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#4492 - 09/28/01 02:30 PM Color codes revisited
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
I was thinking about color codes again and looking through my one & only U.S. wiring book.

Two questions:

#1. Cases where a switch is at the end of a run with 14-2 or 12-2 Romex. All the examples in the book show the black wire run switch to light and the white wire, tagged black, for the hot feed to the switch. Is this the usual arrangement, or is it sometimes done the other way around?

#2. 277/480V services again. If the neutral is gray and the 3 phases are brown, orange, yellow (or brown, purple, yellow), what colors are used for a single-phase branch to, say, 277V lighting? Brown & gray?

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#4493 - 09/28/01 06:10 PM Re: Color codes revisited
Anonymous
Unregistered


#1

A. If it is done the other way, there is the potentially confusing or hazardous situation of having to hook two white wires to the luminaire.

Reversing the wires at the switch is of no consequence.


#2 (Orange is not a choice for the phase color in this case as it is reserved for a high-leg.)

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#4494 - 09/28/01 08:55 PM Re: Color codes revisited
resqcapt19 Offline
Member

Registered: 11/10/00
Posts: 2209
Loc: IL
DS,
Where does it say that you can't use an orange conductor unless it is the high leg of a 120/240 volt delta system?
Don(resqcapt19)
_________________________
Don(resqcapt19)

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#4495 - 09/28/01 09:31 PM Re: Color codes revisited
Nick Offline
Member

Registered: 08/13/01
Posts: 603
Loc: Riverside, CA
#1: Yes, this is the way it is required to be done. (Article 200-7(c)(2)

#2:Orange is a choice for this set up. 215-8 states to use orange, or tagging or other effective means. 310-12(c) lets you use any color you want other than white, natural grey or green. The brown, orange yellow, grey scheam is so common around here a lot of people here think it is in the code.
To answer your question, Pauluk, if I understand it correctly, the individual branches are the color of the associated phase. In other words, A phase is brown b phase is orange and c phase is yellow. If you run a lighting circuit as circuit 5 (c phase) it will be yellow. If you run circuit 3 (b phase) it will be orange etc. This is not an NEC requirement just a common practice.
Nick
PS: Identification of the high leg is only required when the neutral is present.

[This message has been edited by Nick (edited 09-29-2001).]

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#4496 - 09/28/01 09:42 PM Re: Color codes revisited
Anonymous
Unregistered


As you know, the NEC doesn't prohibit you from using orange elsewhere. But since it specifies where orange is to be used (high leg), it is a good practice not to use it on other three phase systems.

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#4497 - 09/29/01 06:09 AM Re: Color codes revisited
Scott35 Offline

Broom Pusher and
Member

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
Hi Paul,

On #1 - I know it sounds a little odd, but it makes sense after thinking about it for awhile. Using the White conductor for the "Line" to the switch would fall in the lines of the "Common" part of the loop. Also, if the loop is for a simple 1 pole switch and the branch circuit is feeding into the light outlet, the spliced wires in the light outlet box will automatically have only one Black wire for the switch leg, and hopefully all the branch circuit "Neutrals" get spliced with a pigtail for the luminare [light fixture].
Heard mention that at some time, the NEC requested the OPPOSITE connection scheme - but still re-identified the White wire [any color except White, Gray, or Green tape/paint/etc.]. Not sure when this took place, or if it's true! Maybe someone can chime in with an answer.

For #2, the color code being mentioned is simply one that is preferred in the field.
The colors used for 277 VAC Multiwire circuits [4 wire] would be:
A: Brown, B: Orange [or Purple], C: Yellow, "N": Gray.
For simple 277 VAC 1 phase 2 wire circuits, this equals out to be:
A: Brown / Gray,
B: Orange [or Purple] / Gray,
C: Yellow / Gray.
On the same system [480Y/277 3ph 4wire], L-L colors could be:
480 VAC 1ph 2 wire:
Brown / Orange [or Purple], Orange [or Purple] / Yellow, Brown / Yellow.
480 VAC 3ph 3 wire:
Brown / Orange [or Purple] / Yellow.
However, it has been common [for me at least], to just follow the "Black / Red / Blue" color scheme for L-L or 3ph 3 wire circuits regardless of system type [unless situations require different].

These color codes are something that needs to be "agreed upon" by everyone involved on that particular installation, in order to keep things uniform.

I am sure you know of this, plus it's been mentioned here, but the color codes we use in the field are mostly just trade preferred schemes.
The NEC only limits colors to use of White, Gray, Green, Green w/"tracer", Bare [uninsulated] and "sometimes" Orange [4 wire Delta], on general low voltage power systems of 120 VAC upto 600 VAC. I wanted to be sure and include this redundant statement just for clarity regarding color codes.

Although you could install all Black ungrounded conductors on any of these systems - such as a job with 480Y/277 3ph 4 wire and 208Y/120 3ph 4 wire - and still be in compliance with the NEC, you would get a lot of flack and strange looks from others in the trade.

Hopefully this message and others will answer your original questions with minimal corn-fusion [confusion]

Scott SET
_________________________
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

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#4498 - 09/29/01 08:08 AM Re: Color codes revisited
Bill Addiss Offline
Member

Registered: 10/07/00
Posts: 4196
Loc: NY, USA
 Quote:
#2. 277/480V services again. If the neutral is gray and the 3 phases are brown, orange, yellow (or brown, purple, yellow), what colors are used for a single-phase branch to, say, 277V lighting? Brown & gray?


Single and even multiphase circuits wired with cable will usually just contain the standard colors of that cable (Blk, Red, Blue, White, Green) if that is your question. Many times the only way to tell which system they are from is to test with a Meter.

Bill

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#4499 - 09/29/01 09:27 AM Re: Color codes revisited
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Phew, thanks for all the replies.

#1. Switch cables.
I asked about this because it's done the opposite way here. Just to refresh your memories, our normal colors are line=red, neutral=black. On switch drops we use red as the live feed and black (tagged red) as the switched output to the light.

I take your point about ending up with two white wires for the light, as obviously our system means we end up with two blacks.

This isn't "code," by the way, but I've never seen one wired the other way. The IEE just specifies that if a black wire is used for anything other than a neutral it should be marked accordingly. The black live on switches often ISN'T marked, however.

#2. 277/480V wiring.
I'm getting a little confused here. Phase colors on 120/208 are normally black/red/blue, but someone here said that on a single-phase branch you just use black, because a single-pole C/B could get moved to another phase so identifying the phase on a 1-ph branch would be pointless.

I understand that, and with different colors follows standard practice here. (Phase colors red/yellow/blue, 1-ph branches always red.)

So..... Why then would you identify the phase on a 277V 1-ph branch from a 277/480V panel? Surely a single-pole 277V C/B could get moved to another phase as well? I'm puzzled.....

Re NEC definitions: Yes, I realize that the NEC doesn't specify "hot" or phase colors specifically and only reserves white/gray/green (plus high-leg orange).
Thanks.

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#4500 - 09/29/01 10:57 AM Re: Color codes revisited
Nick Offline
Member

Registered: 08/13/01
Posts: 603
Loc: Riverside, CA
 Quote:
Originally posted by pauluk:
#2. 277/480V wiring.
I'm getting a little confused here. Phase colors on 120/208 are normally black/red/blue,

Right
 Quote:
but someone here said that on a single-phase branch you just use black, because a single-pole C/B could get moved to another phase so identifying the phase on a 1-ph branch would be pointless.




 Quote:
So..... Why then would you identify the phase on a 277V 1-ph branch from a 277/480V panel? Surely a single-pole 277V C/B could get moved to another phase as well? I'm puzzled.....


Around here the standard practice is to do 120 single phase branch circuits just like we described 277 single phase branch above. If you move it to a different circuit you change the color. The problem is the color doesn't usually get changed so if there is a lot of changes you end up with confusion.

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#4501 - 09/29/01 01:33 PM Re: Color codes revisited
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
I forget who it was said you didn't match up phase colors when running a 1-ph 120V branch from a 120/208 panel. Sounds as though it may be another of those regional practices or personal prefereces then.

I can sure see why the phase colors often don't get changed on a breaker move to another phase. One heck of a lot of work! So basically, when seeing a single-phase circuit, never believe what the phase color is telling you until checking it, right?

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