What is the standard color coding (wires) for a good panel?

[leitmotif]

Come on Vooduk... keep up... we're in 2010!

Welcome to the forum. .

Yeah but look at the brightside - he did a search like everyone advises and found the info.

Dan Bentler

 

[brucechase]

Hello,

UL508a specified:

Yellow or Orange- ugrounded control circuits that remains energized with disconnect in OFF position.

Are you sure about Yellow?

See this thread.
http://www.plctalk.net/qanda/showthread.php?t=49445

 

[MikeW]

What About A Color Blind Electrician?

Trying to standardize on a "uniform" color code losses sight of a possible larger problem for those who can't distinguish colors very well, if at all. (Yes, I work with a top notch panel builder who has trouble with this, he can not wire a RJ45 connector without someone helping him figure which wire goes to what pin as the thin colored stripes are hard to tell on the white wires.)

Tag all wires with numbers that match the wiring diagram and color is unimportant.

 

[OkiePC]

Tag all wires with numbers that match the wiring diagram and color is unimportant.

I agree that wiring should be labelled, but color is still very important. Certain colors have certain meanings to the 92% of us who are not colorblind, and those color standards should be followed.

I don't want to see a green wire used for anything but ground, or a black wire used for a 120vac neutral...etc.

Just my opinion,
Paul

 

[kamenges]

Originally posted by OkiePC:

I don't want to see ... or a black wire used for a 120vac neutral...etc.

...unless you happen to be in Australia.

Keith

 

[bernie_carlton]

Are you sure about Yellow?

NFPA79 - 2002 this was Orange OR Yellow

NFPA79 - 2007 this was only Orange

 

[mdprice55]

There is no standard UL color code other than for grounding conductors.

 

[silva.foxx]

 

[TConnolly]

Welcome to the forum mdprice55. We certainly hope to see more of you around.

UL standards do carry considerable clout, not just in the US but worldwide. It behooves us all to follow UL standards. Underwriters Laboratories is not a regulatory authority. It is a private, for profit, testing corporation which licenses companies to carry the UL label which certifies that the product meets certain standards.

In the USA electrical codes are regulated for the most part by NFPA 70 (The NEC), and with regard to control panels - the subject of this thread - NFPA 79. Local jurisdictions (AHJ) have the final say but it is very rare that an AHJ doesn't follow NFPA 70 and/or NFPA 79. NFPA 79 is the standard for electrical machinery and it specifies a few color codes and explicitly reserves some colors for specific applications. The colors are spelled out in NFPA 79 13.2. Even though UL might not spell out something, it would be difficult to obtain a UL marking if a manufacturer cannot demonstrate that his product meets regulatory standards or standards mandated by the AHJ. In this case UL follows NFPA 79.

This is an old thread which has been resurrected and the subject has been discussed in many different threads since this one originated. I'll simply reiterate that its probably a good idea for anyone building control panels to get the current copy of NFPA 79 and become familiar with it. Some things have recently changed, such as the change in YELLOW/ORANGE mentioned earlier.

 

[The Plc Kid]

What about 24 volts Ac? Would it still be red?

 

[TConnolly]

Yep.
NFPA 79 13.2.4.3(2) There are however four exceptions that are pretty broad.

 

[daba]

Judging by the diversity, and contradictory, discussions on this topic, the only SAFE way to approach a panel's innards is with the knowledge that the panel-builder MIGHT have followed a published and accepted colour scheme, but it is safer to assume he didn't, unless there is a conformitory declaration attached to the panel.

I have NEVER seen a panel that has any documentory evidence that states what standards the panel is wired to.....

best not to assume anything

 

[Mike Lamond]

Judging by the diversity, and contradictory, discussions on this topic, the only SAFE way to approach a panel's innards is with the knowledge that the panel-builder MIGHT have followed a published and accepted colour scheme, but it is safer to assume he didn't, unless there is a conformitory declaration attached to the panel.

I have NEVER seen a panel that has any documentory evidence that states what standards the panel is wired to.....

best not to assume anything

At my first job, our standard practice was to put notes on the first sheet of each panel's electrical schematic, including such details as conductor size and color, terminal symbols and other useful information. I still do that. Of course there's no guarantee that the same colors were used for field wiring or wiring changes by others or that there are still drawings in the panel 15 years later...

Note to beginning engineers: Do not try to coordinate control panel wire colors with building power distribution. There is no need to use #12 AWG pink instead of black for the small DC drive outputs to the chemical pump motors.

 

[robsimpson]

Question from Canada. I'm getting a panel from a US vendor for a gas plant I'm working on. We have a project spec for panel colors. The vendor says he MUST follow UL505A for the colors. There will be likely 15 other PLC packages on site, I don't want 14 the same and this one different.

Is UL508A mandatory or recommended for control panel wire colors? Also the panel must be either cUL or CSA, I don't actually care if it is UL508A or not. I think the vendor is just accustomed to meeting UL508A. If the vendor is planning on providing cUL would that mean that he then needs to meet UL508A?

Thanks in advance.

 

[OZEE]

UL508A does not specify wire colors.