I have a 75 kva 480volt 3phase generator no fla is listed so took the kva and converted it to amps with the equation so roughly 90.3 amps. I then multiplied it by 1.15 via nec section 445 so i got 103.75 roughly. Im gonna use 75 degreed column cause thats what lugs rated for. At 1 awg thats good for 130 amps but with 4 to 6 conductors I derated to 104 amps so 1 awg should be good for the 75kva generator anyone see anything wrong with this or is this correct?
Generator wire size.
- Thread starter kjroller
- Start date
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
Is there a set mounted circuit breaker on the generator? If so, size the wire based on the breaker size.
There is its 95 amps so either way i believe im fine but when a 3rd party comes to do arcflash calc they always take the nameplate ratings so they they would say its undersized so for sake of making them happy I figured I would calculate off of the kva in which case i dont see a problem doing so I believe those calculations are right.
Cause they also open up all buckets and panels and make sure that their onelines match what was installed its part of there projected matinence package along with arc flash calc basically a way for them to keep a foot in the door so they can get more work
If they do things like that, I’d hire somebody else next time.