Color coding for solar voltaic systems

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rbwelch

Member
The fire department wants to know if there is a particular color that could be used to identify conductors coming in from solar voltaic panels. Aside from the white or gray specification for neutral / grounded conductors, I could find nothing in the code. Any ideas??
 

electricalperson

Senior Member
isnt a photovoltaic system DC? im probably wrong but my guess would be red and black until it comes out of the inverter then its probably the normal colors
 

mh183

Member
are you worried about a disconnect means for safety of the fir fighters.
it is all at the main panel
 

jdsmith

Senior Member
The code requires the same for DC as AC - the grounded conductor must be white or gray, the ungrounded conductor can be anything other than white, gray, or green. There is also a color coding exception that allows conductors of ANY SIZE in a PV system to be re-identified by tape or paint. This is because all that is commonly available is #10 AWG black wires, I believe type XHHW/RHW-2. For the cables that connect directly to the PV panels you're stuck with that because they use MC-3 and MC-4 connections and I don't think they have those connectors that can be made up in the field. For folks with larger arrays that have JBs on the roof they typically wire nut in the JB and run THWN in 3/4" liquidtight down the side of the house to the inverter.
 
DC Module Wiring Color Codes

DC Module Wiring Color Codes

"Back in '97 - that is 1897- when the first edition of the Code was being drafted, Thomas A. Edison was generating power. And it was direct current (dc) power, not that alternating current (ac) stuff those heavy, costly transformers developed by Westinghouse and/or Tesla. AC came later, and the early code dealt with direct current, including color codes for that dc power. If the conductor is a grounded circuit conductor, the insulation or marking on larger conductors must be white or gray. If the conductor is an equipment grounding conductor, it must have green or green with yellow stripe insulation or be bare.​
Those color codes apply to both ac and dc electrical systems. There is no special color code for dc systems. Nearly all past PV systems and those being currently installed are grounded systems and one of the conductors in the dc parts of the system should be white. PV installers insisting that red is positive and black is negative are to be relegated back to their electronics workbenches where such color codes originated.​
Yes, in the future, we will see the installation of ungrounded PV arrays (see 690.35) that will be used with transformerless inverters, and those systems will not have a grounded PV dc conductor. Then red and black conductors may become more common; but on the current grounded systems, they are incorrect..."

-IAEI Magazine, March/April 2008
(Common PV Code Violations)
 

dereckbc

Moderator
Staff member
To my knowledge there is none that exist as the panels are DC, and niether polarity is grounded, both polarities are fused in my experience with it.
 

SegDog

Member
PV

PV

Hello,

Beside the inferences, PVs and intertie systems should be properly labelled. I have problems with some of the labels that I've seen, and these can be improved.

SegDog
 

kkwong

Senior Member
Black and red are the colors for a D/C system. If you are talking about the raceway, there are no requirements for labeling the raceway (as yet).

Where are you, RB?
 

rbwelch

Member
Thanks

Thanks

Thanks to all who responded. I'll relay the info to the Fire Dept...
I'm in Daly City, CA.
 

newenergy

Member
Another voice for it being just like AC. White for grounded. Colored (non-green) for ungrounded. Generally either all ungrounded are black or the first string is black and the second is red.

In electronics or in automotive it's red/black +/-, but not in buildings, at least not in California.
 

gndrod

Senior Member
color codes

color codes

I agree with Fast Eddie and Newenergy posts. The synergy of both electrical and electronics may finally be forced to come together with AC, DC circuit differentiation and isolation.

The White Book lists 'Solar Panel Wire' under Special Purpose (ZMHX) that can fall under UL general catagory basic ANSI standards. The 'listing' mark should appear on the reel or packaging box and not necessarily on the wiring. No mention of color codes are evident. rbj
 

tom baker

First Chief Moderator
Staff member
The IEC and UL standard for control panels require white with a blue stripe for the DC common and blue for the positive.
 

RHJohnson

Senior Member
I sure don't want to get into a debate about color coding wires. But, I do think everyone should know there are probably thousands of industrial plants, and power plants throughout the U.S. that have battery systems in place for various reasons. Red is positive and black negative. Always, except one time on a new power plant, where the young design engineer specified black for positive and white negative. Problems everytime someone went to make a connection or trouble shoot......All that engineer would say - it's only a color, it does not matter. I'll bet those black and white wires added 10% to the cost with lost time - and finally, when the job was all done, the plant electricians went over the whole system with tape - red and black to color code those battery systems.
Oh - The DCS systems - usually 12 vdc - black positive, white negative.
 

SegDog

Member
better labelling

better labelling

Hello,

The subject of color-coding came-up years ago, when cars with high-energy batteries (electric and hybrid cars) were getting into wrecks and the firemen had to deal-with cutting the cables.

Now the subject is houses with solar-modules and high-energy DC. Well, better labels with better, uncomplicated language is the answer. Colored wiring doesn't help if you can't see it.
 
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