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Posted By: pauluk Color codes revisited - 09/28/01 09:30 PM
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?
Posted By: Anonymous Re: Color codes revisited - 09/29/01 01:10 AM
#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.)
Posted By: resqcapt19 Re: Color codes revisited - 09/29/01 03:55 AM
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)
Posted By: Nick Re: Color codes revisited - 09/29/01 04:31 AM
#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).]
Posted By: Anonymous Re: Color codes revisited - 09/29/01 04:42 AM
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.
Posted By: Scott35 Re: Color codes revisited - 09/29/01 01:09 PM
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] [Linked Image]

Scott SET
Posted By: Bill Addiss Re: Color codes revisited - 09/29/01 03:08 PM
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
Posted By: pauluk Re: Color codes revisited - 09/29/01 04:27 PM
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.
Posted By: Nick Re: Color codes revisited - 09/29/01 05:57 PM
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.
[Linked Image]


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.
Posted By: pauluk Re: Color codes revisited - 09/29/01 08:33 PM
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?
Posted By: resqcapt19 Re: Color codes revisited - 09/29/01 09:04 PM
Scott35,
Quote
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,...

If both of these systems are in the same building and you are using multiwire branch circuits, then 210-4(d) requires that each ungrounded conductor be identified as to phase and voltage. The method of identification is left to the designer/installer but must be posted at each branch-circuit panelboard in the building. This requirement only applies to multiwire branch circuits and does not require the use of special identification of the grounded conductors. 200-6(d) would require that where both grounded conductors are in the same raceway, junction box, ect that the first grounded conductor be white or natural gray and the second grounded conductor be white with a colored stripe other than green.
Posted By: pauluk Re: Color codes revisited - 09/29/01 09:47 PM
Two more questions occurred to me while pondering on all this.

1. Normal 120/240V 3-wire residential. When connecting black and red (whether Romex or conduit) to a double-pole C/B for 240V branches, do you always match colors?

That is, will red on say the dryer branch be to the same hot busbar as red on the range branch, or are black and red just connected randomly?

2. When Romex is used for 3-way switching, which way round are the colors normally used? White (marked) still for the common in and out, then black and red for the travelers?
Posted By: Anonymous Re: Color codes revisited - 09/29/01 09:59 PM
>1. Normal 120/240V 3-wire residential. When connecting black and red ... to a double-pole C/B for 240V branches, do you always match colors?
No.

>will red on say the dryer branch be to the same hot busbar as red on the range branch, or are black and red just connected randomly?
Generally random.

I occasionally orient them if circuits will be in proximity.

>2. When Romex is used for 3-way switching, which way round are the colors normally used? White (marked) still for the common in and out, then black and red for the travelers?
It depends on where the source is with respect to the load, of course.

I like to end up at the luminaire with black and white. That means that sometimes white is remarked yellow or blue.
I use white from the source to the luminaire.
I use black from the source to the first switch.
I use black from the last switch to the luminaire. I think that is enough for you to figure out how I do it.

My way is probably uncommon.


[This message has been edited by Dspark (edited 09-29-2001).]
Posted By: Anonymous Re: Color codes revisited - 09/29/01 10:05 PM
For single phase, I put black on the left or bottom (same as with receptacles). The means that red goes on the right (same as white on a receptacle).

When I put multiple panels in a house, they are all this way. That usually puts red on the left side busbar. It is useful only in those rare instances when I deliberately want to distribute two loads, and when I want to avoid a 240 V situation (e.g., a bathroom).
Posted By: electure Re: Color codes revisited - 09/30/01 02:08 AM
DSpark.
Please explain why this puts red on the left busbar.
I don't get it!!!
(you're talking nonsense!)
Posted By: nesparky Re: Color codes revisited - 09/30/01 02:21 AM
Its been my habit to start all the 2 pole 240 volt circuit breakers at the top of the panel in residential work. When I do a multi-family building all the panels are hooked up the same way as far as possible. It makes for a neater panel. No code requirement just a work habit I got into years ago.
On 3 way and 4 way switches I use either 14-2 or 12-2 romex from panel to first switch 14-3 or 12-3 to next and/or last switch then 14-2 or 12-2 to the light fixture(s).
Again a work habit. This keeps the white as a neutral the bares as ground thru out. I found this sure cuts down on mistakes and helps eleminate trouble shooting time when something is not right. It also makes teaching newbys a lot easier.
Posted By: Anonymous Re: Color codes revisited - 09/30/01 02:46 AM
>Please explain why this puts red on the left busbar.

Many main breakers cross the feeds. Cutler-Hammer 200 A single phase panel is a suitable example.

If you check the instruction, they make this very clear and a simple voltage test proves that they are correct.


[This message has been edited by Dspark (edited 10-05-2001).]
Posted By: Anonymous Re: Color codes revisited - 09/30/01 02:51 AM
>Its been my habit to start all the 2 pole 240 volt circuit breakers at the top of the panel in residential work.
If I can lay them out in advance, I like to group them by story and wing.

>This keeps ... the bares as ground thru out.
I should hope so!!!!

>It also makes teaching newbys a lot easier.
But it can require some extra wire and a lot of extra wire to add another four-way into a circuit.
Posted By: pauluk Re: Color codes revisited - 09/30/01 03:28 PM
The pics of residential panels I have here all seem to have the main lugs at the top and busbars arranged for two columns of breakers, mounted sideways. All the panels I saw while over there were like this as well.

Is this the norm for residential panels, or are there other layouts as well?
Posted By: Anonymous Re: Color codes revisited - 10/04/01 08:23 PM
>Is this the norm for residential panels, or are there other layouts as well?

Yes. The panels are made to fit between 2"X4" studs on 16" centers.

The main breaker may be at the top or bottom and sometimes in one column, both, and sometimes even oriented vertically rather than sideways.

Sideways orientation turns out to be a good thing when labeling the individual breakers, which of course, everyone does.
Posted By: electure Re: Color codes revisited - 10/04/01 11:01 PM
Although this is generally true, it is not a requirement.
Some older panels have the breakers mounted vertically with the busses horizontal.
I haven't seen newer ones that way for awhile,tho.
Posted By: pauluk Re: Color codes revisited - 10/04/01 11:48 PM
Just about all domestic panels here have a horizontal busbar (usually at the bottom) and breakers or plug-in fuse carriers mounted vertically in a single row (only one hot leg remember).

Three-phase is generally two vertical rows of breakers mounted sideways with a main switch at the bottom.
Posted By: Anonymous Re: Color codes revisited - 10/05/01 11:43 PM
>Although this is generally true, it is not a requirement.
1999 NEC 240-33?
Posted By: electure Re: Color codes revisited - 10/07/01 02:15 AM
240-33 says only that the enclosure must be mounted vertically if possible.

(I actually did see a service mounted sideways one time)
Posted By: Anonymous Re: Color codes revisited - 10/07/01 02:21 AM
I hadn't thought of that way.

So does this just prohibit mounting it with the back against a floor, ceiling, and anything that isn't a vertical wall? But not which way the box itself has to be oriented?
Posted By: electure Re: Color codes revisited - 10/07/01 01:34 PM
Another word for "box" is "enclosure."
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