200.7 Using white wire as ungrounded conductor

[mikepett]

I'm currently debating whether or not the white wire, as part of a cable assembly (more specifically 12/2 NM) can be used to switch a light fixture where power is brought into the fixture junction box and fed down the 12/2 cable to the switch and back up to the fixture on the white. I understand the the white must be reidentified with black. The debate is over whether or not the white insulated conductor can be used for the switch leg period. Can anyone clear this up?

Regards,
Mike

 

[Richardrlr]

white conducter

white conducter

Yes it could be used you might want to phase the wire.

 

[raider1]

Welcome to the forum.

Take a look at 200.7(C)(2).

Chris

 

[rcarroll]

200.7(C)(2) the white conductor has to supply power to the switch. Not as the return conductor. Also, it can be re-identified with any color other than white, gray, or green.

BTW, welcome to the forum

 

[mikepett]

It seems I am getting different interpretations here as well. I guess the debate is over what 200.7(C)(2) actually means. Some are saying it means it can only be used as the supply to the switch. Others are saying this is strictly talking about whether the wire must be reindentified or not, and it is not saying that it can't be used period. In other words, it used to be that if the wire was only used as supply and not return it didn't have to be reidentified but now it does regardless and this is what this is addressing; it has to be reidentified if it's used as supply only. Further thoughts?

We may need Mike Holt himself to answer this one!

 

[iwire]

We may need Mike Holt himself to answer this one!

I think all we have to do is read the NEC section.

You may use the white wire in a cable as the supply (not the return) to a switch if you do so you must re-identify it as any color but green or white or gray.


You can not do this with a white wire in a raceway.

 

[roger]

We may need Mike Holt himself to answer this one!

Why?

As Bob points out, the section is clear that it can only be used to supply the switch.

(2) Where a cable assembly contains an insulated conductor for single-pole, 3-way or 4-way switch loops and the conductor with white or gray insulation or a marking of three continuous white stripes is used for the supply to the switch but not as a return conductor from the switch to the switched outlet.

BTW, Mike very seldom posts.

Roger

 

[mikepett]

But is this saying the wire "can only be used as supply". I don't see that. It's saying "Where" it is used as supply and not the return, it must be reidentified. That's were we are in disagreement. You are "assuming" that because it's saying the wire must be reidentified if used as supply and not the return that it can only be used as the supply. That's not clear to me.

 

[roger]

You need to read 200.7(C) first.

(C) Circuits of 50 Volts or More. 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).

Now you read (1),(2),or (3). and the "Where used" is just an extension of the 200.7(C) rule itself.

There is no assumption here.

Roger

 

[mikepett]

If you read 200.7(C) first and then read (1) (2) and (3)... Occording to (1) you can use a white wire just about anywhere (as part of a cable assembly) as an ungrounded conductor. (2) goes on to say that where you use it as supply to a switch and not return it also has to be identified. (Because previous versions of the code to my understanding said that it didn't have to be reidentified if it were used as supply and not return). I understand your points, but to me, that still doesn't say I can't use it as a supply. It looks like I'm going to have to admit I'm interpreting the code wrong here, but I feel uneasy about excepting this more so than I've felt about excepting anything else in my 10 year electrical career.

 

[roger]

BTW, welcome to the forum.

Roger

 

[rcarroll]

It looks like I'm going to have to admit I'm interpreting the code wrong here, but I feel uneasy about excepting this more so than I've felt about excepting anything else in my 10 year electrical career.

I've been associated w/ the trade for over 30 years. Stay with this forum. It might change the way you thought about a lot of codes, trust me.

Ron

 

[mikepett]

Thanks for the warm welcome guys! I look forward to many "discussions" and educational experiences on the site. I appreciate your thoughts, opinions, facts, whatever you have contributed to this topic.

Regards,
Mike

 

[Pierre C Belarge]

If you read 200.7(C) first and then read (1) (2) and (3)... Occording to (1) you can use a white wire just about anywhere (as part of a cable assembly) as an ungrounded conductor. (2) goes on to say that where you use it as supply to a switch and not return it also has to be identified. (Because previous versions of the code to my understanding said that it didn't have to be reidentified if it were used as supply and not return). I understand your points, but to me, that still doesn't say I can't use it as a supply. It looks like I'm going to have to admit I'm interpreting the code wrong here, but I feel uneasy about excepting this more so than I've felt about excepting anything else in my 10 year electrical career.

#1 does permit the use of the grounded conductor in a CABLE ASSEMBLY to be installed as an ungrounded conductor, as long as it is re-identified properly.

#2. Go back to the paragraph that starts (C). It is permitted only as described in 1, 2, and 3.

 

[LarryFine]

Because previous versions of the code to my understanding said that it didn't have to be reidentified if it were used as supply and not return.

Mike, that's exactly my understanding. Now, both are required. I prefer using a Sharpie to taping.

Welcome to the forum.

And the NEC.

 

[480sparky]

Why?

As Bob points out, the section is clear that it can only be used to supply the switch.

Where in that section does it say you must use the reidentified white to supply the switch? I think it merely states that if I use the white to feed the switch, it must be reidentified.


Let's rewrite that section a bit. Finish the following paragraph:

(2) Where a cable assembly contains an insulated conductor for single-pole, 3-way or 4-way switch loops and the conductor with white or gray insulation or a marking of three continuous white stripes is used for the return conductor from the switch to the switched outlet. In these applications, the conductor with white or gray insulation or with three continuous white stripes...............

 

[LarryFine]

(2) Where a cable assembly contains an insulated conductor for single-pole, 3-way or 4-way switch loops and the conductor with white or gray insulation or a marking of three continuous white stripes is used for the return conductor from the switch to the switched outlet. In these applications, the conductor with white or gray insulation or with three continuous white stripes...............

... can't be used.

 

[roger]

Where in that section does it say you must use the reidentified white to supply the switch?

Why would you re-identify a white or gray conductor? I personally see no reason for this.

Roger

 

[al hildenbrand]

. . . but I feel uneasy about excepting this more so than I've felt about excepting anything else in my 10 year electrical career.

Welcome to the Forum, Mike.

This passage is a great way to really start working with Charlie's Rule of Technical Reading. Click on it to read the full rule. . .it's short.

And then try this:

2008 NEC
200.7(C)
& 200.7(C)(2)

(C) Circuits of 50 Volts or More. 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).

2. Where a cable assembly contains an insulated conductor for single-pole, 3-way or 4-way switch loops and the conductor with white or gray insulation or a marking of three continuous white stripes is used for the supply to the switch but not as a return conductor from the switch to the switched outlet.

Take the red bold parts in my quote above and read it as a single sentence. What I've done is strip a more general bit language down to the simple 12/2 NM-B switch loop case, while carefully staying true (I think) to the structure of the sentence (think of diagraming sentences, if you had that in school.)

Here's the stripped passage:

The use of insulation that is white for other than a grounded conductor shall be permitted only Where a cable assembly contains an insulated conductor for switch loops and the conductor with white insulation is used for the supply to the switch but not as a return conductor from the switch to the switched outlet.

Hope that helps. . .

 

[al hildenbrand]

Where in that section does it say you must use the reidentified white to supply the switch? I think it merely states that if I use the white to feed the switch, it must be reidentified.

Hey Ken,

As Pierre pointed out, above, it helps to include the openning lines in (C) with (C)(2).