# DC / Automotive codes - WTF?



## aricsavage (Oct 6, 2007)

As for cars I have no idea, but in the DC world for telcom there are several "standards".
In -48volt (+ is the grounded conductor) black is neg, red is pos.
AT&T -48volt systems use red for "A" plant and blue for "B" plant (redundant systems).
In +24volt systems I think neg is black and pos is red.

The solar inverters we install are also positive ground but neg is red and pos is white.


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## SparksNY (Feb 10, 2007)

No real standard, it varies by manufacturer. Green is often used as 12 VDC + and black is often used as ground.


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