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Is there an NEC article that addresses an equipment grounding conductor to the utility transformer?

I have a building that has a 600 amp 3phase 480/277v service and has an equipment grounding conductor from the utility transformer that is going through the grounding bushings and is landed on the neutral bar. The connection between the neutral and the equipment is just the jumper strap.



I have the same issue on the load side of this equipment. The equipment ground conductor is connected to the neutral bar and is looped through the ground bushings to an MCC.

Should the EGC be run to the utility transformer?
Is there a code article for this or is this the utility standard? I have never run an EGC to a utility transformer. I have seen engineers do this on the drawings, but we have never installed it this way.

We are supose to correct the grounding on this job for a VFD installation.
 

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Electrical Simpleton
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I see the same thing proposed on many electrical designs.

I always ask the engineer to state the purpose of the additional wire and to demonstrate that a violation of 310.10(H) will not occur.

Magically, the additional wire is not in the resubmitted design.

Pete
 
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There should never be an 'EGC'* between a utility transformer and the service enclosure. The neutral must be used for grounding equipment on the line side of the service disconnect.




*It is actually impossible to have a true EGC on the output of the utility transformer as there is no over-current protective device and EGCs are only on the load side of OCPDs.
 

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Had a set of drawings call for an egc from utility one time and the run was so short and if I remember correctly it was just a #2 so I went ahead and installed it instead of wasting time with the engineer. POCO came to energize and they were a bit confused about what to do with it so they made me rip it out.
 
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