Equipment Grounding cond. insulation

[MJReigle]

Here is my situation.....Installing new 4160 switch gear to feed multiple industrial motors. The engineer is specifying MV-105 cable to feed these motors(3-conductors + gnd.) My question is this...does the grounding conductor need to be MV-105 as well or can it be of a different insulation such as THHN?

 

[jbt260]

The EGC may be bare or insulated (250.184(B)) for a solidly grounded neutral system. It is not required to be of the same insulation level as the phase cables.

 

[petersonra]

Here is my situation.....Installing new 4160 switch gear to feed multiple industrial motors. The engineer is specifying MV-105 cable to feed these motors(3-conductors + gnd.) My question is this...does the grounding conductor need to be MV-105 as well or can it be of a different insulation such as THHN?

Depends on whether you are trying to comply with the NEC or with his specification. The NEC may not care (and I think it does not) but the engineer may care.

 

[MJReigle]

Thanks for the responses, the engineer specified it that way on his interpretation of the code. Now that I can convince him with an NEC reference I believe I can change his mind.