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Posted By: Fred Grounding/bonding residential services - 12/09/03 08:01 PM
I need some help with 2002 NEC references to clarify an issue. Here's the situation:
My local REMC is the last electric utility in the area that still wants a grounding electrode connection from their meter base to the grounding electrode. All other utilities in the area forbid this and want to see this connection made only in the first means of OCP. This REMC had the same line super and operations manager for the last 42 years and it was policy to require the connection in the meter base, grounding the neutral there and nowhere else. Well now they have a new Ops manager and a new line super. The line super is a 27 year lineman and a good common sense guy. The Ops manager is also a good guy but he is now requiring an additional GEC to be ran from the grounding electrode to the main OCP. The line super doesn't think this is right and contacted me for specific code references to support his position since he isn't and hasn't had to be well versed in the NEC in his career as a lineman/serviceman with the utility. His take on the situation is that the neutral should be grounded at the first means of OCP and no GEC connection should be made in the meter base. The meterbase is bonded to the neutral and with the neutral being bonded in the main OCP that bonds the meter base enclosure. My understanding is the service neutral should only be bonded in one place, either the meterbase or the main OCP, to avoid parrallel(sp) paths. The line super is asking for my help so he can pitch a policy change to the board next month with sound references for his proposal. He would like to see this REMC get on the same page as the surrounding utilities. He is to be commended, in my opinion. Specific 2002 code article references would be much appreciated. Thanks in advance.
Fred,

Can you get some input from the neighboring Utilities? It seems it would be in their best interest to be on the same page too.

Bill
Posted By: Fred Re: Grounding/bonding residential services - 12/10/03 01:40 AM
Bill,
The neighboring utilities policy is no ground connection in a sealed meter base. They don't want anyone other than the utility to have a reason to be in there. One utility sites parallel ground path but doesn't back it up with any code substantiation.
Fred,

There is a picture in the NEC handbook on page 182 which shows that the grounding electrode conductor (GEC.) The figure (Exhibit 250.8)shows that the GEC can be connected at the service head, service meter enclosure or in the service equipment. That is as per sec. 250.24(A)(1) However some utilities don't want the GEC attached in their meter enclosure, if you look at 250.68(A) the GEC shall be accessible. Maybe once the meter is locked off, the GEC is no longer accessible.
Posted By: Fred Re: Grounding/bonding residential services - 12/10/03 02:52 AM
I'm with you Harold. My question is, Can or should you require the neutral to be grounded in the meter base AND in the disconnect? I'm thinking one or the other but not both. If it doesn't matter if we bond at both places why don't we bond at every sub panel down-stream from the main?
I think I know why but I need code references to back it up. Thanks for your input.
Posted By: Roger Re: Grounding/bonding residential services - 12/10/03 03:04 AM
I wouldn't consider inside the meter unaccessable.

If the GEC connection was a problem connection, wouldn't the current carrying conductors be more so?

Although it might be agravating, we can get access back into a meter enclosure.

Harold 250.68(A) would be the connection to the electrode.

Fred, I would point out 250.6(A), you might need to draw out the scenario of multiple paths to accompany this code reference.

Good luck

Roger
Our utility requires the GEC from the ground rod be connected in the meter can. The GEC from the water pipe or other electrodes is connected at the service disconnect. 250.24(A)(1) permits the GEC connection to be made at any point on the line side of the service disconnect. I do not find any rule in the NEC that requires all of the grounding electrodes to use a common grounding electrode conductor nor a rule that says multiple grounding electrode conductors must be connected to the grounded conductor at a common point.
Don
Posted By: txsparky Re: Grounding/bonding residential services - 12/10/03 03:29 AM
Our PoCo (Entergy) actually requires parallel paths. [Linked Image]
This is from their installation standards...
Quote
11.10 Meter Grounding
Grounding the metering installation is a safety consideration both for the
Company and the Customer. The grounding connection shall be made in
accordance with NEC Article 250 and any other referenced code and preferably
in the meter socket. If the grounding connection is made anywhere other than
the meter socket, the Customer shall be responsible for grounding continuity
between the point where the grounding is made and the meter socket.

[This message has been edited by txsparky (edited 12-09-2003).]
Posted By: winnie Re: Grounding/bonding residential services - 12/10/03 04:12 AM
txsparky,

Are you saying that Entergy requires that neutral be bonded to the meter socket ground even if the neutral is bonded to the ground elsewhere?

I would read the paragraph that you quote as requiring that the meter socket be grounded, but _not_ requiring that the neutral be bonded to ground in the meter socket. If the bond between neutral and ground is elsewhere (eg in the main disconnect), then the customer is responsible for proper ground continuity to between the meter socket and the point of the ground bond.

I don't see a required parallel path unless it is required to bond ground to neutral in the meter socket.

-Jon
Posted By: txsparky Re: Grounding/bonding residential services - 12/10/03 04:23 AM
Winnie,
The neutral lug(s) in the meter can are bonded to the can. They are not mounted on insulators.
Quote
The neighboring utilities policy is no ground connection in a sealed meter base. They don't want anyone other than the utility to have a reason to be in there.
Fred,

For what it's worth our POCO is the same way here. I don't know what the reasoning is though. I once left a 6" solid tail coming out for other utilities to connect to because service piping was all non-metallic, but was asked (TOLD) to remove it.

Bill
Posted By: Roger Re: Grounding/bonding residential services - 12/11/03 12:43 AM
Donnie, actually any service where a metallic raceway is installed between the first main and the meter enclosure, puts the EGC and neutral in parallel.


Roger

[This message has been edited by Roger (edited 12-10-2003).]
Actually my POCO for the longest time would not allow the GEC in their meter pan. Just this year, they are starting to allow it.
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