Wire color codes for photvoltaic systems

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I just learned that some manufacturers are headed in the direction of standardizing on black and white on the DC side, where black is +ve (!!!!) and white is -ve. This is already causing some electricans to tear their hair out. Especially when an inverter allows you to select operation with either a positive ground array or a negative ground array by setting an internal switch and moving the GFDI fuse. If you do select negative ground, then you have white as the negative and ungrounded conductor carrying maybe 600vDC while black is the grounded conductor!!

Do we think this is smart?

I say let us suggest that the color code be Red for +ve, Black for -ve, and either one or neither can be grounded (depending on whether it is a +ve ground, -ve ground or balanced system) but, when the GFDI operates, both are potentially "hot" anyway (as the madatory warning label says) , so the colors black and red seem appropriate.


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The use of the color White is restricted to identifying grounded conductors, so the PV manufactures must make sure that White not be used for another conductor other than a grounded conductor. (See 200.7)



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I have wired PV systems that have been positive ground and systems that are negative ground in either case I used white as the grounded conductor for our part of the wiring.

As far as the manufactures it really makes no difference what color leads they hang from the panel as they are not bound by the NEC.

Out in the middle of a 'string' there really is no 'grounded' conductor as it is a series circuit.
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