EGC for Delta Connected System

[FaradayFF]

Greetings,

I've got a feeder going from a breaker in MV switchgear to Delta-Y connected transformer. The transformer is connected Delta on the primary and there is no neutral conductor included with the phase conductor feeding the primary of the transformer. Am I required to run EGC with the phase conductors? The system ground will be established at the Y point of XMFR and carried through down to MCC and the loads.

Thanks,
EE

 

[LarryFine]

Am I required to run EGC with the phase conductors? The system ground will be established at the Y point of XMFR and carried through down to MCC and the loads.

Yes and no. You're actually extending the derived neutral from the transformer to the first disconnect(s) it's supplying, which is where the premises grounding system begins. If there is only earth between the transformer and the MCC, you'll need to provide another grounding electrode system at the destination end.