DC power circuit color codes

[spiworks]

What is the color code standard for DC power. For example +15VDC -15VDC. +12VDC -12VDC and so on. There seems to be quite a few answers on this subject. Any information would be appreciated.

 

[xnuke]

Refer to NFPA 79. I believe DC power cables are supposed to be blue.

xnuke

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Warpspeed]

I believe the only forbidden colour is green or green yellow. I have seen every other colour used for both negative and positive dc voltages.

Where there are multiple voltages, it is sometimes pretty difficult to do otherwise. Especially when available standard commercial multi-cored cable has to be used.

 

[ScottyUK]

The following may be of use to European users. There is a table on the second page which summarises the new harmonised colours which have been agreed across the EU.

http://www.iee.org/Publish/WireRegs/IEE_Harmonized_colours.pdf

In the UK, use of blue cable for all conductors in an installation tends to be reserved for IS circuits. That appears to be prohibited under the new scheme.



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If we learn from our mistakes,
I'm getting a great education!

 

[richs]

A popular color coding convention for DC voltages can
be found in the "ATX specification". I believe that this
color code is used by many manufacturers of electronic
equipment. Automotive, telco, and others have their own
color coding "conventions". Anyway, the ones here are
the ones I usually use:

red- +5V
black- GND 0V
orange- 3.3VDC
yellow- +12VDC
blue- -12VDC

Again, YMMV and depending upon application and industry.
But many of the computer types use this.

Hope it helps.

Cheers,

Rich S.