Generator Equipment Grounding Conductor

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xguard

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Baton Rouge, LA
We have a 3 phase 200KW (250 KVA) 120/240 V generator. It was installed around 2010. The generator circuit breaker is rated 700A and the feeder to the automatic transfer switch is parallel 350 MCM. We have a 2 awg equipment grounding conductor installed with each set of conductors. This is not a seperately derived system, the neutral is not switched. I think there should be a 1/0 equipment grounding conductor with each set of phase conductors instead of the 2 awg, based on table 250.122. We are doing other work in the area and I would like to fix it if it is not correct. I'm basing this off of soares stating it should be sized based off 250.122. I see the reference in 250.35 for the situation without a circuit breaker but I actually don't see for the one with the breaker (load side) as soares states. Appreciate any feed back.

Also the automatic transfer switch is only rated for 600 A, is there a requirement that the generator circuit breaker protect the transfer switch?
 
agree with the 1/0 and off-hand I can not think of any reason the breaker could exceed the rating of the ATS. What size is the breaker on the utility side ?
 
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