Grounded conductor

[hhsting]

I have fire pump fed from POCO transformer 208V, three phase, FLA 143A and service phase conductos of 3#3/0. Grounded conductor has to be brought to service equipment. Question is the size of the grounded conductor. Would 250.24(C)(1) or 250.24(C)(3) apply?

 

[david luchini]

I have fire pump fed from POCO transformer 208V, three phase, FLA 143A and service phase conductos of 3#3/0. Grounded conductor has to be brought to service equipment. Question is the size of the grounded conductor. Would 250.24(C)(1) or 250.24(C)(3) apply?

250.24(C)(1)

 

[hhsting]

Which case would 250.24(C)(3) be used? 480V three phase fire pump?

 

[infinity]

250.24(C)(3) is for a Delta service. A 480 volt fire pump can be fed from a Wye service.