Meter & Riser

[Therealcrt]

I don’t do a lot of residential so quick question. Customer wants a new meter can installed with a new riser. Does the meter can need a ground from the grounding electrode (ground rod). Does the meter can need to be piped to the main breaker panel with rigid conduit or can it be pvc? Does the meter can even need a ground wire at all? I know the main breaker panel has the bare ground from the ground rods and neutral and ground is bonded there but what about the meter can itself..

 

[electrofelon]

I don’t do a lot of residential so quick question. Customer wants a new meter can installed with a new riser. Does the meter can need a ground from the grounding electrode (ground rod). Does the meter can need to be piped to the main breaker panel with rigid conduit or can it be pvc? Does the meter can even need a ground wire at all? I know the main breaker panel has the bare ground from the ground rods and neutral and ground is bonded there but what about the meter can itself..

the meter socket is factory bonded to the neutral. No other bonding is required. You can land the GEC there if you want (as long as allowed by power company. Also some dont have a lug for the GEC which is a bit annoying so you would have to split bolt onto the neutral).

 

[Charged]

Check utility’s service guide. It’s something that’s typically addressed and usually has its own ground wire to rod not connected to the buildings grounding system but again , check service guide available online and it’s usually covered in one of the exhibit sketches related to your service size.

 

[electrofelon]

usually has its own ground wire to rod not connected to the buildings grounding system but again , check service guide available online and it’s usually covered in one of the exhibit sketches related to your service size.

I have never heard of that, plus it would be an NEC violation. Have you seen that required? Is it actually in the POCO construction specifications?

 

[infinity]

I have never heard of that, plus it would be an NEC violation. Have you seen that required? Is it actually in the POCO construction specifications?

I agree, the meter enclosure would need to be bonded to the neutral even if the POCO required a connection to a ground rod at the meter.

 

[augie47]

You need to run both those questions by your POCO. Our local POCOs require a (1) ground rod regardless of any other grounding.
One of our POCOs requires rigid conduit to the service disconnect (even though it's not their jurisdiction--no rigid, no [power) but unless they require PVC is normally a better choice due to bonding required for metallic.

 

[Charged]

 

[electrofelon]

That doesnt say anything about not connecting to the buildings grounding system, in fact it says the opposite.

 

[infinity]

That doesnt say anything about not connecting to the buildings grounding system, in fact it says the opposite.

Yes it does. And why would the ground rod go to the meter pan with a CT service? It should go directly to the CT cabinet.

 

[electrofelon]

Yes it does. And why would the ground rod go to the meter pan with a CT service? It should go directly to the CT cabinet.

My comment about a separate ground rod connected to a meter socket being a code violation centered around the "all electrodes available shall be bonded together" principle. In the case of a self-contained meter, I don't believe this could be considered an anxiliary electrode as it would be connected to the neutral not to an EGC. In the case of an instrument meter however, I believe an isolated electrode would be acceptable as it could be connected to the EGC and thus considered anxiliary.

 

[don_resqcapt19]

My comment about a separate ground rod connected to a meter socket being a code violation centered around the "all electrodes available shall be bonded together" principle. In the case of a self-contained meter, I don't believe this could be considered an anxiliary electrode as it would be connected to the neutral not to an EGC. In the case of an instrument meter however, I believe an isolated electrode would be acceptable as it could be connected to the EGC and thus considered anxiliary.

Our utility requires two ground rods and a GEC connection to the meter can. If there are other grounding electrodes for the building the GECs for those electrodes are connected at the service equipment. These are not an isolated electrodes as the GECs are connected to the grounded conductor at both locations. There is nothing in the code that prohibits this.
Even in the case of a CT meter, our utility requires the two ground rods at the CT cabinet connected to the grounded service conductor in the CT cabinet and bonded to the enclosure.

 

[electrofelon]

Our utility requires two ground rods and a GEC connection to the meter can. If there are other grounding electrodes for the building the GECs for those electrodes are connected at the service equipment. These are not an isolated electrodes as the GECs are connected to the grounded conductor at both locations. There is nothing in the code that prohibits this.
Even in the case of a CT meter, our utility requires the two ground rods at the CT cabinet connected to the grounded service conductor in the CT cabinet and bonded to the enclosure.

Right, I agree you can have two different grounding electrodes, each with their own GEC connected to different parts on the line side and up to the service disconnect. The NEC actually implies with their wording that the GEC is singular and there is only one, but I have never come across anyone who cares or interprets it that way.

 

[Charged]

My intent with the post was to indicate the utility probably has some requirements for grounding the meter can outside what is going on at the service disconnect, Point is noted they are connected