Colors for Ungrounded Conductors

ibarrola

Member
Location
Houston
Hi,
Did a quick search on the forum and could not find a topic on this (there probably is). I did see a post on control wiring today but could not find an answer.
I see standard industry guidelines for the different wiring colors for ungrounded conductors throughout articles on the web. And they mention this is per NEC but they do not reference a section of the code. Are the colors of ungrounded conductors part of the code?
I know county's and cities might have there own compliance for color coding but I am wondering if this come from code...

The city requires brown-yellow-purple, but a product we are purchasing has standard industry colors for 480/277V which is brown-orange-yellow. And I see the standard industry colors all over the articles I am finding.

Thanks you
yogi
 

ron

Senior Member
No standard colors for 480/277V in the NEC other than for an EGC and neutral (grounded conductor). The ungrounded conductors can be whatever you want as long as you identify them (or if the jurisdiction amended the national code)
 

tom baker

First Chief Moderator
Staff member
The NEC used to have required colors, but they were removed in the mid 70's. The comments were that you should not assume any color is any voltage and test to be sure. For example green could be used as a ungrounded conductor before the 2005 code. and at one time gray could of been a hot conductor.
There are required colors for neutrals, and EGC, in Art 200 and 250
What the code does say for building with more than one nominal voltage, choose colors, and post what you use. Example 120/208 could be pink yellow blue, but you have to use those throughout.
See see 210. 5 C 1 and a similar section in Art 215
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Retired Electrical Engineer - Power Systems
No standard colors for 480/277V in the NEC other than for an EGC and neutral (grounded conductor). The ungrounded conductors can be whatever you want as long as you identify them (or if the jurisdiction amended the national code)
There are a few places in the NEC which require or recommend the use of 'orange' therefore some localities, such as yours, use purple as a common color instead.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Do the green/gray/white restrictions apply to control wiring, too?

The six small control conductors in a Generac system, for example.
 

Greentagger

Senior Member
Location
Texas
Occupation
Master Electrician, Electrical Inspector
Do the green/gray/white restrictions apply to control wiring, too?

The six small control conductors in a Generac system, for example.
Appears white or gray not covered if 50 V or less and not required to be grounded. 200.7(B). Doesn’t seem to be much wiggle room with green unless it complies with 250.119 Exception No.1.
 

Carultch

Senior Member
Location
Massachusetts
No standard colors for 480/277V in the NEC other than for an EGC and neutral (grounded conductor). The ungrounded conductors can be whatever you want as long as you identify them (or if the jurisdiction amended the national code)
Is there any set of colors that you'd recommend specifying for non-standard voltages in the US? E.g. 347/600V?
 

Tesla1960

New User
Location
Woodland Park Colorado
Occupation
Journeyman Electrician
Hi,
Did a quick search on the forum and could not find a topic on this (there probably is). I did see a post on control wiring today but could not find an answer.
I see standard industry guidelines for the different wiring colors for ungrounded conductors throughout articles on the web. And they mention this is per NEC but they do not reference a section of the code. Are the colors of ungrounded conductors part of the code?
I know county's and cities might have there own compliance for color coding but I am wondering if this come from code...

The city requires brown-yellow-purple, but a product we are purchasing has standard industry colors for 480/277V which is brown-orange-yellow. And I see the standard industry colors all over the articles I am finding.

Thanks you
yogi

I recently worked in the Houston Texas area and B phase on 277/480 Y system purple was used to identify it.Being a licensed electrician in Colorado we use orange.I asked around why purple,and I was told that in the shipyards there is alot of high leg services where the high leg is identified as orange.With the humidity and heat,the color will fade so to avoid confusion, B phase on a 277/480 Y system is purple
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Engineer
Do the green/gray/white restrictions apply to control wiring, too?

The six small control conductors in a Generac system, for example.
250.119 Exception 1: Power-limited Class 2 or Class 3 cables, power-limited fire alarm cables, or communications cables containing only circuits operating at less than 50 volts where connected to equipment not required to be grounded in accordance with 250.112(I) shall be permitted to use a conductor with green insulation or green with one or more yellow stripes for other than equipment grounding purposes

Low voltage thermostats have used green for the fan control wire forever. White is usually call for heat.
In old phone wiring, the green on the line 1 pair goes to the tip, and the red goes to the ring. The ring may be grounded, but not the tip.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
I recently worked in the Houston Texas area and B phase on 277/480 Y system purple was used to identify it.Being a licensed electrician in Colorado we use orange.I asked around why purple,and I was told that in the shipyards there is alot of high leg services where the high leg is identified as orange.With the humidity and heat,the color will fade so to avoid confusion, B phase on a 277/480 Y system is purple
Why? B phase on a 480Y/277 is the same as A&C
 

Carultch

Senior Member
Location
Massachusetts
Why? B phase on a 480Y/277 is the same as A&C
The issue is that if all you can see is the B-phase marked orange, and the other two colors faded beyond recognition, you wouldn't be able to tell the difference between brown/orange/yellow and black/orange/blue. I find it a very unlikely event that orange in particular would remain visible when the other colors would fade. Black I can understand, but I would expect orange to be just as likely to fade as any other color.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
The issue is that if all you can see is the B-phase marked orange, and the other two colors faded beyond recognition, you wouldn't be able to tell the difference between brown/orange/yellow and black/orange/blue. I find it a very unlikely event that orange in particular would remain visible when the other colors would fade. Black I can understand, but I would expect orange to be just as likely to fade as any other color.
Makes sense..
Of course I struggle with a lot of the darker colors..
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
250.119 Exception 1: Power-limited Class 2 or Class 3 cables, power-limited fire alarm cables, or communications cables containing only circuits operating at less than 50 volts where connected to equipment not required to be grounded in accordance with 250.112(I) shall be permitted to use a conductor with green insulation or green with one or more yellow stripes for other than equipment grounding purposes
So, no in my example, especially pulled wires.
 

kwired

Electron manager
Location
NE Nebraska
250.119 Exception 1: Power-limited Class 2 or Class 3 cables, power-limited fire alarm cables, or communications cables containing only circuits operating at less than 50 volts where connected to equipment not required to be grounded in accordance with 250.112(I) shall be permitted to use a conductor with green insulation or green with one or more yellow stripes for other than equipment grounding purposes

Low voltage thermostats have used green for the fan control wire forever. White is usually call for heat.
In old phone wiring, the green on the line 1 pair goes to the tip, and the red goes to the ring. The ring may be grounded, but not the tip.
Not a system that is required to be grounded. Often is on newer units, but not required. But the "L2" is often the grounded conductor and often only color left to use for it in many cables is a blue conductor.
 
Top