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I'm pulling 2 hots, 1 neutral and 1 ground through conduit to a subpanel and I was wondering if it's possible to use the same color wire and just relabel the endings. I was thinking of using 6 AWG white.

My understanding is that the ground needs to be either bare or green, so no relabeling on that. Also neutral needs to be white, which is the color I'm using anyways.

So can I just relabel the 2 hots with black & red tape at the endings? Any NEC reference would be greatly appreciated, thanks!

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    Switch to 4 AWG aluminum and you can do it, and your wire is cheaper to boot. It's allowed for #4 and larger. – Harper Oct 18 '18 at 1:11
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The colors reserved for the grounded conductors (neutrals) are white and gray, and any base color with three continuous white stripes. You can't re-identify white or gray insulated wires and use them for ungrounded conductors (hots) for circuits over 50V, unless they are a conductor in a cable or cord. This is commonly seen when white conductors in NM (romex) or MC or AC cables are used as hots in switch loops.

The code section to refer to is

200.7 Use of Insulation of a White or Gray Color or with Three Continuous White Stripes.

So I'd just buy black for the hots, and relabel the one leg with red.

  • @JimStewart ...yes ty! – batsplatsterson Oct 18 '18 at 0:04
  • If you use B only for hots and relabel the one leg with red, if you were running more than one circuit in a conduit, would you take care to associate all the reds with the same leg? What terminology do professional electricians use to distinguish the two legs? right and left? A and B? One and two? – Jim Stewart Oct 18 '18 at 0:35
  • @JimStewart - in the US the usual convention is for120/240 split phase, A or L1 is black and B or L2 is red. For three phase L3 blue. Brown, orange and yellow are used for 277V/480V systems with gray neutral. But these are conventions, the NEC doesn't mandate this. – batsplatsterson Oct 18 '18 at 1:12
  • In a 120/240 split panel is the convention that L1 is on the left and L2 on the right at the buss connections? – Jim Stewart Oct 18 '18 at 1:15
  • @JimStewart - yes, I can't think of any panel that labelled them otherwise... – batsplatsterson Oct 19 '18 at 13:19
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With #6 you cannot re-mark. You can with #4 though, and #4 aluminum has the same ampacity as #6 copper at less cost.

You want NEC 210.5.

  • By default you are not allowed to re-mark conductors at all.
  • in multiconductor cables only, you are allowed to re-mark only neutrals to be only hots. This is not allowed for individual wires in conduit.
  • for wires 4 AWG or larger, you are free to re-mark anything (except ground colors, 250.119) to anything else including ground.

So you have the right idea, but use #4 aluminum instead of #6 copper.

Don't get overexcited about distinguishing hot wires from one another. In North American split-phase, it usually doesn't matter. Black/black is fine. What's much more important is distinguishing each circuit from other circuits. I have one job where the installer installed four 240V circuits in one conduit: each is black/red and you can't tell em apart! Since there was another conduit parallel to that one, a better choice would've been 2 black and 2 red in each conduit.

Also, don't forget to use your all-metal conduit instead of the ground wire. No need for grounds in EMT or rigid, for instance.

  • I have very limited experience; I have never pulled wire in conduit, but I'm trying to learn. Wouldn't you want to use both B and R for hots so that in wiring 240 V circuits you could use only B for L1 and only R for L2 to avoid shorting L1 and L2? What is the special problem with having 4 circuits in one conduit compared to 2 in one conduit and 2 in another? In each case wouldn't you identify the partner to a given hot by having its 2-pole breaker on and all the others off? Would it be a benefit to have 6 or 8 rolls of different color tape to use a different color for each circuit? – Jim Stewart Oct 17 '18 at 23:58
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    @JimStewart you would only care about distinguishing L1 and L2 if you were bringing them back together, i.e. Paralleling, which you definitely should not be doing. Yes, you are correct, multicolored tape would be a fine way to identify pairs. He used numbered tape. It was found in the bottom of the service panel, having fallen off due to age. – Harper Oct 18 '18 at 1:09

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