Neutral insulation for Generators at 13.2 kv

[danedi]

Good Morning to everyone.

I have this big question going around in my mind for a while. I am designing a paralleling system @13.2 KV for 3 generators 2 MW ea. The size of the phase conductors is 3#1/0 at 15 kv, but the neutral conductor we are designing as 1/0 AWG-600V, to be connected to a neutral resistor (this is a low resistance grounding scheme).
I can not find any place in the NEC that requires a 15kv insulation level for the neutral conductor to be connected from Xo at the generator to the LRG system. Any suggestions here?
Thanks
Daniel

 

[don_resqcapt19]

Re: Neutral insulation for Generators at 13.2 kv

Take a look at 250.186(B).
Don

 

[danedi]

Re: Neutral insulation for Generators at 13.2 kv

Thanks for the information.

Best regards,

Daniel