Bit-by-bit, I am bumbling my way through a Generac 10kw generator install and am learning quite a bit about NEC along the way. To make a long story short, I am extending the wiring from the transfer switch to the generator and the wire run includes a stretch through underground conduit. Looking at the prepackaged wiring (and also how my detatched garage was wired) led me to the (wrong?) conclusion that the ground wire needed to be insulated. However, I can't find any such requirement in the code (other than spas and pools) and at least two electricians tell me that it is OK to run bare ground wire in conduit if I want.
So ... the question is ... can anyone tell me if there is a specific reason why Generac includes an insulated equipment grounding wire in the jbox-ATS flex conduit? If you want to weigh in on bare vs insulated ground in underground conduit, feel free. Thanks.
You can install a bare EGC per 250.118 (1) 2008NEC. But on your 10kw you probably have a 50amp breaker on it? If so then the EGC should be a #10. To pull a bare conductor that small it may be a special order $$$ from a supply house. Where #10 green insulated can be bought at the local Slowes or Home despot. For ease of pulling I would pull stranded. Just make sure you do not splice the wire in the conduit, it must be in a J-box.