# Machine Control Panel Wiring Colour



## splatz (May 23, 2015)

These color code questions are always tougher than they should be. 

I think with black for the 230V you'd be safe but you probably want something to distinguish it from the 120V. I don't know if it would be compliant with the standard, but if you used black with a blue stripe for 230v and black with a red strip for 120V the person working on it would like that. 

For the interlocks, I think there's a consensus that "foreign voltage" / "excepted voltage" such as those interlocks is orange, but that conflicts with your orange for 480V power phase B. Again the standard would seem to have them all black, and if you bought black with orange stripe, brown stripe, and yellow stripe, I'd appreciate it, but I don't know if the standard tolerates the stripes. 

It's also a lot to ask to distinguish orange stripes from brown etc., that is, stripes aren't that great, but may be better than nothing. 

I found the attached table here: 

https://www.electricneutron.com/wire-cable/electrical-cablewire-general-requirement/


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## MikeFL (Apr 16, 2016)

splatz said:


> These color code questions are always tougher than they should be.
> 
> ...


And if you find multiple sources, they often conflict with each other.

UL508 has panel color codes.


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## Navyguy (Mar 15, 2010)

MikeFL said:


> UL508 has panel color codes.


I actually was just reading an article about this and it says it has been replaced with UL 60947-4 which is an amalgamation of the various NEMA, UL, ETL, CSA, etc standards under one cover.

I am looking for a copy actually now.

Cheers
John


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## telsa (May 22, 2015)

Go with a unique color.

Doing so makes future diagnosis drastically easier.

My first impulse would be purple, because out in San Francisco, it's so available. 

Its usually a substitute for 277VAC over ground BPY being the color scheme @ 480 often enough.

Red is too 120VAC for my taste.

But as you can see, what ever color you use -- even seasoned folks would have to look it up.

I'd be CERTAIN to slap a label on the chassis -- inside// outside -- that lays out what each color means.


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## splatz (May 23, 2015)

The truth is there are not enough colors, there are more possible voltages etc. than there are colors. So making a color code that works for everything everywhere in the world is impossible. 

If the standard just said to include a durable legible legend identifying the voltage, frequency, foreign / excepted, etc., that would be a good standard. 

Using all black and letting the poor bastard working on the machine figure it out would also be a realistic standard.


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