Separately derived generator grounding electrode conductor size

[hhsting]

I have separately derived generator system. The generator has to two main breakers 1600AT and 400AT. The 1600AT has feeder 4 sets of 600kcmil and the 400AT breaker has feeder 1 set of 600kcmil.

Engineer has provided #2/0 awg grounding electrode conductor. I am not sure how to size grounding electrode conductor should it be sized based in sum of feeders 1600AT and 400AT, summing parallel sets or the largest one of the two breaker feeders. What should the grounding electrode conductor size be #2/0 awg or 3/0wag? How to size it?

 

[infinity]

What size conductors are between the generator and where is taps off to the two switches? Even if you had only the single 1600 amp feeder the GEC would be a #3/0.

 

[hhsting]

What size conductors are between the generator and where is taps off to the two switches? Even if you had only the single 1600 amp feeder the GEC would be a #3/0.

Are you referring to conductors size between generator and the main breakers? See snapshot below. If you are then those are internal manufacturer provided wiring of the generator. The dash line is the generator enclosure.

 

[don_resqcapt19]

The maximum GEC required is 3/0, and the conductors on the load side of the 1600 amp OCPD trigger a requirement for the maximum require size GEC.

 

[infinity]

Are you referring to conductors size between generator and the main breakers? See snapshot below. If you are then those are internal manufacturer provided wiring of the generator. The dash line is the generator enclosure.

Then as Don stated and I mentioned prior the 1600 amp switch requires the #3/0.