Grounding

[gmtt]

Question
1) Is the ground wire pulled from POCO transformer to the meter or only phase(s) and the neutral are pulled from the POCO transformer to the meter and then ground is derived from local water main?
2) If 1) is true, why not ground is pulled from the POCO transformer where neutral is grounded at the transformer?
Both will work though, but in later case the ground will be direct rather than thru earth as in case 1.
My general question is, in practice how grounding scheme is achieved; from POCO to customer Panel point.

 

[iwire]

From the power company to the service the grounded conductor serves as the grounding means.

The power company will handle the 'earth' connections at the transformer and the electrician handles the earth connections at the service.

 

[nakulak]

poco uses code other than NEC for its wiring (NESC ?). I have never seen a poco ground run to a meter or ct cabt, only neutral. NEC says that premesis wiring is grounded at first means, and that is where it is derived. In the case where premises owns own transformers or substation, grounding is derived there. hope that helps.

 

[Dennis Alwon]

Since the neutral is bonded to the meter can then pulling a grounding conductor would be like paralleling the neutral. No need for this as Bob mentioned the poco will take care of the grounding at the trany.

 

[augie47]

I think one reason is that you have very limited access to the POCO transformer. Generating your grounding system at the meter/1st disconnect serves the same purpose and makes inspecting and servicing the connections more convenient.

 

[iwire]

I think one reason is that you have very limited access to the POCO transformer.

That and the fact that the NEC has no authority to say what happens in / on power company equipment.