generator

[puckman]

we have a service at 400 amp 3 phase 240 v red leg with 3 disconnects to shut service down. 1@ 200amps , 1@ 150 amp, and a 150amp. we like to install a generator to the the 200 amp cb that controls 3 panels. a ats would be installed next to the 3 panels , a 60 kw 3 phase ng generator will be used. the existing 200amp cb is feeding the 3 panels with 4/0 alum. {180amp.} . we plan on using 3/0 copper from the ats to the generator. would i have to replace the 4/0 alum. , a 80' run ?. this is for a resturant that has lost power a few times in the past year. any suggestions on this job will be very helpfull.

 

[jrannis]

we have a service at 400 amp 3 phase 240 v red leg with 3 disconnects to shut service down. 1@ 200amps , 1@ 150 amp, and a 150amp. we like to install a generator to the the 200 amp cb that controls 3 panels. a ats would be installed next to the 3 panels , a 60 kw 3 phase ng generator will be used. the existing 200amp cb is feeding the 3 panels with 4/0 alum. {180amp.} . we plan on using 3/0 copper from the ats to the generator. would i have to replace the 4/0 alum. , a 80' run ?. this is for a resturant that has lost power a few times in the past year. any suggestions on this job will be very helpfull.

I dont see any reason to change the 4/0 if its protected by a 200 amp breaker.

 

[360Youth]

4/0 ALU is good for only 180 amps, so yes I believe it would need to be replaced. 4/0 alu and 2/0 cu can be used for 200 amp in residential applications, but not here, unless I am missing something.

 

[jrannis]

Next standard breaker size UP is 200 amps. Nothing to do with being commercial or residential.
4/0 Al is good