White conductor

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calvin1010

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Can you use a white colored wire as a switch leg to a light fixture? seems to me there would end up being two white wires .can't find it in the code book.I know it's in there
 
Rule of thumb -

Down on white, Back on black.

Poet, and don't know it :D
 
CharlieB,

Lots of simple nursery rythme stuff out there to help get through the day, and keep it right. Getting to old to have a photographic memory :)

That's okay, I see everyone else is all over it, with the correct approach.

In addition, going down on the white eliminates having two whites being in the box and no clue to which is a traveler, and which is a neutral.. It matters on top of a ladder, it's late, and brain power is fading fast.
 
White should only be used for the netural or grounded conductor. The only time the white can be used for current carrying/switch leg is when it is part of a listed cable assembly. Then if it is current carrying it is permitted to re-identifed. 2008 NEC 200.7 C 2
 
Reading the 2008 NEC, I don't agree with the idea that 200.7(C)(2) is a restriction on 200.7(C)(1). My take is that 200.7(C)(2) is an obsolete paragraph, since the permission it currently gives is a subset of the broader permission in 200.7(C)(1). I believe the history of the two paragraphs bears that out: if I recall correctly, at one point 200.7(C)(2) allowed a use without reidentifying, while 200.7(C)(1) always required reidentifying.

Of course, my reading of 200.7(C) is based on the idea that the list (1)-(3) is a set of alternatives, i.e. a logical OR. You could read the list as a set of requirements, all of which must be satisfied, i.e. a logical AND. But my understanding is that for this situation, the NEC will use terminology like "all of the following". That language is not present in 200.7(C).

Cheers, Wayne
 
wwhitney said:
Reading the 2008 NEC, I don't agree with the idea that 200.7(C)(2) is a restriction on 200.7(C)(1). My take is that 200.7(C)(2) is an obsolete paragraph, since the permission it currently gives is a subset of the broader permission in 200.7(C)(1). I believe the history of the two paragraphs bears that out: if I recall correctly, at one point 200.7(C)(2) allowed a use without reidentifying, while 200.7(C)(1) always required reidentifying.

Of course, my reading of 200.7(C) is based on the idea that the list (1)-(3) is a set of alternatives, i.e. a logical OR. You could read the list as a set of requirements, all of which must be satisfied, i.e. a logical AND. But my understanding is that for this situation, the NEC will use terminology like "all of the following". That language is not present in 200.7(C).

Cheers, Wayne
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imo ,its not a set of alternitives C1 is for constantly energized load situations, like a water heater. C2 is for travelers and switch legs, where some ccc are not constantly energized. C3 pertains to other methods used in appliance cords. apples, oranges,and bananas.
 
Wayne,

I looked at your profile. You truly show the difference between "Electrician think", and "GC think". I wish you the best in being a GC, but take it to heart, the sparky side is right on this one. I agree 100% with jumper. Not because he is an electrician, but because of code, and field experience.

I leave you with Charlie's rule-

Charlie?s Rule of Technical Reading

It doesn?t say what you think it says, nor what you remember it to have said, nor what you were told that it says, and certainly not what you want it to say, and if by chance you are its author, it doesn?t say what you intended it to say. Then what does it say? It says what it says. So if you want to know what it says, stop trying to remember what it says, and don?t ask anyone else. Go back and read it, and pay attention as though you were reading it for the first time.

Copyright ? 2005, Charles E. Beck, P.E., Seattle, WA
Click to expand...
 
Well, I took another look at what is written and still disagree. In the 2008 NEC, 200.7(C) reads:

"The use of insulation that is white or gray or that has three continuous white stripes for other than a grounded conductor for circuits of 50 volts or more shall be permitted only as in (1) through (3)."

I read this as 3 separate permissions: "you can only do this if you meet (1), (2) or (3)." If the permission granted by 200.7(C)(1) was meant to be limited to those cases that don't fall under 200.7(C)(2), then 200.7(C)(1) should say so explicitly. Or 200.7(C) should read "where all of the following conditions are met". That would be my take on how Charlie's Rule applies to this text.

Cheers, Wayne

P.S. I brought up the history of the section to try to understand how this illogical text came about. I verified that in the 1996 NEC, use of white as an ungrounded conductor as the supply in switch legs was allowed without reidentification.
 
Ok, what if it isn't a 3 or 4-way switch (I didn't see anything claiming it was)? For example, take an existing fixture-switched lamp and run nm-2 to a switch box in order to remotely switch it? That would fall under 200.7(C)(1)? Then you could use the white conductor for either direction? Why would that be any different than a 3 or 4-way switch? Or is that completely disallowed? (I've wondered a little about that since it would almost seem that one couldn't run such conductors through a metallic conduit due not having the circuit neutral, which would seem to be required by 300.20(A)? Though I'd argue the return leg acts as to prevent induction heating in that case...).
 
SAC said:
Ok, what if it isn't a 3 or 4-way switch (I didn't see anything claiming it was)?
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200.7(C)(2) starts off "Where a cable assembly contains an insulated conductor for single-pole, 3-way or 4-way switch loops . . ." Single-pole here means 2-way, so this covers all switch loops.

Cheers, Wayne
 
wwhitney said:
200.7(C)(2) starts off "Where a cable assembly contains an insulated conductor for single-pole, 3-way or 4-way switch loops . . ." Single-pole here means 2-way, so this covers all switch loops.
Click to expand...

Duh! I read it as "single-pole 3-way" or "single-pole 4-way" - as if there were such a thing as a "double-pole 3-way" or "double-pole 4-way"! Yeah, I know better! :roll: Kind of like "A big, red or green apple" may seem to mean a "big red apple", or a "big green apple"...

Thanks for setting me straight!
 
The neutral wire is ALWAYS white, but the white wire is NOT always the neutral!!!!:smile:

Feed the switch with the white wire, put some tape on it, return to the load with the black wire.
 
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