself to save 
a future light-changer the same problem you're having.

When you're done, the wiring should look like this:  (* is a connection)

			      Light
			       | |
			      W| |B
			+------+-+------+
		Black	|      |  \	|  Black
Power in   -------------+--------*------+----------  Power out
from		White	|      | |/	|  White     to other 
Panel	   -------------+------*-|------+----------  lights
			|       /|	|
			+------+-+------+
			      W| |B
			       | |
			      Switch


Good Luck!

Paul

    Nice job .3, I second this solution! If fact that is exactly how
    I wired all of my three way ceiling lights. 
    
    Boy isn't this file great! Anyone out there know what next wednesday's
    Mass. megabucks ticket sequence will be?
    

    .3 seems likely, but a simple verification is in order.  Since there
    is an outfeed to some other part of the circuit, then if all wires
    are left unconnected, and the circuit breaker is turned on, them
    there will be at least one other fixture or outlet which is not
    working (probably need the light in question, but maybe anywhere!).
    
    This would be simple to test before proceding with .3
    

    Not so fast .4, .3 may be right but in an appartment I was in I
    had the same situation as .0.  There was no 14/3 wire anywhere.
    If the downstairs switch was off, the upstaris did nothing.  If
    the downstaris switch was on, then you could turn the light off
    and on again from upstairs.  Needless to say, this was a royal pain.If
    an electrition did your wiring, then you probably have what .3 had
    shown.  If the previous owner did, then who knows!!
    
    Chris D.
    

Existing 14/2 wire shouldn't be a problem as long as you don't plan to run 
a radial arm saw on the porch - or, for that matter, to vaccuum the porch
while running a hair dryer in the bathroom. 

If you do plug in anything on the porch that's likely to trip the GFI, 
walking around into the bathroom to reset it could be a pain, especially in 
the dark.  You might consider a second GFI on the porch itself.  If the 
porch is weathertight, you don't NEED GFI protection on the porch at all.

You mention adding two legs to the existing bathroom outlet box.  Adding
additional wires to an existing box can cause you to exceed the Code-
specified maximum wire count for the box size.  These calculations are
certainly detailed, but straightforward once you get the hang of them. 
Code considerations aside, trying to work with too many wires crammed into
too small a box is unpleasant work, and increases the likelihood of a
short. 

The GFIs I've installed are quite large, and take up most of the space in 
the box.  You may need to replace the existing bathroom box with a larger 
(i.e. deeper) one just to fit the GFI in.

One last parting shot:  "a circuit that now powers one upstairs bathroom 
outlet" doesn't strike me as a typical configuration, especially for
pre-GFI construction.  I'd double-check to make sure the circuit really 
does serve just that bathroom.

	When I traced all my house circuits last winter I taped a sheet of 
paper on the box that said what each fuse runs.  When I looked at the 
bathroom fuse again I realized that that fuse doesn't run only the 
bathroom just yet.  Right now it also runs the washer, the gas drier, the 
dishwasher, and one kitchen counter outlet!  When I wrote the base note I guess
I was thinking of what would be on that circuit when I got all the stuff off
that doesn't belong there.  This is the same circuit that had a 30 amp fuse in 
the box when we moved in.

	After re-evaluating the situation I've decided to run a separate circuit
for the porch.  The GFI will be the first oulet on the this circuit.  It's this
circuit that will power the bathroom.  As I originaly planned, the washer and 
drier will get their own circuit as well as the dishwasher.  The kitchen 
outlet that was on the dishwasher/drier/bathroom/clothes washer circuit will 
be wired to one of the other kitchen circuits.

Thanks for all the help.

Oh yeah, one more thing.  For a circuit with a clothes washer and gas drier 
is it best to use 14-2 or 12-2

    One person's opinion:  I'd use the 12-2.
    
    - Mark

I used 12/3, two opposite-phase 20A circuits in a single cable, to power 
the washer and gas dryer separately.  Arguably overkill, and 20A isn't 
enough if somebody wants an electric dryer there; but I still like it that 
way.

Separate, dedicated circuit for dishwasher too.  I think Code requires it 
that way, since the dishwasher is built in and hard-wired.  The clothing 
applicances are plug-connected, so the rules aren't as strict.

I ran into similar problems with an electric radiant cove heater.  I didn't
find the electrical supply stores around here too helpful in telling me what
the thermal rating was for the wire they were selling me.  I put some wire in
boiling water and it didn't seem to affect the insulation at all.

So far, I have been through one heating season with the heaters installed and
didn't have any problem.

/Steve

re: .6
    
    Isn't your neutral connection carrying twice as much as it should?
    If you can pull 40A from your box with your configuration, isn't
    all of the return current flowing through 1 wire????
           
    just wonderin',
    ...bill

>    Isn't your neutral connection carrying twice as much as it should?

No, that's the beauty of it.  Since the two circuits are opposite in phase, 
they cancel rather than adding.

"Worst case" is when one circuit is drawing 20A and the other zero:  the
neutral carries 20A, i.e. normal.  When both circuits are drawing something, 
the neutral carries their difference, and when they match, the neutral
actually carries zero! 

P.S. This technique is perfectly legal, and is described in some detail in 
the Code under the name of "3-wire circuits".

As mentioned before, the size wire you use is not an option if it's a 20A 
circuit.  You HAVE to use 12 gauge wire.  You can only use 14 gauge if the 
circuit is 15A.

Paul

    What's the likelyhood of getting away with a washer and a fridge
    on the same 20A 12-2 circuit?  I don't have anymore room in my panel,
    and they don't make "double" breakers for Cutler Hammer (yet).
    
    ...bill

    A dish washer and clothes washer cannot hack the same 12-2 20A circuit
    in our house.    

>    What's the likelyhood of getting away with a washer and a fridge
>    on the same 20A 12-2 circuit?

I don't think code has any objection to this arrangement as such, although 
I wouldn't recommend it.

You're pretty likely to trip the breaker when both appliances demand high 
power at the same time.  But that's likely to be when you're in the house 
and awake, and you can go reset it.  Annoying, but not disastrous.

If you're in the habit of leaving the washer running when you go to bed, 
plan to wake up to a warm refrigerator once in awhile.

Better would be to put the washer on a circuit with lights and infrequently-
used outlets, and put the fridge with kitchen outlets.  (Code requires two
circuits dedicated to kitchen outlets, but the fridge may be on one of these). 

Be sure to read the rating plates on both appliances before you decide 
anything.  If you report those ratings here, you might get more free 
advice...

	When you're running wires between studs that will also have 
fiberglass insulation between them do you put the wires behind or in
front of the fiberglass?  Does it matter?  

    Ahh, a catch-22 of wiring.  Wiring run horizontally has to pass
    through holes which must be more-or-less centered in the stud. 
    Otherwise you run the risk of nail penetration, plus cuts close
    to or on the edge will weaken the studs.

    However this forces you to compress the insulation either behind
    or in front of the wire.  The electrical code doesn't care, but
    neither is a great idea from an insulating effectiveness point of
    view.
    
    You will notice most professional electricians in new houses solve
    this problem by not doing it.  Wiring on walls to be insulated will
    run up from the floor below or down from the attic directly along
    the studs, even if this means using a lot more wire.  In fact you
    will usually see this even on interior walls, since it's a matter
    of habit.
    
    If this is a basement wall you are finishing, it is legal (and
    saves a lot of drilling) to run the wiring between the back of the
    studs and the concrete wall, if you have space there.

    re .14:
    
    You could slit the fiberglas batt (but no the facing) where it will
    intersect the wire, to allow it to wrap around the wire without
    comperssing.

    Thanks to all of you who responded to my wiring problems described
    in note 966.  Unfortunately, none of them worked.  Rather than restate
    the problem, I'll just continue where I left off in that note. 
    I spent 2 1/2 hours last night climbing the ladder, wiring the light
    fixture, going down to the basement, turning the circuit back on,
    going upstairs to check the light, finding it still wasn't right,
    and then doing it all over again with a different wiring arrangement.
    I labelled all the wires to keep track of all the different
    combinations.  There are 3 sets of wires coming into the ceiling
    box.  I labelled the black ones A, B, & C and the white ones 1,
    2, & 3.  The kitchen ceiling light also comes from the same circuit,
    so, I believe my dining room box is also a junction box leading
    to the kitchen light.  The explanation given by Paul Weiss in note
    966.3 makes a lot of sense (thanks Paul) and, yes, there is a red
    wire running between the 2 wall switches in the dining room, but
    not to the ceiling box.  However, I tried connecting it up Paul's
    way and it still didn't work. I connected all 3 black wires together.
    Then I connected 1 white wire to the black wire from the light,
    and the other 2 white wires to the white wire from the light.  I
    tried this in all 3 possible combinations, but the dining room light
    never lit.  I also tried another suggestion which
    was to  connect 2 black wires together, 2 white wires together,
    and the remaining black and white wires to the light.  I tried this
    in all 9 possible combinations and I got the following results:
    1. The kitchen light worked, dining room light didn't
    2. The kitchen light was out, but the dining room lit (although the
    dining room switches didn't turn it off, but the kitchen switch
    would dim the dining room light)
    3. Nothing would light 
    
    I'm sure this sounds confusing; I could draw a picture of the wiring
    and all the possible combinations I tried, but probably couldn't
    do it clearly on the screen. If anyone loves the trill of a challenge
    and lives in Manchester, NH, I'm sure I could stock my fridge with
    beer and have a LIGHT-WIRING PARTY this weekend. 
    
    Now, I know that the previous owner had a working light in that
    room, and I guess the next step is that I'll call him up and see
    if he can help, but I suspect he's not too knowledgeable about such
    things.  I am certainly open to any suggestions.  The last thing
    I want to do is to PAY an electrician to come over and sort it out,
    but if I get desperate enough....
    
    
                                         

The solution!



Rip out all the wires, leaving a wire or string or twine or rope between
the switches and lights to allow you to pull new wires through, and wire
it up in a way that you understand it!

Jim.

    are you getting power to the box?  i would think that the first
    thing to do would be to hang all three black wires and all three
    white wires out of the box, turn on your circuit breaker, and find
    out which pair, if any, is live.  if you don't have a test light,
    now is the time to spring for the $1.29 and get one.
    
    once you have a live pair, one of the other pairs should go to the
    kitchen circuit.  connect your live pair to one pair (you may turn
    off the circuit breaker when doing this) and try the kitchen light.
    if it doesn't work, connect your live pair to the other pair and
    try the kitchen again.  
    
    once you get the kitchen going, connect the black wire from the
    remaining pair to the two blacks, connect the white wire from the
    remaining pair to the black wire of your new dining room light,
    and connect the white wire from the dining room light to the two
    whites.
    
    if this doesn't work, you need a new lightbulb or switch!
    
    good luck, and let us know how you make out.  i'd love to stop by,
    but i'm busy with my own home_work this weekend.
    
    brian (225-7285)

More questions:

You say: "The kitchen ceiling light also comes from the same circuit,
so, I believe my dining room box is also a junction box leading
to the kitchen light."  Does this mean that if you don't connect any wires, the 
kitchen light won't work?

Other than the 3-conductor wire running between the two dining room switches,
there should be just one 2-conductor wire going to just one of those switches.
Are there any other wires in those switch boxes?

Does the kitchen light have 1 or two switches?  You said that the kitchen 
switch would dim the dining room light.  Do you mean that the kitchen switch is 
a dimmer switch and it controlled the dining room light?  Or is it a regular 
switch, and would dim the dining room light when turned on?

How many wires come into the kitchen light and switch boxes?


If we can't figure it out from your description, there's another way to find 
out what's going on.  Go spend $2 on a cheap voltage tester.  Now separate all 
the wires in the box, and go turn on the breaker.  *Carefully* try the tester 
between each black wire and the ground wires until you find the hot wire.  Now 
you'll at least know where the power is coming in from.  Now open up both 
switch boxes, plus the switches and light in the kitchen (don't forget to mark 
which wires go where in these boxes - you don't want to make the situation 
worse :^)), and get all the wires separated and loose in those boxes.  Connect 
the known hot wire in the dining room box with another black wire, then go turn 
the power on again, and check the other boxes to see where that wire went to.
You can keep doing this until you've identified where all the wires are going,
and then you ought to be able to figure out how to wire it.

Paul

    SOMEHOW THE END OF .4 GOT CUT OFF.  Here's the rest:
    ...and wire it according to the suggestion in .2.
    If it still doesn't work, I may try replacing the switch and dimmer
    and hope that they are the cause of my misery.  
    
    I am open to all suggestions until the weekend.  Then I'll go home
    and try them all.  I'll report back to you on Monday.

You want to try .4 again?  From my terminal, it all got cut off.

Is your kitchen light a flourescent?  If so, then maybe when you turned on the
kitchen light and it dimmed the dining room but did not turn on the kitchen, 
perhaps it did turn on the kitchen, but the flourescent would not work with the 
lower voltage.  That would help in figuring it out, because it would mean you 
had the two lights in series.

Paul

    I guess .4 got screwed up so let me enter it again here:
    
    Re questions from .3 and .6:
    
    The kitchen has 2 light switches (neither is a dimmer).  When I
    said that the kitchen switch dimmed the dining room light, I meant
    just that.  I couldn't turn off the dining room light, but flipping
    the kitchen switch dimmed the dining room light. (Pretty wierd,
    huh?)
    
    The kitchen light is not a florescent; it is a track light.
                                                       
    I believe that if I leave all the wires in the dining room box
    unattached, then the kitchen light will not work (it won't have
    power).  I haven't actually tried it, but I will.
    
    There are only the 3 sets of wires going into the dining room box.
     No other wires feed into it.
    
    The suggestion made in .2 is basically the same as made by Paul
    in 966.3.  I do believe that it is the correct way, but for some
    reason it did not work.  I will get a line tester, identify the
    power wires, identify the wires to the kitchen light, and wire
    it according to the suggestion in .2.  If it still doesn't work,
    I may try replacing the switch and dimmer and hope that they are
    the cause of my misery.
    
    I am open to all suggestions until the weekend.  Then I'll go home
    and try them all.  I'll report back to you on Monday.
    
                                                         

With a 3-way switch is important to know where the switch is in relation
    to the power feed and the lights.   Try looking at the TIME-LIFE
    Basic Electricity Book, but be careful, it doesn't show all the
    possibilities for this kind of wiring.  If you diagram your circuit
    and it looks like the one in the book, you're probably ok.  By the
    way, a wiring diagram of your whole house will be invaluable later
    on when you want to add more circuits or check a fuse.
    
    Dave Van Cleave

    Dimmers have a habbit of kicking the bucket if the circut they are
    attached to trips a breaker.  If the wiring was incorrect the first
    time you turned the switch on, you may have killed the dimmer.
    
    	One of the previous replies said that one of your switches for
    the dinning room must have a 14-2 AND a 14-3(red) wire.  Wire the
    box as stated in note 966.3 and then use a single pole switch between
    the 14-2 in the switch box.  Have you tried this?
    
    Still pretend I'm an electrician every Saturday,
    Brian Mac

    Thank you Brian Mac (.9).  If my dimmer blew when I tripped the
    circuit, that would explain a lot.  How about if I remove the dimmmer
    switch and just connect the wires together (the ones that ran to
    the dimmer switch) as a means of bypassing the switch?  Then I could
    test out the circuit without the dimmer in the way.  Does that make
    sense?  What do I do with the red wire that leads into the dimmer
    box?                                                    
    
    Boy, this is great.  I almost look forward to tackling the wiring
    tonight.  

> What do I do with the red wire that leads into the dimmer box?
    
Here's how a simple 3-way switched circuit looks:

          white
     -------------------------------------------------+
power                                                 |
     ----+           black                          LIGHT
         |      /----------------\                    |
         +-----/                  \-------------------+
          black  ----------------     black
                     red

So, if you want to replace one of the switches with a hard-wired connection 
for testing purposes, you have two options:

1. Wire black to black, ignore the red.  Don't connect that leg to the
   circuit at all.  The other switch will turn the light on when it 
   connects to the black leg, off when it connects to the red leg.

2. Wire black to both red and black.  Thus both legs are always hot.  The 
   other switch will turn on the light no matter which way it's switched.

Option 1 is most useful for most purposes, including yours.  Option 2 is 
useful for such applications as determining whether the red wire has 
continuity, or determining whether the other switch is working properly.

    You can use a 3-way switch as a single pole switch.  There are three
    points on the 3-way, one of them is usually a copper color, this
    is the point.  By taking the wire that is coming from the celling
    box to the switch (the 14-2) and connecting one of them (white or
    black) to the point terminal and the other to either of the remaining
    two terminals you have a single pole switch.
    
    Brian mac

    Well, here's the final chapter of my story.  I went home on Friday
    and did the following:
    
    I removed the dimmer switch and wired that box to complete
    the circuit without the switch.           
    
    Then I used a circuit tester (bought it Friday afternnon at a hardware
    store for $1.89) to determine which of the wires coming into the
    ceiling box carried power. 
    
    I connected the power wires to another set of wires in the ceiling
    box to determine which wires led to the kitchen ceiling light.
    I then labelled all the wires.
    
    The remaining set of wires going into the ceiling box obviously
    went to the wall switches.  I then wiring the light according to
    the recommendations in notes 992.2, 992.3 and 966.3 and IT WORKED!!
    I then danced a little euphoric jig around the house.  Apparently,
    the dimmer blew when I tripped the circuit breaker in an earlier
    wiring attempt (a possibility suggested in note 992.9) so that even
    when I did have it wired correctly, it wouldn't work.
                                                                    
    I installed a new dimmer switch on Saturday and now everything works
    great.  Thanks to everyone who responded with suggestions.  This
    notes file is the greatest.
    
    I do have one more question.  When I dim the light, it hums.  I
    have had this occur with other dimmed lights in the past.  Is this
    something you learn to live with, or can it be cured?  It's not
    terribly loud, but it is noticeable.
    
    THANKS AGAIN FOR ALL THE HELP!
                                  

Hooray!!

Glad it worked out.  Just goes to show once again that the SUM of the 
experience of the people in this file is amazing.  I chanced to be the first 
person to suggest the correct wiring, but I never would have suspected that 
wiring it incorrectly before would have busted the dimmer.  Wonderful!  Y'learn
sumpin' new ever day.

As to the dimmer, the reason it humms is that the dimmer does not lower the 
amplitude of the entire alternating current sine wave, it just clips the wave 
at a certain amplitude, so instead of a nice clean sine wave you get something 
that looks like this:


   ___________________                               ___________________
  /                   \                             /                   \
 /                     \                           /                     \
/                       \                         /                       \
                         \                       /
                          \                     /               
                           \___________________/


All those jerky transitions make the filament hum.  I imagine it takes a bit 
off the life of the bulb, also, but I don't know.

I heard somewhere that if you put a 3-way bulb in the socket, it won't hum, but 
I've never tried it.  Supposedly something about the way the filament is held 
in a three way bulb keeps it from humming.  Let us know if you try it and it 
works.

Paul

    If a 3-way doesn't help the humming lamp problem, you might try
    either long life lamps (designed for places that are hard to get
    to so you don't want to do it very often) or tough lampss (designed
    for being mishandled as in trouble lights, etc.).
    
    The humming is coming from the filament vibrating.  The tough lamp
    has many more filament supports.  Both lamps have thicker than normal
    filaments.  These lamps are more expensive and may not put out as
    much light.
    
    If you can't use these lamp (say you need decorator lamps), there
    are dimmers available that don't cause the humming problems.  They
    are much more expensive and usually can't fit in an outlet box but
    they are available.
    
    Steveg

    Interesting information about why the humming occurs.  The light
    fixture we have looks sort of like an upside down glass bowl (with
    ridges in the glass) suspended from a brass chain.  Because the
    bowl part is clear we have always used a clear bulb in it.  It gives
    off a beautiful glow (especially when dimmed) but I'll try some
    other bulbs, just for the heck of it.  Thanks again. 
    

    Why would the dimmer itself hum?  My electricians just finished
    installing dimmers for the front hall and living room recessed
    lights.  The dimmers are side-by-side.  The hall dimmer controls
    three fixtures without humming.  The living room dimmer controls
    9 fixtures (@ 25 watts per fixture) and hums and heats.
    
    Is this normal?  Is this simply the result of the heavy load 
    or the result of miswiring?
    
    bd

    9x25 = 225, which seems to be a lot of watts for a dimmer.  i think
    that the average dimmer is meant to handle one 100 - 150 watt bulb.
    
    you can overload a dimmer quickly by shorting out the wires, in
    which case it fails quickly (as we have found out here) or you can
    overload it slowly, in which case it fails slowly.
    
    find a dimmer that is meant to handle 225 watts and replace yours
    immediately, if not sooner.  a hot box in a wall is a fire waiting
    to happen.
    
    on dimmers in general - i believe that the more you dim the lights
    the more energy is absorbed by the dimmer = more heat dissipated.
    they have always scared me, because i have felt very hot walls
    when they fail.  perhaps newer dimmers are more reliable, but if
    it were me i'd still try to come as close as possible with the proper
    wattage light bulb, then only dim the lights as little as possible.
    
    correct me if i'm wrong.
    
    brian

    Re .18
    
    Most ordinary elcheapo dimmers are rated at 500-600 watts.  So 225
    should be no problem; however, the humming/buzzing problems will
    increase with a larger load.
    
    Re: Earlier replies.
    
    It's not my experience that sending square waves through a filament
    shortens the life - if it does, then it's more than offset by the
    lengthening of life due to lower voltage.

    Actually, I find the more annoying problem is that the damn harmonics
    from those square waves radiate around the house wiring and introduce
    buzz into radios, particularly AM.
    
    Jim
    
    

    Most of the dimmers out there work by cutting the sine wave apart in
    time, not voltage. 
    
    In other words (or pictures):
    
             |\
             | \
             |  \
             |   \
             |    \
             |     \
    _________|      \_________       ____________
                             |      /
                             |     /
                             |    /
                             |   /
                             |  /
                             | /
                             |/
    
    Where the vertical lines move based on what position you have the
    control at.  The vertical pulse contains all sorts of high frequency
    components.  The interference you get in radios, stereos, etc. is
    due to tha appearance of this pulse of RF 120 times a second.
    
    The good (expensive) dimmers do things to moderate the rise time of
    this pulse.  This cuts down on the RF noise, makes the filaments last
    longer, and helps with humming problems in filaments and dimmers.
    [actually now that the FCC has tightened up the rules on EMI, it may be
    that all dimmers do this to some extent.] 
    
    Note that the dimmer is just acting as a switch (turning the bulb
    off and on 120 times a second).  It is not absorbing any energy
    as was implied in an earlier reply.
    
    Steveg

    You can cut some of the interference by installing a .05mfd
    ceramic disk capacitor between hot and gound and neutral and ground.
    I tried this due to problems with lines on the tv caused by the
    dimmer. Worked fine the 1st time. Besure to properly insulate the
    leads on the cap with old (wire)insulation scraps and tape.
    
    -j
    

    A humming dimmer is not usually a sign that anything is wrong. It
    turns out that the semiconductor device in the dimmer that is doing the
    switching actually vibrates slightly! This happens 'cause it's
    switching 2 or 3 AMPS, 120 times a second. It generates a little
    EMF (for you EE types). BTW, the most noise
    (electrical and audible) occurs at about the mid brightness setting. 
    
    The semiconductor device gets a little warm from all this switching, so
    its mounted (riveted) to a heat sink to keep it cool.  Usually this is
    just the case of the dimmer. Some high power dimmers have "fins" on the
    front of them to help remove the heat. If the vibrating semiconductor
    device is a little bit loose, or if your dimmer is not fastened into
    your electrical box tightly, the sound could be louder. I'd suspect
    that a plastic box would make less noise (I'm guessing). 
    
    The speed control in an electric drill works the same way.  They
    "buzz" or hum at slow speeds too.
                  
    
    ...bill

    
    I bought a beautiful kitchen light fixture from the Lightolier
    catalog for my new house.  The fixture required 2 40-watt lamps.
    After having it installed, I've found it MUCH too bright and
    harsh in my kitchen (I can't remember the type of lamps I
    chose, whether they were soft white, or cool white, or whatever).
    
    Can I change the 40-watt lamps to something dimmer, as I would
    with a regular fixture, or must I use only 40-watt?
    
    Thanks.
    
    Donna_who_didn't_do_enough_homework_and_now_needs_sunglasses!
    

    RE: .17
    
    Does     ME   =   ME   ?????   
             yl
              e
              c
              t
              r
              i
              c
              i
              a
              n
               
    
    Randy
    

The problem with fluorescent fixtures is that the amount of light they produce
is directly proportionate to their size, or to be exact, their surface area. So,
no, you can't just change to a lower wattage 'bulb'. 

However, the above assumes that all other things are equal...  There are
a number of different 'bulbs' that put out different light at the same
wattage...  You could replace the cover with a smoked cover to dim the light...
etc...

Jim.

> (I can't remember the type of lamps I
> chose, whether they were soft white, or cool white, or whatever).
    
The tube should say, right on it.  Most common, cheapest, and most likely
is cool white.  Perhaps what you're reacting to is not the level of light
so much as its harsh, garish quality; if so, switching to soft white or
warm white might well do the trick.


Simplest solution:  just remove one of the tubes.  It may not look very
good, but it'll be less light. 

    Re: .17 - .22 
    Thank you all for easing my fears.  I will rest much
    easier now.  
    
    Re: .23
    This time around I had enough rewiring to warrant hiring
    a real electrician.  I'll putter.  I'll run wire.  But
    I won't rewire an entire condominum unit while I and 14
    other people live in the building.  One screw-up and all
    of us are without light and heat.  I let a pro handle
    this one.
    
    

    You can also purchase the GE watt-mizer lamps they do have a somewhat
    lower lumen output over standard cool white lamps. I belive the
    wattage for the watt-mizer lamps is 34 -vs- 40 watts.
    Not a big savings but... I would sugggest the warm white or day
    light lamps. I use them in every lixture i have and prefer them
    for the reduced harshness and how they make colors appear.
    BTW-they do run 5-10% higher in price.
    
    -jerry
    P.s. Any lighting store worth its name should be able to demo
    the various bulbs for you. GE makes about 20 types of 40 watt
    lamps all different colors,ect. Get a cataloge for more info.
    
    

    
    Use whatever routing is more convenient (less cable, less cutting,
    fewest cables per box, etc). Three-wire cabling is not neccessary for
    what you have in mind.
    
    Do you really need a 20-amp circuit? How big are these lights? A
    15-amp circuit will handle 10 150-watt lamps with a capacity margin
    of 17% (120v.*15a.=1800w., 10*150w.=1500w., 1500w./1800w.=83%).
    And 14ga. wire is so much easier to work with than 12ga. (not to
    mention somewhat less expensive).
    
    I would also check the capacity of the dimmers - most are rated
    in the 300-600w. range. Make sure they can handle the proposed load.

    re: is 20 amp circuit really needed:
    
    Normal (code) calculation is  125% of the permanently connected
    continuous load.. the continuous load for recess lighting is the
    RATING of the fixture. so, if you use 8 fixtures rated at 150W,
    the answer is yes, you can get away with 15 amps. 10 fixtures wouldn't
    work (16.3 amps min.)
    
    ...tek

    re .7
    Romoving one of the lamps will probably prevent the other from working.
    
    
    You might try using one "Gro-lux"  or "Plant-Gro" bulb.  These are
    fairly reddish, and have a much lower light output than standard
    bulbs.  You proably would not like two bulbs of this type, tho.
    
    I would try one Gro-Lux and one Warm white.  The Gro-Lux type are
    expensive, though - about $10 for 1 4'.
    
    __Rich

    I've been renovating an old house and have run into an electrical
    problem.  It seems that there is an excessive voltage drop from any of
    the existing outlets.  Lighting is OK, but whenever a high current
    device is used, the lights dim alot. A "smart" device like a microwave
    oven, sometimes causes the oven to shut off since it "knows" when the
    voltage gets too low. The VCR gets wierd too, when all of the lights
    are on. (I haven't measured yet, but it MUST be a 20 or 30 volt drop to
    do that)!! 
    
    There are some new (<1yr) circuits that are fine. The existing stuff is
    classic 1940 BX two wire, with the shield used as the safety ground.
    I took the breaker panel apart and everything looked nice and tight.
    
    My question is:  Is this old BX stuff inherently high resistance
    wire?  Was copper rare during the war or something??  So far, I'm
    hoping to find a junction box with a loose connection, but I can't
    find one.  I tightened all of the outlet screws (they were already
    pretty tight), but I couldn't see anything funny.  
    
    I'm starting to wonder if the BX wire is high resistance stuff.
    There is a pretty long run of wire up to the second floor. I'm not
    too happy about dissipating all of that power in my wires.
    
    Any info is appreciated,
    ...bill_who_doesn't_like_old_wiring_anyway
    
    

First of all, it may just be that your house is under-powered, or that your 
circuits are poorly configured.  Make a circuit list/diagram of the house, 
listing all loads by circuit.  You may be surprised at the current some of 
your circuits are drawing!

Failing that, it sounds like dirt and corrosion where the existing wires
are connected to the existing outlets, rather than deterioration of the
cables themselves.  You'd do well to get a voltmeter and measure the
voltage at every point where you can get at it, i.e. at each outlet along
each circuit.  That procedure would help you pinpoint which outlets (and
maybe cables) are in the worst shape, and where your corrective efforts
should begin. 

The Old House Journal had an article a few years back with useful 
information about debugging old wiring.  One technique involves shutting
off all circuits but one, unplugging all loads on that one remaining 
circuit, and then checking the electric meter.  If the meter moves at all 
over a period of an hour or so, you've got a slow current leak in that 
circuit somewhere.

All of the above problems are potentially quite serious.  As you mention,
the "missing" power is being dissipated as heat somewhere in the house. 

     A much more common cause of dimming when the fridge turns on (or 
whatever) is old fuses that have developed a resistance.  Electricians 
call them fusistors.  Try replacing your main fuses.  It worked for 
me.

    Corrosion on the terminals in the outlets, maybe?  Or low pressure
    on the plug terminals when one is plugged in?  
    Does the plug heat up on a current-drawing appliance when you plug 
    it in?  If so, changing the outlets might help.  Or maybe run an
    ignition file into the outlet slots (power off first!!!) to clean 
    the contacts?

    check to make sure that they didn't ground the neutral wire when
    they did the original wire.
    
    if neutral is grounded and something is drawing current, ground
    potential can actually go up.  when ground is above ground (!!!???)
    that is like a voltage drop.
    
    i know it sounds screwy, but it really happened in a place where
    i used to work.  they were having voltage drop problems when lots
    of things were on and found that the ground inside the building
    was about 10v higher than the ground outside.  this too is dangerous...

    BEING AN ELECTRICIAN FOR A FEW YEARS, MAYBE I CAN HELP WITH ONE
    SUGGESTION.
    
    14 GAUGE WIRE WILL BE PLENTY BIG ENOUGH FIRST OFF  AND WHEN YOU
    RUN THE WIRE, GO TO THE SWITCH FIRST AND THE TO THE LIGHT THE REASON
    BEING THAT MOST RECESSED LIGHTS HAVE VERY LIMITED SPACE IN THEIR
    JUNCTION BOXES AND THE LESS CONNECTIONS AND WIRE NUTS IN THE BOX,THE
    BETTER AND SAFER
    
    
    JOE

    Thanks for the ideas so far.  I'm going to check this out this weekend.
    BTW, there have been some recent new circuits added to the building
    that are absolutely fine. I doubt if there is a problem with the
    service entering the building. Also, the sevice box was recently
    upgraded to all breakers, so there aren't any fuse panels left. There's
    just something funnie going on with the "old" BX stuff.  The idea about
    ground currents in .4 sounds feasible. I'll get out the "OLD" VTVM and
    do some measuring. 
    
    thanks so far,
    ...bill

    I have a wiring question!  I think I have the right idea in mind
    but when it comes to electricity I'd like to make sure!
    I have one heavy duty cord coming off my bench...when plugged
    in, it turns my fluorescent lights on and makes the outlets to
    my work bench LIVE!  I want to put a switch in so I don't have to
    plug in the cord...just hit the switch..and BINGO!  Now the outlet
    that I plug into is mounted right beside the main power boc to the
    house!  I've mounted the switch box right above this outlet!  When
    I took the outlet apart last night and found that there is only
    a black and white wire coming out of the main box into the outlet!
    Where is the ground?  Shouldn't it be grounded to the outlet box
    it self?  Could someone just walk me through this..
    
    I have one cord with three wires coming off the bench..
    I have the outlet pulled apart and disconnected from the two B/W
    wires coming out of the main box...
    The switch box is mounted just above the outlet..What do I do????
    
    The power is turned off..I'm stupid...NOT CRAZY!
    							John
    
    

    I've seen instances where the ground wire was wrapped around the
    last inch of outer cable insulation in a tight wrap. This just
    happens to be the place where the clamping device in the top (or
    bottom) of the box holds the cable firmly in place;  the effect
    is to make a good connection between the ground wire and the box.
    
    You can determine whether this is the case by loosening the screw
    on the clamp and (carefully!) pull the cable out about an inch or
    so.
    
    Oh, by the way... (getting set to be beaten about the head and
    shoulders here)...
    
    I was thinking of adding a couple of outlets to a room here, and
    the outlets have ONE ground screw.  The ground wire in my 12-2 looks
    rather large for putting two wires on the single screw;  is it
    legitimate (i.e., according to the Electrical Code) to put one wire
    on the screw, and do this wrapping jazz with the other?
    
    Dick
    

    is the outlet connected to the box with conduit?
    
    perhaps that is the ground?
    
    
    also, do you want to run your entire workbench through the switch,
    or just the lights?  you might be better off to leave the bench
    as it is and wire a separate circuit for the lights.
    
    brian

    Brian, I'd like to run everything into the switch!  I was going
    to run the lights into the regular cellar lights that turn on when
    the switch at the top of the stairs is turned on!  I don't want
    my shop lights coming on everytime the kids take a bag of rubbish
    down!  And I am putting the switch where it can't be reached!  Even
    though the kids have been told never to go near my power tools..you
    never know what a kid will do!I like the idea that the bench and
    machinery is dead when the switch is off!  There is conduit coming
    from the main box to the outlet!  Is that my ground?   And if so
    how do I ground the switch box?

Nice guess on the conduit, .2.

re .0 and .3:  Yes, the conduit is your ground, and a good one too, 
assuming all clamps are properly installed.

The idea is to ground both the box and the device (outlet, switch, etc.). 
An old technique was to ground the box (perhaps by conduit clamps or by 
the wrapping technique .1 mentions), then assume the ground is properly 
transmitted to the device by its mounting screws.  Modern Code and modern
practice require that the device be grounded too, by running a ground wire
(usually bare, sometimes green-insulated) to the device's grounding screw. 

In your case, you can assume that the existing box is properly grounded by
the conduit and its clamp.  There should be a (bare or green) wire running
from a screw driven into the box itself to the device's ground screw; if
there isn't one, you should probably install one.  To propogate that ground
to another (new) box, connect the ground wire of your Romex to another
screw driven into the existing box.  Use a proper Romex clamp, too. Even
better (but more difficult), use conduit. 

N.B.  If there are any plastic boxes (as opposed to metal ones) involved, 
the answers are different, since there's not much point to grounding a 
plastic box.

re .1:  

>    ...is it
>    legitimate (i.e., according to the Electrical Code) to put one wire
>    on the screw, and do this wrapping jazz with the other?

The "wrapping jazz" must have been legit once - my father taught me to do
it that way - but it's a no-no now.  Note that your scheme would transmit
the ground for the outlet, plus that for any boxes downstream, through the
outlet's mounting screws - risky, especially for #12 wire. 

As you seem to recognize, the Code NEVER allows multiple wires under a
single screw, so that's not an answer either.

You're supposed to run a bare wire from the device's ground screw, another
from the box's ground screw, and connect both to the ground wire(s) coming
in from outside the box. 

Special topless wire nuts exist that allow you to connect two wires 
together, but pass the end of one or both wires on through to attach to
screws.  Crimp lugs are even better for this purpose. 

If there's only one cable coming into the box, it's also possible to loop
the ground wire around the box's ground screw and end the same wire at the
device's ground screw. 

    So...this is how I'll do it! 
    First I'll run the wire coming from my bench to the switch, then
    I'll put the w-on one side and b-on the other and screw the g-to
    the back of the box.  I'm then going to run a short cord running
    out of the switch box to the outlet box making the connections to
    both the switch and the plug and making a good connection of the
    ground wire from box to box the grounding of the outlet box will
    be cared over to the switch by making the connection to both boxes!
    RIGHT??????!!!!  
    When I do this tonight I don't want any electricity getting me to
    excited!!!!!!!!!!!!
    

Maybe yes, maybe no; I can't tell for sure.  A couple of questions arise 
from your description:

>    First I'll run the wire coming from my bench to the switch, then
>    I'll put the w-on one side and b-on the other and screw the g-to
>    the back of the box.

Well...what type of "wire" is it?  If it's an extension cord (even a heavy-
duty one), you really shouldn't wire it permanently to anything.  You might 
prefer to install a switch-controlled outlet into which you can plug your
"wire", or even re-wire the existing outlet so it's controlled by the 
switch.

Alternatively, if the existing "wire" is Romex that you've attached a plug
to, your existing installation is illegal (but you'll be fixing that).  The
point is that extension cords and permanent wiring are different things,
made of different materials, intended for different purposes, and mixing
them causes problems. 

I don't understand how you plan to wire the switch.  What's usually done is
to switch the hot (black) side of the circuit, and run the common (white)
side straight through the switch box, unswitched. 

..."to the back of the box":  on the INSIDE of the box, right?

>    I'm then going to run a short cord running
>    out of the switch box to the outlet box making the connections to
>    both the switch and the plug and making a good connection of the
>    ground wire from box to box 

The "short cord" must be Romex or other official house-wiring cable of the 
proper gauge, NOT a hacked-up extension cord. 

Your description of grounding both boxes seems OK.

Be sure you NEVER put two wires under the same screw.  In a situation where 
you'd like to do so, you should connect those two wires to each other and 
to a short jumper wire, using a wire nut.  Then attach the other end of the
(single) jumper wire with the screw. 

>    the grounding of the outlet box will
>    be cared over to the switch by making the connection to both boxes!

I don't understand this description at all.  You haven't said anything 
about the grounding screws on the devices (outlet and switch) themselves.

I can't tell whether you understand how to do the job or not - maybe you
just didn't write very precisely.  But I would strongly suggest that you
get a book about wiring (the Time-Life one is probably about right for this
job), and read and understand it thoroughly before you proceed.  Too much
is at stake here to fool around, and your NOTEing friends won't be down in 
the basement watching you!

    .5:
>The "wrapping jazz" must have been legit once - my father taught me to do
>it that way - but it's a no-no now.  Note that your scheme would transmit
>the ground for the outlet, plus that for any boxes downstream, through the
>outlet's mounting screws - risky, especially for #12 wire. 
 
    Oh good.  Guess who showed me that trick?  But I don't understand
    your objection.  I have a 20A duplex outlet made by Leveton here.
    At top and bottom are the little metal tabs with captive screws
    that bolt the outlet into the box.  Turning it over reveals that
    the two metal tabs are part of a metal strip that runs the length
    of the outlet, and  the metal strip has a wing on the side into
    which the ground screw is mounted.  So, unless the mounting screws
    have some sort of nonconductive finish, they too will be electrically
    grounded.  But then again, if the box is grounded, the screws will
    be too, so what's the difference?  (Besides which, I thought I stated
    that this would involve the cable clamp in the back of the box,
    whose screw would effectively be a ground screw for the box -- oh,
    come to think of it, there's TWO such screws in the box, perhaps
    using one of them would be legitimate?)
    
    
>You're supposed to run a bare wire from the device's ground screw, another
>from the box's ground screw, and connect both to the ground wire(s) coming
>in from outside the box. 

>Special topless wire nuts exist that allow you to connect two wires 
>together, but pass the end of one or both wires on through to attach to
>screws.  Crimp lugs are even better for this purpose. 

    Sigh.  Does Spag's carry these topless wire nuts?  Or these crimp
    lugs?  (Are these vanilla looking things, or multi-wire wombats?)
    
    Dick
    

Please understand that I was describing the Code (as I remember it from a
big project several months ago, and as the Maynard wiring inspector
enforced it), not my personal opinion. 

My interpretation is that the Code wants to separate the functions of
mechanical support and electrial/ground continuity.  The idea, I guess, is
that the mechanical support (clamps, mounting screws, etc.) can fail or be
taken apart without loss of ground protection.  So even though you have two 
mounting screws that happen to provide adequate ground, they don't count 
for Code purposes; you still need a separate electrical ground path that 
doesn't serve any mechanical function.

Note that the above is my guess; the Code tells you what to do, not why.

For me, the Code's ratio of worthwhile stuff to foolishness is high enough 
that I don't bother trying to justify each rule.  I just do what it says, 
especially if there are likely to be inspectors, other electricians, or 
other owners involved.

    
>    Sigh.  Does Spag's carry these topless wire nuts?  Or these crimp
>    lugs?  (Are these vanilla looking things, or multi-wire wombats?)
    
Sorry, I don't know.  Crimp lugs are pretty widely available (auto parts 
stores and even K-Mart, I think).  I was lucky enough to receive a Buchanon 
crimping tool as a present, so once I found a source for their special 
lugs, I was all set - used very few wire nuts.

    Well, I hope you didn't try it yet.  If you hook the white wire
    to one side of the switch, and the black wire to the other side
    of the switch, you will blow your fuse/circuit breaker as soon as
    you turn the switch on (if your lucky).  You need to put the black
    wire from your work bench to one side of the switch, and a black
    wire from the other side of the switch to your power supply.  The
    white wire should pass unbroken through the box where the switch
    is, and run directly to the power supply.  Your idea to use a plug
    between the switch and the original outlet sounds OK, but probably
    not to code.  What you are doing is basically using an extension
    cord that has an on/off switch in it.  What I would do is...
      Put a short piece of conduit between the new switch box and the
    old outlet box.  You can buy an offset nipple (is that the right
    name?) that is about 3" long with about a 1" offset and is threaded
    at both ends.  This will ground your new box.  Run the black wire
    from the outlet strip to one side of the switch.  Run a black wire
    from the other side of the switch to the black wire on the original
    outlet.  There should be two screws on each side of the original
    outlet, this new wire goes to the unused screw next to the black
    wire.  Run the white wire from the outlet strip directly to the
    screw next to the white wire on the original outlet.  Run the green
    or bare wire from the outlet strip to a screw in the back of the
    switch box.
    
    ____ 
       |  black       black                          1 is the fuse box
       |----------, ,----------,                     2 is the old outlet
       |        |----|       |----|                  3 is the new switch
     1 |        |--2-|       |--3-|  black
       |----------' '---,      '------------->
       |     white      |                      to work bench>
       |                '-------------------->
    ---|                             white
                                             (plus green wire to ground)    

    Jim D.    

    i like the suggestion in .10.  there is one other way, those of
    you who know the CODE correct me if i'm wrong...
    
    you can wire the switch before the outlet, therefore making a
    switched outlet.  you could leave the extension cord you have
    going to your bench, and use the switch to turn it on and off.
    i'm pretty sure it's ok to have a switched outlet.
    
    if you have tools on your bench that draw lots of power, make sure
    you get a heavy duty switch.  overloading a switch can melt the
    contacts together, and someday you might think you're turning the
    power off but it'll still be on.
    
    if you don't fully understand what you're doing, read up on it or
    find somebody to help.  when houses burn due to faulty wiring
    claims don't get paid.
    
    brian

    RE: .8
    
    Yes, Spags has both the wire nuts and crimp lugs.  In the electrical
    dept., first find the wire nuts in the bins.  Now do a 180 degree
    turn and you'll see the crimp lugs on the top shelf.
    

    >    if you have tools on your bench that draw lots of power, make sure
    > you get a heavy duty switch.  overloading a switch can melt the
    > contacts together, and someday you might think you're turning the
    > power off but it'll still be on.

	I would not run ANY power tool off a switched outlet (well maybe
    a hand drill) but I know I would not like to be around when the
    contacts start to melt!
    
    mac
    

>	I would not run ANY power tool off a switched outlet (well maybe
>    a hand drill) but I know I would not like to be around when the
>    contacts start to melt!
    
Unnecessary paranoia.  If the ratings of the switch, outlet, and wire are 
all greater than that of the power tool in question, all will be well.  If
the power tool's rating exceeds that of the outlet and/or wire, you're in 
trouble whether there's a switch in the circuit or not.

It's just a question of using the proper materials for the job.

    RE: .4

    >check to make sure that they didn't ground the neutral wire when
    >they did the original wire.
    >
    >if neutral is grounded and something is drawing current, ground
    >potential can actually go up.  when ground is above ground (!!!???)
    >that is like a voltage drop.
    
    How can a grounded neutral cause a problem?  If it's grounded at
    the receptical (white to GND), then there would be an additional
    return path (I think).  At the service panel, isn't neutral tied
    to ground there anyway??
    
    ..bill

    
	There is one more reason I never use a switced outlet.  Have you
    ever been drilling a hole with Milwalkee right-angle drill and had
    the power shut off and back on quickly?  That sucker has alot of
    torque.  The drill stops, you say "What the....." and loosen your
    grip (still holding the trigger)  BAM the power returns and it starts
    doing a twist! (Never use the trigger lock by the way!).  You then
    here in the distance "No Bobby, the other switch."
    
    	When you work under unknown conditions (kids in area, or at a
    customers house) I try to reduce risk so I make sure that I am using a
    constant feed outlet and tell the people to send the kids out to
    play.
    
    	By the way, if the drill stops now, I let go of it QUICK!
    
    mac  

    By code, the neutral and ground wires are only supposed to be "common"
    (connected) at one point.  That point is usually in the breaker
    panel.
    
    I am not sure if it would cause a voltage drop but the neutral side
    of a circut can carry a load (voltage).
    
    mac

     The reason is that ground in this case would be carrying current
    which it is never supposed to do except in a fault condition. The
    ground in house wiring is supposed to be a redundant safety and
    not a paralleled conductor. If there is any current flow in the
    ground then there will be a voltage on the wire due to normal
    resistance. This may or may not cause problems with equipment that
    uses ground as a reference. It definitely could cause problems at
    other outlets if you had an open neutral in the circuit in question.
    
    					Kenny

Well, thanks for all your suggestions!  I had the scare of my life!

I wired it the way I described and ....boom!  I knocked the whole house

out!  I am presently in the process of buying the duplex I live in so

instead of messing with it anymore I called the landlord and explained

what I did and that I had no power in the house.  He said I probablly 

had to reset the breaker for the whole house that was located in the 

basement on the other side!  He said not to mess with it and he would have

his electician come over to wire it up!  Its all set now..works great!

He put a seperate breaker in the box for the bench..the bench wire which is

14 gage wire runs to the switch and then a piece of heavy duty solid wire

runs from the switch box to the outlet box!  It looks o.k.!  That wire from

my bench comes out of one of the long black bars with five plug outlets.

I never use more than one power tool at a time and the switch installed will

never be on when I'm not in the workshop working.  I think I'm all set!

Thanks for all your help and concerns.  I learned a good lesson..handyman

or not...when it comes to electricity you better know what your doing!!


							John

    A few questions about wiring. This ifor the third floor of a 3 family
    house with the breaker box in the basement. It is in Boston and
    I'd like the answers to conform to the National and Massachusetts
    code.
    
    1. Does the 1987 code require GFCI's in the kitchen?
    
    2. Does the code require two separate small appliance circuits in
    the kitchen? Of what capacity?
    
    3. My impression was that these two circuits are required and that
    they must/should be GFCI's. Since these circuits are sometimes run
    via a three conductor cable, how is the GFCI incorporated? I assume
    a standard GFCI wouldn't work here.
    
    4. A dishwasher and disposal will be wired on separate breakers
    in the basement. Is there any requirement for there to be an additional
    switch for them in the unit?
    
    Thanks.
    
        mitch  
        

    Not to sound like a broken record, but check with the building
    inspector.  Since he (she?) has the final say, it only makes sense
    to see what he's looking for.
    
    -joet

    Only licensed electricians can do electrical work in Boston. I am
    looking for answers which can be had without asking the building
    inspector. 
    
      mitch

    
    you can pick up the NEC code book at bookstores for about 25 bucks,
    if you'd like something official to use as a guideline.  
    

re: .3

    Anyone know of a bookstore that HAS the 1987 code.  I've been looking and 
can't find it anywhere...


			Andy Ostrom

Disclaimers:  the following is my opinion only, and I don't know if Boston
has electrical code provisions of its own, in general or specifically for
rental property. 

>    1. Does the 1987 code require GFCI's in the kitchen?

Yes, for outlets that are within some defined distance (six feet?) of the sink.
    
>    2. Does the code require two separate small appliance circuits in
>    the kitchen? Of what capacity?

Yes, at least two, 20A each.  Note that a refrigerator is a "small 
appliance" for purposes of this rule.
    
>    3. My impression was that these two circuits are required and that
>    they must/should be GFCI's. Since these circuits are sometimes run
>    via a three conductor cable, how is the GFCI incorporated? I assume
>    a standard GFCI wouldn't work here.

Subtle distinction:  the requirement is that the OUTLETS (and, as we've 
seen above, only certain outlets) be protected by GFCI - not necessarily
the entire circuit.  So one option is to run 3-wire cable to all of the
outlets that don't require GFCI, than use normal 2-wire cable (perhaps
tapped off of a 3-wire circuit) for the outlets near the sink. 
    
You may certainly have GFCI on the entire circuit, either via a 
service-panel-mounted GFCI breaker, or via a GFCI outlet in the first box 
on the circuit.  The problem, as you've noticed, is that the available GFCI 
packaging doesn't lend itself to 3-wire circuits.  Anybody know about 
clever GFCI packaging that's more accomodating (or is there an inherent
restriction that I haven't thought of)?

>    4. A dishwasher and disposal will be wired on separate breakers
>    in the basement. Is there any requirement for there to be an additional
>    switch for them in the unit?

I've never heard of a dishwasher or a disposal that didn't have some sort
of switch associated with it, so maybe I don't understand your question. 
    

re .4, where to find 1987 code:  I don't know for sure, but I would think
that electrical supply houses would be a better bet than bookstores. 

    RE: .4
    
    	Last time I was in, Ralph Pill in Nashua had a large stack of
    	1987 NEC code books.  They also had a smaller stack of 1984
    	code books.  I'm not sure of the price, but a phone call would
    	correct that.
    
    - Mark

                It would be difficult (if not impossible) to construct a
        gfi that would work on a 3 wire circuit (two hots and a neutral)
        because of the way in which a gfi works. A gfi senses an
        imbalance of current between the hot lead and the neutral lead.
        In a three wire circuit, the only time that the current is
        guaranteed to be balanced between hot and neutral is when only
        one side is in use. ANY current drawn on the opposite side WILL
        cause the neutral current to be different from the hot current!
                
                /s/     Bob

    You don't really want the NEC, Mass has a somewhat stricter
    version.  I am not sure about the present, but you should
    be able to find where to purchase a Mass version by calling
    state agencies in Boston.  The Mass version was just the
    NEC book with a prefix of requirements unique to Mass such
    as using insulated staples.

    As to 3 wire & GFI's - the only purpose is to save wire.
    If you are running 3 circuits (2 utility & dishwasher) just
    put the outlets near the sink on the single circuit. Or you
    can just run 3 single circuits.
    
    Another approach would be to run the 3 wire circuit to the
    kitchen with conventional breakers.  Wire one circuit to
    the first GFI protected outlet and use a outlet type GFI.
    Additional protected outlets may be wired from the outlet
    GFI.
    
    If you find the source for the MA code book it might be handy
    to post it in a seperate note.

    - gerry

    Walden Books at Searstown Mall in Leominster had them
    last month.  Might still.
    

interesting thing about GFIs - I just had an electrician put them in 
all 3 bathrooms - instead of putting $30 gfi's in each one, he put in 
regular outlets, and put them all on a dedicated line with a 'gfi 
fuse' in the fusebox - new idea?

    re.11
    No, they have been around for along time...some disagree on the
    protection they offer. Square-d is a popular vendor for these type
    of GFI's but they only work in Sq-d panels federal pacific makes
    them for thier panels.
    Anyone out there care to expand on why the panel GFI's are
    not used as often?
    
    -jerry
    

    Assuming we're talking about a GFCI panel breaker, as opposed to
    a GFCI outlet:
    
    o  The breaker is VERY expensive ($65 retail, $40 if you have an
       electrician friend). The outlet can be had for $10 on sale at
       retail outlets.
    
    o  The breaker seems to be much more sensitive to surges (lightning
       strikes, etc; I have heard of many breakers destroyed by
       near strikes, but the outlets seem to come out ok.)
    
    o  The breaker is more suitable for new construction, when you have
       some control over the wire routing. The outlet can be popped in
       anywhere it's needed, as an afterthought.

    I had a GFI/breaker in the panel for the bathroom and it it/was a royal
    pain in the A**. It had a habit of tripping randomly in the middle of
    the night, usually 2-3 times a month with NO set pattern, ie only in
    electrical storms or wet nights. I replaced the breaker once to no
    avail. 
    
    We would discover that it had been tripped usually in the morning after
    a shower while trying to plug in a razor or hair dryer. Then it was
    either a trip to the basement or a loud cry to some else in the house,
    "WOULD SOMEBODY PLEASE GO DOWNSTAIRS AND RESET THE G*D* CIRCUT
    BREAKER." 
    
    I've since rewired and replaced the bathroom outlet with the more
    common GFI/outlet. It has never tripped but if/when it ever does the
    reset button is right there. 

    Charly

   
    To get the NEC code call the NFPA at 800-344-3555.  As I've said
    in other notes, this is good reading for sleep-less nights, but
    for the '87 code they got smart and sell their own version of "What
    we meant when we wrote this document" as Audel's and others have
    been doing for years.  Get that version (includes the straight text,
    but with explanatory notes, etc., like a lot of the Tax books do).
    
    For the Mass addendum (it's not a seperate book, just a couple of
    pieces of paper mimeographed), call the State Bookstore in boston,
    and they will tell you the order number, and you can send them the
    $$ - they are quick also (NEC takes credit cards).  Or you can go
    pickup the Mass stuff yourself (better like climbing hills!).
    
    Does the City of Boston have their own?  You say that in Boston
    a licensed electrician is required.  That means Bostons has different
    requirements than Mass, which does not require that (FOR YOUR OWN
    SINGLE FAMILY RESIDENCE). If Boston already has one screwey trist,
    better check with the city (call the inspector and hand him a line
    - he cannot trace the call!) they may have others (GFCIs needed
    for alarm clocks, toaster ovens, and portable jackhammers).
    

RE: Main box GFIs

When replacing our service after it was ripped out by the hurricane last
year, I asked my electrician about breaker-box GFIs.  He flatly stated
that he would not put them in.  They often fail right out of the carton
or shortly thereafter and only result in dissatisfied customers and
return trips for him.  And they're expensive.  If you're in love with
having a GFI at the main box control a whole circuit, wire an outlet GFI
next to the main box and connect the whole circuit in question to the
protected side (make sure the GFI outlet is rated appropriately; some
are rated for 20 amps, others are only for 15). 

[Actually, the elecrician when pressed *would* put a breaker-box GFI 
in, but the price he felt he would have to charge was approaching the 
cost of the panel!]

Alex

    Re: GFCI on a 3-wire/2-circuit setup:
    
    I'm absolutely positive that the data sheet with the Leviton that
    I put in recently contained explicit instructions for such a setup.
    This GFCI is the one that has screw terminals for all connections
    instead of the usual braided wire that you use with twist-locks.

    This is a different GFCI question:
    
    I have a GFCI breaker.  Yesterday it tripped, and now I can't get
    it to reset.  When I move it all the way to the OFF position, it
    doesn't stay there, but goes back to the center.  It will stay in
    the ON position, but there's no power to the circuit.  
    Is it dead?
    

    I've sometimes seen cover plates that cover over the reset button on
    the front of a GFI outlet.  Unscrew the cover plate (if it's one of
    those outdoor outlets with a hinged cover) and press RESET. 
    

>        I've sometimes seen cover plates that cover over the reset button on
>    the front of a GFI outlet.  Unscrew the cover plate (if it's one of
>    those outdoor outlets with a hinged cover) and press RESET. 

    I know what you're talking about, but no, that's not what I have.
    I have a GFI breaker, not a GFI outlet.  
    What's the test button do on the breaker anyway?  On mine, it doesn't
    do anything.  Is it supposed to trip the breaker?
    
    I assume the breaker is broken.  BTW, that's the second one I've
    gone through.  I'll be replacing it with GFI outlets (I have 2
    outlets each running directly off the breaker, so I assume
    I need 2 GFI outlets?)
    
    Now I know why GFI breakers aren't used much..... While it was
    working, it tripped very often.
    

re .21

>    I'll be replacing [a GFI breaker] with GFI outlets (I have 2
>    outlets each running directly off the breaker, so I assume
>    I need 2 GFI outlets?)
    
If you really do have two separate cables running directly from the service 
panel to the two outlets, then yes, you need two GFI outlets (barring some 
re-wiring).  

But if the cables run from the service panel to the first outlet, and then 
from the first outlet to the second outlet, then you only need one GFI 
outlet, to be installed in place of the existing first outlet.

It is possible (and common) to wire a GFI outlet so that "downstream"
outlets are GFI-protected.  It is also possible to wire it so that
downstream outlets are NOT protected - although it makes sense to protect
downstream outlets whether you're required to or not, unless you have some
overwhelming reason for not doing so.  Instructions for both styles of
wiring should come with the GFI outlet. 

>    BTW was the breaker ever exposed to the weather, perhaps as part of a 
>temporary service; or a leak during construction?  Did it get itself
>cycled on a regular basis?  Can you tell us the brand?    

    It was never exposed to the weather or used as temporary service.
    BTW:  The one I did use in my temorary hookup also broke after a
    couple months.
    
>    Did it get itself cycled on a regular basis?
 
    What?
    
>    Can you tell us the brand?
    
    Bryant.
           

>>    Did it get itself cycled on a regular basis?
 
>    What?

Yup, breakers last longer (and are more likely to be re-settable when they 
trip) if they're manually switched off and on periodically.  A couple of 
times a year is plenty.

I stopped by the State Book Store the other day.  They no longer publish the 
"entire" Electrical Code, but just the changes for Mass.  It cost a whopping 
$1.25 (might have been $.75, can't remember).  I'd be glad to make some copies 
for folks -- or if there's enough interest maybe two or three of us could 
divvy it up and type it in.  Then we could put the parts together and add it 
as a note -- it should remain current till 1990.

They also sell lots of other books including a cut-down version of the state 
Building Code with only sections 1 and 21.  These apply to one and two family 
dwellings.  The cost was $7.00 and it came in its own loose leaf binder.


			Andy Ostrom

BTW -- Good luck getting them on the phone -- I tried 3 or 4 times a day for
	a week.

It's been a while, but I finally got this electrical problem solved.  
Initially, the problem was excessive voltage drops.  After some 
investigation, I found 3 outlets with NO ground continuity, and 2 with 
backwards polarity. At this point I got suspicious that the previous owner 
did something stupid.  Sure enough, after 2 whole Saturdays of tracing 
circuits, and running up and down to the basement 300 times turning power 
off and on, I found the problems. It seems that the previous owner lowered 
the kitchen ceiling a few years back. Since there was a light fixture in 
that ceiling, he just ran an extension wire from the old ceiling fixture 
to the new lowered one. Pretty stupid: reverse polarity, no ground, wire 
size too small, loose conections, bare wires.  I'm just real happpy I 
found it.  Luckily, the "old box" was directly above the new one, so I 
only had to enlarge the existing opening slightly to do my handy work.
I installed a complete new box at the "new" ceiling level.  All of the 
wiring in that area now terminates in this new box. I'm happy, everything 
works right, and I can use my u-wave in the kitchen!
BTW, I still get a 10V drop in this circuit, but at 10Amps and 200 ft of 
wire, 1 ohm ain't too bad.

I guess the previous owner was proud of his wiring.  After all it worked 
didn't it?  :'))


..bill

Congratulations, and thanks for reporting back to us.

A helper and a pair of walkie-talkies or intercoms are indispensable for 
that type of work.

Then again, maybe the  l - o - n - g  walk to and from the breaker box 
makes us take enough time to think over the problem thoroughly, encourages
us to make every test count. 

    I hate writing new notes (2nd one today) but this
    electrical/woodworking combo question seems to be new.
    
    How do you install horizontal tongue-and-groove boards over electrical
    boxes?  This one has me baffled - the 1x8 boards have about a 3/4"
    tongue.  If I cut out the hole exactly where the box is, then I
    can't lower the board onto the one below it because the box is in
    the way, and that's the only way you put t&g boards on. If I elongate
    the hole by 3/4" such that I can press it over the box rim and clear the
    tongue below it before lowering it in place, then the hole is too
    big to seat the ears of the outlet/switch nicely against the finish
    wood (it's also pretty close to being exposed under the switchplate.
    
    I have the same problem even if I straddle the box over a joint
    (upper piece is OK, but lower piece has the same problem).
    
    I suppose I could put the boxes in after the fact (use old-work
    boxes with ears), but I'd sure like to do all my rough wiring first.
    
    Is there some standard solution to this problem?
    
    Jim
    

    One thing that I have done to install T&G over electrical boxes
    is to cut out the desired size opening, then back bevel the edge
    parallel to the tongue (or groove as the case may be).  There is
    usually enough give in the tongue & groove to allow then to engage
    while still keeping the exposed surface gap to a minimum.  I usually
    use about a 15 or 20 degree angle for the bevel.
    
    - Mark

    I had the same problem.
    I cut my bottom board to just the right width so that there was
    a T&G joint where all my outlets were.  If 2 boards meet at the height of
    the boxes, you don't have the problem.
    
   

    In order to install some skylights, I need to move a couple
    of wires out of the way.. unfortunately, the wires themselves are
    too short to be routed any way other than the current routing.
    
    So, I have a couple of choices:
    
    1.) replace the wires from source to destination. This would be
    a bear to do; I'd have to remove and rewire 6 nailed-to-the-studs
    boxes (some double-gang), snake wires through walls with blocks
    in them, etc... 
    
    2.) stick some junction boxes up in the rafters and splice. Sounds
    rational, but it seems to be a technical violation of the Code
    (junction boxes must be accessible without removing any of the
    building, 370-19).  
    
    I can't believe that Joe Contractor would go through all the hassle
    of (1). Do people really do (2) and nobody cares, or is there a
    special method of splicing in concealed spaces?

    ...tek

One possibility is to put the splice boxes behind an access panel.  If you'll 
be putting fancy trim boards around the indoor skylight opening, make one of
those trim boards removable, and hide the boxes behind that.  Or, if you'll 
have a light shaft through the attic, you can put the access panel up in a
side wall of the light shaft. 

    I mounted a smoke detector over my junction box, it looks
    like it belongs there. I didn't need another smoke detector
    but it solved the cosmetic problem.
    
    This situation may need two splice boxes, two smoke detectors
    might look a bit silly, any chance you can have a removable
    piece of trim somewhere?  In the spirit of the code, a stranger
    should be able to find it.
    
    Once I did cheat and covered a splice. I soldered the wires
    and  carefully insulated them.  This was as close as I could
    get to an "unspliced" joint.
    
    - gerry
    

I recently remodeled a bathroom, and part of the renovation was alot of 
rewiring. The electrician said that I'd have to have access to the old box 
in the ceiling. I wasn't too pleased about having an access cover in the 
middle of my new ceiling, but I went along with it.

Anyhow, a few weeks ago I discovered a wierd wiring problem left over 
from the previous owner/hacker.  After tracing wires all over the place, I 
*needed* to get at the bathroom connection to test the circuit.

I was VERY tempted to bury that box; luckily I didn't.  It doesn't bother 
me much any more....

    You could always pull another wire of the proper length.
    
    -joet

    
    	Add the length of wire needed to get them out of the way,
    	add the necessary boxes to house the splices, solder the 
    	connections and use "wire nuts" on top, tape them if you wish
    	and bury them....no problem. Re-running new wiring is out
    	of the question. you'd be tearing the house down to do it.
    
    				___GM___

>      	and bury them....no problem. Re-running new wiring is out
>    	of the question. you'd be tearing the house down to do it.

    yes, this is exactly the problem; I'd have a few days of sheetrock
    work if I wanted to run new wires; the wires are stapled (so I can't
    pull a new wire through with the old one), and the walls have blocks
    in them, so I can't snake... plus, the boxes are all new-work boxes
    that won't come out without a fight (read: rip and patch sheetrock).
    
    I guess I don't feel too bad about doing a concealed splice; it's
    not a junction (where I might need to get into test some part of
    the circuit), it's just a striaght-thru splice.. 
    
    time to close my eyes....
    
    ...tek

    HOWEVER:
    
    No matter HOW you do it, an inaccessible splice is against the code.
    
    If you still go ahead and make one, at least put it in a box.

>    HOWEVER:
>    No matter HOW you do it, an inaccessible splice is against the code.
    
ALSO:

	Should (God forbid) you have a fire, and the splice be (or even
suspected to be) the cause, your insurance could be negated.

	Is it worth the risk?

						--Mike

I'm surprised that none of the preceding suggestions was practical.  Here
are a couple more, mostly obvious ones, mostly inspired by Gerry's smoke 
detector.  Sometimes you gotta do what you gotta do, but I urge you to
think hard one last time about alternatives. 

1. Attach a lamp to the workbox, either recessed or hung from the ceiling.

2. A track light power feed.  You don't need to install the track light;
   having the power feed there makes it look like there used to be track
   lighting, or like you're planning for future track lighting.

3. Just a duplex outlet.  Good conversation piece.  Explain that it's for 
   Christmas lighting, or for your roof heat cables.  (Doesn't have to be 
   true...).

4. Don't put a switch up there.  Code calls for switches to be within some 
   distance from the floor, something like seven feet.

5. There exist blank box covers that are meant to be unobtrusive in
   ceilings, to cover up now-unused boxes or as placeholders for future 
   lamps etc.  The ones I've seen are round and white.

6. Use a regular blank box cover, carefully install it flush with the 
   ceiling, and paint over it.

It sounds like whatever you do will be near the new skylight.  Thus it's 
more likely than your average electrical work to be exposed to water
problems, and to structural weirdness as your skylight framing settles 
under load.  And if you bury this work on the roof side of the attic 
insulation, it'll also be exposed to more temperature variation (and, 
again, moisture) than usual.  My point is that, if I HAD to bury a box 
someplace, this is not the location I would choose.

    Since there is no note on aluminum wiring, I'll start one.
                                                 
    I have read several notes on the hazards of using aluminum (AL) wiring
    in the house. I have not seen anything on AL wires on lamps, appliances
    etc.                                                    
                                                            
    SPECIFICS:                                              
                                                            
    I have a clear glass lamp and I want to use the "clear" decorative
    wiring sold in many hardware stores. After purchasing it and cutting 
    it to size, I suddenly noticed that the wire is AL. The light 
    socket has screw connections (one copper, one AL), and the plug
    I used is the clip on plug -- which has brass connections.
             
    QUESTIONS
    
    Is there any danger in using AL wire?
    Is there any danger in mixing the copper of the light socket and
    plug with the AL wire? If so, are there AL light sockets and plugs?
    
    

Are you sure the wire is AL? Never heard of aluminum wire being used
in light gauge cord. I'll bet it's tinned or plated copper. Strip some
insulation and scrape the wire with a knife a while. If it turns reddish
it's copper. If it's real soft and stays silvery white, it's AL and I'd
throw it out and get some clear insulation copper wire from Radio Shack.

    I'll also bet on the tinned copper.  Virtually certain.  99.99999%.
    

    You were right. Thanks I can sleep easy now.

I have a situation similar to that described in .0 but I really dont
want to run the power to the switch first (as recommended in .3).  The
switch is on a finished wall and there is only one wire going to it now.

My question:  what is the correct wiring configuration?

      Power                                                       Dimmer
      Source  ==================================================  Switch
                    ||             ||              ||
                    ||             ||              ||
                |-------|       |-------|       |-------|
                | Light |       | Light |       | Light |	
                |-------|       |-------|       |-------|

	Thanks.   Jim

    I don't understand your comment about "... there is only one wire
    going to it now."  I'm assuming you mean one cable, containing three
    wires (black for hot, white for neutral, and bare copper for the
    ground).
    
    If the wiring is indeed as shown in your diagram, wire each light
    up like this (for simpicity, the grounds are not shown; they should
    be connected together, as well as to each junction/switch box):
    
                             (junction box)
                      +------------------------------+
    >>>===============|------------------------------|===============>>>
     (power in from   |\    (white neutral wire)    /|   (power out to
      source or pre-  | \                          / |    next light or
      vious light)    |  \    (black hot wire)    /  |    dimmer switch)
                      |   \_________    _________/   |
                      |             |   |            |
                      +-------------|---|------------+
                                    |   |
                                <out to light>
    
    At the dimmer switch, just connect the two leads of the switch to
    the black and white wires.  If the switch has screws instead of
    leads, the black wire goes to the brass screw while the white wire
    goes to the silver-colored screw.
    
    P.S.  I'm assuming your switch can handle the load of the three
    lights... you should not!
    
    Jim

    Obviously, the disadvantage of this wiring circuit is that if one
    lamp burns out, they all go out (since the blown bulb breaks the
    looped circuit to the other two).  Because you don't want to or
    can't run the power to the switch first, this is the price you have
    to pay.  Since there's only three lamps on the switch, it shouldn't
    take too long to find the burned out bulb.
    
    Jim

Can you run power to the "last" light box first?  Then you could connect 
the switch and power the remaining lights from right to left (per your diagram).


I'd avoid series lighting at ALL costs.  I'd go to the dentist before I'd 
do a series wire.  Besides, each light will be 1/3 as bright.


...bill

RE:1047.4 

>I have a situation similar to that described in .0 but I really dont
>want to run the power to the switch first (as recommended in .3).  The
>switch is on a finished wall and there is only one wire going to it now.

	Jim
		I assume that what you currently  have is this.

      Power   -------------------------------------------------- Dimmer
      Source  ---------------------- --------------------------- Switch
                                   | |              
                                   | |              
                                |-------|
                                | Light |	
                                |-------|

	If you don't want to rerun the entire leg but can get at the middle
	section you could wire it thusly (grounds not shown for clarity):

           14-2                                          14-2
         Existing              New 14-3                Existing       Dimmer
             <--|                                      |-->           Switch
                                       BLK
   Line   BLK ---x-------------------------------------x-------- BLK Line
  Neutral WHT -----x---------------x----------------             
                   |               |   WHT         | 
                   | --------------|-x-------------|-x---------- WHT Load
                   | |             | | RED         | | 
                   | |             | |             | |
                   | |             | |             | |
                |-------|       |-------|       |-------|
                | Light |       | Light |       | Light |	
                |-------|       |-------|       |-------|

	Good Luck

Thanks to all that responded.  Re .8, one clarification question.  Which
WHT wire (the neutral or the load) goes to which wire (WHT or BLK) on
the lights?

           14-2                                          14-2
         Existing              New 14-3                Existing       Dimmer
             <--|                                      |-->           Switch
                                       BLK
   Line   BLK ---x-------------------------------------x-------- BLK Line
  Neutral WHT -----x---------------x----------------             
                   |               |   WHT         | 
                   | --------------|-x-------------|-x---------- WHT Load
                   | |             | | RED         | | 
                   | |             | |             | |
                   | |             | |             | |
                |-------|       |-------|       |-------|
                | Light |       | Light |       | Light |	
                |-------|       |-------|       |-------|

Re: .7, could you explain why you do not like this type of wiring?  I
do not understand why each light would be 1/3 as bright.

Re: .5 - .8, all assumptions are correct.

	Thanks.  Jim

RE:1047.9 

	Hi Jim,

> Re .8, one clarification question.  Which WHT wire (the neutral or the load)
> goes to which wire (WHT or BLK) on the lights? 

           14-2                                          14-2
         Existing              New 14-3                Existing       Dimmer
             <--|                                      |-->           Switch
                                       BLK
   Line   BLK ---x-------------------------------------x-------- BLK Line
  Neutral WHT -----x---------------x----------------             
                   |               |      WHT      | 
                   | x-------------|-x-------------|-x---------- WHT Load
                   | |     RED     | |    RED      | |            ^  
                   | |             | |             | |           /   
                   | |             | |             | |        This wire should
               WHT | | BLK     WHT | | BLK     WHT | | BLK    have black tape
                |-------|       |-------|       |-------|     wrapped around 
                | Light |       | Light |       | Light |     the white plastic
                |-------|       |-------|       |-------|     to indicate it
                                                              is a hot line.

>Re: .7, could you explain why you do not like this type of wiring?  I
>do not understand why each light would be 1/3 as bright.

	.7 illustrates a series connection of lights, like the old christmas
	strings.  In a series connection with equal loads the total available
	voltage will be proportionately divided against the loads.  In the
	illustration shown 1/3 or approx. 40 volts.  The current in this
	configuration will be the same for all loads.

	In the illustration above the lights are wired in parallel though 
	each will have its own current draw, they will all have the same
	voltage across the load.

	Hope this helps - Randy

RE:.5 and RE:.6 assume series wiring which isn't cool.   The last 
reccomendation is a parallel connection wich is fine (that's what I'd 
do).  Each light has a direct shot to the power line.

...bill

    Re .11
    
    Yup, I agree....  Although a little more complicated, it does avoid
    the problems with series wiring.
    
    Jim

  I'm confused about electical grounding!  

  I have an OLD house that has a NEW 100A service.  The feed in has the ground
  wire attached to the "GROUND BAR" like what I expect.  Some of the house 
  circuits are TWO wire with NOGROUND and others are THREE wire.  On the
  THREE WIRE circuits the BLACK (hot) is connected to the circuit breaker but 
  the WHITE and BARE wire are attached to the same point on the BAR??

  Is this some MICKEY_MOUSE wiring setup or what??

  I want to splice some THREE wire onto a TWO wire circuit running out of a
  light fixture.  What do I attach the ground wire to??  The WHITE ??

  If I didn't have to face snaking wire around/throught 10" beams,  I'd
  rewire the whole thing from scratch with THREE wire but....

  Can anyone shed light on what's going on here....

						-=Dennis

What you see is correct.  The three wire circuit gnds connect to the same point
electrically in your panel.  The idea though, is that at the other end
of the circuit the white or neutral wire is your normal path to ground...
there will be current in this wire.  The ground wire is a separate (but
basically equal) path to ground for things like chassis, metal parts on
appliances that get handled, etc. This does not carry current.  If there
should be a short, the ground wire will safely carry the current to ground.

I believe that GFCI's somehow use this to work... ie: if current goes thru
the ground wire, the circuit trips and/or if current in white wire does
not equal current in black circuit trips... I'm not sure of this, but it
works something along those lines...

    The tying of the White(AC low) to the Bare Ground wire is common
    in three wire house wiring.  They are trying to make them at the
    same Power Reference Point.
    
    As for connecting or tapping power from a light fixture, be careful.
    If the Black(AC High/Hot) is being switched, then you could have
    a Amperage problem for the circuit that you are trying to create.
    The switch can be your weak link for the circuit.  Always verify
    your source when tapping into another box.
    
    What are you trying to power off this light fixture??
    
    
    		John

I've always been confused about electrical service grounding... and I'm supposed
to be an electrical engineer! :-)

The way I understand it, there's this here wire with you on one end, and the
electrical company on the other end.  There may also be God only knows howmany
transformers on the wire between you and the electrical company, but I'm
confused enough as it is, so I'll skip that part.

Anyway, you have this here wire from the electrical company, and it's *hot*,
electrically speaking.  Now there's a couple of other wires that come into your
house from the electrical company, but basically they are there so that you
think that you are getting more for your money from the electrical company and
electricians.  

Only one of the extra wires has any meaning, it's the opposite phase of the
*hot* wire from the electrical company.  I think it's the electrons the
electrical company sold you last month, or something.  This wire is for when the
electrical company wants to sell you more electricity, and rather then replace
the wire you already have with a bigger one, they give you two wires, and charge
you twices as much by selling you the electrons twice.

One of the other extra wires simply goes out to your telephone pole, and goes
into the ground, in other words, it's grounded.  Ah Ha! you say, that's where
the ground is, right?  Wrong!  There's a half dozen or so grounds, and this is
only the first one. Again, these extra grounds are to make you feel like you are
getting your money's worth.  All these grounds go into the ground, and a bunch
of wires tied to a common point all have the same voltage, right?

So then you have two or three or more (I'll forget about the other wires if you
will) wires coming into your house.  Now they start putting colors on the wires
to confuse you.  They call one wire "white", and one wire "black". The "white"
is supposed to be the *hot* one, but that doesn't mean anything at this point,
because you can get the blue spark fairy to come forth from either one of them,
so just forget about that distinction. 

Usually close to where your wire come into your house, there is a fuse or
breaker box.  Here they add another wire, and call *it* ground, too.  This wire
usually doesn't have any insulation put on it; the electricians save money this
way, and immediately pass the savings on to their bank accounts.   This wire
also goes into the ground, so I suppose they have a good reason for calling it a
ground, but what did they do to that perfectly good ground that they had? Nobody
knows, all I can tell you is that it's ruined, forever, and ever.

Now you have three of four or more wires (see above...) that you run all over
your house.  Now the electrical code is written by electricians, for
electricians, to make money...  that is why the code says that you have to have
an outlet every six feet of wall.  Sheeash, you'd think they never heard of
extension cords.

Eventually, all these wires go to a box in the wall that you can stick a plug
into (or your fingers) to get electricity out of the wall.  And this plug goes
to a cord that goes to a transformer, and a power supply, and there is another
entirely unassociated ground on the other side of the power supply. This is my
home territory, where I went to school, where the electrons and grounds behave
as the laws of nature and God intended them to.   

But wait... there's three more grounds here: ground, chassis ground, and
floating ground!!!  AAAAAARRRRRGGGGHHHHhhhhh...... <silence> <except for a few
whimpers> 

Jim.

Re: .3
>to confuse you.  They call one wire "white", and one wire "black". The "white"
>is supposed to be the *hot* one, but that doesn't mean anything at this point,

    NO!  The **BLACK** wire is hot, the ***WHITE*** is neutral.  
    
    Re: .0
    
    Yes, the neutral and ground get tied together at the service entrance,
    AND AT THAT POINT **ONLY**!!!  Do NOT connect them together anyplace
    else.  You cannot ground boxes, outlets, etc. on your 2-wire circuits.
    According to code, for a 2-wire circuit with no separate ground
    wire available, you're supposed to use only 2-prong sockets (without
    the hole for the grounding prong on a 3-prong plug).  That's to
    keep somebody from thinking an applicance with a 3-prong plug is
    grounded just because he plugged it into a 3-prong outlet.  If you
    want a grounded outlet on a circuit that is currently 2-wire, you'll
    have to run a new line from the service entrance and rewire that
    circuit.
    

    
    I'm glad someone came out of the closet. I was always embarrassed
    that I was an Electrical Engineer and could not explain it either.
    I'm convinced it's a secret and they tell you when you get your
    electrical license or something.
    
    Tim
    

    Re: .0 again
    
    You shouldn't splice 3-wire onto a 2-wire circuit, because you can't
    ground it properly.  Either go all the way back to the service
    entrance with 3-wire, or extend the 2-wire circuit with 2-wire.
    You can probably use 3-wire and just clip the ground wire short
    so it's obvious that it's not to be used, but I'm not sure about
    that.
    
    Is the present wiring BX (armored cable)?  If so, the metal armor
    may be grounded.  HOWEVER, it may not be an acceptable ground
    according to the code.  If it's BX and IF it has an internal metal
    strip inserted inside the sheathing (like a wire, only it's sort
    of flat), then you can use the sheathing as a grounding path.  If
    there is no metal strip, then the sheathing is not acceptable as
    a grounding path and you must treat the circuit as a 2-wire circuit.

    Assuming the metal strip is there, you should be able to connect
    the ground wire of your 3-wire cable to the junction box where you
    are making the splice and continue from there.  However, I am a
    little hazy on the details here, and that may not be correct.
    
    To explain things a bit further, BX cable, by itself, has a relatively
    high resistance.  It's steel, which is not all that great a conductor
    compared to copper, and the spiral construction doesn't provide
    a very good ground path exept around and around and around and
    around...the spiral.  Hence the inserted metal strip; it runs linearlly
    inside the armor sheathing and provides a ground path of acceptably
    low resistance and good reliability.

	WOW!!! Thanks for the plentify and rapid response!

  There is TWO wire running from the panel to a "pull_chain" light fixture.
  A piece of BX cable is spliced to the two-wire coming into the light and
  runs to another "pull_chain" light fixture in another room.

  I want to replace the OLD fixtures (can't find globes to fit them) with
  NEW pull_chain fixtures and since there are only two lights on the entire
  20A circuit, I'd like to tap off the line and add 4 outlets (2 in each room)

  I think I'll use three-wire for the outlets and tape up the ground for now.
  After the holiday crunch, I'll go back and feed new wire from the panel...


						-=Dennis

When you "tap off the line", be sure the box from which you do so is big
enough to hold the additional wires and wire nuts.  Cramming too many
things into too small a box is difficult, dangerous, and contrary to Code. 

I trust your "20A circuit" uses 12-ga. wire in addition to having a 20A 
breaker.

    The difference between grounds (chassis, equipment, safety, etc.)
    may be confusing, but what it boils down to is this:  there should
    be only one point in an electrical system where all the grounds are
    brought together and joined.  This avoids something known as ground
    loops.
    
    First, what the wires are....  Most houses have three wires coming
    off the pole:  two insulated wires and a bare wire.  They usually
    appeared to be all twisted together, but in some localities may
    be seperated.  Older houses that do not have 220 volt service have
    only one insulated and one bare wire; the reason why will hopefully
    become apparent after reading the following.  If you measured the
    voltage on the bare wire by putting your meter between it and "ground",
    it should read close to if not 0 volts.  The other two wires contain
    110 volts measured relative to the bare wire (meter probes placed one
    on the bare wire and one on either of the two other wires).  However,
    a meter placed between the two insulated wires will read 220 volts.
    This is because the voltage is constantly switching back and forth
    between positive and negative phases; when one wire is at +110v, the
    other is exactly 180 degrees out of phase, or -110v.  Remember the
    old sine wave??
    
    These three lines are brought through the meter and into a circuit
    or fuse box.  The bare wire gets connected to a copper bar containing
    many connection points, while the two "hot" wires go through a double
    (a.k.a. ganged) main breaker.  Notice that the bare wire does not
    get interrupted by a breaker; this is an important safety feature!!
    Once through the main breakers, the two hot lines feed both single
    110v circuits and larger capicity 220v circuits.
    
    The larger circuits that feed electric dryers, hot water heaters,
    and stoves contain both a red and a black wire (along with one or
    two others:  a white and possibly a bare).  The black wire gets
    attached to one of the two insulated feeds from the power company,
    while the red wire goes to the other insulated feed.  The smaller
    110v circuits contain only a black wire, in addition to the white
    and bare wires.  This can go to either of the above two feeds, but
    the system as a whole should balance the load drawn from each feed
    as closely as possible (it makes the power company very happy by
    causing less wear and tear on their equipment!).
    
    Every electrical circuit contains a white wire.  These get connected
    to the bar containing the bare feed wire.  If the circuit also has
    a bare grounding wire, that too gets connected to this bar.  This
    bar is also attached to a good ground point, either a cold water
    pipe coming into the house, a grounding rod driven several feet into
    the ground, or a cable that's buried along the foundation.
    
    In the simple case where's there's only one fuse/breaker box, the
    white and the bare wires are tied together and grounded.  It gets
    more complicated when there are multiple fuse/breaker boxes.  In
    this case, the white and bare wires should not be joined together
    in the secondary distribution boxes, but attached to seperate bars
    that are isolated from each other.  But that's another story.
    
    I hope this clears up the confusion about what the lines coming
    from the power company provide you.  Sorry if this has been boring
    for any other power distribution junkies!
    
    Jim

>    two others:  a white and possibly a bare).  The black wire gets
>    attached to one of the two insulated feeds from the power company,
>    while the red wire goes to the other insulated feed.
    
    Least anyone misunderstand what I wrote in .9, the red and black
    wires must go through a double breaker (and the main breaker) before
    they connect to the main power company's feeds.

    Jim

    re: .9
    
    	I understand, I think, what you, and others have said, I have
    just one question left concerning the original scenario.
    What is the problem with connecting the ground and neutral (white)
    wires to the neutral wire of the existing 2 wire circuit?
    It seems that the net effect will be the same.
    

    				       +-- junction box
				       V    
 neutral bar in box - old white ooooooo+oooooooooo new white - fixture
   					\________________ ground
    
    
	versus a complete three wire circuit
    
        
 neutral bar in box -oooooooooooooooooooooooo new white - fixture
		     \_______________________ ground
    
    With your comment on "ground loops" I can only assume that in the
    former circuit the electricity which should go all the way from
    the fixture, at the end, to the neutral bar (and thence to ground?)
    will "loop" back TOWARD the fixture from the connection at the
    junction box, probably because the resistence on the old white
    wire is higher than the new white or new ground, depending on which
    wire (white or ground) is carrying the current.
    And the reason that this doesn't happen in the three wire circuit
    is that the neutral bar (aka ground) is the path of LEAST resistence.
    
    
    Or am I totally lost?
    
    Alan who had an electrician wire the new range outlet
    
    
    

    .8:
    
    If I read the code synopsis book correctly, the minimum acceptable
    box for an outlet with 2 12-3 cables (i.e., a daisy-chained set
    of boxes) will be the size that's about 3 1/2 inches deep
    (approximately the depth of a planed 2 x 4 -- we ran into a bit
    of hassle with the screws going a little beyond the 2 x 4, and hitting
    foundation).  It was an annoyance to discover that I'd bought
    about 8 boxes that were too shallow, but at least the ones of the
    correct size allow you to fold the wires and push them and the outlet
    in without being a Hercules.
    
    If you're getting the boxes at Spag's, look for the deeper of the
    two sizes of metal boxes (don't know what the measurements are for
    the plastic ones, which I thought I saw recently).
    
    Dick
    

    I've seen the book 'Richter's'  touted here and elsewhere in this
    file.
    
    Anyone know where I can obtain a copy near Nashua N.H. ??

    dennis, your 100a service hook is fine. its wired correctly.
    you should also find a ground going to the incoming water line.
    or perhaps a ground rod. (make sure one of them is there)
    we're in the same boat when it comes to old houses. mine
    is 100 yrs +????. i have the old "knob and tube" in some places.
    my wifes uncle is an electrician, he tells me the knob and tube
    is good wiring and to leave it alone, or replace it.
    in your last question are you saying you are looking at a light
    fixture that has only one wire????
    jim

    Re: .11
    >It seems that the net effect will be the same.
    
    Yes, it does, doesn't it?  However, doing what you suggest is
    absolutely positively NOT permitted by the electrical code.
    The problem is "ground loops" as you suggest.  I'm somewhat vague
    about the exact details of the phenomenon, but I seem to recall
    a note in this file someplace that did an excellent job of explaining
    ground loops and why they are A Bad Thing To Have.  
    Do it right, do it according to code; that's what separates competent
    do-it-yourselfers from house butcher do-yourself-iners.

    The reason you can't just connect the white and bare conductors
    together is that the voltage drops along the white wire will get
    connected to the case of the washing machine that's sitting in a
    puddle in your basement (or the case of that electric drill, etc...)
    the "equipment grounding conductor" is kept separate to keep these
    voltages in line...
    
    (as he scratches the back of his brain) The rules for outlets on
    2-wire circuits are:
    
    a.) Can't add a new, non-grounding (2-prong) outlet. 
    b.) existing non-grounding outlets are to be replaced with
        grounding (3-prong) types unless there is no way to provide
        the ground (see the BX-discussion a few replies back..)
        (you can install a GFCI, but you can't extend a new ground
        from it.)
    c.) NEVER, EVER install a grounding outlet without a proper
        ground. This is serious stuff, here... people have been killed
        by violations of this rule.

    houses with 2-wire circuits are not fun, unless you are an electrician;
    then they pay for your kid's education.
    
    ...tek
    

I'm surprised this wasn't listed already, unless it's buried under some 
unrelated topic as much of this stuff is...

Is there any general opinions about metal vs. plastic boxes?  It seems that in
almost any new construction I see that everyone uses plastic, yet SPAGS only
carries metal.  In fact, one can get plastic boxes virtually anywhere cheaped
than the metal boxes at Spags.  My thought is if plastic is better than metal,
why would Spags even bother carrying the metal?

-mark

    SPAG'S DOES carry the plastic! But you do have to look for them, they
    are hidden, believe it or not, in the ELECTRICAL DEPARTMENT. 
    
    They have a trash barrell FULL of the single boxes in the back row near
    the door bells. They list for $.33, the same as I've seen in other
    stores, but at least they're not MORE. The doubles are in the same row
    as some of the metal work boxes (middle row). I don't remember the
    prices of them or the availibility of the triple boxes. 
    
    I prefer the plastic boxes for new work in the single size. 
    
    The double and especially the triple are too flimsy for my liking. My
    experience with the triple has been when you mount the box on the stud,
    the box does not remain square but rather takes on a trapazodal shape.
    The switches and the switch plate then are mounted on a slant and look
    like S#%T. I'll stick with the metal boxes for the few places that
    require more than a single.
    
    Charly

    
    	Plastic boxes suck, they are brittle and snap very easy and
    I have never seen a pro use one ! If you screw them down too tight
    or you nail them in too hard or you tighten the cable clamp too
    much and SNAPPPPPPPPPPPPPPPPPP!
    
    	-Steve-
    

    Can two 220 appliances (range, dryer, (is a dishwasher 220?)) share one
circuit?  The arrangement I have in mind would put a toggle switch of some
kind in the loop, enabling one appliance and disabling the other.  (This
is in a full-circuit-breaker-box-type-house.  And I'm not including any
baseboard heat in the loop.)
    It shouldn't be too hard to plan certain non-meal times to use the
dryer - just flick the switch.

    
    
    
    
                               ??? WHY ???
    
    

    
    
    Even if there aren't or weren't any code restrictions it is generally a
    not a good idea to do something that is too far from what most people
    would consider normal. Future owners (and who ever does the laundry and
    cooking in your house) will curse you 'till the day you die and then
    some. 

    Charly

    Considering that the dryer would have a 30 amp or 40 amp connector,
    you're talking quite a large switch(a transfer switch would do the
    job quite well, but be rather expensive). A big question would be
    the electrical code in your area. Unless the two locations are near
    each other, you may be better off running two separate circuits,
    once the cost of everything is considered.
    
    Eric

    Someone with the code book handy could comment, but I think these
    heavy appliance circuits must be DEDICATED (that is my recollection
    of reading the code at the library).   DEDICATED means NOT SHARED,
    so you can't do it...

I agree with the other replies - your proposed scheme is inconvenient, requires 
an expensive switch, and is probably contrary to Code.  There are likely to be 
better ways to share capacity and free up breaker-box slots.

But if you're still considering this option, check with your local wiring
inspector _before_ buying the materials or investing substantial planning time.

    Not all 220VAC appliances are the same. A/C compressors are 220V
    only while stoves and dryers uses the neutral for the 110V timer
    and lights.
    
    Though some places allows for aluminium wires, get the copper if
    you can afford the copper. I had thought about using the 220V line
    to the A/C from the old stove plug since I converted over to gas
    stove. The cost of the connectors and stuff made running the line
    from the C/B box more feesible.
    
    /cal

    The dryer has a 30 amp. plug and the range has a 50 amp.  Feeding
    the 30 amp. receptacle with a 50 amp. breaker is a code violation.
    Feed the 50 amp. w/ a 30 amp. breaker and you risk tripping the
    breaker if all of the range units are on.  Not a real good idea
    at best.  Run two separate circuits.  You will be much happier in
    the long run.
    
    

    This little project you have conjured up is really turning a horse
    into a camel.
    
    -1 is absolutely right, you are violating basic wiring rules, and
    the standard electrical code (for MA I'm sure).
    
    It will take less time, effort and money to just run 2 separate
    lines. Otherwise, you will need a switch, heavy duty relay for the
    poser, indicator lights, have to run wire to the receptacles anyway.
    
    Enough said
    
    JMB
    

    Well!  I didn't expect to get my head bit off!
    Just kidding.  These responses comprise a perfect example of the benefit
of Home_work.  Thanks.  Now, just one more peep, and I'll be quiet.
    We have a 3-family house and inadequate wiring (I mentioned our full circuit
box, I neglected to mention its capacity - 100 amps! - that handles 3 range
circuits, 1 dryer circuit, and one room's electric baseboard, with only two
tripped circuits in 4 1/2 years - one of my first projects was separating two
ranges that shared 1 circuit!).  Before we inherited a dryer, one of our tenants
started using the one dryer hookup, in a central hallway.  OK with us.  And then
I started wondering why couldn't we share the one circuit.
    So, adding another circuit is out (unless we add another 100 amps - $$$$).
Sharing a 50-amp device with a 30-amp (or whatever) isn't a factor.  And, I'll
check out the dedicated aspect with the town/state codes (NH).
    One reply listed 4 or 5 things I'd need, even if it was legal.  More info?

    
    I've run into many situations like yours and all of them have scared
    the daylights out of me. I was looking at a house once and the owners
    had an air conditioner attached to small extension cord. I mentioned
    the potential hazard to the owner and they laughed. I was going
    to show them how the cord would crack from heat, but when I touched
    it, ALL of the insulation fell off in my hand, there was a big spark
    and the owner almost fainted.
    
    I know you mentioned that $$$$ was an issue, but 100  amps for 3
    families is VERY dangerous. You should get quotes from local
    electricians for running 100 amp services for each appartment and
    then have a detailed inspection done of the wiring. For me it's
    more than $$$$, but's it piece of mind and the safety of my family
    and possesions that's important. Electrical fires are very common,
    expecially when heating and old or inadequate wiring are involved.
    
    I wouldn't use "only 2 tripped breakers in 4 1/2 years" as a comfort
    indicator. What you may have is damaged insulation on the wire that
    was sharing 2 ranges. The ranges themselves won't last as long.
    Sort of like working in a brownout all the time. The service cable
    should be checked. I'll bet it's warm most of the time. Circuit
    breakers are supposed to be toggled every 3 months or so to be sure
    that they will operate. Do you do that???? Most folks don't.
    
    In short, your initial question didn't even begin to discuss your
    real problem. You should fix that before you are reparing fire damage!!
    
    Sorry for any harsh statements, but I've seen situations like yours
    turn into tradegies.
    
    JMB

    
    I agree with all of the replies; you really need to install dedicated
    services for each unit, and size your ciruits correctly.
    
    The only thing that might be marginally acceptable (and despite
    this, I believe that what I'm going to tell you is against code
    regs) is if you had a piece of baseboard heat requiring a 20 amp
    230 circuit, as well as something such as say an air conditioning
    unit.  If you could safely assume that you'd not use either at the
    same time -- such as the heat and the AC together, then you could
    safely do it.  However, I have this situation in my house, and I
    have 2 separate circuits.  The wire and the breakers are cheap enough,
    so I'd certainly encourage you not to compromise your property and
    safety.  Do it correctly and you won't have to fix it later.

    I'm doing some minor kitchen remodeling (counters, lights, paint,
    etc.) and I'm contemplating adding another outlet to my new
    counter space when I take the old counter out.  Adding this outlet
    will involve extending from one of two existing outlets. 

    Presently, there exists one outlet already on the counter.  It
    uses old, 2-wire (ungrounded) wire and shares a 20 amp breaker
    with the kitchen overhead light and 4 living room receptacles. 

    On an adjacent wall is another outlet, on 12 (14?) ga. 3-wire by
    itself on a 20 amp breaker.  Very virtuous looking. 

THE QUESTION:

    1. Is it safe/acceptable to add a ground wire to a 3-prong outlet
    and ground the receptacle directly to plumbing (under the sink)? 

    This way, I could extend the old 2-wire outlet and put in grounded
    3-way receptacle without going through the hassle involved in
    extending from the existing grounded supply on the adjacent wall
    outlet. 

    Thanks for your help, 

    -Brian 


 

    I'm not an electrician, but, from perusing this file and talking
    to folks who know about such things the answer is a resounding NO!
    You should not run a 3 wire from a two wire, in fact it is not
    up to code and, therefore, illegal.
    
    Find out if that grounded outlet on the 20A breaker is 12 or 14
    ga. wire, 'cause if it is 14 then the breaker is too big for the
    wire and unsafe, also.
    
    If I were you I'd have a qualified electrician look at your wiring
    given that the house is old and has obviously had some additional
    electrical work done.
    
    Alan

    It's interesting how much trouble that can cause if the pipe is
    ever replaced with plastic.....
    
    (However, I have done something similar to get a ground-fault
    interrupter installed. Don't do as I do, do as I say....)
    

    The real reason is that the Nat'l electrical code requires that
    all grounds for circuits emanating from a given main panel be
    connected to physical ground at one and only one point.  This is
    to eliminate any possibility of ground loops - a dangerous phenomenon
    caused by potential differences between two different grounds due
    to leakages, imperfect conductivity of pipes/earth/etc.
    

I suppose enough people have told you that you shouldn't ground to a 
pipe by now.  There's another potential problem in your message though: 
The Code now requires that the outlets in your kitchen be separate from 
the lighting cicuit. (Makes sense -- kitchens are filled with dangerous 
things, and if you just popped a breaker 'cause the mixer cord is 
frayed, you don't want to stumble around in the dark.)  I believe it's 
ok for the light to be tied in to the living room circuit, but not the 
kitchen outlet.

This isn't a problem in your present situation, because your old wiring 
is "grandfathered" in under the new code, but if you go to make changes, 
you may be required to bring  the whole kitchen into compliance.  It 
would be a good idea to voluntarily make the change anyway while you're 
snaking the wire over from your modern outlet. :-)

					>>>==>PStJTT

    In my "old" (1955) house in Seattle, I had the same problem: two
    prog outlets in the kitchen, and I wanted to add another outlet
    and GFCI.  I had already fiddled the wires from the new outlet down
    to the basement, and was prepared to run a new grounding wire back
    to the panel.
    
    However, when I finally managed to rip out the metal box that housed
    the existing outlet, I found that it WAS grounded.  The grounding
    wire had been installed before the sheetrock, and was attached to
    a screw on the OUTSIDE of the box.  So, the box WAS grounded, although
    I couldn't tell from the inside.
    
    If you have a metal box, you may find the same thing.  Get out your
    test lamp and see if the box is grounded.  If so, rip it out, bring
    that grounding wire through the knockout, and you are home.
    
    Now for my problem:
    
     >> The Code now requires that the outlets in your kitchen be separate
     >> from the lighting cicuit.

    Oh dear!  My kitchen has a main light and a small one over the sink.
    They used to be on the same circuit, but I recently re-wired the
    one over the sink so that it is on a different circuit from the
    main light, but on the same circuit as an outlet.  I did this (without
    a permit, of course) for two reasons:
                                
    (1) When I turn off the main light circuit, to work on the living room
    or the breakfast room, or something else, it is nice to have at
    least the small light over the sink still work.
    
    (2) I wanted to use a pair of three-way switches on the light by
    the sink, instead of the existing single switch.  Normally that
    would mean running three-core cable to replace the two core, which
    means ripping out the outlet box, which typically means major repairs
    to the wall.   However, this switch shared the box with an outlet,
    so by using the power supply to the outlet the feed the common side
    of the switch, I was able to avoid all that.
    
    My question:  have I broken the new code?  (Which code introduced
    this requirement?)  Or is it OK as long as ONE light is on a separate
    circuit?
    
    	Andrew
    

Well, against my nature, I broke down and decided to do the project the right
way ... 

I added a new circuit.  This required using up my last breaker in the panel,
cutting a hole in the wall for wire-snaking, as well as removing a baseboard so
I could sneak the wire behind it. 

But hey, I'm glad I did it.  According to code, you're supposed to have
two (2) "small appliance" circuits in a kitchen, separate from the lighting
circuit.  That's what I've got now.

-Brian

    is there any danger in replacing 2 prong outlets with 3 prong outlets?
    Maybe another way of asking the question is: What uses are there
    for 3 prong outlets that are dangerous when there are only 2 wires
    backing up the 3 prongs?
    Just bought a bunch at Spags for 60c and have installed several.
    

    Re: .8
    
    The danger is if you use an appliance which, for safe operation,
    requires the ground pin to be grounded, and something goes wrong...
    
    				Steve

    The basic problem is, if you put in an ungrounded 3-prong outlet,
    the outlet is not telling the truth.  It's lying to whoever plugs
    a 3-prong plug into it.  
    I can see one danger.  You hire a contractor.  He plugs his 3-wire
    extension cord into one of your outlets, runs the cord outside,
    plugs his 3-wire saw into it, pulls the switch, and promptly gets
    zapped.  He sues you.  

    Thnx for help .10,.11
    Called around and discovered that two prong outlets are not made
    anymore, are not stocked, and are apparently out of code (in Mass)
    One store suggested that a 3 prong outlet can be properly grounded
    simply by running appropriate-guage-wire from the ground screw in
    the outlet to the back of the junction box. Does that make the outlet
    "3-prong-safe"?

re .11

Only if the junction box itself has been properly grounded.  If I remember
correctly, one type of system uses the metal of the electrical conduit that
the wires run through as the ground.  (Might be an out-of-date or state
memory though.)  This works fine as long as all the junction boxes are
properly connected directly to the conduit and nobody has broken the path
in subsequent renovations.

/Dave

.11>    Called around and discovered that two prong outlets are not made
.11>    anymore, are not stocked, and are apparently out of code (in Mass)

They won't be easy to find, but they are in fact _required_ by Code when
the box isn't properly grounded.  This should only be true when replacing a
defective 2-prong outlet - if you're installing a new box or running a new
cable, it must be properly grounded, and then you must use a 3-prong outlet. 

Maybe your fellow NOTErs will have enough 2-prongers lying around for you. 
I know I have at least one you can have. 


.11>    One store suggested that a 3 prong outlet can be properly grounded
.11>    simply by running appropriate-guage-wire from the ground screw in
.11>    the outlet to the back of the junction box. Does that make the outlet
.11>    "3-prong-safe"?

As .12 indicated, this advice is correct only if the box itself is properly 
grounded - a dangerous assumption.  If the box were properly grounded, you'd 
most likely already have a 3-prong outlet there!

_Never_ get this type of advice from a store.  The people behind the counter 
and answering the phones may know their stock (often they don't even know 
that), but they don't know the Code.  If they knew the Code, they'd be out 
working as electricians and making lots more money. 

	What kind of cable do you have? My house had two pronged outlets
    also and, unless you looked carefully, 2 wire cable to match.
    BUT, they took the ground wire and wrapped it neatly around the
    cable under the cable clamp (holds the cable to the box) grounding
    the box. I could then run a pigtail to the box for my new three
    prong outlets.
    
    	Alan
    
    PS I may still have some two prongs you can have, if necessary.
       I'll let them go REAL cheap ;^)
    

    I have about 20 million two-prong outlets, free for the taking
    (In fact, I might pay someone to take them out of my sight!).
    This is due to the replacement of 90% of the existing outlets in
    my house with 3-prongers.  And, yes... the new outlets are indeed
    grounded.  The existing wiring has the ground wire brought out
    of the outlet box and attached with a neat little spade lug to
    a screw on the outside (i.e., inaccessible within the wall!) of
    the box.
    
.12> Only if the junction box itself has been properly grounded.  If I remember
.12> correctly, one type of system uses the metal of the electrical conduit that
.12> the wires run through as the ground.  (Might be an out-of-date or state
.12> memory though.)  This works fine as long as all the junction boxes are
.12> properly connected directly to the conduit and nobody has broken the path
.12> in subsequent renovations.
    
    You're probably thinking of armored cable, more commonly known by
    a trade name:  BX cable.  Your last point is an important one!
    
    Jim

     There have been other notes stating that two-wire BX cannot be used 
to ground a three prong outlet.  The metal shield is not considered a good 
enough conductor back to ground.  

     Yet another earlier note stated that you can put a GFCI on your 
two-wire-plus-BX circuit.

     I have some 12-2 and 14-2 romex with a much smaller diameter ground 
wire.  How can it be legal to use this to ground the third prong?  If the 
third wire is smaller, how can it carry the full load in a hard fault?

    thnx for good analysis and advice guys. Will try to determine if
    in fact the wiring is 3 wire. (House was built c. 1954)
    
    
    			herb

>They won't be easy to find, but they are in fact _required_ by Code when
>the box isn't properly grounded. 
    Richter and Schwan's (sp?) Wiring Simplified calls this out.
    
>Maybe your fellow NOTErs will have enough 2-prongers lying around for you. 
    True.
    
      I replaced all of the two-prong recepticles in my house with
    grounded ones. I saved the ones that appear to be in reasonable enough 
    shape to be used again and meant to put in a note offering them to
    anyone that needed them for the reason stated above.  I believe I have 
    at least a dozen left (maybe more).  If anyone needs some/all, let
    me know. No warranty/liability is expressed or implied. 
     
    
>				If the box were properly grounded, you'd 
>most likely already have a 3-prong outlet there!

      I think it really depends on when the house was wired. My house
    was built in '55 and ALL of the boxes are properly grounded (or
    at least were when they were installed) yet none of the recepticles
    were the grounded type.  I don't understand this but then again, I 
    don't know what the code was thirty years ago. 
    
    -Jim
    

    BX armor can be used as a ground *IF* it has a bonding strip
    running along inside it.  This is just a thin metal ribbon, running
    inside the armor but outside the wire bundle.  The armor, by itself,
    isn't considered a suitable ground because the spiral-to-spiral 
    connection isn't very secure, and the only path that has any reliablity
    is around and around and around and around and around and around...
    following the spiral, which ends up being too high a resistance.
    The bonding strip gives a straight-line path, and makes it acceptable.
    (Or so the theory goes).
    The bonding strip ought to be bent over the end of the BX armor
    and clamped under the cable clamp; and don't forget the anti-chafe
    bushing.

NHD hardware (and I think some true value stores) sell 2 prong outlets

    Re: .19
    Yes, that seems to have been the code at one time.  My parents' 
    house was built around 1953 and it has grounded boxes with 2-prong 
    receptacles.  I guess the theory was that if a fault developed 
    in the box and a hot wire touched the box it would blow a fuse, 
    not just sit there ready to zap somebody.

.17>     I have some 12-2 and 14-2 romex with a much smaller diameter ground 
.17> wire.  How can it be legal to use this to ground the third prong?  If the 
.17> third wire is smaller, how can it carry the full load in a hard fault?

The ground wire does indeed carry the full load in a hard fault, but 
_not_for_very_long_ - just long enough to trip the breaker.  At the power 
levels 12-2 is used for, it takes a while for the resistance of the smaller 
ground wire to generate enough heat to be dangerous.

But the Romex I've used has a ground wire of about the same size as the
other conductors (I think).  Is yours some special-purpose product?   Does
it have "Type NM" printed or stamped on the outer jacket?  ("Type NM", for
"non-metallic", is the Code's name; "Romex" is one brand, and the universal
trade name.) 

Not to be insulting, but just covering all the bases:  you're comparing the 
ground wire's size with the conductor _inside_ the white and black 
insulation, right?  Of course the "black and white wires" are bigger than 
the bare one when you include the insulation!

    re: .23 etc.
    Yes, I think the ground wire can, by code, be one size smaller than
    the other wires, so with 12-gauge insulated wires you can have a
    14-gauge ground.  (At least this used to be true - haven't checked
    the latest book.)  I saw, some time ago, some NM wire in which 
    this was done; most of what I've seen has the ground the same size
    as the others though.

    A while ago (10+ years) there was ROMEX around with a smaller ground
    wire.  When they started to produce it with same size ground, they
    advertised it as "14-2 Romex with full size ground".  I think it
    would be hard to buy some now though.
    
    bjm

    The '87 code does NOT allow a smaller ground anymore.

Well, I have a question on a similar-but-dissimilar topic as .0. My 
situation is that I'm living in a townhouse now, which has 220V service
in the bsmt. with a plug that looks sorts like:

   L
  \ /

and I'm thinking of buying a planer, also 220 (230?) V which seems to 
come with a plug shaped like:

   o
  _ _

As I don't want to rewire this townhouse, which I'll only be in for a 
few more months, is it possible and/or SAFE (!!!) to somehow make up an
extension/conversion cord to allow the planer to plug into the dryer 
circuit, or are these types of circuits incompatible???

                                                   ken

I think it should be fine to make a short conversion cord.  The only difference
in the two plugs is amperage.  Luckily, the planer is lower amperage than the
outlet - it would clearly be unsafe to do the conversion if it were the other
way around.  The planer plug is a 20A plug, I'm not sure the exact amperage of
the outlet, but it's at least 30A, maybe as much as 50A.  Make sure you use
wire rated for at least 20A for the cord, and that there is only one outlet on
the cord - if there were two outlets, the cord would have to be rated for the
amperage of the wall outlet since it could take more than 20A. 

At first I wasn't sure about the safety of putting the lower amperage planer
on the high amperage line, but then I thought about 18 guage stranded lamp 
cords being safely plugged into 20A circuits, and that convinced me it would be 
fine.

Paul

    I thought that I would answer the question that I asked in .5, since
    no-one else has!  
    
    I bought a new Richter and Schwann (no, I don't have the real code)
    and they are quite explicit:  the kitchen must have two 20A circuits
    for appliances.  These circuits MAY also serve the dinning room,
    breakfast room and pantry, , but MUST serve the kitchen.   They
    MAY have an electric clock recepticle, but MAY NOT have ANY LIGHTS.
    The refrigerator MAY use one of these circuits.
    
    So, I disqualified one of my circuits from this provision when I
    connected the supplimentary light to it.   BUT it turns out that
    the refrigerator is on its own 20A circuit, so I DO still have the
    two circuits required by the Code.
    
    	Andrew
    

    Go to the hardware store and buy a "PIgtrail" for a dryer -- about
    three feet of flexible cord with the 30A dryer plug molded on the
    end.  Then put a handybox (one of theose metal boxes with rounded
    corners) on the other end, with a cable clamp -- you may hev to
    enlarge the knockout to get the cord into the box.  Put a 20A socket
    into the box, and connect the wires.
    
    Voila -  one extension lead.  Should cost you ~ $15

    I've never seen the 30A plugs on sale other than connected to the
    pigtail, but I bet DEC has a source for them!
    
    	Andrew
    

Thanks, folks! I may get this thing flying, after all. If I make up the 
rig Andrew suggested, which wire goes where? I suspect that wiring the 
plug improperly could be exciting....

                                              ken

    .14:
    
    Some wiring books (Richter & Schwann?) may describe the proper way
    to wire various plugs.  Come to think of it, the code might, too.
    
    Dick
    

Wiring's pretty simple.  In the cord from the plug, there'll be three wires.  
One of them will either be bare (no insulation) or will have green insulation.  
This is the ground.  On the outlet, there will be three screws - one will be 
in a distinctly different place from the other two and should be green.  
Connect the ground wire to this screw, and the two other wires to the other 
screws.

Paul

    Wouldent it be a good idea to change the breaker in trhe panel too?
    Seems a 20-30 amp device on a 50 amp feeder could be a tad dangerous
    at least to the planer. It would have to draw 50 amps before tripping
    the breaker. Or am I missing something?
    
    -j
    

>    Wouldent it be a good idea to change the breaker in trhe panel too?
>    Seems a 20-30 amp device on a 50 amp feeder could be a tad dangerous
>    at least to the planer. It would have to draw 50 amps before tripping
>    the breaker. Or am I missing something?
    
I thought that at first too, but then I thought of what would happen to, say, a 
clock radio if it really drew all 20 amps that it's circuit would allow.  POOF!
I guess the point is that it's common practice to have devices with far less 
capacity than the circuit.  Think of wiring a shop such that you could run more 
than one machine on one circuit - you'd make that circuit 40 amps or so, yet 
none of the machines would draw that much.

Paul

    re: Last couple.
    
    The purpose of the panel breaker is to protect the building and
    its internal wiring.   If a plugged-in device wishes to protect
    itself it may do so by a breaker on the device rated at the device
    current (seen on many motors, good stereo equipment, etc).  But
    it's not required on the device by the NEC.
    
    Failure modes of a device where it draws enough current to become
    a hazard but not enough to trip the breaker are considered rare
    enough that the NEC doesn't worry about it.  The underwriter's lab
    has some say in this matter when they UL approve a device - one
    of their criteria is the implications of various kinds of failures.
    
     
    

    I have a similar question.  I was hooking up the power for a dishwasher
    (Sears) and found what seems to be aluminum wiring.  I am hooking 14
    guage solid copper wire to 14-16 gauge stranded aluminum (appearing)
    wire.    The wire appears to be a solid silvery color, i.e. I look at
    the end and there is no copper color seen.  I guess that this is AL,
    not clad CU.  I'm using copper wire nuts for the connection.  Is there
    any problem with this?  BTW, the dishwasher runs on 110VAC.

    As a more general question, when is there a problem using AL and CU?
    The instructions for the dishwasher warn about hooking "stranded copper
    wire to solid aluminum wire," exactly the opposite of what I have.

    ---Phil

    re-.1 the wire nuts should be rated as AL/CU anything less could/will
    be a problem later it is also against code. BTW-most wire nuts are
    rated for both but be 100% sure before using them I dont think you
    want a fire later on.
    
    -j
     

    I would also consider using a dab of anti-oxidant before using the
    wire nut.  I usually goes by the name NOALOX, or some such thing.
    (I don't have my bottle in front of me.)
    
    - Mark

Re: -.1,-.2

    Thanks for the tips, I'll check the wire nuts to see that they are
    rated correctly and look around for the anti-oxidant.

    Anyone want to tackle the general AL-CU question?

    ---Phil

    The latest Popular Science has an article suggesting the use of
    a GFCI outlet to replace a 2-prong outlet, in the absence of a ground
    wire.  They claimed that this gave some protection against leaks to
    ground, but I am very dubious about this.  Anyone else care to comment?
    
    				Steve

    re .7:
    
    I thought it had something to do with the comparitively large
    expansion/contraction that AL goes through as normal currents
    generate heat, which over time can cause a bad connection, extreme
    heat and fire.

     If it's really a two-wire circuit it will need a ground installed
    before it can have fault current through it.!

    
    I've been successful installing GFCI's in two-wire circuits. 

    According to an electrical consultant (actually, an instructor), GFCI's
    work by comparing the current in both sides of the circuit.  Any
    mismatch triggers them to shut off.  A ground is not required.
    For some reason, "code" doesn't allow installation of outlets beyond the
    ungrounded GFCI. 

    Assuming this is correct, it substantiates the information in .28, and
    provides a measure of protection to ungrounded, two-wire circuits. 

    Further evidence for the lack of a ground requirement is that it works.
    I've installed GFCI's in all exterior locations, some fed only by knob
    and tube wiring.  I intentionally shorted one to ground (via a long
    wire) and, yes, it cut out as hoped. 
 
-Bruce                                  
    

                Aluminum and copper have different rates of expansion
        and contraction. This causes any connection between them to
        eventually work loose. Once it is slightly loose, heat starts to
        build up in the joint causing more loosening. And on and on it
        goes until the resistance is high enough to cause enough heat to
        be generated to cause a problem, like a fire.
                
                The electrical devices (outlets, etc.) which are marked
        as aluminum usable use an alloy for their terminals which has a
        close enough coefficient of expansion to aluminum so that the
        loosening doesn't occur (assuming proper installation). The
        NoAlOx (or other preparations) also reduces the problem by
        keeping the aluminum from oxidizing and provides a conductive
        path to reduce the resistance in the joint. Less resistance
        means less heat;  thus less expansion and contraction; thus less
        problems.
                
                /s/     Bob

    From a theoretical point of view, .30 is right -- the GFCI will
    fulfill its ground-fault function without a grounding conductor.
    
    However, the GFCI outlets ceom with three-hole outlets, and it is
    probably not acceptable to have what appears to be a grounded outlet
    when the ground is not connected.

    I went back and looked at the PS article.  It stated that the "code"
    (they had a citation which I don't recall) explicitly allows for
    a GFCI to replace a two-prong outlet.  Says nothing about the
    unconnected ground pin.  However, the article goes on to say that
    you CAN do a feed-through with this method, contradicting what an
    earlier reply here said.
    
    I agree that a GFCI is better than nothing, but I would be inclined to
    fill in the ground pin with something (silicone sealant?) rather than
    allow the possibility of someone depending on that being a ground.
    
    					Steve

David,

1. Given the description, I'd suspect that Neutral and Safety ground have
   been bonded elsewhere in the wiring.

   I've NEVER seen anyone intentionally strap safety ground to neutral in
   in outlet box. One wonders why they bothered to clamp the safety
   grounds together.....

2. As far as the ethics/law are concerned, I'd have told my neighbor that
   you believed there was a genuine hazard there and let the neighbor
   take whatever decisions fell out of that.

   Given you were likely not looking at the only instance of crossed
   neutral/safety ground, genuinely correcting the hazard would have
   been lots of work.

Dennis

    This note is also in REAL_ESTATE.
    
    I'm interested in buying a 118 year old Victorian in Hudson.  The
    building seems to be very stable and in good shape.  It's about
    2700 square feet of living space.  One sticking point for me is
    that over 50% of it still runs on the ancient "ceramic" insulated
    wiring from the vintage 20's.  The other half has been upgraded
    to the metal-sheathed wiring (mental coil) and modern wiring.  My
    question is how dangerous in the old wiring.  The amount that it
    will cost to replace is going to be a strong indicator on the price
    we are willing to pay for the house.  Any rough estimates on
    replacement costs for the old wiring... does it need to be done
    right away.  We would like to run a couple of air conditioners in
    some of the floors to branch wiring may be necessary.
    
    
    Thanks for the information,
    
    
    -Don-

    The official name for that kind of wiring is "knob and tube."  
    It's basically safe.  I wouldn't worry about it.  You'll want 
    to replace it someday, but don't panic in the meantime.  After 
    all, it's been there for a long time already with no problem.

    I'll admit that I'm a little concerned about the hazards of it.
    I'm more concerned whether it will be able to meet our needs.  I
    couple of air conditioners will need to be used... can this wiring
    handle it.  If we do want to change it (a lot of people have), any
    ideas on cost estimates... we just want to know what we're up against.
    
    Thanx,
    
    Don

    I still have two circuits (out of 17 )that are knob and tube in
    my 1917 vintage house. No problems ...

    More important that what kind of wiring it is, check what's
    on each circuit and see how many outlets are in the rooms for
    the air conditioners.  We have a lot of this wiring and the
    only problem have is that many of the rooms only have one
    outlet.  If you want to run an AC off it could present a
    problem.
    
    As for cost to replace, if you don't want to rip out the walls
    and/or ceilings, its very labor intensive.  Took us 8 hours to
    snake a new line into the kitchen.  To pay someone could get
    very expensive.
    

    The wiring itself is probably OK if noone has seriously overloaded
    it in the past creating problems. The problem is that you probably
    have a 60 amp service running only 4 - 15 amp circuits throughout
    the house. All of the lights for a lot of rooms could be on the
    same circuit. Now you want to take two air conditioners which draw
    about 30 amps when the compressor kicks in, and put it on the existing
    wiring. From experience let me tell you, buy about 10 boxes of slow
    blow fuses and have them ready. What I did to solve the problem
    was to add a circuit breaker box capable of adding 8 new circuits.
    Then, you can string a seperate line to each place you want a air
    conditioner or a grounded outlet for hooking up you home computer.
    There is nothing wrong with knob and tube wiring, except that it
    does not provide a ground at outlets. Mine is still in excellent
    shape and is 65 years old. I can't imagine that the previous owner
    hasn't added another box! Hasn't the kitchen been remodeled?
    
    Tim
    

I do not know MA electrical codes very well, but doesn't the 50% rule 
kick in when he adds the additional circuits.  The 50% rule says that if 
more than 50% of the current electrical capacity is remodeled, upgraded or 
added to then the entire system must be upgraded to current code levels.
I know this was the case in Arizona.  

Brian

    
    Knob and tube was the best way to wire in the "old" days. Those
    days also saw lots and lots of house fires started by faulty electical
    systems. The major problem with K&T is that there is no ground,
    or third wire back to the fuse box to open the circuit in the event
    of a short. I've heard of cases and actually ran into one where the 
    old wiring became frayed inside the box, and everytime something was 
    plugged in, a spark came out. The fuse never blew.
    
    With today's ever increasing dependence on elecrticity, the last
    place to scrimp is in the wiring. 
    
    A previous note made a good suggestion to upgrade the service. I know 
    the MA code doesn't allow K&T wiring to run into a new box. Most
    electricians run new wiring to the first junction box and connect
    there. I personally have made every effort to replace all K&T that
    can be reached without major work.
    
    For your A/C's, I would run dedicated circuits. They tend be be
    real noisy (electically) so you may get interferrence on appliances
    or blinking lights if they share circuits.
    
    While you're at this project, don't forget to install electric smoke
    detectors that are connected together on all floors. I got cheap
    at my mothers house and a careless tenant nearly caused a disaster.
    I'm installing them this weekend!!.
    
    As for costs, you can usually count on not exceeding $100 per device.
    A device would be a plug, light etc.. This sounds like a lot, but
    as a previous noter discussed, it can take lots of time for old work
    wiring. Get several estimates and references, and make sure that
    the inspector does more than a walk through inspection.
    
    Sorry for the long note for a simple question, but I've seen too
    many bad things happen due to faulty wiring.
    
    good luck
    
    JMB

FWIW:

Until very recently (a couple months ago) there were knob-and-tube circuits in
use in the Mill, carrying 550 volts.

-Mike

As stated, the knob and tube is probably ok especially if not overloaded.  
The trick here is not over loading it.  Unscrew one fuse and go see what 
goes out, you can find out the extent of the circuits like this.  Most knob 
and tube is 14 ga. wire, that means 15 amps max.  Hardly suitable for ac. 
What I would suggest is putting in new wiring to handle everything except
ceiling lights and some switches to run them.  The rational is that light
bulbs will not overload the wire and those fixtures are usually the
toughest to get to. 

Adding the new wiring is very expensive if done right.  I rewired my
complete house like this and it took me a year.  The house is only 1200 sq.
ft. (ok, I didn't work on it 24 hours a day).  I called in an electrician 
to run the huge 200 amp cable, put up the meter socket, and hook them up to 
the wire from the street and my new panel.  This took all of 4 hours and 
cost about $500.  If I had paid for the whole job it would have run over 
$5000 I'm sure (lots of outlets and circuits).

Another thing to consider is, are the walls accessable to run wires?  I ran 
one 3-wire to the attic and then everything top down for the 2nd floor.  
This was ok but still lots of work.  I've seen lots of surface conduit in 
old victorians; gets the job done but doesn't look too great.

I guess there's no simple answer for you.  Just don't put in bigger fuses, 
the 15 amp ones will blow if they're supposed to.

Craig

    I think that 14 guage wire in knob and tube can safely carry more
    than 15 amps.  14 guage NM cable can carry 15 amps, but knob and
    tube can safely get hotter than NM cable with paper and plastic
    in direct contact with the wires.
    
    However, voltage drop may certainly be a problem with 14 guage.
    
    

re .10:

Open wire *is* rated at a higher current capacity than cable (a wire table I
have rates #14 as able to take 32A continuously as a single, bare open-air
wire), *BUT* try explaining that to your insurance company should your house
burn down and they find 20A fuses for #14 knob-and-tube wiring, even if it
wasn't at fault!  Run #14 gauge with 15A breakers/fuses and use its "open-ness"
as a safety factor to make up for its obsolencence, if you keep any of it.

-Mike

    
    My husband is currently wiring up a new addition.  There are
    several places in the room where we need to go thru about 4-5
    2 x 4's, which is about 6-7.5".   Last night my husband was
    drilling thru the middle of one of these and broke our new
    drill,  because of the 16" distance he needs to start with
    a small drill then put a larger one in the hole and attach
    the drill to it.  Seems the larger drill wasn't tightened enough
    and it damaged the holders.  Is there an easier way to do this ?
    Could the 2 x 4's be notched and then covered with metal to
    still meet code ?  What would be the easiest way to notch them ?
    
    thanks
    Karen Curran

Yes, the Code allows you to install wiring in notches or grooves and then 
cover them with metal plates to protect them from nails and other damage.

It goes into some detail about how thick the metal plates need to be.  I
was going crazy looking for material that would meet these specs until my
wiring inspector let me in on the secret:  just use the box sides that are 
left over when you disassemble boxes to gang them.

I used a router to cut a groove along some framing lumber.  Repeated passes
with a circular saw (with its blade set to the proper depth of cut) might
be faster for cutting notches.  Actually, just cut the notch top and bottom
with the saw, then hit between the cuts with a hammer; a good-sized plug
should pop right out.  Neatness doesn't count much, as long as you leave
something sound enough to attach the metal plates to. 

Don't notch so deeply that you weaken the structure, especially in multiple 
adjacent boards.  And don't count on the metal plates for any structural
help; their purpose is to protect the wiring from nails, not to hold the
house up.  If you go deeper than, say, 1/3 of the board's width, you should
be drilling holes, not cutting notches. 

    	4-5 2x4's sounds like a supporting post for a beam or a header
    which would make me leary of notching it.  There are two things
    you might do.
    
    	1. Notch the 2x4's and then replace the notched out section
    	with a piece or wood so that the strength of the post is not
    	impaired.  (If in fact it is a supporting post of some kind)
    
    	2. There are 90 degree drill attachments that are sold for just
    	this purpose.  It allows you to get into tight places.  The
    	unit goes into the drill chuck like a regular bit, then forms
    	a tight 90, into which you insert the drill bit.
    
    	3. Rent a 90 degree drill.

    Another way I've seen wiring done is instead of drilling or notching
    2x4's, run the wire up into the attic or the space above the ceiling
    and then back down to where ever and then up again and so on. This
    uses more wire but you don't have to drill so many holes and the
    holes you have to drill, you can get at. The good thing about this
    is if you want to cut a hole in the walls for something the wires
    aren't in the way..
    
    BD  

    
    At the risk of sounding out of line, if he can't get holes drilled
    in 2x4's, are you sure he should be wiring the house???
    
    I can't imagine why he can't drill a 3/4" hole in studs with a regular
    drill set-up. And why can't the smaller drill go through all of
    them? Is he pushing too hard, or not pulling the drill out occasionaly
    to clear the saw dust? Or is the bit dull?
    
    The previous suggestions of using a 90 degree drill, or going to
    the attic or basement are excellent alternatives. Most electricials
    I've worked with over the years use notching as a last resort. For
    one thing, if you don't also notch for the plate, it will make the
    sheet rock bulge in that spot. Not much granted, but it will show.
    Also some inspectors are real tough on the depth of the notch. Why
    risk having to add more support.
    
    good luck
    
    JMB

    Does anyone know where you can buy spools of varnish coated copper
    wire for rewinding motors? I've called every electrical supply place
    and motor repair shop but noone sells the wire. I'm in N.H., Mass.
    
    Thanks
    Tim
    

    The problem is that you don't have the normally 14-1/2" between
    studs when you encounter 3, 4, or 5 of them together.
    
    The regular drill setup won't fit.
    
    He's probably having a problem because he's going at an angle and
    then trying to straighten out once in the stud pocket.  This would
    put undue sideways pressures on the drill and bit.

    I've found a spade bit is better for these jobs than an auger bit.
    Because the shank is smaller than the head, to some extent one CAn
    straighen out the hole.
          
    You can get 6", 12" and 18" bit extenders for the Irwin spade bits.
    Drill the first 6" with the bit, add a 6" extender and drill the
    next 6", remove and add the 12" extender, etc.
    
    The first 6" could be a slightly larger diameter, too.
    
    If all else fails, how about removing the stud adjacent to the 6"
    pillar, drilling the hole, and putting the adjacent stud back.                                             

    Notching should be OK too.  The nail plates to cover the notch cost
    a quarter each at Ralph Pill's.  (I have 10 or so such plates if
    you want 'em -- I ended up drilling holes instead!)
    
    	Andrew
     

	The wire is called "magnet wire". What gauge are you looking for?
	the thinner stuff can usally be purchased from electronic supply
	houses, not electrical. You could also look in the yellow pages
	under wire-insulated or wire products.

Larry

    Notching is certainly a last resort - lots more work to get it flush
    with the 2x so the sheetrocking is not a problem.  Code says you
    can notch up to 1/3 of the width, fyi.
    
    I disagree on the spade vs auger point.  What I did when I started
    my wiring, after trying a spade bit a couple of times, was to go
    out and get a 5/8" x 18" auger bit (costs around $15 at Spags).
    I never regretted it.  Especially for going through multiple 2xs
    in one swipe - the auger would have been a pain in the a**.  The
    auger pulls itself in nicely. 
    
    If the combined depth of the 2xs is real deep, then you end up hitting
    it from each side, pointed towards the outside wall (making a sort
    of V), and then either pushing the wire through, or maybe having
    to fish it through, depending on how well you got the two holes
    lined up.  I never had to do that though - but then I used 2x6s
    and that gave me the necessary additional depth.  
    
    I doubt if this is a supporting post or anything.  Probably is either
    at the corner of an inside partition wall, and the extra 2x are
    there to both give nailing surfaces for the wallboard on all sides
    and to give a solid surface for the partition to be nailed into,
    or else an inside corner along the outside wall, again to give added
    nailing surfaces for the wallboard.  
    
    

    I'm looking for 20 gauge. Somebody I called yesterday also suggested
    an electronic supply house. Do you know of any good ones off of
    495? I didn't look under wire in the yellow pages either. I'll check
    it out.
    
    Thanks
    Tim
    

>    Do you know of any good ones off of 495? I didn't look under wire in the
>    yellow pages either. I'll check it out.
    

	You could try Active electronics in Westboro. It's on Flanders Rd.,
	about 1/2 mile west on Rt. 9 from 495. Phone is 366-9684 or 366-
	8899. Also, You-Do-It Electronics just off Highland Ave. in Needham.
	That is just off Rt. 128 though.

	Radio shack sells the stuff too, but the thickest they have is 22
	gauge.

Larry    

    
    
    Wow,  I really pleased to see so many responses.  
    The 2 x 4's are for supporting beams and headers on either side
    of 8' windows.  Going to the attic was an alternative and we did
    do that in the areas we could.  On the end wall this was not possible.
    He is most capable of doing the work, you must admit that after
    working a 10 hour day, and then working around the house anyone
    is likely to have their patience tried.  
    
    What we did was bought a 1/2" drill, the one we had was 3/8"
    and we bought the Irwin spade bits with the extenders.  He's
    going to give that a shot this weekend.  
    He was using just regular drills to begin with.
    The auger bit sounds like a good idea,  We missed that at Spags
    yesterday, are they where the other drill bits are ?  On the main
    isle ?
    
    I was looking thru the Sears catalog and the have a right angle
    attachment for $7.99, perhaps we'll try that with the auger bit.
    
    thanks for the help
    Karen
    
    

    On comment on the extensions: make sure the set screw is TIGHT.
    There is nothing worse than having the set screw loosen up leaving
    the spade bit still on the hole.  (I had this happen when I was
    drilling through 2 4x4s and 1 2x4 nailed together.)  Also, remember
    to pull the bit out frequently to let the wood chips out.  Otherwise
    the bit may bind up in the hole.
    
    If I has it to do over again, I would not have used the short (6")
    spade bits.  I would have located one of the longer auger bits or
    an 'electricians' long (18"-24") twist drill of the right diameter.
    
    - Mark

    Mark's point is well taken.  Extension bits are inexpensive but
    don't really work all that well.  The problem is that they have
    to serve the function of the drill chuck but in a space equal to
    the smallest spade bit they support (3/8" to 1/2" typically).
    Allen-head setscrews just don't cut it given the torque generated
    by drilling through 5 2*4's or whatever.  If you can get it tight
    enough, you'll probably strip the setscrews or your wrench.

    An electronic supply house should carry it. Belden is one brand
    Carol Cable is another you may have to special order to get a spool
    with enough footage to wind a motor depending on gauge most of the
    spools I have seen were only 100-200' for 20-32 ga. sizes.
    
    -j
     

re. < Note 2328.10 by STAR::SWIST "Jim Swist ZKO3-4/U14 381-1264" >
>    Mark's point is well taken.  Extension bits are inexpensive but
>    don't really work all that well.  The problem is that they have
>    to serve the function of the drill chuck but in a space equal to
>    the smallest spade bit they support (3/8" to 1/2" typically).
>    Allen-head setscrews just don't cut it given the torque generated
>    by drilling through 5 2*4's or whatever.  If you can get it tight
>    enough, you'll probably strip the setscrews or your wrench.
>

                  I did just that recently, the allen head set screws 
                  stripped, and I went out and bought a longer extension
                  at Sears.  Same thing though, after I use it 15 or 20 times
                  the screws will strip again I would say.

Steve

One evening last week we had a thunder storm.  Although we didn't lose power, 
our lights did flicker a few times.  The following morning 3 electic 
outlets in our house were dead.  I don't know if the storm had anything 
to do with it or not, but I thought it was worth mentioning.

The three dead outlets are all in bathrooms (one outlet in each 
bathroom).  The outlets are NOT GFI outlets. They are regular outlets, 
just like everywhere else in the house (the house is 10 years old and 
the only GFI outlet is in the garage).  

I checked the cicuit breakers and they are all ON.  I even flipped them 
all off, and then on again, just to be sure.  I used a line tester and 
confirmed that there is power at each of the circuit breakers 
themselves.  I also used the line tester at the outlets (removed the 
cover plates and tested at the screw terminals on the outlets) and found 
that there is no power at any of the outlets.  That is, there doesn't 
seem to be power leading in to any of the outlets.  As far as I can 
tell, there doesn't seem to be anything on this circuit except for these 
three outlets (one of which is used for the washing machine).

What do I do now?  I'm looking for suggestions.

Obviously, I could call in an electrician, but I usually try to handle 
these kinds of problems myself if I can.  However, when I run out of 
ideas, I will call an electrician (anyone know a good one in Manchester, 
NH?)

    Its a pain, but you'll need to trace the circuit from the breaker
    to the first outlet. You may find a junction box somewhere in between
    tat first outlet and the panel which has a very high resistance.
    Its a nuisance job, but its probably the only way to find the problem.
    
    Eric
    

    Did you check the GFI that you mentioned in the garage. The garage
    GFI may control the three outlets in all the baths. With one GFI
    oulet you can easily protect a number of outlets that follow the
    GFI in the same circuit. Otherwise you have to start tracing the
    circuit as mentioned in .1
    
    Good Luck!

    In ref to .2, the house I had in NY had all the bathrooms and the
    one outside outlet on the same GFI (in panel box), so that's probably
    a good shot. 
    
    Eric
    

    Thanks a lot.
    I'll check that GFI tonight.  That sounds like a very likely suspect.
    I didn't realize that one GFI would protect the other outlets on
    the same circuit. I'll post the result tomorrow.

    One more thing....
    RE: .3
    You said you had a GFI in the panel box.   What exactly would that
    look like?  None of my circuit breakers look unusual.

Not to pick on .0, but this episode underscores the importance of having an
accurate electrical map of your house - a list of every electrical outlet,
light, and appliance in the house, what circuit they're on, how much current 
they draw, and ideally how the cabling runs. 

Making this list while things are working properly is infinitely easier than 
trying to figure it out after something fails.

    RE: -.1
    
    > Making this list while things are working properly is infinitely 
    > easier than trying to figure it out after something fails.

    For those of you that normally have a properly working system :^}
    

    A basic house wiring question:
    
    The green wire is the ground.  I connect this to the recepticle
    green screw and also to each metal outlet box?  The more connections
    to metal conduits and boxes, etc. the better?  My reasoning would
    be that if a bare hot wire would touch any of the metal then a
    short circuit would develop and the circuit breaker will trip.
    Otherwise a piece of metal could be electrified and if some
    poor grounded soul touched it they would be shocked.  Is this
    principle correct: all metal that could come in contact with
    an electrified wire is best off grounded?
    
    

    There are other needs for grounding; your terminal at home or your
    PC might generate RFI or radio frequency noise that radiates to
    tvs and radios. Grounding reduces the RFI.
    
    Lightening strikes dissipates better if the ground is within a grid
    (cage). multiple ground paths are used to lessen the effect of the
    lightening. 
    
    cal hoe

    I went home last night and checked the GFI outlet in the garage
    and, sure enough, the button was out.  The electrical storm must
    have tripped it.  I hadn't relaized that it was on the same circuit
    as my bathrooms, but when I reset the GFI, all the outlets came
    alive again.
    
    Thanks again.  

    re: .6
    YES, I agree it's one of those things that homeowner SHOULD do.
    Now the question. What method do you use to trace how the system
    is wired. i.e. to find out where the 1st outlet, 2nd,... etc., without
    tearing down the wall.

Your reasoning in .0 is good.  But there's more to it than that; electricians 
and safety experts have built up a significant body of knowledge over the 
years on grounding and related electrical subjects. 

This body of knowledge is contained in the National Electrical Code.  It calls 
out the techniques and materials that should be used to achieve safe grounding 
in a variety of circumstances. 

Thought experiments such as the one in .0 are valuable for understanding why 
the Code says what it does; but when it comes to doing the work, don't try to 
derive your techniques from first principles.  Get a copy of the Code and/or 
the various commercial guides to it (as recommended elsewhere in this
conference), and follow it. 

I thought I remembered existing discussions of circuit-tracing techniques 
in this conference, but I can't find them.  Can anybody help?

The first step is to make the list of what outlets, lights, applicances,
etc. are on which circuits.  This list will give you many clues in tracing
the cabling. 

Any cable paths that are exposed in the basement or attic are relatively 
easy, although time-consuming and error-prone, to trace.  A flashlight, a 
helper, and lots of patience are necessary.

If there's a GFCI in the circuit, tripping it will tell you which outlets 
are downstream and which are upstream.

It's more work, but you can use the same technique with any electrical box, 
by opening it up and disconnecting the wires that go downstream.  You need 
to use appropriate safety techniques, of course, and be prepared to repair 
any wiring you might break, especially in very old work.

A thorough job of cable tracing is sufficiently painful that it's probably
reasonable to put it off until you have a problem - although it may be more
difficult then.  The indispensable thing to have is the list of what's on
which circuit, and that's relatively easy to make - even enjoyable if you
make it a family project.  The cabling information is a useful-but-optional
adjunct to that list. 

    	Funny this should come up now. Last night I was working on some
    wiring in my basement & garage for auto door openers and shop lights.
    Well, I've been lazy and never di a check of what circuits were
    connected with what. I figured it was pretty simple as the house
    is only 3 years old and all the breakers labeled. So i figure I
    can safely add 2 outlets for door openers & 2 fluorescent light
    fictures to 3 basement & garage lights 75W; 3 smoke detectors; 1
    300W spot light; and 1 15amp GFI outlet. All this on a 15 amp circuit.
    	Now the fun part; I turn off the circuit to work in the switch
    box and while the power is off I decide to take a break and move
    the sprinkler in the front yard. I go up stairs and start to head
    out the front door but stop first to turn on the front entry way
    lights. Guess what? No lights. Turns out in addition to the above
    the outside front 2 lights (2 x 60W) and front foyer chandelier
    (8 x 40W or 50W) are also on the same circuit. Does not leave much
    on the 15 amp circuit for that 1 outlet I have in the garage for 
    plugging in the powertools.
    	Good thig I'm adding additional dedicated outlet for powertools.
    
    			...Dave
    
    	Who will be checking every outlet and light this week.
    
    

    I don't believe everything I read either. My house is 3 years old
    and I bought it with an unfinished second floor. There were two
    pairs of wires going up to the second floor, two for heat and two
    for lighting/outlets. The ends were dangling in the cellar marked
    as north or south sides. When I was finishing the electrical installation
    I figured I could electrify the side I was done with (north) so
    I proceded to connect the lighting wire to the panel. Much to my 
    surprise, when I flipped the breaker on I heard a pop and the breaker 
    tripped. The wires on the south side shorted since they were touching 
    the junction box. It looks like the electrician that did the original 
    wiring didn't know north from south. 

    I finally have bought this old (>200 years) house in Chianti
    (that's in Italy for those of you who don't drink wine).
    
    The existing electrical wiring seems to be at least as old, if not
    from Roman times...
    
    To be frank, seeing the system would cause any US/German/Scandinavian
    inspector to die of heart attack (or be electrocuted) immediately.
    Nevertheless, ENEL, the State Energy company, connected power without
    a whisper...
    
    Basically, in Italy, they bring a two-wire (single phase) system
    into the house (live and neutral). But neutral isn't necessarily
    quite neutral (this is a rural area and the xformer may be quite
    far away) and you are not supposed to ground the neutral at the entry
    to the house as would be done here (in Germany) [and in US].
    
    In fact, there's no ground whatsoever in the house. Despite that,
    the person who did the wiring used only 3-prong outlets, just leaving
    the center (ground) unconnected (probably just to enable him/her
    to connect grounded devices easily to any outlet).
    
    So eventually I would like to provide a ground in the system
    before it grounds me. I think I should also use GFI's extensively.
    
    I know how things are wired in Germany (I am an EE) but I have never
    encountered a system like this. I'd be grateful for any ideas to
    make a safe & simple wiring, as well as advice on any pitfalls.
    
    There's a steel water pipe going from the house to a well about
    1000 ft away (in fairly wet soil) which should provide a fair ground.
    On the other hand, I keep thinking that there's no great need for
    a ground if everything is protected by sensitive GFIs... (remember
    that there's no code this installation has to conform to - just
    has to be reasonably safe). This might be a problem with things
    like the water heater which may have some leakage here and there
    and make the GFI trip even when no real fault exists. Same thing
    might apply to some other appliances.
    
    Any ideas?
    

>             -< true ground could develop voltage in your neutral >-

From what I understood of what he said, there already IS current in the 
'neutral'.  If he connected the ground to it, then if he plugged a grounded 
plug of, say, a power drill into a socket, it would charge the case of the 
drill, which is probably a bad idea.  :^)

I think he's planning on creating a 'ground' for the ground of the plugs that 
is separate from the neutral.  Different from wiring here in the states, but it 
doesn't sound like a bad idea to me.  The case of the drill would be connected 
to true ground, which is what you want anyway.  Course I'm no EE, so I'll defer 
to the greater wisdom of nearly anyone, but it seemed like you had missed a 
significant piece of what he'd said.

I agree, though, that I'd use GFIs wherever I could.

Paul

    re .1,.2: .2 is right - as I said in .0 you are not supposed to
    connect neutral and the (yet non-existing) ground together - because
    the 'neutral' may not be quite neutral. When I measured the difference
    between neutral and the water pipe was just about 2 volts - but
    if one of the vineyards hanging on the same 220 volt (three phase)
    line switches on a big machine, it might well be mich higher.
    
    Also, if the power company's neutral breaks somewhere between the
    transformer and my house, and I connect neutral to ground, then
    everybody's power (after my house) would flow through my ground...
    
    In the normal German (and US as far as I know) system all the neutral
    and ground wires coming from the outlets are connected at one single
    point (the fusebox) and nowhere else, the same point being connected to
    a separate ground in the house (about 600 ft of flat galvanized steel
    strip is usually used here, buried around the house) and of course the
    neutral brought in by the power company.
    
    There's a tendency to use very sensitive (10 mA) GFI's here in
    Germany for special purposes though these are not yet approved by
    VDE. These should offer quite perfect protection for humans (and
    animals) in all circumstances, but may be too sensitive for some
    purposes.
    

    
    
      The wiring system in Italy sounds alot like the French one. 
    You might try contacting John Simpson in Valbonne he was the
    European Area environmental specialist for a long time and is
    extremely knowledgeable in all of the European power systems.
    Just say I pointed you in his direction and I'm sure he'll help
    out if he can. I know he could be easily bribed with a few bottles
    of good Chianti.  :-)
    
    
      -mike          
    

    I'm no electrician but I have done alittle wiring in my day. Why
    can't you just drive a normal copper grounding rod into the ground
    (usually 6 to 8 feet long) and connect a ground wire, connected
    to a common bar and ground all wiring to that, If your going to
    rewire the old place anyway. 
    
    P.S. I always thought tha inorder for a GFI circuit to work
    effectively, you have to have a good ground system already intact
    inorder to connect the GFI circuit breaker too????

    The fact that neutral floats with respect to ground seems to me
    to be basically irrelevant to the way you want to do the wiring.
    Except at the main service panel (and ***ONLY*** at the main
    service panel), here in the U.S. the neutral is kept strictly
    separate from ground.  I'd think that you would want to do the
    same thing, except with the added premise that the neutral/ground 
    connection point for you is "somewhere else", outside your house, 
    and you have nothing at all to do with it, even at the main
    service panel.  Just keep neutral/ground separate everywhere.
    
    I think your idea of using the water pipe going to the well for
    your ground is good.  It ought to work just fine.  

    re .6: A normal GFI doesn't rely on ground for its operation, it
    trips based on the difference in current in neutral and live
    (I think this has been discussed extensively elsewhere in this file).
    

                I think that the way you want think about this situation
        is to consider that the two wires which enter the house are both
        hot (think 220volt line here in US with only 220volt equipment
        hung from it - thus no neutral needed). Now it becomes obvious
        what to do. Wire up the ground to all the desired outlets and
        appliances, but NEVER connect it to either of the two "hot"
        wires coming into the house. 
                
                As for GFI's - use them anywhere that you would normaly
        use one (and they do sense on the difference between the two
        power carrying conductors) and forget about it otherwise.
        Remember that ground is there to keep the case of an appliance
        at a potential that would be safe for you to touch when you are
        grounded. It performs no other function at an appliance
        connection point.
                
                /s/     Bob

So I went back to Richter & Schwan and looked it up.  What I said about 
sub-panels was in error, and I've removed it from the file to avoid 
confusion to others.  (However, what I said IS the way the subpanel in 
my house is wired... more work to do, I guess.)

However, there was reason behind my madness, and it's this; if the 
neutral is developing voltage with respect to a local ground, then
equipment that uses ground for a reference will have problems.  There's
more to grounding than saftey, these days. 

					>>>==>PStJTT

    My husband and I are in the process of buying a house, and we
    just had it inspected and they found aluminum wiring throughout
    the house.  The house is 17 years old.  The inspector recommended
    that we have the branch circuitry changed to copper, and that
    rewiring was not neccessary.  
    
    Has anyone had any experience with this?  Is this procedure 
    satisfactory, and any idea what it costs?  
    
    thanks for any advice!
    -Joanne

    I am not an expert but I seem to remember that aluminum wire was
    found to cause fires if not installed properly. I think the wire
    became loose after a period of time. Special procedures had to be
    followed to install aluminum properly. Notice that aluminum wire
    is not used in houses anymore. It may be in your best interest to
    consult with an electrician. Maybe you can use wire replacing as
    a bargaining chip to reduce the price. It is supposed to be a buyers
    market. Good luck.

See also note 1450 for some discussion of aluminum wiring.  I left this note 
here to address the issue of whether the wiring should be replaced and if so 
how to go about it and how much it would cost.

Paul [Moderator]

    
    	RE: 0
    
    	I don't think it's necessary to replace the wire but you should
    	have an electrician check it out.  There is a "goop" used for
    	aluminum wiring to keep it from corroding and loosening as .1
    	suggested.  Although aluminum wire is no longer used in general
    	house wiring, 14-2, 12-2, the service entrance cables and most
    	other big stuff, is still all aluminum.

    
    the goop is called no-al-ox.
    It is a cleaner/deoxidizing compound that keeps the aluminum from 
    becomming oxidized on the terminals. I have had NO problems for 12
    years except I have taken off the mains ands cleaned them with this
    stuff.
    ---------------------------- I DO NOT----------------------------
    recommend anyone but an experienced electrician doing this as the
    volts/amps are enough to ruin your day.
    ------------------------------------------------------------------
    
    If it has to be done at all.
    
    chuck

>< Note 2520.3 by SMURF::WALLACE "Life's a beach, then you dive!" >
>
>                            ...the service entrance cables and most
>    	other big stuff, is still all aluminum.
      
      Service  Entrance  Cables  are  the ones from the meter box to the
      main breaker box, if I recall the code definitions. Or do you mean
      the  wires  from the transformer on the pole to the meter box?  In
      either case I thing your wrong. I know from first hand observation
      that  ALL  the  wires in my meter box are copper.  I think this is
      general practice.  The 'extra care' required for  Aluiminum  isn't
      worth it.
      
      However  on  the transmission line side of that transformer on the
      pole you're almost sure to find Aluminum.  

      It may depend on which electric company you are serviced by or
    whatever the electrician felt comfortable with.  I asked the electrical
    inspector about the aluminum wire at my house which is all of the
    wire from the pole to the breaker box.  He said that it is getting
    very uncommon to use copper wire for this cable since it costs so
    much more.  I'm guessing but I believe the numbers were something
    to the effect of $1.10/ft for aluminum and $3.50/ft for copper.
    I know that at least part of the wire to my cooking range is aluminum
    but I think it is only the ground wire.  As was said before, aluminum
    wire has been determined to be safe WHEN INSTALLED PROPERLY. 

    
    -Jim

    
    
    	Price is the key.  I have Aluminum entrance service cable from
    	the pole transformer to the meter box, and from the meter box
    	to the service circuit box.  All the wires from the service
    	to the house (individual circuits) are copper.  When you get
    	to #4 and larger wire sizes, I think you'll find aluminum to
    	be more popular. (cheaper)

    re last couple
    
    Right - WHEN INSTALLED PROPERLY.
    
    All the fame (on infame) that AL wire has received has been because
    it was used to wire houses and the Al just pushed into the Cu sockets
    on outlets.  Oxidation, expansion, contraction - high resistance
    connection - heat - fire.
    
    I recently installed a subpanel in the garage as well as changed
    over from 100 to 200 amp service.  The cable from the street is
    Al and the cable I used for the subpanel ~75 feet is Al.  The Al
    is at least 2 sizes larger the Cu I would have needed but is one-third
    the cost.  The 75' Al cable cost me $93.00.  I forget exactly what
    the quote was on the Cu but I know I nearly fainted.
    
    Then I got educated on how to install and work with Aluminum.  The
    problem was when they used it to wire houses, the electricians treated
    it the same as they did copper.  You can't do that.  And as long
    as you treat it properly, it's just as safe as copper.  And a hell
    of a lot cheaper.

    AL branch wires have 2 problems;
    
    In the 60s they were installed without proper treatment and
    with fixtures not suited for AL.
    
    The wires break easily if bent too many times.
    
    New branch wires can be very expensive to install, somewhat
    dependent upon the house construction.
    
    I would suggest checking all fixtures to ensure that they
    are suited and treated for AL wire. Be very careful not to
    bend the wires too many times - they will break.
    
    This may be a job for an electrician.
    
    - gerry

      Continuing a theme from -.1 ...
      
      Yes,  if  aluminum wiring is installed correctly -- meaning proper
      wiring devices and proper installation techniques, which are  BOTH
      DIFFERENNT  from  whats  used with copper wire -- then it is safe.
      But will it stay that way?  Aluminum becomes  brittle  and  breaks
      easily when it is bent repeatedly and/or sharply. I've never lived
      in a home in which switches/outlest/light  fixtures  haven't  been
      changed  from  time to time, either to replace worn out devices or
      to modernize.  The simple act of disconnecting aluminum  wire  and
      reconnecting  it to a new device is usually more than the wire can
      safely tolerate.  In theory you should be able to do this  without
      significant  flexing  of  the  wire.   In pratice it is just about
      impossible.
      
      I  worked  for ALCOA for a while after I got out of college.  They
      had  (surprise!)   aluminum  wiring  and  whenever  they  replaced
      anything  they cut the wire back and butt spliced a new piece onto
      the end, just to avoid this problem.
      
      The  price argument is valid for heavier gages of wire, expecially
      since these tend to be 're-worked' less often.   As  for  aluminun
      anwhere  inside  the  breaker box, well, I might make some limited
      exceptions, but I think it is trouble looking for a place to happen.
      

I am in the process of wiring my new workshop and would like to include 
some 220 circuits so I can run my larger tools on 220.  Can someone give me a 
quick lesson in whats involved in changing a motor to 220 and wiring for it?

- I plan to run 12/3 and use a 20 Amp breaker with probably only 2 boxes to a 
    breaker.

- I have not looked at the motors closely but I think the re-wiring diagrams 
   are on them.  But  do i need to replace the electrical cord?? 

- what type of outlet and plug do i need?


thanx

    Check the instructions for the given tool. Many large power tools
    can be wired for either 110 or 220v. The type of plug/outlet is
    dependent on how much the unit draws and any local codes. A 220v/15A
    plug is different from a 20A plug, and even within the same current
    ratings, can be multiple styles (ie straight plug in, twist lock,
    etc).
    
    Eric

    By the way, most 220v tools do not need a neutral, unless you have
    a 100v lighting fixture. 12/2 wg should be fine, tape the white
    wire red in the outlet box and breaker panel.
    
    						Chris

    My dad had the same problem in his house - his wife wanted the couch
    in the middle of the room with the lamp next to it.  He took a knife
    and made a slit in the carpet, drilled a whole thru the flooring
    big enough to fit a plug thru and then wired an outlet in the joist
    in the basement.  He stuck the plug thru the slit in the carpet,
    thru the hole in the floor and plugged it into the new outlet. 
    
    There is no cover plate at $63 and dog would have to be a REALLY
    good aim to be able to make it in the slit in the carpet and into
    the outlet on the joist.  You could move the outlet 6-10 inches
    away from the whole in the floor just as long as the cord from the
    lamp would go the distance.
   

    .12 is, of course, in violation of the National Electrical Code.  I
    hope that the insulation on the lamp cord is in good shape, and that
    somebody inspects it frequently.

>    .12 is, of course, in violation of the National Electrical Code.  I
>    hope that the insulation on the lamp cord is in good shape, and that
>    somebody inspects it frequently.

Could you elaborate, Dave?  I know that it's a no-no to run a cord under a 
carpet, becuase of the wear of people walking on it and grinding dirt into the
insulation.  But if the hole in the floor were clean and smooth with no
projections that could damage the insulation, it seems like the outlet-in-the-
joists solution would work safely.  But I don't really know the electric code. 
Why is this dangerous and outlawed? 

Paul

    Re: .13
    
    Can you quote chapter and verse of what part of the code it violates?
    It seems as though it's one of those things that *ought* to be in
    violation of the code, but I'm not sure it is.

    re .14, .15:  I don't have my Code book handy, but I'll look it up and
    post the information when I get a chance.  The issue is probably that
    only permanent wiring may be run through structural members (such as
    floors), and lamp cord with a plug on the end is scarcely permanent
    wiring.
    
    It also makes sense to plug an appliance into an outlet that's located
    in the same room as the appliance, so you can unplug it conveniently
    and safely if it develops a short.

    
    I'm with DCL, it's against Code. Temporary wiring can't be installed
    under carpeting. And any permanent receptacle must be surrounded
    with non combustable material. Thus you need an honest-to-goodness
    floor receptacle. It's your insurance loss.
    
    CdH
    

    The permanent receptacle down in the basement on the beam is
    certainly legal; it's in a legit box.  I'm not sure if lamp
    cords, etc. are classed as as "temporary wiring"; I thought temporary
    wiring was what you would do at a construction site, etc. until
    the real wiring was in: Romex tied together with wire nuts
    and dangling off nails driven into ceiling joists, etc.  The "under 
    the carpet" restriction might apply, but this is "through", not "under".

    The real problem here is there is a receptacle in the floor, ie
    the female cord cap. In my 1984 code book, 370-17 (b) on floor
    boxes, it states "boxes listed specifically for this application
    shal be used for receptacles located in the floor". The only
    exception is for show windows. You can not run lamp cord, SJ cable
    etc, through a wall or floor legally, only conduit, NM cable, BX,
    etc. Article 480-8 on flexible cords states " Flexible cords shall
    not be used (2) where run through holes in walls, ceilings or floors.
                                                     
    
    						Chris

    480-8 is it!  It's illegal.  Thanks for hunting that up.
    

      1)  Check  the  directions that came with them motor/tool.  If you
      don't have  instructions  for  converting  vrom  110  to  220  you
      probably  can't  do  it.   i.e. the motor has to be designed to be
      convertable -- not all motors are.
      
      2) re .3 
          
>          Hopefully  you  mean *1* box to a breaker, this is 230V right?
>          Check the NEC, you are allowed  to  do  multiple  boxes  to  a
>          breaker only as an exception around 120V circuits, this is not
>          generally allowed.  
          
      Could  you be more specific, please?  I ask because I have two 230
      volt outlets and two 110 volt duplex outlets wired to a single  20
      amp  breaker in my "shop" (read "back of garrage").  Since all the
      wiring devices are rated for 20 amps (I think the 230 volt outlets
      are actually rate higher) I don't see any way I could overload the
      circuit without tripping the breaker (which I could probably do if
      I  plugged  in  and  ran enough stuff at the same time, but then I
      could also do that on a 110 volt circuit).  I also don't  see  any
      other hazzard.  What's the purpose of this code requirement?

    re .5
    
    A 230 volt outlet wired to a single 20 amp breaker?  Is this possible?
    
    I thought two adjacent breakers ganged together were needed to get
    230 volts.  Otherwise the circuit is being fed by only one of the
    two hot legs in the panel.
    
    - gene
         

Re: .9
>    The larger circuits that feed electric dryers, hot water heaters,
>    and stoves contain both a red and a black wire (along with one or
>    two others:  a white and possibly a bare).  The black wire gets
>    attached to one of the two insulated feeds from the power company,
>    while the red wire goes to the other insulated feed.  The smaller
>    110v circuits contain only a black wire, in addition to the white
>    and bare wires.  This can go to either of the above two feeds, but
>    the system as a whole should balance the load drawn from each feed
>    as closely as possible (it makes the power company very happy by
>    causing less wear and tear on their equipment!).

I've been meaning to ask this question for twelve months, and I'd better
ask it now bacause I'm going next week.

Pity an ignorant lad. Why do US domestic electrics use 110 V and have all
this damned tinkering around with load balancing and the like ?  Anyone
know why 240 V was not chosen as in most of the rest of the world ?

Just _very_ curious

Henry Gillard - TSC Sydney

>< Note 2744.6 by MILVAX::HO >
>
>
>    re .5
>    
>    A 230 volt outlet wired to a single 20 amp breaker?  Is this possible?
>    
>    I thought two adjacent breakers ganged together were needed to get
>    230 volts.  Otherwise the circuit is being fed by only one of the
>    two hot legs in the panel.
>    
>    - gene
         
The two hot leg "busses" alternate down the panel on both sides.

Any double pole breaker inserted in the panel will attach to both legs.
				


			A	B
			B	A
			A	B
			B	A
		
Ross

    I assume by "single 20-amp breaker" the author must mean one double breaker.
    

    I suppose because for most domestic use, 240 volts is much more
    than is necessary; who needs 240 volts to run an electric shaver
    or a fan?  120 volts is presumably less dangerous in the case of
    accident, too.
    
    My guess.

    re: .-1 
    There isn't enough safety difference between 120 and 240 for that to be
    an issue.


    The answer to your question is historical.
    
    It goes back to finding the right balance in the simple equation
    W = E*I.   What you need to run electrical things is power (measured
    in watts) - theoretically the volts and amps are irrelevant as long
    as when multiplied together they yield the power you need.  Practically
    speaking, too low a voltage will require too high a current - this
    is inefficient to transmit, requires huge transformers, expensive
    heavy wire, and heat buildup/fire problems if connections get loose.
    Too high a voltage can break down insulation easily, and is difficult
    to switch without expensive devices.
    
    I believe the history is that 120V was arrived at in the early days of
    power transmission planning as the best balance in the above equation
    (some old systems (USA as well as foreign) are still 120V).  What
    wasn't figured in the equation was the demand for electricity - no one
    figured it would find as many applications as it did.  Doubling the
    voltage was a fairly cheap solution to this problem since the
    insulation and switching problems are really not much worse at 240 than
    120.  The alternative of keeping the voltage the same and doubling the
    current would have meant rewiring a large percentage of users and
    transmission facilities. 
    
    That's the story as I understand it.  Upward compatibity, inertia,
    and history are all responsible for having both 110 and 240 devices
    as well as entire systems.
    

>< Note 1742.21 by MTWAIN::WELLCOME "Steve Wellcome (Maynard)" >
>
>
>    I suppose because for most domestic use, 240 volts is much more
>    than is necessary; who needs 240 volts to run an electric shaver
>    or a fan?  120 volts is presumably less dangerous in the case of
>    accident, too.
>    
>    My guess.


I was always told in school etc., that 120v became an industry U.S. standard
at the turn of the century and stuck. Too costly to change.  Actually the
higher voltage appliances would be more efficient, motors lighter, less windings
and all that good stuff.

    
    	Besides, when has the US ever worried about being standard?  Don't
    we still speak in terms of those silly inches and yards?? :-)
    
    								-c

>                      <<< Note 2744.7 by WILKIE::THOMS >>>
>
>The two hot leg "busses" alternate down the panel on both sides.

      I  believe that this is always, or almost always, the case for the
      type of breaker box you have in mind.  However,  there  are  other
      kinds! 
      
      I have a six position breaker box in my garage.  The breakers run
      across the box. The phases follow a pattern something like this: 
      
                  A B B A A B
      
      (This may not be exactly right since I don't have the box in front
      of me to look at, but the point is as follows.)  Obviously  it  is
      physically  possible to put a two-pole breaker in two positions in
      which both poles will  contact  the  same  phase.   It  is  highly
      unlikely  that there is any goo reason to do this; it would almost
      certainly violate the code prohibition of conductors  in  parallel
      (or  whatever).   This  box  is  clearly  labeled indicating where
      two-pole breakers may and may not be used.
      
      So...  Check your box before you plug in two pole breakers.

<    	Besides, when has the US ever worried about being standard?  Don't
<    we still speak in terms of those silly inches and yards?? :-)

	Inches/feet/miles is better then inches/feet/ kilometers they use in 
	Canada.:-)

RE:9   Hmmm, Never run across a panel as you've described. Double check
the panel when you get a chance. If it is as you described, might be an old
panel, but the layout still doesn't make sense.

Ross

>                      <<< Note 2744.10 by WOODRO::THOMS >>>
>                           -< Double check please! >-
>
>RE:9   Hmmm, Never run across a panel as you've described. Double check
>the panel when you get a chance. If it is as you described, might be an old
>panel, but the layout still doesn't make sense.

      No need to double check; I know the insides of it. It was used for
      our temporary electric service when our house was built.  I  saved
      it  when  the permanent electric was connected and installed it in
      our garage.  At that time I had it all apart to install a separate
      ground buss and to de-ground the neutral buss.  At that time I saw
      the actual shape  of  the  power  busses.   I'll  try  to  draw  a
      reasonable facsimile below.
     
              .-------------------------------. 
              |                            (A)|     (A),(B)--Place where 
              |  .----------.        .--------'             phases A & B 
              |  |.--------.|        |.--.               connect to buss      
              |**|| **  ** || **  ** ||**|                               
          =====1====2====3====4====5====6=====    ==== -- Bar onto which 
              `--'|        |`--------'|  |               breakers attach 
         .--------'        `----------'  |                               
         |(B)                            |        ** --   Point at which
         `-------------------------------'         breakers contact buss
      
      NOTE:  Neutral and (separate) Ground Buses not shown.  There is no
      "Main" breaker as this is a distribution panel.  (Its fed  from  a
      breaker  in  the  main  panel.  This may not be real accurate; the
      point is the SHAPE of the phase buses.

Again, I've never seen a panel as you've described, doesn't mean that there 
aren't any. I've been a part time Master electrician for the past 14 years
and have seen a few odd ball panels. Who is the vendor of this particular
panel?

Ross

re: .-1 Interesting!

On thing I notice is that if you want to put double breakers in the box,
you are ok as long as you put the double breakers in first, and single
breakers in last.  3 double breakers can be accomodated.   Weird, but 
functional.

Bob

      RE .12, .13 
      
      I'll  try  to remember to check the brand/model on the box tonight
      and post it here.  If you'd like to come by in Bedfore NH and  see
      it  your welcome.  I assume its a perfectly standard box -- I went
      into Seamans Supply (sp?)  and asked for a temporary  service  and
      this is what they gave me.
      
      Meanwhile back at .5 -- can you answer the question there?
      (under 2)

>< Note 2744.14 by POOL::HAMMOND "Charlie Hammond -- ZKO3-02/Y05 -- dtn 381-2684" >
>
>
>      RE .12, .13 
>      
>      I'll  try  to remember to check the brand/model on the box tonight
>      and post it here.  If you'd like to come by in Bedfore NH and  see
>      it  your welcome.  I assume its a perfectly standard box -- I went
>      into Seamans Supply (sp?)  and asked for a temporary  service  and
>      this is what they gave me.
>      
>      Meanwhile back at .5 -- can you answer the question there?
>      (under 2)



I think the question was (correct me if I'm wrong): Is it o.k. to have multiple
outlets on a 240v brach circuit?  The NEC says: Article 210-4 Multiwire
branch circuits (C) Line to Neutral Load. Multiwire branch circuits shall supply
only line to neutral load.

Exception No 1: A multiwire branch circuit that supplies only one utilization
equipment.

Exception No 2: Where all ungrounded conductors of the multiwire branch circuit
are opened simultaneously by the branch circuit overcurrent device.


Exception #2  is the key exception for your example. If you have the circuit 
protected by the proper size overcurrent device (circuit breaker) and when
the breaker trips it opens all ungrounded wires (hot), you're o.k..
However, I would be concerned on what load you're placing on that circuit!
Article 430-25 and 210-22 state you must calculate the first (largest) motor 
load (if over 1/8hp) at 125% full load current plus the sum of the other loads.
I bet that circuit you're using isn't up to the task of handling all of the
"possible" load. < It must be rated for the sum possible load!

Ross

>< Note 2744.5 by POOL::HAMMOND "Charlie Hammond -- ZKO3-02/Y05 -- dtn 381-2684" >
>          
>      Could  you be more specific, please?  I ask because I have two 230
>      volt outlets and two 110 volt duplex outlets wired to a single  20
>      amp  breaker in my "shop" (read "back of garrage").  Since all the
>      wiring devices are rated for 20 amps (I think the 230 volt outlets
>      are actually rate higher) I don't see any way I could overload the
>      circuit without tripping the breaker (which I could probably do if
>      I  plugged  in  and  ran enough stuff at the same time, but then I
>      could also do that on a 110 volt circuit).  I also don't  see  any
>      other hazzard.  What's the purpose of this code requirement?



You have the attitude that many home electricians have: Hey if I smoke the
wiring by placing too heavy a load on the circuit the breaker will protect me!
You should wire a circuit so the breaker will "never" have to trip due to
overload!

Ross

>                      <<< Note 2744.16 by WILKIE::THOMS >>>
>
>You have the attitude that many home electricians have: Hey if I smoke the
>wiring by placing too heavy a load on the circuit the breaker will protect me!
>You should wire a circuit so the breaker will "never" have to trip due to
>overload!

      Re:  above -- Your admonishment is properly taken, but unneeded. I
      DON'T have that attitude. I was trying to understand what might be
      wrong with the way my shop is wired.  I didn't intend my (possibly
      poor choice of) wording to imply undue reliance on a breaker.
      
      Re:   .15 -- Thanks for the information.  O.K. Both conductors are
      controlled by one, two-pole 20 amp  breaker,  so  the  circuit  is
      within code in that regard.  Now as to the load -- nothing is hard
      wired into this circuit; it has 2-240v outlets and  2-120v  duplex
      outlets.  Some place I have information as to how to rate the 120v
      outlets; how do I rate the 240's?  
      
      My gut feeling is that I'm well within the limits. Reality is that
      the heaviest simultaneous load I  place  on  the  circuit  is  the
      radial arm saw plus a dust collecting shop vac.  (The 120v outlets
      are there for lesser tools, not  used  simultaneously.   But  that
      doesn't  mean  that some one, some day... After there are 2 of the
      240v outlets!  

>      
>      Re:   .15 -- Thanks for the information.  O.K. Both conductors are
>      controlled by one, two-pole 20 amp  breaker,  so  the  circuit  is
>      within code in that regard.  Now as to the load -- nothing is hard
>      wired into this circuit; it has 2-240v outlets and  2-120v  duplex
>      outlets.  Some place I have information as to how to rate the 120v
>      outlets; how do I rate the 240's?  
>      
>      My gut feeling is that I'm well within the limits. Reality is that
>      the heaviest simultaneous load I  place  on  the  circuit  is  the
>      radial arm saw plus a dust collecting shop vac.  (The 120v outlets
>      are there for lesser tools, not  used  simultaneously.   But  that
>      doesn't  mean  that some one, some day... After there are 2 of the
>      240v outlets!  


O.k., Let me put in my last two cents about your shop circuit!
I believe it's in violation of code due to the fact there is
the potential to overload this circuit. In real life, if you have the skill
and the knowledge to do proper wiring methods (good connections, properly
stripped wire, etc.), your circuit will probably never cause you a 
problem. However, what if you sell your house to a person that wants to
hook up his 2hp table saw, 3 hp compressor, a drill press and a shop
heater to this circuit? Let's also suppose that the 20 amp breaker fails
to trip at ~ 20 amps. (believe me this happens!)
Personally, I would stick with exception #1 that I quoted out of the NEC.
This recommends one multiwire circuit to one device/load.


Ross

>                      <<< Note 2744.18 by MAMIE::THOMS >>>
>                               -< Sorry, But... >-
>
>O.k., Let me put in my last two cents about your shop circuit!
>I believe it's in violation of code due to the fact there is
>the potential to overload this circuit. ...

      I appreciate your opinion and I may in fact change this circuit.  

      On  the other hand you may have knowledge that you aren't sharing.
      I'm quite certain that "potential to overload" is not a cause  for
      any code violation. If it were, every circuit with an outlet on it
      would be in violation!  (Let alone circuites with muliple,  duplex
      outlets!)

      What  I have is a circuit that I'm certain is quite safe the way I
      use it.  I also don't think that this circuit presents any greater
      danger  than any of the other, clearly "code legal" circuits in my
      house. I had thought it met code requirements, but an earlier note
      raised a question about this.  
            
      In a previous reply I asked specifically HOW the code requires you
      to calculate the load froma 240v outlet.  By adding 2x the  result
      of  this  calculation  plus the load for the 2 110v duplex outlets
      I'll know if it meets code or not. Isn't this the correct thing to
      do?

>< Note 2744.19 by POOL::HAMMOND "Charlie Hammond -- ZKO3-02/Y05 -- dtn 381-2684" >
>
>      I appreciate your opinion and I may in fact change this circuit.  
>
>      On  the other hand you may have knowledge that you aren't sharing.
>      I'm quite certain that "potential to overload" is not a cause  for
>      any code violation. If it were, every circuit with an outlet on it

You're dead wrong! Home circuits are certainly designed "not" to be overloaded!
Why do you think the code requires (2) 20 amp circuits in the Kitchen, (where
the potential to overload is the greatest in a home). Also, don't confuse
living space with shop area, two totally different areas.


>      would be in violation!  (Let alone circuites with muliple,  duplex
>      outlets!)
>
>      What  I have is a circuit that I'm certain is quite safe the way I
>      use it.  I also don't think that this circuit presents any greater
>      danger  than any of the other, clearly "code legal" circuits in my
>      house. I had thought it met code requirements, but an earlier note
>      raised a question about this.
  
 I'm glad you don't wire houses for living. If you wire a problem in, at least
it will be yours.
           
>      In a previous reply I asked specifically HOW the code requires you
>      to calculate the load froma 240v outlet.  By adding 2x the  result
>      of  this  calculation  plus the load for the 2 110v duplex outlets
>      I'll know if it meets code or not. Isn't this the correct thing to
>      do?

I believe I told you how to calculate the load on your shop circuit in one of 
my previous replies. There is no formula like X # of amps/outlet (like there is 
for living space, 120v circuits). Mulitwire cicuits are sized to the "load".
BTW, I bet any good electrical inspector would fail your circuit due to the
reasons I stated in earlier replies. (I'll re-state : "the potential to overload
the circuit you've described is too great").

Let's suppose you have a  3hp compressor, a 2hp saw, a 1000 watt heater and a
3/4 hp drill press attached.

3hp x 746w /240 x 1.25 = 11.7 amps

2hp x 746w /240        =  6.2

3/4 x 746w /120        =  4.7

     1000w /120	       =  8.3    (Portable, not fixed)
------------------------------
			 30.9 amps

This example is basically the equipment I have in my shop.
My table saw is wired 120v. Each piece has it's own dedicated circuit with
the exception of the portable heater which is rarely used.


Ross

Typical home circuit, with the potential to plug 8 items in...(4 duplex
outlets)...

OK... I plug in my 1500 watt heater, my 1200 watt hair dryer... (that's 2)

Now, I plug in 6 more heaters  (because I ran out of oil) ...  My wiring
is to code, and I've just exceeded the limit.  Of course the breaker 
trips (if its working...whens the last time you toggled your breakers?)

What .-2 was trying to say is that it IS POSSIBLE to exceed the limits on 
the normal BY THE CODE circuits.  

Of course, the above senario is extremely stupid, but it proves the point.

I ran a dedicated 220v circuit for my table saw, and I have two outlets...
one in the garage and one in the cellar.  The only thing I own that is
220 is the saw, and it can't be on both outlets at the same time.
When I move, I'll pull one of the outlets and take it with me.  If that's
against the codes then the codes are wrong, and I'm not going to worry
about it.

Bob

    
    You should have a seperate circuit for your garage, preferably a
    subpanel.
    
    CdH
    

>< Note 2744.21 by MISFIT::DEEP "This NOTE's for you! " >
>                                  -< WRONG! >-
>
>
>
>Typical home circuit, with the potential to plug 8 items in...(4 duplex
>outlets)...
>
>OK... I plug in my 1500 watt heater, my 1200 watt hair dryer... (that's 2)
>
>Now, I plug in 6 more heaters  (because I ran out of oil) ...  My wiring
>is to code, and I've just exceeded the limit.  Of course the breaker 
>trips (if its working...whens the last time you toggled your breakers?)

Come on give me a break! The code is written to cover most "normal" situations.
Your scenario is absurd.



>What .-2 was trying to say is that it IS POSSIBLE to exceed the limits on 
>the normal BY THE CODE circuits.  

Yeah and the code is written to make the possible overload conditions minimal!


>Of course, the above senario is extremely stupid, but it proves the point.

The only point you've proven is wiring should be left to professionals that
are licensed by the State.

>I ran a dedicated 220v circuit for my table saw, and I have two outlets...
>one in the garage and one in the cellar.  The only thing I own that is
>220 is the saw, and it can't be on both outlets at the same time.
<When I move, I'll pull one of the outlets and take it with me.  If that's
>against the codes then the codes are wrong, and I'm not going to worry
>about it.
>
>Bob

Why tell me, why don't you write to the NEC and convince them that you know more
about correct/safe wiring procedure than they do and the code should be changed.

Ross

re .1-:  The point here is that, for 110V circuits, the code does **not**
prevent overloads, it just tries to make them unlikely.  Lots of people
pop their circuit breakers, so it isn't fair to say that the code prevents
overloads in all "normal" situations.

The rules for 220V circuits are apparently must more restrictive, but even
they do not seem to totally prevent the possibility of an overload.

So I'd say that, while following the code is important, understanding
the reasons behind the code rules is even more important.  That's what 
this note used to be about.  I'd guess that none of us have houses that 
are 100% code compliant (I've found really awful examples in my house),
so it is important to understand which things are really bad (eg, I've taped
over my outlet with hot and neutral reversed until I fix it) and which 
aren't as serious (eg, .-2 shouldn't have two 220V outlets on one breaker, 
but so long as only one is used at a time, it can be fixed later).


Now, back to business.  I'd like to know if one should test circuit
breakers.  If so, how?  Is physically flipping them enough?  How can
I be sure that my 15A breaker is really going to trip if I one day
accidentally put 20A through it?  

	Larry

>< Note 2744.24 by RGB::SEILER "Larry Seiler" >
>                             -< Let's lighten up >->
>
>re .1-:  The point here is that, for 110V circuits, the code does **not**
>prevent overloads, it just tries to make them unlikely.  Lots of people
>pop their circuit breakers, so it isn't fair to say that the code prevents
>overloads in all "normal" situations.

I agree to the point that it is always possible to overload a circuit. But
if a circuit is wired to code, an overload is "not" a normal occurrence. A
homeowner would have to do something really stupid! 

>The rules for 220V circuits are apparently must more restrictive, but even
>they do not seem to totally prevent the possibility of an overload.
>
>So I'd say that, while following the code is important, understanding
>the reasons behind the code rules is even more important.  That's what 
>this note used to be about.  I'd guess that none of us have houses that 
>are 100% code compliant (I've found really awful examples in my house),

I wired my Nashua home in 1982. I had three electrical inspections by an
inspector that overruled the code to be more stringent in certain circuits.
My home passed 100%, no calls. Some of the really awful examples you've
found in your house probably came about from some past homeowner doing
his own wiring. I know and have seen/repaired some truly unbelievable
wiring jobs.


>so it is important to understand which things are really bad (eg, I've taped
>over my outlet with hot and neutral reversed until I fix it) and which 
>aren't as serious (eg, .-2 shouldn't have two 220V outlets on one breaker, 
>but so long as only one is used at a time, it can be fixed later).

That's o.k. if this homeowner wants to run a circuit (in his own house)
in this manner. But don't tell me the code is wrong because (in this case) the 
homeoowner is either unable or unwilling to do a proper job.

>Now, back to business.  I'd like to know if one should test circuit
>breakers.  If so, how?  Is physically flipping them enough?  How can
>I be sure that my 15A breaker is really going to trip if I one day
>accidentally put 20A through it?  

>	Larry

No, flipping the breakers will tell liitle about the breaker. Sometimes a
breaker will go bad and not be able to be reset.  (Safe failure).
The only way to test your breakers would be to pull them from the circuit
and set up some kind of test load. Not really feasable.
Again, the key to a safe circuit is to set it up so it's not normally
in an overload condition. 

Ross

Well!  Since my intent was to draw a little heat away from the guy everyone
was beating up on for a simple question, I guess I was successful!  8-)


>>(eg, .-2 shouldn't have two 220V outlets on one breaker, 
>>but so long as only one is used at a time, it can be fixed later).
>That's o.k. if this homeowner wants to run a circuit (in his own house)
>in this manner. But don't tell me the code is wrong because (in this case) the 
>homeoowner is either unable or unwilling to do a proper job.

First of all, lets remember why the code is there in the first place.  It's
to establish a safe set of standards for electricians to use to keep them
from getting sued when your house burns down.  It's extra protection for
the insurance companies, because if they can prove your house was not wired
to code, they can get out of paying you.

The code is not BIBLE and is not practical for all occurances.  In some it is
inadequate (for my peace of mind) and for others, overkill.   I have no problem
sleeping at night with a circuit that runs from my panel in the garage to the 
workshop in the cellar, with two 220v outlets on it, knowing that only one
can be used at a time.  I wouldn't leave it that way for the next guy who might
own two 220v tools.  The code says that I am in violation, and I say that the 
code was not written to take into account a person who only owns one 220v 
device, and wants to use it in two possible places.   I am neither unable
nor unwilling to do a proper job... I have!  It just isn't according to the
code, which is not designed for this particular occurance.   Thats called
making an intellegent decision, and people are still allowed to do that
once in a while, regardless of the insurance companies, and lawyers, and
inspectors, and I resent the implication that I am an accident waiting to 
happen, simply because I use some common sense.

Dismantle SOAPBOX  (according to code, of course)  8-)

Now then:

>No, flipping the breakers will tell liitle about the breaker. Sometimes a
>breaker will go bad and not be able to be reset.  (Safe failure).

Right, but flipping the breaker WILL tell you if its frozen closed... the most
common failure, usually due to corrosion from high humidity or the elements.
The feel of the breaker as it is toggled can also tell you if it may be
gunking up...(that's a technical term!) 8-)

Now then...  what does ALL this have to do with rewiring 220v motors? 8^)

Bob

>< Note 2744.27 by MISFIT::DEEP "This NOTE's for you! " >
>
>
>
>Well!  Since my intent was to draw a little heat away from the guy everyone
>was beating up on for a simple question, I guess I was successful!  8-)


No Bob, I don't feel we were beating up on anyone. It was a disagreement and
I certainly hope no feelings were hurt. However, I was asked about a particular
circuit and I gave my thoughts. I'm open to any argument about safe wiring and
don't profess to know all of the answers. I did work as an Apprentice 
electrician, took many hours of classroom on wiring and passed the State exam
to become a Journeyman electrician, than later Master electrician. But then
again, I currently don't work electrical problems daily or even weekly.



>First of all, lets remember why the code is there in the first place.  It's
>to establish a safe set of standards for electricians to use to keep them
>from getting sued when your house burns down.  It's extra protection for
>the insurance companies, because if they can prove your house was not wired
>to code, they can get out of paying you.
>
>The code is not BIBLE and is not practical for all occurances.  In some it is
>inadequate (for my peace of mind) and for others, overkill.   I have no problem


The NEC is the Bible for safe wiring. If you want to disregard it in your own
wiring, that's your call.


>sleeping at night with a circuit that runs from my panel in the garage to the 
>workshop in the cellar, with two 220v outlets on it, knowing that only one
>can be used at a time.  I wouldn't leave it that way for the next guy who might
>own two 220v tools.  The code says that I am in violation, and I say that the 
>code was not written to take into account a person who only owns one 220v 
>device, and wants to use it in two possible places.   I am neither unable
>nor unwilling to do a proper job... I have!  It just isn't according to the
>code, which is not designed for this particular occurance.   Thats called
>making an intellegent decision, and people are still allowed to do that
>once in a while, regardless of the insurance companies, and lawyers, and
>inspectors, and I resent the implication that I am an accident waiting to 
>happen, simply because I use some common sense.
>
>Dismantle SOAPBOX  (according to code, of course)  8-)

Again, If you want to disregard the code, fine. Just make sure you don't tell
the Municipality you live in about it.

>Now then:


>Right, but flipping the breaker WILL tell you if its frozen closed... the most
>common failure, usually due to corrosion from high humidity or the elements.
>The feel of the breaker as it is toggled can also tell you if it may be
>gunking up...(that's a technical term!) 8-)
>
>Now then...  what does ALL this have to do with rewiring 220v motors? 8^)

>Bob


Like I said, flipping the breakers will tell you little about their condition.
One of my college professor's once did a lab experiment for our class. He 
randomly picked new breakers and tested them at the rated capacity. If I
remember correctly approx. 10% didn't trip anywhere near their ratings.
This professor was an old time electrical engineer that used to design
many electrical components for Westinghouse, very knowlegable in electrical
equipment.


Ross

    Last night as a way to waste an evening, I looked up the multiple
    receptical problem in the NEC 1987 edition.
    
    In article 210-19 it says:
    GENERAL.  Branch-circuit conductors shall have an ampacity not less
    than the maximun load to be served.  In addition, conductors of
    multioutlet branch circuits supplying receptacles for cord- and
    plug-connected portable loads shall have an ampacity of not less
    than the rating of the branch circuit. ...
    (FPN):See Part B of Article 430 for minimum rating of motor
    branch-circuits ....
    220-3.  Computation of Branch Circuits. ...
    (c)Other loads -- all Occupancies.
    (2)Outlet for motor load      See Sections 430-22,-24 and 440.
    (5)*Other outlets      180 volt-amperes per outlet
    For receptacle outlets, eachj single or multiple receptacle shall
    be considered at not less the 180 volt-amperes.        
    
    [Basically this says to figur 180VA (1.5amps) per outlet regardless
    of whether it has 1, 2, 4 or more recepticals included + add the
    motor loads as determined in article 430. -tom]
    
    Article 430.24 says:
    
    CONCUCTORS SUPPLYING SEVERAL MOTORS.  Conductors supplying two or
    mote motors shall have an ampacity equal to the sum of the full-load
    current rating of all the motors plus 25 percent of the highest
    rated motor in the group.
     
    Where one or motors of the group are used on
    short-time, intermitent, periodic, or varying duty, the ampacity
    of the conductors shall be computed as follows:
    
    (1)Determine th needed amprere rating for each motor used for other
    than continuous duty from Table 430-22(a) Exception. [table says
    use 90% of nameplate current rating -tom]
    
    (2)[pertains to continuous duty -tom]
    
    (3)Multiply the largest single motor ampere rating determined from
    (1) or (2) above by 1.25.  Add all other motor ampere ratings from
    (1) and (2) above and select the conductor ampacity for this total
    ampere rating.
                                   

>< Note 2744.29 by WOODRO::BERKNER "Tom Berkner 264-7942 MK01" >
>                     -< Sizing conductors for motors etc. >-
>
>    Last night as a way to waste an evening, I looked up the multiple
>    receptical problem in the NEC 1987 edition.
>    
>    In article 210-19 it says:
>    GENERAL.  Branch-circuit conductors shall have an ampacity not less
>    than the maximun load to be served.  In addition, conductors of
>    multioutlet branch circuits supplying receptacles for cord- and
>    plug-connected portable loads shall have an ampacity of not less
>    than the rating of the branch circuit. ...
>    (FPN):See Part B of Article 430 for minimum rating of motor
>    branch-circuits ....
>    220-3.  Computation of Branch Circuits. ...
>    (c)Other loads -- all Occupancies.
>    (2)Outlet for motor load      See Sections 430-22,-24 and 440.
>    (5)*Other outlets      180 volt-amperes per outlet
>    For receptacle outlets, eachj single or multiple receptacle shall
>    be considered at not less the 180 volt-amperes.        
>    
>    [Basically this says to figur 180VA (1.5amps) per outlet regardless
>    of whether it has 1, 2, 4 or more recepticals included + add the
>    motor loads as determined in article 430. -tom]
 
You're correct in this statement for normal household branch circuits, with
the exception you didn't point out: small appliance branch circuits (kitchen).
However, for the shop question 220.3 (c)  (1) Outlet for a specific appliance
or other load except for a motor load................. ampere rating of
appliance ot load served. 

		and.
(2) Outlet for a motor load................ See Sections 430-22 and 430-24 and 
Article 440.

These are the pertinent passages. The 180 volt-amp calculation is for
"occupancies" (branch circuits).




   
>    Article 430.24 says:
>    
>    CONCUCTORS SUPPLYING SEVERAL MOTORS.  Conductors supplying two or
>    mote motors shall have an ampacity equal to the sum of the full-load
>    current rating of all the motors plus 25 percent of the highest
>    rated motor in the group.
>     
>    Where one or motors of the group are used on
>    short-time, intermitent, periodic, or varying duty, the ampacity
>    of the conductors shall be computed as follows:
>    
>    (1)Determine th needed amprere rating for each motor used for other
>    than continuous duty from Table 430-22(a) Exception. [table says
>    use 90% of nameplate current rating -tom]


Say what??? "Any motor applications shall be considered as continuous duty 
unless the nature of the apparatus it drives is such that the motor will
not operate continuously with load under any condition of use." (fine print
on the bottom of 430-22(a)).

I say Exception No. 1: Conductors for a motor used for short time, intermittent,
periodic, or varying duty shall have an ampacity not less than the percentage
of the motor nameplate current rating shown in Table 430-22 (a)
Exception unless the authority having jurisdiction grants special permission
for conductors of smaller size. 

Try Varing duty, continuous rated motor! 
    
>    (2)[pertains to continuous duty -tom]
>    
>    (3)Multiply the largest single motor ampere rating determined from
>    (1) or (2) above by 1.25.  Add all other motor ampere ratings from
>    (1) and (2) above and select the conductor ampacity for this total
>    ampere rating.
                                   

Agreed, I stated this before.

Ross

I just re-read my last reply (hastily written) and I don't think I gave
enough information. What I wanted to say is the 180 volt/amp branch circuit
calculation is for occupancies, such as living rooms, bed rooms, etc. 
Shop loads are a different story, see last note for pertinent articles in the
code. 
Tom, The chart you were using, 430-22 (a) is an exception chart for motors
that see varying duty such as elevators, welders, conveyors, etc. Depending
on the application, these motors are either lightly used, intermittent, light
loads or "hammered" on or off with a full load. That's why the charts there.
The lightly loaded, lightly used motors would be rated at less than the full 
load current and the on/off heavily loaded motors are rated at a high 
percentage.
Tom, if you wanted to try and use that particular chart for a shop application
such as a table saw, the Varying Duty, Continuous rated motor would apply. This
is an overkill for a normal shop circuit and a continuous duty motor.
The motors we were discussing are Continuous Duty and should be rated at 125%
full load current. If multiple motors are on the same circuit, the first/largest
motor is rated at 125% and the next at 100%.

Ross

      In reading the last few replies I could conclude that every outlet
      in my shop should be on a separate breaker,  and  that  even  this
      would be illegal since some yo-yo could plug an overload into that
      outlet. Of course that's absurd and of course I don't think anyone
      intended  that  message.  (But what difference does it make if set
      the saw for 120 vs 220 and plug it in????)
      
      Which  comes  back  to  the question I tried to ask at least twice
      before and which I'll now re-word, perhaps better:
          
          In  a home, 120v outlets are rated at 1.5 amps for purposes of
          determining the load on a circuit. What load factor applies in
          a "shop" for 120v and 220v circuits which are not dedicated to
          specific equipment?  
          
          The  implicit  question  here  is  something like "what is the
          difference between what I have and just pluging the  saw  (set
          for 120v) into any of the outlets in my home?
      
      If  there's  an answer to this in previous replies I can't pick it
      out.
      
      BTW  using  1.5  amps  per  120v  outlet and 225% of the nameplate
      amperage (figuring a possible second device of  the  same  rating)
      from  my  saw  my  circuit  is loaded to ~18-19 amps, which surely
      sounds O.K. to me for a 20 amp circuit.  (I did  this  at  home  a
      couple days ago and don't have the actual figures in front of me.)

>< Note 2744.32 by POOL::HAMMOND "Charlie Hammond -- ZKO3-02/Y05 -- dtn 381-2684" >
>
>
>      In reading the last few replies I could conclude that every outlet
>      in my shop should be on a separate breaker,  and  that  even  this
 
Listen, you've about got it! Basically you should have separate circuits
for your heavier loads. How many diy out there have plugged in a good size
table saw to a regular 15 amp branch circuit and tripped the breaker when
starting the saw or ripping some thick wet wood? I have and I bet many
have done the same. I recommend running separate circuits to your more
or less fixed equipment (table saw, compressor, drill press, mig welder etc.)
I definitely like to have my 240v circuits, separate.

>     would be illegal since some yo-yo could plug an overload into that
>      outlet. Of course that's absurd and of course I don't think anyone
>      intended  that  message.  (But what difference does it make if set
>      the saw for 120 vs 220 and plug it in????)
>      
>      Which  comes  back  to  the question I tried to ask at least twice
>      before and which I'll now re-word, perhaps better:
>          
>          In  a home, 120v outlets are rated at 1.5 amps for purposes of
>          determining the load on a circuit. What load factor applies in
>         a "shop" for 120v and 220v circuits which are not dedicated to
>          specific equipment?  
>          
>          The  implicit  question  here  is  something like "what is the
>          difference between what I have and just pluging the  saw  (set
>          for 120v) into any of the outlets in my home?
>      
>      If  there's  an answer to this in previous replies I can't pick it
>      out.
>      
>      BTW  using  1.5  amps  per  120v  outlet and 225% of the nameplate
>      amperage (figuring a possible second device of  the  same  rating)
>      from  my  saw  my  circuit  is loaded to ~18-19 amps, which surely
>      sounds O.K. to me for a 20 amp circuit.  (I did  this  at  home  a
>      couple days ago and don't have the actual figures in front of me.)


Geez Charlie, I don't know how else to tell you. I've quoted code, I've come 
flat out and told you in the plain English. I give up, anyone else want to try?

Ross

>                      <<< Note 2744.33 by WILKIE::THOMS >>>
> 
>I definitely like to have my 240v circuits, separate.

      Beleive it or not, this was apparent from your various replies.

      O.K.  'nuff  o'  this.  Lets talk for a moment about some possible
      ways to make this situation better.  
      
      The  garrage has a six position breaker box which is fed from a 50
      amp breaker in the main breaker box.  At present these are used as
      follows:   Position 1 -- inside lights in the garrage and enclosed
      breezway. Position 2 -- outslide lights. Position 3 & 4 -- the now
      infamous  shop  circuit.   Position 5 -- garrage door openers (2).
      Position 6 -- outlets in the garrage and breezway  (excluding  the
      "shop").   All of these are 20 amp circuits.
      
      Running  additional  circuits  from the main box is not reasonable
      because most of the wiring is inside a wall.  Installing a  larger
      breaker  box in the garrage is not reasonable for the same reason,
      but adding a second box in the garrage may be reasonable. (see D &
      E) 
          
      Here's some ideas in order of difficulty -- easiest first.
      
      (A)  I  could  easily  eliminate one of the two 240v outlets.  Any
      future 240V tools would have to take turns.
      
      (B)  I  could  move  the  4 110v outlets (2 duplex outlets) to the
      circuit which is now used only for the garrage door  openers  (two
      garrage  doors).   I don't like this idea because (1) simultaneous
      use of both garrage doors and some tools could  possibly  overload
      the  circuit,  and  (2)  I like to be able to turn off the garrage
      door openers independently -- like when I have  something  leaning
      on them.  
      
      (C) I could run #10 wire and upgrade the entire circuit to 30 amps.
      
      (D) I could run #10 wire to the shop and install a new breaker box
      with a 20 amp 240v and 2 15amp 110v circuits. This would mean that
      a shop distribution panel would be attached to a 30 amp circuit in
      the garage distribution panel which is, in turn, attached  to  the
      main breaker box.  Would this be legal?  (I'm not certain that I'm
      using the terms "distribution panel" and "breaker  box"  according
      to any NEC definition here.)

      (E)  I could continue the 50 amp feed from the main breaker box on
      to a second box in the  garrage  and  use  this  to  feed  several
      seperate  circuits  to the shop.  There's enough space next to the
      current box for another small (4-6  position)  box.   (This  might
      actually be easier than (D) because I could probably still use the
      existing circuit for the 240V outlet(s).  

      I'll appreciate any and all comments on these ideas.

      ...and  since  I  won't  see your replies till after Thanksgiving,
      have a happy Thansgiving.

>< Note 2744.35 by POOL::HAMMOND "Charlie Hammond -- ZKO3-02/Y05 -- dtn 381-2684" >
>                       -< How can we make this better? >-
>
>>                      <<< Note 2744.33 by WILKIE::THOMS >>>
>> 
>>I definitely like to have my 240v circuits, separate.
>
>      Beleive it or not, this was apparent from your various replies.
>
>      O.K.  'nuff  o'  this.  Lets talk for a moment about some possible
>      ways to make this situation better.  
>      
>      The  garrage has a six position breaker box which is fed from a 50
>      amp breaker in the main breaker box.  At present these are used as
>      follows:   Position 1 -- inside lights in the garrage and enclosed
>      breezway. Position 2 -- outslide lights. Position 3 & 4 -- the now
>      infamous  shop  circuit.   Position 5 -- garrage door openers (2).
>      Position 6 -- outlets in the garrage and breezway  (excluding  the
>      "shop").   All of these are 20 amp circuits.
 
O.k., Here's what I would do: If you're currently only running (1) 240v tool,
wire in (1) appropriate amperage outlet using position 3 & 4. Combine circuits
1 & 2 to one breaker  (#1), Run a new 20 amp circuit off of postion #2 with
(2) duplex outlets in convenient locations. If you add another 240v piece of
equipment, calculate the the "new" load on circuit #3 & 4 and if acceptable,
add a second outlet. 

This is the easiest and safest way to redistribute the loads as I see it. 
However, You might be able to do something with the lighting and breezeway
circuits. I don't know the area size or number of outlets, number of
outside lights, etc.
Another option might be running a new breezeway circuit from the main service
and in doing this, freeing up sub panel space and allowing you to add another
240v circuit in the future.


     

Ross

    Combining the 120v circuits is the way to go.  Getting the right
    conbination so that overhead lights stay on if receptacles pop is
    the tricky part.  Dedicate your high load 240v circuits.
    
    					paul b

      RE: .36 & .37 -- Thanks.
      
      After  thinking  about this over turkey, etc., I realized that the
      "key" is to combine the 2 lighting circuits to free up a  position
      for  a  dedicated  120v  outlet  circuit in the "shop".  I'll also
      remove one of th 240v outlets.
      
      What  is/are  your  opinion(s)  on  those  breakers  which put two
      circuits on one position in the box?  I was thinking about  useing
      one  of these for the two lighting circuits.  I think they only go
      to 15 amps max, but thats no problem -- although wired for 20 amps
      (as are all circuits in my house) neither of the lighting circuits
      would even come close to 15 amps.  (i.e they'd  easily  fit  on  a
      combined 20 amp circuite.)

               <<< Note 2744.39 by HANNAH::DCL "David Larrick" >>>
                               -< Rathole alarm >-

.38 set off my rathole alarm - rather belatedly for this topic!  The double
breaker that fits in a single slot is a subject of sufficient general
interest, and sufficiently unrelated to "rewiring motors for 220", that
I've started a new topic in 2846.  Please, let's continue this particular
tangent there.

			DCL with moderator hat on

    I've looked, but have not been able to find anything in the file.
    I am in the process of refinishing my foyer. The contractor put
    a small (independently controlled) electric baseboard heater there.
    I will be doing some wain's coating (sp?) there. Since I have never
    used the heater in its trhee year existence I want the thing out!
    
    The question is can I just cap the wires with wire nuts. Does it
    get more complicated if the heater is on a circuit with other things
    that I can't disable. 
    
    Any suggestions on the best course of action. I want to do the easiest
    and safest thing!
    
    Chip

    
    Forget about the easiest or safest way, you should do it by the
    Code. That way you're covered if there's a fire.
    
    Remove the power to the circuit by the switch or overcurrent device.
    Then remove the wires from the heater. Trace the wires back to the
    junction box they originated from. Disconnect and remove the wires
    from the jbox that go to the heater. Then all you have is a wire
    that's disconnected at both ends. If the power for the heater
    originates in it's own circuit in the panel, then you have to
    disconnect main power, pull the breaker, and replace it with a blank
    breaker cover.
    
    If you plan to use the heater, or that circuit, in the future, then
    you can remove the wires to the heater, and install a junction box
    in the area. Install the wires in the jbox with the proper hardware,
    wire nut the ends (a little tape over the nuts won't hurt), and
    close up the box with the proper cover.
    
    Both ways are safe and should be legal in your area.
    
    CdH
    

    Thanks. Maybe I will put an outlet there as an alternative as there
    isn't one now.
    
    Chip

    Just make sure if the feed is 110v or 220v before installing an
    outlet (hint-usually a 220 feed uses black and red wires for the
    hot).
    
    Eric

    Will do and thanks.
    
    Chip

    I don't know about the States, but here in Canada you can't take
    a two wire 220 volt feed and split it into two 110 volt lines *without*
    a white neutral(sp?) wire. 
    
    Heaters are usually 220 volt, two wire. (Two conductors (red/black)
    and a bare ground wire). Otherwise you'd be drawing twice the power 
    (current) through the line. (Read WIRE HEAT and breaker load -
    you can only load your breaker to 80% of its rating. (Canada again)).
    You would need a *large* breaker 30 : 40 Amp instead of 15 : 20
    Amp. Now, split receptacles are allowed (usually manditory (X3)
    for kitchen counter outlets). You need a three wire feed
    (black/red/white) with a bare ground. Black and red are HOT lines,
    white is neutral. The black and red wires go on the brass colored
    terminals of the outlet, (AFTER BREAKING OFF THE TAB THAT CONNECTS
    THE BRASS COLORED SCREWS "PLATE" TOGETHER!). You'll see it sort of 
    between the screws. The white wire is secured to the silver colored 
    screws, without breaking the tab on that side. Ground (bare) goes 
    to the green ground screw on the outlet.
    
    IF A SPLIT OUTLET IS NOT INSTALLED THIS WAY, IT IS ILLEGAL. 

>< Note 2897.5 by POLAR::PENNY "For the Benefit of Mr. Kite" >
>    I don't know about the States, but here in Canada you can't take
>    a two wire 220 volt feed and split it into two 110 volt lines *without*
>    a white neutral(sp?) wire. 

	Wouldn't it be easier to just swap the double pole breaker in the box 
 to a single pole, 20 amp one?  (then put a blank cover over the exposed 
 opening that remains).  Assuming that there is no other 220v device on
 the circuit, this would allow the use of a standard 110v outlet.

							--Mike

    
    I looked through keywords and did a dir/title and couldn't find
    anything that is exactly what I want so instead of starting a new
    note, I figured this was as good a place as any.
    
    Does anyone know if I can get or where I can get a double switch,
    one of which is a dimmer switch??? Places like Grossmans dosn't carry
    anything like it.
    
                         -----
                         |   |
    	                 | > |    <------ Switch (normal)
    	                 |   |
                         -----
                         |   |
    	                 | > |    <------ Switch (dimmer)
    	                 |   |
                         -----

    
    Mike    

    
    I've never seen such a beast.  I've seen the double regular switch
    only.  I think dimmer switches are usually considerably larger than
    a regular switch and it may be physically impossible to have such
    an arrangement.  If one does exist, it'll probably cost $100 since
    its probably a very demand item.
    
    Good luck with the search.
    
    Phil

    Have you thought of putting a regular and a dimmer switch together
    yourself?  You would need the appropriately sized box and may have
    trouble finding a switch cover to fit, but it would probably be
    cheaper than trying to find a combination switch.
    
    Ed..
    

    If you have to fit everything into a single box, I think your out
    of luck. Dimmers can dissipate considerable heat (depending on the
    load), and I doubt anyone has crammed two of those toasters into
    the space of a single box.
    
    If you can use a double box, a normal double switch cover will work
    with both rotary and the newer up-n-down dimmers

    Do they have to be one above the other ???
    
    Side by side is a piece of cake.

	When I was working on a job in the south shore area the home owner
	changed her mind several times on what she wanted to be switched,
	dimmed, outlet etc.  We ended up trying to find the device in 
	question and after trying three different elect. supply houses 
	we gave up.  Each one said "the don't make it".  We knew it was
	a long shot anyway.

	bjm

    
    Side by side is what I was trying to stay away from. The switch
    is located in the bathroom surrounded by tile. To put another switch
    in I'd have to cut the tile, not an easy task and at the some time
    make it look nice. I had never heard of that kind of switch either,
    but then again, I'm not an EE or electrician. It was a long shot
    I have to admit, but it was worth a try. Looks like I'll have to
    cut the tile.
    
    Mike

    Maybe there's a way you can re-configure a rotary dial dimmer switch
    so that turning the dial dims one light, and pushing the rotary
    dial turns the second light on or off.
    

	Reply .24 got me thinking of a single gang device that the
	Casablanka (sp??) (the Calf. ceiling fan company) make to control
	BOTH the fan and the light kit on it.  It look very much like a
	dimmer but it has two knobs (similar to a car radio).  One is a
	three position unit for the fan the other is a push-on/off, turn
	to dim control for the light kit on the fan.  Depending on how
	the motor speed control portion handles the voltage it may be 
	possible to get a three position dimmer and a full range dimmer 
	into a single gang box.  
		I don't know if this would work.  This device does exist
	and is UL listed.
    
	bjm

    re .24:
    
    I'll bet the three-position control is just a rotary switch to turn
    on the different windings of a three-speed fan, and would not provide
    a dimming effect.

If re: .25 is correct, than it would probably work for Mike's application.

.23 is a good idea, but of course, it would be against the code.  8^)

Bob

    .23, .26:
    
    Perhaps what .23 has in mind is something like what you see for car
    headlights, or the reverse of a common car radio control:  the knob
    rotates, and at one stop it also throws a switch, with a second switch
    controlled by push/pull on the knob.
    
    No, I haven't seen such a beast.  Sorry!
    
    Dick

    re: 1729.16 , request for a double switch w/dimmer
    
    I replied directly to the author but thought I would also enter
    the info here in case anyone else is looking for the same switch.
    
    I have seen a switch of this type in an electrical store in
    New Hampshire, near the Pheasant Lane mall.   I don't remember
    the name of the store or the manufacturer of the switch, but if
    anyone is interested, contact me and I'll find out the next time
    I am in the area.

    
    re .28
    
    Well I went to that store at lunch (happened to be in the area)
    and they don't have the switch. Maybe they did at one time but not
    now.
    
    As for the other switch some of you are talking about, I saw something
    like that at Builders Square. One was a three position fan and the
    other was a full dimmer for a light. Now my question is will this
    work in my situation. What I need the switch for is to hook up a
    exhaust fan for my mother's house. She has one switch there right
    now that is a dimmer which controls the light. Every exhaust fan
    I've looked at says to only hook it up to a timer switch or a standard
    on/off switch - nothing about being able to use a variable control
    switch. Does anyone know if these fans can be used with a variable
    control switch???? When I installed the fan on my woodburning stove
    the directions warned me from using it with a variable control switch.
    Are these fans built the same way????
    
    Mike

    RE: .6
    
    You would still have the wire coloring to contend with. In Canada,
    you may do what you mentioned, IF, you properly color code the wires.
    In effect, put white tape over the red wire where it enters the
    "outlet" box AND the main panel. 	dep

    
    I'll ask this here since my house is reasonably old, has several
    2 wire circuits and the question isn't worth a brand new note.
    
    I'll be replacing my 7 fuse boxes with a breaker panel soon and
    have come across some wiring I'll need help with.  I have what I
    believe is called a "3-wire" circuit.  It's basically a 220 line
    but it's not used as 240.  It's used as 2 110 circuits.  
    
    My questions are:
    
    Is this a common practice today?
    
    What type of breaker should be used for this beast?  2 singles
    or 1 double?
    

    I know there are multiple existing discussions of 3-wire circuits
    someplace in this conference, but the only one I could find was in
    topic 931, beginning at reply 6.

    
    RE: .12
    
    Thanks for pointing to 931 but it doesn't address my main question
    which is how is a 3-wire circuit connected in the service panel?
    Do I use 2 singles, a double or doesn't it matter?
    

>< Note 2412.11 by VINO::GRANSEWICZ "Which way to Tahiti?" >
                             -< "3-wire" circuit >-

    
 >    have come across some wiring I'll need help with.  I have what I
 >   believe is called a "3-wire" circuit.  It's basically a 220 line
 >   but it's not used as 240.  It's used as 2 110 circuits.  
    
 
In older homes it used to be common practice to snake /3 romex (to the attic)
and use it for two circuits, sharing a common neutral. If this is the case
in your scheme, use two separate breakers.

Ross

    The Code has some specific provisions regarding 3-wire circuits, and I
    would suggest that you read and heed them.  Under some circumstances
    you do need to use a double breaker (two breakers in a double-size
    package, with their handles mechanically connected together so they
    turn off together).
    
    I think the rule is something like:
    
    - If the two circuits are both present in any outlet box or switch box,
      they must be connected by a double breaker
    
    - If the two circuits split apart in a workbox (and so are never both
      present in any outlet box or switch box), they may be connected by 
      single breakers
    
    The idea is to avoid the situation where someone wants to work on an
    outlet, switches off a breaker that appears to turn off that outlet,
    and gets shocked anyway by the other circuit in the outlet box. 
    Presumably people expect this sort of thing in work boxes.

    One thing to remmeber is to have each of the hots attached to a
    different leg of the 220 feed into the panel (different bussbar).
    The reason for this is that there is only one neutral, and as long
    as the two hots are out of phase with each other, the neutral won't
    be overloaded. Normally, with full size breakers, the bussbar the
    breaker attaches to will alternate on each side top to bottom:



                           A  B              
                           |------- (breaker)
                              |---- (breaker)
                           |-------     .
                              |----     .
                           |-------     .
                              |----     .
  
    However, on panels that support the half size breakers, two adjacent
    breakers can be attached to the same bussbar and cause problems.
    
    Eric                          
                               
                            
    
    
    

    
    Alright!  Now we're getting somewhere.  As far as I can tell, the
    2 circuits are only in the ceiling light where they then split off.
    
    Richter's also got into the whys of putting the different legs of
    the circuit on different legs of the bussbar.  I don't believe it's
    connected that way now though.  I got a typical 4 circuit fuse box
    with the 2 large pullout cartridges above.  If the numbering of
    the fuses is 1, 2, 3, 4 then the legs were connected to 3 & 4. 
    This sounds like it was connected wrong but what are the consequences
    of this situation?  Everything has been working properly with no
    blown fuses.
    
    

>    Richter's also got into the whys of putting the different legs of
>    the circuit on different legs of the bussbar.  I don't believe it's
>    connected that way now though.  I got a typical 4 circuit fuse box
>    with the 2 large pullout cartridges above.  If the numbering of
>    the fuses is 1, 2, 3, 4 then the legs were connected to 3 & 4. 
>    This sounds like it was connected wrong but what are the consequences
>    of this situation?  Everything has been working properly with no
>    blown fuses.

if I was you i'd double check this out.  the consequences are fire.  ok, so 
it's working so far.  with breakers not popping and safety factors you 
simply have not loaded things up enough to melt plastic.  but basically, if 
3 & 4 are on the same leg, you have two separate circuits, both with a 
15 (20?) amp fuse, pushing up to 30 (35, 40?) amps back through the same 
single nuetral wire.  take the cover plate off the box.  behind you can 
trace the wires from the big cartridge fuses to the plug fuses.  if one 
cartridge fuse leads to both fuses of your 3-wire circuit, it's wrong.  
just switch one of them with one of the circuits coming from 1 or 2.  i 
suppose it's possible for one cartridge to feed fuses 1 & 3, and the other 
2 & 4, so do check.
    
craig

btw, it's times like this when it's helpful to have found out what runs off 
what fuses.  then you can understand why the load has been low enough to 
not cause problems so far.  like the air conditioner was on one circuit and 
the furnace was on the other.  :^)

.17>    Alright!  Now we're getting somewhere.  As far as I can tell, the
.17>    2 circuits are only in the ceiling light where they then split off.
    
A nit, but perhaps an important one:  the term "outlet", as used in the
Code (and in .15) includes lighting fixtures as well as receptacles for
plugs.  So if the circuits split in a box that also has a ceiling light
attached to it, that box is technically an outlet box.  To conform to Code,
the two circuits must be on the same double breaker.

I don't know whether the equivalent of a double breaker exists in fuse
technology.

But if the two hot wires are indeed on the same leg, you've got bigger
problems than technical Code violations.  Please check this out right away.

    
    Thanks for all the help and info.
    
    Well, the 7 old fuse boxes are history and I now have a 100 amp
    breaker panel for my main service panel!
    
    I currently have the 3-wire circuit on 2, single pole 15 amp breakers
    and they are on seperate legs.  Do 15 amp double poe breakers exist?
    I don't recall seeing them on the list at Spag's so maybe they are
    not a common item.
    
    Another question:    
    I replaced the BX wire to the furnace with Romex.  Hell, it was
    a short run and while I was having sooo much fun ripping out wires
    ;-) I figured I do it.  Does the wiring to the furnace have to be
    in conduit?  If it does, then how much it (same area protected by
    firecode sheetrock?)?  

    
    Let me explain the situation in more detail:
    
    The old power source to the furnace was BX cable which went in above
    the firecode sheetrock to the thermal switch right above the furnace.
    However, the cable exited the sheetrock through a 1" square hole.
    To me, the fire protection offered by the sheetrock appears to be
    compromised.  Should I instead run the power feed through EMT conduit
    to the thermal switch and seal up the 1" hole?  The wire to the
    shutoff upstairs is also just stapled to the firecode sheetrock.
    I would think that that wire should also be in conduit.  Or am I
    going overboard here?
    

I have an extend-the-2-wire grounding question that is skirted over
here and in 1980.* and 1992.*.
My brother has a 50/60-ish year old house, two wire circuits, some knob 
and tube, some BX (also one legged, that is, 110 only).
I've been helping him out by adding outside lighting fixtures for him.
One was a motion detecting yard light, the other a new porch light.

The Question:  What should one do with the grounding wire in the new boxes
and fixtures?  I had been clamping them together and to the boxes, hoping
for local integrity.  Of course, there is no safety ground for this
local circuit to connect to, so am I compounding the problem by connecting
boxes together?  Some boxes are, of course, switches (with metal boxes
and covers) so safety is a consideration.  Should I actively AVOID wiring
the bare wire to the fixtures so shorts at the fixture will NOT propagate
to other areas of the circuit?  Of course, I know better than to connect
ground and neutral.  (That's the one message conference members here continue
to beat into one another's heads!  Rightfully so, since it's so hard
to justify it on simple first principles.)

- tom powers]

RE:-1 The code says: 250-50 (exception) For replacement of nongrounding-type
receptacles with grounding-type receptacles and for branch-circuit extentions
						    ^^^^^^^^^^^^^^^^^^^^^^^^^ 	
only in existing installations that do not have an equipment grounding conductor
in the branch circuit, the grounding conductor of a grounding-type receptacle 
outlet shall be permitted to be grounded to a water pipe which is bonded in
accordance with Section 250-80(a). 
Also take a look at Article 210-7, (c) and (d).
210-7 (d) (exception): Where a grounding means does not exist in the receptacle
enclosure either a nongrounding or a ground-fault circuit-interrupter type
of receptacle shall be used. A  grounding conductor shall not be connected from
the ground-fault circuit-interrupter receptacle to any outlet supplied from
the ground-fault circuit-interrupter-type receptacle.





"Don't wire in a grounding type device on a ungrounded system!" It's o.k.
to use a non-grounding device or add a ground. But don't provide false security
of an apparent grounding-type device.



Ross

RE:27  		I re-read your note and assume you're not connecting any
receptacles to your extension. However the rule still applies, keep
the circuit two wire or upgrade to a true 3 wire with a grounding conductor.
If you connect your extension like a 3 wire, what would keep some future
unsuspecting homeowner from adding a grounding type receptacle on that 
particular branch? Also by staying 2 wire, (assuming the upgrade to three wire 
isn't practical), if you should have a short to metal,
at least the short would be isolated from the rest of the circuit.


Ross

Also...  read article 250-33. Other Conductor Enclosures. Exeception No. 1:
Metal enclosures for conductors added to existing installations of open wire,
knob-and-tube wiring, and nonmetallic-sheathed cable, which do not provide an
equipment ground, if in runs of ***less than 25 ft*** (7.62 m), if free from
				^^^^^^^^^^^^^^^^^^^^^
probable contact with ground, grounded metal, metal lath, or other conductive 
material, and if guarded against contact by persons shall not be required to 
be grounded.

Back in the dark ages of Data Communication, before the world got smart
and started using Ethernet, we used to use a device for tracing particular
cables out of a bundle.

I think it was some for of inductive amplifier.  You would connect a tone
generator (supplied as part of the set) on the ends of the wire, and then
trace along walls, cable troughs, etc., listening for the tone with the 
receiver end (jokingly called the "banana" because of its yellow color and
shape).   You could detect the tone without touching the cable...as much
as 1/2 foot away. 

WARNING!   USE ONLY ON UNLOADED (READ DISCONNECTED FROM BREAKER PANEL)
WIRES!

Your local telecomm people will probably have one... maybe you could borrow
it.  They still live in the dark ages!  8^)

Bob

    If you have access to the attic or cellar above and below the wall,
    look for wires coming and going.  You can often get a feel for the
    location of wires by where they enter/exit the wall and by looking
    at what electrical services are provided on the wall(lights, swithes,
    outlets, etc.)
  

    re .3 - I have access to either attic or cellar, but not both, since
    the situations are on the first and second floors of my two-story
    home.  In fact the particular cases that most concern me both concern
    what my educated guess thinks/hopes might be horizontal runs involving
    outlets, switches and lights in a fairly small area of the room(s).
    
    The item described in .1 sounds like it's close to what I want,
    it's probably the same principal as .2 except using the 60-Hz field
    instead of coupling an induced tone into the cable.  Anybody able
    to give me a lead on the sort of gizmo described in .1?
    
    Thanks!

    Find someone who has a metal detector for locating coins and metal
    underground and ask them to find a buried wire for you. Nothing
    pleases these hobbyists more than a challenge like this; a good 
    operator will be able to do the job within minutes, distinguishing
    between wires, nails, and outlet boxes.
    
    Every respectable neighbourhood has at least one.
    
    Bernie

    Carol cable used to market a device used for locating wireing hidden
    in walls. It worked very much like a stud sensor except it picked
    up the 60hz and used it to create a signal(audible). Sorry I forget
    the name.
    
    -j

    You will probaby have more luck tracing the wiring from the attic than
    you think - when houses are wired, horizontal runs are usually rare -
    vertical runs are a lot easier and faster, so that is what they do in
    most cases.   Orienting yourself is the hardest part (ie, sitting in
    the attic saying "what the &*@ am I above?), but all that really takes
    is having someone on the floor below tapping on the ceiling, or
    listening to your tapping.
    
    I was doing exactly waht you are, and this worked out fine in my case.
    
    

If you have access to both the attic and the cellar, it should be
possible to figure out a lot of it even without metal detectors.
Here's a couple rules that I discovered in the two houses in which
I have traced wires -- I appreciate knowing if they are more general.

1)  First step, of course, is to find out which outlets are on which
breakers.  Then apply the following steps to each breaker individually.

2)  Look for outlets (on the same breaker) in similar positions on 
different floors.  It's a good bet that the wire runs vertically.

3)  Look for outlets (on the same breaker) around the walls in the
same room, or on opposite sides of the same wall.  If you can't
find the wire running between them in the basement or attic, it
probably runs inside the wall, at the level of the outlets.

4)  Outlets added after initial construction will be wired more
obscurely, but they're easier to find, since they almost certainly
go directly up into the attic (from the second floor) or directly
down into the basement (from the ground floor).  You may have to
dig in the insulation to find them all.

5)  Another simple trick is to take the covers off the outlets to
see whether the outlet is at the end of a run, or whether there
are wires both in and out -- or maybe 3 or more wires.  Note that
a wire out of a box could go to a light, instead of to another outlet.

6)  If you find a junction box (or outlet with multiple wires) 
and you can't figure out which branch heads for the breaker box, 
disconnect it and see which wires/outlets you've just disabled.
And be careful of those bare wires when you turn the breaker back on.

	Enjoy,
	Larry

    Besides the methods in .8 something I have had moderate succes with is
    using an amplifier and a telephone pickup coil. (available at rat-snack
    for about 15 bucks) plug a load into the outlet like a light bulb hold
    the coil to the wall and listen in the amplifier's speaker for the 60
    cycle hum. This works sometimes it has a lot to do with the composition
    of the wall and how close the wire runs to the surface.
    
       Good luck,
      Bill
    

    .7>  when houses are wired, horizontal runs are usually rare -
    .7>  vertical runs are a lot easier and faster, so that is what they do in
    .7>  most cases. 
    
    Depends on the age of the house.  Modern wiring is done .7's way.  Back
    when labor (even skilled labor) was cheap and wire was expensive, it was 
    more common to go to the trouble of drilling through lots of framing
    members to save a few feet of wire.  So the older the house, the more
    likely you are to find runs through walls, diagonal runs through
    joists, etc.
    
    To the excellent list in .8, I would add:  consider the framing
    complexity of windows, doors, bays, stairwells, etc.  Such things
    require substantial pieces of lumber (headers, sills, cripples, etc.),
    which limit the possible routes that wiring can take to get from one
    place to another.  It also helps to know the history of any additions
    and/or electrical upgrades to the house.
    
    This won't help you much now, but:  whenever you open up a wall, take
    photographs of its innards before you close it up again - and leave the
    photos behind when you sell the house.  They're invaluable for answering 
    questions about framing, plumbing, wiring, insulation...

    Sorry about the late reply but there is indeed such a gadget. I have
    just bought one for $15 made by Draper (do they distribute in the US?).
    
    It detects wires, pipes etc. I wanted to locate the wires for a servant
    bell system. These (the wires, not the servants) are buried in the
    walls, running through lead conduits.
    
    It also detects ac power, flowing or not.
    
    I'm very impressed with it, hope you can find one over there.
    
    Cheers
    
    Dick

    Is it just a metal detector? Will it also work as a stud finder?
    
    The stud finder I have is useless... maybe the Draper product would
    solve multiple 'finding' pproblems.

    Sorry, it's pretty versatile but locating studs is something it won't
    do. It's a metal/field detector.
    
    Right next to it in the shop was a stud detector made by Black and
    Decker. Is that the one you've got? - in which case I'll bear your
    negative recommendation in mind. I was tempted to buy it to avoid
    having to poke piano wire through the walls to locate studs.
    
    Dick
    
    

    	You should be able to get a good idea of where a run is by looking
    at where the wire enters the room from the cellar/attic AND turning
    off breakers and seeing what outlets/lights went off. This will
    also tell you how much is on the line already so you can decide
    if you want to use it or not.
    
    	Secondly, you should be able to remove the cover and the
    switch/outlet (and if your real lucky the box itself), which will give
    you an idea of where the wire is coming from/going to.

    	Ray
    
    BTW - If your adding/changing wiring in a bathroom keep in mind that you 
    need a ground fault breaker or outlet.

	You can buy electric wire finders.  They essentially amount to SCR 
	circuit to generate pulses and a amplitute modulator hooked upto a 
	speaker to detect the pulses.  You can easily do the samething with 
	a lightbulb, dimmer switch and cheap transistor radio.  Plug the 
	light in through the dimmer and pass the transistor radio in the 
	general vacinity of the wire.  As you get closer to the wire the 
	clicking becomes louder.  

	The transistor radio picks up the magnetic field created by the
	change in current in the wire.  The magnetic field is proportional to 
	the change in current, so the SCR is used to quickly pull the 
	current to zero.  Sometimes just the normal 60Hz AC is adequate to 
	generate a detectable pulse.

	I have some Radio Shack books at home that show how to build everything
	that is needed.  I'll draw the circuit in here when I get a chance.
	It probably is nothing more then aa triac and a few pots to adjust 
	sensitivity.

	Brian

    Does anybody out there know how I can loosen the screws that 
    hold the white/ground wires to the busbar in a circuit breaker
    box.  They all seem to be frozen in place.  
    What I am trying to do is add another circuit in my house, 
    (remodeling the ole kitchen) and most of the existing screws
    are stuck.  Also it seems like a good time to remove the old
    circuits from the panel.

    adTHANKSvance

    Dick -

Dick,

After turning off the main braker, try squirting some penetrating
oil into the screws. Most of the time, the screws are gulled in
position. Sometimes, an over zealous electrician may have
stripped or cross threaded the screws.

Cal

    
     Try a hand impact tool with the CORRECT size screwdriver blade. This
    has always worked for me. Sometimes a little heat applied will help
    to break the bond between the screw and the bonding bar.
    
    			Wayne

re: .1
    Thanks Cal.
    I'll try the oil.  (Probably in combination with Wayne's reply.)

re: .2
    Thanks Wayne.
    Will a small "tap" on the end of a screwdriver suffice in the absence 
    of a hand impact tool?
    How does one apply heat to a particular screw safely?    
    
Question:
    What is the white stuff around the bar?  My suspicions are similar to
    the white stuff around my car battery.  Is this safe?  At least as the
    house is concern?

Dick - :-)

    re: .3
    
    While a small tap on a screwdriver may help, and probably won't hurt,
    it's not the same as a hand impact tool.  A hand impact tool is design
    to convert the linear energy of the hammer blow into rotational energy. 
    You hold the tool tightly in the direction you want the screw to turn,
    and hit it with a hammer.  An internal wedge transmits the force of the
    blow into turning force on the tool's bit.  It sounds like a reasonable
    idea in this case, so long as you don't get carried away.  Remember,
    only some of the force is converted to rotational; the rest is the same
    as a solid hammer blow against the screw.
    
    Along the same lines:
    
    Is there an easy way to remove a plastic clamp from the service box?  I
    want to remove the cables that were left from our electric heaters when
    we converted to oil.  The wedge holding the cable in the clamp is
    positioned facing a neighboring clamp, so there's no room to simply
    pull out the wedge, and I'm not sure I could get it out, anyway.  The
    clamp is in the back row, making it difficult to get in there with
    pliers, to hold down the latches and pull the clamp out.  I'm perfectly
    willing to destroy the clamp and replace it with a metal one, but I'm
    not sure if there's an easy way to do that without electrocuting
    myself.
    
       Gary

RE: .3 (oxidization)

    Probably not a problem (read: dangerous) ... but to avoid that in the
    future, use some DeOx (elec conn lubricant) - the stuff is designed
    primarily for split-bolt wire unions, but works well on breakers
    and panel screws.

RE: .4 (to destroy or not to destroy)

    What kind of clamp, and what size wire?  Clip mounting or threaded with
    a nut?  If the former, I'd destroy it.  If the latter, the nut should
    be 'toothed' - you can use a screwdriver/hammer to get the thing to
    come out.  Either way, a good pair of diagonals can be used to cut the
    screws that secure the wire pinch - UNLESS the screws are on the inside
    of the box.  In that case, shoot the electrician. 8-)

    An aside - given the nature of the oil market (and assuming that the
    wire is in decent shape), you might be better off putting the loose end
    of the old wire in a box and cap it off.  You might want to use it
    again.

-b

    re: .5
    
    It's a plastic clamp that's clip mounted.  It looks as though you push
    it in from the outside, and it locks in place.  Similarly, once the
    cables are inside the clamp, it looks like you push a plastic wedge in
    from the side to hold the cable, and the wedge locks in place.  In
    other words, the whole thing seems to be designed to be
    permanent/non-reusable.
    
    I will dead-end the old heater wires in a separate box, just for
    posterity.  I just want to get the wires out of the service box, to
    make things neater for when we finish wiring the addition, and to avoid
    having to punch another knockout.
    
       Gary

      I'm  not  sure  I  like  the idea of spreading oil around inside a
      cirucit breaker box.  I suspect it could have a detrimental effect
      if  it  got on/in the breakers themselves.  I'd use WD-40 instead.
      Its safe for use on electical stuff.
      
      If you DO use oil, keep it to a minimum only where neded. (i.e. on
      the neutral or ground bus.)  Wipe it off when done.

     I use a BIG soldering iron to get the heat on the bar. Works for me!
    
    I am not big on the idea of oil in a breaker box. WD-40 or a electrial
    contact cleaner are better ideas!   If possible,highly recommened!,kill
    the juice to the panel before you start to work on the bus bar.
    
    
    			Wayne

    A neighbour of mine called last night with a problem which he thought
    I'd be able to help with, but it beats me... can someone help?
    
    He's installing a bathroom fan, and has tapped into a cable in the
    roof, and connected the fan across it as shown in the diagram below.
    The fan doesn't run and putting a meter across the terminals at
    the fan shows 80 volts. What's wrong?
    
    


                -------o-------- black
	               |   
                       |
                -------(-----o-- white
                       |     |
                       |     |
                       |     |
                  ------     -------
                  |                |
                  |                |
                  |                |  --
                switch            fan   80 v across here
                  |                |  --
                  |                |
                  |                |
                  ------------------


    All suggestions gratefully received, I'm a recent 'import' from
    the UK and I don't understand this 120v system very well.
    
    Thanks,
    
    Andy
    
    

                -------o-------- black    --
	               |                     Whats voltage here??
                       |                  --
                -------(-----o-- white
                       |     |
                       |     |
                       |     |
                  ------     -------
                  |                |
                  |                |
                  |                |  --
                switch            fan   80 v across here
                  |                |  --
                  |                |
                  |                |
                  ------------------


    See if you have 120 at the source; if so, then either the wiring is bad,
    (maybe a bad connection) or the switch or fan is bad.  Try removing them
    from the circuit one at at time (bypass them with a jumper) to see if
    the 120 comes back.  

    My guess is a bad connection or bad switch; the fan itself wouldn't cause 
    a voltage drop like that, the fuse would blow due to overcurrent.  Double
    check all conections.  You're using wirenuts for connections, aren't you? 

     Steve       

    
    The other 40v is across some other load.
    
    It appears that your neighbor tapped into a switch cable.  I've added
    to your drawing to illustrate what is going on.  As long as the switch
    is open, the fan will be in series with whatever load the switch is
    meant to control (probably a light fixture).  If you close that switch,
    the fan won't work at all, and there will be 0 volts across it.
    
    I suspect that this wouldn't work in the UK either. 8^)
    
    Bob
    
    P.S. Does your neighbor do his own plumbing too?
                                                           black
               ----------o-------- black---------- load ------
	       |         |                        
              swtch      |                                    source
               |         |                                 white
                ---------(-----o-- white ---------------------
                         |     |
                         |     |
                         |     |
                    ------     -------
                    |                |
                    |                |
                    |                |  --
                  switch            fan   80 v across here
                    |                |  --
                    |                |
                    |                |
                    ------------------
    

	I agree with .2, though load is probably "downstream" of
	"swtch", and downstream of the white tap:

               ----------o-------- black----------------------
	       |         |                        
              swtch      |                                    source
               |         |                                      
                ---------(-----o-- white ---------load--------
                         |     |               
                         |     |
                         |     |
                    ------     -------
                    |                |
                    |                |
                    |                |  --
                  switch            fan   80 v across here
                    |                |  --
                    |                |
                    |                |
                    ------------------
    

	Let's see, 40V is 1/2 of 80V, so the load is about 1/2 the
	resistance of the fan.  Very crudely, it's about double the 
	fan's wattage (or is it 4 times the fan's wattage?  Hmmm...).  
	So some device with twice (or four times) the fan's wattage is
	under suspicion.  (If the fan isn't turning at 80V, does it make
	sense to estimate resistance/impedance for a stopped motor, versus
	some unknown load?)

	Regards, Robert.

				WARNING

	You are assuming that the white lead is netural or unswitched.
Take the enhancment to the drawing below. This would be to code for mass.


               ----------o-------- black-----------+        +--white---
	       |         |                         +--load--+
              swtch      |                                      source
               |         |                                      
                ---------(-----o-- white --------------o-------black---
                         |     |                       ^
                         |     |                       wirenut
                         |     |
                    ------     -------
                    |                |
                    |                |
                    |                |  --
                  switch            fan   80 v across here
                    |                |  --
                    |                |
                    |                |
                    ------------------
    

	Your assumption of the load value is twice the wattage. To
find the switch that it is connected into..... you should place the meter
across the fan and turn on the fan switch. You should then try switching other
switches in the house and observe for voltage changes.

	Be carefull that you don't get zapped....

Bill

    Does anyone  have  a table showing resitance of wire (ohms/ft) for
    various  gauges?  Since  some of what I'm doing is low voltage and
    low  current, I'd appreciate numbers for wire from 10 to 20 gauge.
    At  this  point even a few values would help. Please state whether
    the resistance is for one or both legs of the circuit.  Thanks.

--David

    Assuming copper (!) wire, this is the resistance in Ohms per
    1000 feet.  If you have two legs then sum them (i.e., a 20
    foot run of 2-wire cable is 40 feet as far as voltage drop
    is concerned).
    
    #10: 0.9989		#12: 1.588	#14: 2.525
    #16: 4.016		#18: 6.385	#20: 10.15
    

    Thanks for the information. The bicycle light system I just bought
    uses 22ga. copper for a 5 ft. run carrying 1 amp. (at 6 volts). So
    about 2% of the power goes into the wires. I'm going to upgrade it
    probably to 16 ga.

--David

    re:.14:  Your bike lighting system uses 22 ga strand wire doesn't it?
    The numbers in .13 are for solid.  I think someone told me a long time
    ago that strand wire has the same resistance as the next higher guage
    of solid wire so the 22 ga strand is about the same as 20 ga solid.
    -- Until you get a bunch of strands broken :-).
    
    ed

    Yup, they  use speaker wire. It's stranded wire. Even if I use the
    resistance  for  20  ga., I'm still loosing over 1%, and batteries
    are a lot heavier than the wiring, so it's worth conserving power.

--David

    I reduce the voltage drop by shortening the distance from the battery
    to the light.  1 ft is good but it means putting a cage up front.
    
    ed

    
    I did a DIR/TITLE="wirenut" and didn't find anything, therefore
    this new NOTE.  If there is something somewhere else, please
    point me to it and/or move this note there.  Thanks!
    
    I have a question regarding wirenut sizes/capabilities.
    
    I need to be able to connect 2 #10 and 2 #14 solid copper conductors
    together inside a junction box.  All I have seen (and currently
    have a box of) are red "large" wirenuts.  The box says they are
    capable of 2 #10 and 1 #16 or #18 and 2 #10's alone are tough to
    "wrap"..
    
    Does anyone know if a larger one is made and, if so, where in the
    Central MA area I can get some (preferably 6 or so)?
    
    				Joe

>< Note 3617.0 by REGENT::MOZER "H.C.C. ;-)" >
>                              -< Sizing wirenuts >-

Go to an electrical supply outlet that carries "Ideal" wirenuts and
buy the grey colored.
Ross

another possibility since you already have reds; and greys are a car-ride
away....

use 2 wire nuts to connect them, putting 2 #10's on one, and 2 #14's on
the other, and connect them with another length of #14, leaving you with
2 #10's and 1 #14 on one, and 3 #14's on the other. The latter may be
a yellow connector (check box; i'm not sure). You could also use a #12
as the short length between the wirenuts.

    
    Thanks for the responses!!  Definitely gives me way(s) to do it!
    
    I will let you know which way I do it and how it works out!
    
    				Joe

>use 2 wire nuts to connect them, putting 2 #10's on one, and 2 #14's on
>the other, and connect them with another length of #14, leaving you with
>2 #10's and 1 #14 on one, and 3 #14's on the other. 

     This will work but will have a drastic effect on the number of 'wires' 
in the box.  You've added two more wire nuts and an extra piece of wire.

    
    Right now it's a 4" square box, but I've already decided that I
    NEED to get a 4" one with front and back open to double the depth
    of the box based on a single 4" square one got filled last night
    with 4 "red" wirenuts joining 2 pcs. of #10/3 with ground.
    
    				Joe

    There are wire nuts available which can easily handle several larger
    wires, and the space they occupy is about 1/2 bigger than the 
    larger standard wire nuts you are probably using.
    
    These larger ones come in two pieces, an inside brass hollow cylinder
    (sleeve-like) which can have an opening of about 1/4 inch into which
    you slip the wires to be joined (no twisting); they are held inside 
    this cylinder by a large flat set-screw in the side wall. The 
    set-screw is tightened and clamps the wires.
    
    This brass cylinder, with the wires clamped inside, has one end
    threaded over which you screw the plastic insulator completing the
    junction. It really does not look different than the standard twist-
    the-wire-and-screw-on-the-nut type. Any good electrical supplier should
    have them, but you probably won't find them at the local hardware.
    

RE:< Note 3617.2 by CIMNET::LUNGER "Dave Lunger, 291-7797, MET-1/K2" >

>use 2 wire nuts to connect them, putting 2 #10's on one, and 2 #14's on
>the other, and connect them with another length of #14, leaving you with
>2 #10's and 1 #14 on one, and 3 #14's on the other. The latter may be
>a yellow connector (check box; i'm not sure). You could also use a #12
>as the short length between the wirenuts.

	Huh, depends on what your doing, but I'm not sure this is code.
	I'd go with the larger wire nuts or insulated splices.  But if you
	do use this method be sure that you keep the 10's together in one
	wire nut because of ampacity.

							- Randy

Mr. Moderator,  I have looked thru the other notes listed under 1111.34/.35.36
and didn't find anything for surge/spike protection.  If I've overlooked a
better place for this note please feel free to redirect.

I have a new home therefore new electrical system.  When I arrived home
yesterday I found that we had experienced a 2 hr. power failure sometime
during the day.  The resulting damage consisted of tripping (2) GFI panel
circuits, a remote control ceiling fan, an electric garage door opener and
one of the PC boards in our new TV.  I will be calling Mass Electric to voice
my concerns and losses.  What I would like to do is protect my home from a
reoccurance of same.  I do not have any lightning protection nor surge/spike
protection in the house, I didn't think either would be necessary.  I know
hind-sight is 20-20  :-).....  Anyway, does anyone know what, where how I can
protect my; house from this sort of loss/disruption in the future..
We are located in Westford Ma with power supplied by Mass Electric. 200A 
service and it's all circuit breakers.  

Thanks in advance   Frank

    Sounds like you had more than a simple power outage, the results you
    describe are serious - I had the same symptoms when I had lightning
    hit my underground telephone cable.
    
    I would lodge a serious complaint with the local Power Co. that you
    experienced a major surge or transient which caused the described
    damage, and first ask them to identify what happened (something of
    this magnitude should have been known). Since you are in a new house
    assume it may happen again, you may be on a power network with major 
    industrial loading - which can cause this type of disruption; I could 
    be wrong but it is worth asking about.
    
    With regard to some form of protection, the standard hardware variety
    "surge eliminator" or "noise reducer" probably would not do the job;
    these are designed for reducing noise and such from appliances that
    otherwise would interfere with you TV. To do the job properly, your
    incoming power line should be monitored for disruptions and then the
    protective device sized accordingly. A good Power Co. could provide 
    some assistance/guidance regarding this.
    

You can buy a voltage surge protector from DEC through the Employee Purchase
Plan - I think it works out to under $100.  This is wired into your breaker
box and protects the whole house.  I know several people who have done this,
and the DEC unit provides a lot more protection than the individual outlet
types.

			Steve

Thanks Steve,
	Do you happen to know how I can contact one of them and ask some
	installation specifics?

Frank

Re: .3

You won't get any installation help from DEC!  I suggest asking in
ELECTRO_HOBBY.  Or send mail to Vernon Miller (OPAMP::VMILLER) - I 
know he's done this.

				Steve

    The same thing happen to me in Sterling, Home of Sterling Flicker and
    Flash, a tree limb fell on one of the main feeder lines during a 
    snow storm. Why was the limb that close to a feeder.... Anyway, 2
    T.V. sets, Stanley Garage door opener (The Sears was fine) VCR
    and 1 GFI bit the dust. Metropolitan covered the claim, I had to
    pay the deductable. They only pay to a certain point then they 
    have to review it, I think it was $700.00 worth of repair and I 
    came close. Check with your insurance co. I found out they would
    have paid to have the garage door opener and my large tv removed for
    the repair, no big deal. I didn't know my GFI was bad until it started
    tripping once a day then more frequently. If you suspect their bad, 
    have them replaced. I wasn't the only one who had damage and we got
    no satisfaction from the power company. I put surge protectors on 
    all the outlets that had equipment that was damage due to the surge.
    
    Good Luck,
    Ray

This might have been mentioned elsewhere, but I could not find it anywhere.

I replaced a dimmer switch on our house.  When I took the old one off, I 
noticed there were three wires coming out of the switch.  The new one did not 
have the three wires so I just hooked up the black and white wires to the ones 
coming out of the box.  I don't remember doing anything to the bare ground 
wire.  Should I have?  The box is plastic and the house is fairly new (8 yrs 
old).

Thanks for any and all replies.

scott

I'd guess that you had a three-way dimmer in the box and you replaced it with
a two way.  It sounds like your installation is a single switch installation,
so the third wire on the old dimmer can float, as long as it it taped so
it won't short to something.

    Does that mean, it is ok to leave the bare ground wire not attached to
    anything?  The bare ground wire I'm referring to is coming out of the
    box.  The old switch had  metal plate on it that dimmed the lights if
    you kept your finger on it after awhile.  The new switch has a dial on
    it that you turn to dim the lights.
    
    Should I tape the bare ground wire coming out of the box or just leave
    it hanging?
    
    scott

    The last dimmer I bought (a GE) mentioned in the instructions that if
    the old switch was grounded (with a bare wire to the green screw) that
    you should ground the frame of the dimmer by attaching the bare wire to
    the front (metal) frame.
    
    	-Barry-
    

    	The reason that there is a ground wire coming out of the dimmer
    is if it is installed in a nonmetallic box, all exposed metal parts
    of the dimmer must be grounded. To do this you should tie it to
    the branch circuit ground in the box. If you have a metal box and
    the dimmer is mounted on a metal plate, (most are) and the metal
    plate will be mounted to the box the disregard the ground wire coming
    out of the dimmer.

    
    				CB

    
    	Always connect the ground wire coming from the dimmer to, 1)
    the ground wire run with the other circuit conducters, 2) if the
    box is a metal box connect the groung wire to a ground screw that
    is then screwed into the metal box. As long as the metal box is
    properly grounded.
     
    	If you don't do the above you are depending on the mounting 
    screws for the ground connection, which is not allowed by NEC, also 
    if you were to remove the switch from the box with the power on for 
    trouble-shooting purposes, the switch would no longer be grounded 
    which would allow the metal parts of the switch to possibly become live....
    I think you can see what the results would be....
    
    
    
    	

   RE-1
    
    	There may be some confusion on this topic. Are we talking about
    Grounding type receptacles, or general purpose snap switches 
    (dimmers)?? 
    
    	First of all the NEC requires that metal enclosures for switches to be
    grounded. (380-12) However it does NOT require the YOKE (strap) of the
    switch to be bonded other than the mechanical connection to the
    grounded box (yes the mounting screws are an approved method, in fact
    you can use the mounting screws to ground a receptacle when there is
    direct metal contact to the yoke of the receptacle). Now remember, the
    ground of the receptacle is going to serve some type of portable or
    cord connected equipment, and therefore should have excellent
    integrity. However, the yoke of a switch is *really* only grounding the
    strap and at worst the metal face plate. Remember that the face plate
    is only held on by the 6-32 screws and you are depending on them to
    provide an adequate ground. The only way that the yoke of the switch
    could become energize is 1) faulty wiring, 2) a wire coming off of the
    device (see #1), or as you had stated 3) a QUALIFIED person working on
    it. Now if this *qualified* person should work on this device while
    energized, he/she is aware of the hazards involved (art #100), and if
    they are uncomfortable with this situation they should shut that
    circuit down. 
    	
    
   	 The intention of the green wire coming out of the dimmer, was to ground
    the yoke (strap) of the switch when mounted in a nonmetallic box. The
    same goes for the green screw on some snap switches. They are only
    required when the switch enclosure is not grounded (nonmetallic). 

    
    	If you are not satisfied with this information I ask you to print
    the article #'s that support your theory. Remember an inspector
    cannot reject your work unless he/she can point out the *violation*
    in the code.
    
    				   CB

    Hi,
    
    	RE.6
    
    		After a quick review of what I wrote in .5 I agree
    with what you have pointed out in .6. I was thinking non-metallic
    boxes but not writing what I was thinking. :')
    
    	Sorry for any confusion caused by my reply.
                                                  
    Paul L.

    No problem.
    
    	That's why we all use NOTES, for discussion.
    
    				CB

  I need to connect some new romex wiring to an existing 2 wire (knob and tube)
 circuit.  The romex, will be 14-2 with ground.  If the old wiring was easily
 accessible, I'd rip it all out and replace it.  But it goes between the
 1st and 2nd floors, and I don't want to rip the floor up to replace the wiring,
 which does not necessarily need replacing.

  I must connect these two types of wire in a junction box, of course.

  The question is:  What tyoe of junction box must be used?  The two wire system
 wires are enclosed in a (somewhat) flexible tube, presumably to protect against
 mechanical damage.  This needs to enter the junction box and meet code, and
 be connected to the romex.

  Is there special junction box for this application?

  Then what do I do with the ground wire on the romex?  Just ground the box?


   Thanks

   Steve

    If you have ever wired a log home, perhaps you can advise me.....

    	How do you wire the outside walls of a log home?  

    	Do you do the same pre-planning that a post and beam requires, and 
    avoid outside wall wiring where ever possible?  

    	Do you wire the outside walls by installing the boxes in the logs, and 
    lead the wires between the logs.  Do you route out the logs and provide
    a path for the wires?

    	If so, is there a danger of pinching a wire or driving a spike through 
    the wires?

    	Any information you can share or lead me to will be appreciated.

    Eric

    I wired a log home from top to bottom.
    
    1) First of all you AVOID wiring in the outside walls where possible. 
    You may have to get an electrical inspector to agree, for example, that
    an outlet on an interior wall 6" from an exterior wall is just as good
    as an outlet on an exterior wall 6" from the same interior wall.
    
    2) Yes, you have to preplan outside wall wiring and drill each course
    of logs as the walls go up.  A (serious) router with a (serious) bit is
    needed to make box openings unless you have years to do it with a
    drill/chisel or other such means.
    
    3) Outlets near the floor are relatively tolerable to deal with.  Ones
    higher up like light switches or kitchen counter outlets are the pits. 
    The wire has to pass through many courses of logs and it always seems
    to catch on something no matter how well the access hole is lined up
    and cleaned out.
    
    4) For places where appearance is not a consideration, think about
    using wiremold or some on-wall wiring system (if you think wiremold
    is attractive, think about using it on ALL outside walls :-).  I
    did this where the through-log wiring would have been ridiculous.  It's
    also the ONLY alternative for after-the-fact wiring on outside walls.
    
    I love my log home and most of building it was great fun; however, I
    would have to say that wiring the outside walls was NOT fun.

      For outlets around the exterior perimeter I offer two suggestions:
      
      1) Put the outlets in the floor -- run the wires between the floor
      and the ceiling of the floor below.
      
      2) Use an extra large/thick "baseboard" to create a wiring raceway
      around the perimeter.
      
      For  switches  and  lamps mounted in/on the perimeter wall you can
      often build a vertical wiring raceway that ends up  looking  much
      like  a  post.   Alternately,  put  the  lamps  and switches in/on
      interior partition walls near where they intersect  the  perimeter
      walls. 
      
      *THE*  key  to  wiring  in  a  log home or a post and beam home is
      advance planning.  In a conventionally framed  home  (i.e.  "2-by"
      construction)  you  don't  need  to  think about wiring until the
      house is fully framed.  Wire can be run through the wall  cavities
      before installing insulation and sheetrock. But in a log home or a
      post and beam home the wiring has to be planned in advance so that
      wire can be run during construction.
      
      If  you're  not doing the work yourself -- maybe even if you are --
      you might want to look at different electricians till you find one
      who  has  wired  this type of building.  Better to profit from his
      experience that to pay for the learning experience of someone  who
      has never done this type of job.
      
      Also  --  Is it a "kit home"?  If so the kit supplier probably has
      information including mistakes to watch out for.

    You might also want to post this in SUSHI::LOG_HOMES.  That conference
    caters to all aspects of Log Home building and maintenance.  
    
    Hit keypad 7 to add SUSHI::LOG_HOMES to your notebook.

    	I have wired a log home before. If you have proper planning,
    it really isn't all that bad. Make sure that you bore your holes
    using an auger bit (the home I was involved with the homeowner used
    a flat bit and the chips fell into the next lower course). Also
    clean your holes after *every* drilling. With proper planning you
    can place your receptacles and switches where you want them. I feel
    that in the long run you will appreciate the added convenience of
    having your receptacles and switches where they *should* be and not
    where they were easy to install.

    
    				Cary

    Re: all

    Thanks for the good replies - I'm in the planning stage right now, and
    will do my own construction when I've finally decided upon what I want. 
    I have plans for a house that I like, but haven't decided on stick, log,
    or post & beam, so I'm weighing all the alternatives.  I'm leaning to log
    or post & beam.
    	
    Pre-planning sounds like a must - so I'll give that part more
    consideration.  I like the idea of wide baseboards, wiring in floors 
    or upright support logs(posts).  The prospect of boring long holes to 
    get fixtures/outlets where I want them seems like a reasonable place 
    to put some extra energy.

    I'll search the LOG HOME conference too, and cross post the request if
    the subject has not been covered yet.  

    I appreciate all the ideas,
    Eric 

    Comment: aren't in-the-floor outlets against code now?  Even if
    they aren't, I'd avoid them.  They fill up with crud, and there's
    no way to get it out if a vacuum cleaner doesn't work.

    Does anyone know of any "hi-tech" switch/dimmer suppliers.  I've seen
    the Stanley remote control set ups, but I'm looking for something that
    is more flexible than that.
    
    I would like to have multi point dimmer control (>2 points) for some
    lighting.  Also, it would be nice to have a lot of switches at a given
    point without them taking up too much room.
    
    I've checked a couple of lighting stores, and they seem to go for
    lo-tech traditional switches.  Should I be investigating electrical
    supply stores?  Or U Do It Electronics?  Or what?
    
    
    							-JP

Try the ATSE::X-10 conference for info on the BSR X-10 system.  The Stanley
Lightmaker system is just a tiny subset of X-10 (but isn't compatible with
other X-10 devices).  There's a lot more out there.

If you have a recent DAK catalog, look at the descriptions of the X-10
devices there.

			Steve

    	An in-between (between traditional switches and the X-10 systems)
    is low-voltage (24V) switching of relays. I just ordered half a grand's
    worth yesterday. You come off your panel right into a relay cabinet.
    Each relay can be connected to any number of switches. Relays are
    available with pilot light contacts for remote switches with pilot
    lights. Two switches can be put into a standard outlet box (that would
    normally hold one switch, or a duplex outlet). There are high narrow
    switch plates that hold up to three switches and you can put 3 or 4
    switches in a double-width box.	
    some rough prices: relays $20 to $28 each 
                       switches 5 to 10 each
    		       cabinet with transformer, rectifier, relay mounts
    			about $150
    These are available from GE.  Source in E. Mass is G.E. Supply in
    Woburn. 
    	Obviously, you don't want to use these when you don't need multiple
    switches separated by long distances (3-way stuff works fine, thank
    you).  But, if you have some situations with 3 or more switching
    locations, some over 100' from the device, I think this is the way to
    go.  - Chris

      RADIO SHACK sells X-10 type controls.  They frequently have sales.

I've used regular boxes for this application.  The "somewhat flexible" sleeve 
fits nicely in both types of Romex clamps (integral and external).

Re ground:  if you're replacing knob and tube starting from the service panel,
and re-attaching an old knob and tube run to the new run of Romex, then you're 
fine just to ground the junction box - the knob and tube won't be grounded, but
it's no worse off than it was before.  

But if you're tapping a new Romex run off of an existing knob and tube run,
then your new Romex run won't have a ground.  Your options in this case, it
seems to me, are:

1. Use ungrounded Romex, ungrounded outlets, etc.  The Code makes an exception
   to its usual grounding requirements in cases like this, but the materials may
   be hard to come by.

2. String a ground wire from your service panel to your junction box.  
   Logically, you're converting the knob and tube run into a grounded circuit.

3. String a ground wire from a conveniently-located grounded circuit.  Not as 
   good as the other options because of potential ground loops and crosstalk, 
   but better than nothing.  (Electrical junkies please confirm this opinion!)

>2. String a ground wire from your service panel to your junction box.  
>   Logically, you're converting the knob and tube run into a grounded circuit.
>
>3. String a ground wire from a conveniently-located grounded circuit.  Not as 
>   good as the other options because of potential ground loops and crosstalk, 
>   but better than nothing.  (Electrical junkies please confirm this opinion!)

      My  reading  leads  me  to  believe  that  there are problems with
      running a seperate ground wire.  I have been told that a  seperate
      ground  wire  will NOT be accepted in new work; it must be part of
      the cable the contains the neutral and hot wires. I think that the
      problem  is  that  there  is  no  other  way  to  be sure -- well,
      reasonably sure -- that you will have a good ground  and  that  it
      will  stay  good.  Of course, a grounded type outlet iln which the
      ground prong is NOT properly grounded is  a  disaster  waiting  to
      happen. 
      
      My advice?  Run an entierly new, properly grounded circuit.  don't
      attempt to add a ground to an existing circuit.
      
      Another  good  piece  of  advice  is  to  check  with  a  licensed
      electrician or with a building inspector.

    	Take this as COLORADO code and might be different back your way:

    	A separate ground wire MAY be run to EACH circuit IF it returns to
    the grounding stud in the breaker panel.  This separate ground must run
    NEAR TO or with the existing wire for safety purposes.  If the wire is
    inside a conduit, a separate ground wire MUST also be enclosed WITHIN
    the conduit.  The conduit itself is NOT adequate for grounding
    purposes.  

    	As a sidelight to the above statement of facts, you MAY run as many
    ground leads as you wish as long as you have ONE continuous grounding
    wire attaching to the ground lug of the breaker panel.  For VERY HIGH
    FREQUENCY equipment, it is ADVANTAGEOUS to run a GROUNDED GRID for the
    equipment and keep the ground impedance LOW.  So, in this type of stated
    case, you will have one ground wire (LONG) inside the conduit or in the
    vicinity of the original wire in ADDITION to an entire grid of wide,
    flat, LARGE bars or etc. to drain the high frequency signals.  The
    single wire meets the code of providing a grounding path for safety, and
    the grid grounds the radio frequency.

    A basic question -

    I have an electric clothes dryer that is marked 3 wire, 120/240 60
    cycle.

    And an outlet that is marked 125/250.

    Are these compatible? The dryer plug is slightly different than the
    outlet; like this -

    outlet		dryer

    \   /		\   /

      |                   |
                         -+ (like a backwards L)


    I'm hoping that a new cord on the dryer will save me a call to an
    electrician, but don't want to change anything that would be
    dangerous.
    
    Thanks for your advice and experience.
    
    Mike

    One configuration is for a Dryer and the other is for an electric
    range/stove.  You can change the pigtail (the cord on the appl.) or you
    can change the outlet.  Check the rating of the fuse before using the
    applicance on that outlet.  You probably only need a 30 amp fuse for a
    dryer and a 50 amp for a range.  Check the documentation with your
    dryer.  Don't change the fuse from 30 to 50 unless the wire is rated
    for that load.  It is ok to go from 50 to 30.
    
    Either someone switched the pigtail on your appl. or the outlet was
    used for a different appl.
    

    
    	Amperage rating is the key to your question.
          
    	All appliances have an amperage rating and need to be fed by
    a circuit that is suitable for that appliance. You need to determine
    what the amperage draw for you dryer is an then determine which
    receptacle applies in your situation. That information can be found
    on the nameplate attached to the appliance where you found the voltage
    rating.
    	
        The appliance cord with the backwards L at the bottom may be
    the correct configuration for the dryer, if it was designed to be run 
    on a 30 amp 120/240 circuit. The receptacle with this configuration is 
    known as a NEMA 10-30R and is rated at 30 amps at 120/240 volts.
    
    	The other receptacle you have drawn is known as a NEMA 10-20R
    or a NEMA 10-50R depending which side the larger blade socket is
    located on. They are rated at 20 amps and 50 amps in that order.
    at 120/250 volts.
     
        In either case, the receptacle that is currently installed is
    probably not the correct one for the purpose. I would consider 
    having someone look at it if you are not comfortable with trying to 
    determine if the wire size is adequate, and if it is fused correctly 
    for the wire and dryer ampacities. 
      
    	None of the above would be correct if this dryer outlet were
    being fed from a sub-panel in either a multitenant building or
    a mobile home. These types of installations would require a 4 wire
    receptacle that has a seperate ground wire and associated blade
    socket. You would then have to have a 4 wire appliance cord to match
    this. The type of receptacle that would satisfy this requirement
    would be a NEMA 14-30R.
             
    	I hope this helps you out,
    
    	PL
    	   
    
       		

    
    thanks to both of you for your detailed replies. I've called an
    electrician friend and he'll be coming over to look at things. 
    
    thanks, and i'm happy i didn't just swap cords.

    My wife and I will start building our NorthEastern Log Homes kit later
    this summer.  Wiring is a big concern I have.  The NELH homes I have
    seen use door jams for channels for some of the light switch and
    exterior wiring.
    
    I though of "in-floor" outlets, too.  Commonly used in computer rooms,
    etc.  I don't think there are restrictions against them.  Cleaning can
    be a problem if they are in a traffic area...but, removal and
    maintenance is easy.  Problelm with them is carpeting.  They are a pain
    in the A#* if you have to put carpet around them.  
    
    Our kit dealer suggested cutting the box hole into the second tier of
    logs (that'd put the bottom of the outlet about 12 inches above floor). 
    That way you only drill two logs for each outlet.  
    
    tony

My old roomie did a lot of research before buying her log home.  The one she 
bought uses a wood stove for heat, with an electric backup.  All of her outlets
are built into the electric baseboards.  If you are not going to have electric
heat, you could set up some wooden baseboard enclosures, and run all your wiring
thru them.  For wall wiring, it depends a lot on the finish for your walls. 
Rounded, chinked logs would be difficult.  However, her home uses a lot of 
surface type wiring, except instead of metal channels, they are wooden, to match
the walls and ceilings.  Looks nice, and is barely noticeable.

    You might also want to check out Tedd Benson's book "The Timber-Frame
    Home" and the June/July 1988 (number 47) issue of Fine homebuilding.
    
    These two primarily deal with wiring and plumbing in timber-frame homes
    and stress skin panels, but there are probably some ideas you could
    use.
    
    Another thought would be to check with Jim Swist (a fellow HOME_WORK
    noter).  He fairly recently finished a log home he was building.  He
    could probably give you some good hints and gotchas.
    
    - Mark

    	I need to move an outlet.  The most convenient place to move
    it to (for use - not wiring) is in the wall that contains the chimney.
    the chimney is only used for the gas water heater and furnace and
    I'm talking about an outlet on the second floor.  Now, intuition
    tells me that there's no way that this is allowed in "THE CODE"
    but I figured I'd ask.
    
    Can I do it?
    
    Thanks,
    
    George

I am having the same problem.  My house is 24 years old and most of the
wiring has some sort of fabric outer insulation.  I haven't yet looked to
see if it has a temperature rating printed on it.

I called an electrical distributor and asked about a sort of heat shield as
was described in .5.  I was told that these did not exist in the US, and that
my only choice was to rewire the box with newer wire.  Sigh.  I can't find
anything in the NEC either that would allow a heat shield.

Actually, there was one alternative - use lower wattage bulbs.  The fixtures
I have use two 40W bulbs.  In some cases, two 25s would be ok, but elsewhere
no.  Augh....

				Steve

    Here's my story: I just moved into an apartment.  I made the mistake
    of looking behind/under the stove, saw how filthy the floor was and 
    decided to wash it.  

    The outlet for the stove is mounted on the floor along the wall.  
    Instead of using the mop for this area, I got down on my hands and 
    knees and used a sponge and was very careful not to slosh water at 
    the outlet.  However, the tile that the outlet "sits" on was loose 
    -- or it loosened when the water hit it/seeped under.  After the 
    floor was dry, I plugged in the stove.  After a little while (a 
    minute? a half minute?) I heard zzzzt!  After a lot of unproductive 
    running around, I unplugged the plug and when I did that, there was 
    more zzzzzt-ing and a small whisp of smoke.  (I was sure the house 
    was going to go...)

    This happened Friday and the stove's still unplugged, though I did
    turn the main breaker back on (couldn't find a separate breaker for 
    the stove).  Is it OK to plug the stove back in, or could there be
    a problem here?  I can't say for certain that NO water got into the 
    prong-slots, but I doubt it.  This house is OLD, it's had 4 owners
    in the last 9 years, and I've not yet been impressed that the 
    current owner is the conscientous sort.  

    Thanks,

    Christine

If it were me, I'd unscrew the outlet cover (with the power to it turned
off, of course) and look inside.  If I saw any blackened insulation, I
would close the cover again and call the owner to let him know (as nicely
but firmly as possible) that he's got to get an electrician out on an
emergency basis because the stove isn't safe to operate.  If he gives
trouble about that, I would *immediately* call the town hall and ask who
I could talk to about a landlord who doesn't provide an operable stove
or safe wiring.  

After what you described, If I opened the box and didn't see any blackened 
insulation, I'd be very surprized!  I'm also surprized that it took that
long for the arcing to start.  Could the cord to the stove, or something
inside the stove, possibly have been wet?

	Luck,
	Larry

    An apartment?  I would suggest leaving it alone, call the landlord and
    tell him/her to come down right away.  Most likey they do not want the
    place to burn down.  Even if they are the "slum loards" type, all you
    have to do is threaten him with the health department or city housing
    authority (if such exists).  If in MA, I don't think you can rent an
    apartment without a working stove.

I was in the General Doroit Auditorium in the mill yesterday,
and noticed the the outlets installed at desk level in the arena
for members of the audience were colored orange.  Each outlet also had
a small inverted green triangle symbol.

What did this indicate?  GFCI or spike protection?

A related question:

How are hospitals wired?  I was on a hospital tour recently, and noticed that
many of the outlets were colored or had tiny symbols attatched.
I suspect that for certain applications in a hospital, it doesn't
matter if a circuit is starting to overload, you want that lif-support
system to keep running.  How do they deal with this?

Thanks,
-Dave
(Want to make sure that intensive care addition to my house is wired correctly
:-)

I would guess that in a hospital, only certain outlets are hooked up to
emergency power.  When the generator kicks in, you don't really need the
TVs to work.

The green dot or triangle indicates a special grounding requirement.  I'd 
have to look at the NEC to see what it is.  You should too.

			Steve

     The green sticker means the outlet has a "safty" ground. The normal
    ground in your house socket attaches to the ground prong of the outlet
    and the metal box (if you have a metal box) the outlet resides in.The
    Hospital has two seperate ground wires.One for the ground prong of the
    outlet and the other attaches to the metal box and frame of the outlet 
    It is a added safty feature. Hospital's have their own special spec on
    wiring and its own grade of electrical parts.
    
    
    		Wayne

    
    re: .39-.41
    
    Thanks for all the replies!  I haven't lived in an (old) apartment for 
    10 years and am relearning how to react in this sort of "emergency".
    
    The outlet (and wiring to it) will be replaced tomorrow.
    
    CQ

    
    	Hi,
    
    		What you have seen there is an "ISOLATED GROUND"
    receptacle. Designated by the green triangle on the face of the
    device. It is used to supply an isolated ground to a computer load
    to minimize the possibility of the introduction of noise etc into
    the computer. 
    
    	The Hospital grade wiring devices will have a green circle on
    the face and serve a completely different purpose than the "IG"
    types for computer loads.
                  
    	Did this help any?
    
    	PL
    

The new computer wiring of the Mill is "clean" power.  The computer recepticles
are fed off a separate breaker panel that has a separate feed from the other
loads.  Lights and normal outlets have their own breaker panel separate from
the computer loads. 

I don't know if the "isolated ground" is simply from being separate feeds back
to the feed that supplies the breaker panels (and maybe further, I don't know)
or if they're grounded in some special way.

-Mike

    RE: a few
    
    The following is from the 1987 NEC book.
    
    Article 517 covers health care facilities which includes in-home care.
    
    517-11. Grounding of Recepticles and Fixed Electrical Equipment.
    	In areas used for patient care, the grounding terminals of all
    recepticles and all noncurrent-carrying conductive surfaces of fixed
    electrical equipment likely to become energized that are subject to
    personal contact, operating at over 100 volts, shall be grounded by an
    insulated copper conductor.  The grounding conductor shall be sized
    according to Table 250-95 and installed in metal reaceways with the
    branch-circuit conductors supplying these recepticles or fixed
    equipment.
    
    	Exception No. 1:  Metal recaeways are not required where Type MC
    cable, Type MI cable, or Type AC cable with an insulated grounding
    conductor is used.
    
    	Exception No. 2:  Metal faceplates shall be permitted to be
    grounded by means of a metal mounting screw(s) securing the faceplate
    to a grounded outlet box or grounded wiring device.
    
    	Exception No. 3:  An equipment grounding conductor enclosed in the
    sheath of a nonmetallic-sheathed cable assembly installed in accordance
    with the limitations of Sections 336-2, 336-3, and 336-4 sdhall be
    permitted to be used in accordance with Parts C and D of this article.
    
    517-13. Recepticles with Insulated Grounding Terminals.
    	Recepticles with insulated grounding terminals as permitted in
    Section 250-74, Exception No. 4, shall be identified; such
    identification shall be visible after installation.
    
    	(FPN): Care is important in specifying such a system with
    recepticle insulated grounds since the grounding impedance is
    controlled only be the grounding wires and does not benefit
    functionally from any parallel grounding paths.
    
    ================================================
    
    250-74. Connecting Recepticle Grounding Terminal to Box.
    	An equipment bonding jumper shall be used to connect the grounding
    terminal of a grounding-type recepticle to a grounded box.
    
    	Exception No. 4: Where required for the reduction of electrical
    noise (electromagnetic interference) on the grounding circuit, a
    receptical in which the grounding terminal is purposely insulated from
    the recepticle mounting means shall be permitted.  The recepticle
    grounding terminal shall be grounded by an insulated equipment
    grounding conductor run with the circuit conductors.  This grounding
    conductor shall be permitted to pass through one or more panelboards
    without connection to the panelboard grounding terminal as permitted in
    Section 384-27, Exception No. 1, so as to terminate directly at an
    equipment grounding conductor terminal of the applicable derived system
    or service.
    
    (FPN): Use of an isolated equipment grounding conductor does not
    relieve the requirement for grounding the raceway system and outlet
    box.

    If you are building a new home, is it worth starting out with copper
    wire everywhere (including the feed from the road)?  I know aluminum is
    cheaper for the main feed and any runs to subpanels (and I'm
    considering several subpanels), but how much more can copper cost when
    you are starting from scratch?
    
    Willie

By the time you spend the extra time and money buying recipticles and switches
rated for Cu/Al the copper would be cheaper. Al is best used for the service
drop and copper for the rest. I worked in a electrical supply warehouse before
joining DEC and the smallest aluminum wire we carried was 2/0 a tad overrated
for a 20A outlet.

-j

    I don't think you can use AL for anything under 30A runs (dryer).  Back
    in the late 60's/ early 70's (I think that was the time frame) there
    was AL Romex available in 12/14 guage.  I never installed it but had to
    play with it in a few junction boxes.  You had to be very careful not
    to nick the wire because a few twists after the nick and it would break
    off.  Never mind the fact that it could not handle the load, it was
    just a bitch to work with.
    
    bjm

    OK, is it worth paying extra for copper from the street as well, or can
    you 'assume' (and we know what happens when you assume boys and girls,
    you burn your house down) that an aluminum drop is OK and is properly
    done?  The only alumimum feeds I've seen have had some of the strands
    cut off to allow them to fit into their clamps... :+{
    
    Willie

    re: .-1
    
    For the extra cost (probably > 2X), I would say that copper for the
    feed is not worth it.  As long as there is NO-Ox on the junctions at
    the meter socket and panel, you shouldn't have a problem.
    
    Dan

    
    Is aluminum still legal in MASS?  I thought due to all the problems
    in the 60's it wasn't.
    
    However I do know that it costs a lot more to have Aluminum wiring
    in a house vs copper, something to do with resistance.
    
    Cal.
    

>>    Is aluminum still legal in MASS?  I thought due to all the problems
>>    in the 60's it wasn't.

	Yes it is, but only for large item like ranges, service entrances
and maybe dryers.

>>    However I do know that it costs a lot more to have Aluminum wiring
>>    in a house vs copper, something to do with resistance.

	Al cost more?  I don't think so, not with the price of copper. 
Given a one-to-one price per foot for same gauge wire, AL would cost more
because you are required to oversize the AL wire for the breaker it is on. 
Ie if you could get away with #12 copper, you would have to use #10 AL. 

>>    However I do know that it costs a lot more to have Aluminum wiring
>>    in a house vs copper, something to do with resistance.

I presume that you mean Al has a higher resistance than copper (true),
and hence you get more voltage drop with aluminum than with copper, 
thus losing electrical energy to heating up your wires.

Well, I don't think so.  I believe that the codes required larger
conductors for Al house wiring than for copper house wiring, thus
equalizing the resistance per length.  That's certainly the case for
service conductors.  You can get a copper service conductor if you want
to, but copper costs maybe 3 times as much at the same allowed amperage.

Of course, if connections between the aluminum house wiring and the
receptacles loosen, that raises the resistance and wastes energy.
Eventually, that can cause a fire, which will definately cost more!

	Enjoy,
	Larry