Generator feeder sizing

[kevc66]

Hello Everyone,
What is the easiest and most effective way to size single and three phase generator feeder cables?

Thanks

 

[tom baker]

Take the ampacity and look in Art 400 in the appropiate table.

 

[JoeStillman]

I would pick the smallest cable that is protected by the generator output breaker. If you don't know the breaker size, use the generator kVA rating. The kVA rating is usually 125% of the kW rating, but you need to check to be sure. Some small single-phase gensets have kW=kVA.

For 3-phase, I=1000xkVA/(Vx1.732)
For 1-phase, I=1000xkVA/V