How well do you know the Code? Think you can spot violations the original installer either ignored or couldn't identify? Here's your chance to moonlight as an electrical inspector and second-guess someone else's work from the safety of your living room or office. It's your turn to identify the violation.
Hint: More sunscreen, please
Find the Answer
Just as the sun can damage our skin, it can also damage the insulation on cables and conductors, if they are not sunlight-resistant rated. This photo shows clear evidence of the damaging effect sunlight can have on wiring methods that are not listed as sunlight-resistant. This cable, installed on a sunny rooftop, has deteriorated to the point where the cable jacket is simply gone.
Section 310.10(D) contains requirements for insulated conductors or cables installed where exposed to the direct rays of the sun. In order to be Code-compliant, the conductors and cables must be ”listed, or listed and marked as being sunlight-resistant.” Another option is to cover the conductors and cables with a sleeve or tape that is “listed, or listed and marked as being sunlight-resistant.” None of that was done for this installation, leaving the cable to slowly degrade from the harmful ultraviolet rays of the sun.
For this Class 2 control circuit cable exposed to the sun, Sec. 725.3(L) requires compliance with Sec. 300.6(C), which also requires this nonmetallic cable to be identified or listed as being sunlight-resistant. For this wet location, Sec. 110.11 requires conductors to be identified for the use.
