Bonding of the main panel

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midamericairon

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I have been having a conversation with the local power company over bonding the neutral and the ground in the main breaker panel of a residence.

The power company is requiring us to bond the neutral and the ground in the meter base attached to the house. By doing this, should the main breaker panel be treated as a sub-panel and the neutral bus and ground bus be isolated?

The power companies argument is, by having the main breaker panel neutral and ground bonded it is creating a parallel path to ground. I tend to agree with them on this issue.
 
The NEC allows for multiple bond points in the region between the meter and the service disconnect under some circumstances.
Or, as long as you provide a raceway or wire EGC separate from the POCO neutral, you can separate EGC and neutral in the panel.

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midamericairon said:
The power company is requiring us to bond the neutral and the ground in the meter base attached to the house.
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What exactly do you mean by this? The Neutral is factory bonded to the cabinet in a meter enclosure. Do they want you to bring your GEC into the meter socket?

The power companies argument is, by having the main breaker panel neutral and ground bonded it is creating a parallel path to ground. I tend to agree with them on this issue.
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A few things to note: The NEC doesnt specifically prohibit "a parallel path" at the service (it does use the term for separately derived systems, see 250.30(A)(1) Ex #2). 250.6 discusses "objectionable current" but it is not clear what objectionable current is.

One final thing: Note in the above I was discussing current flowing on raceways. You said "parallel path to ground " which is different if that is literally what you meant. The NEC does not require a single point earthing system. One could have multiple GEC's connected at different points or auxiliary electrodes (see 250.54).
 
POCO's bond the neutral to everything and is a little surprising they mentioned anything here.

According to NEC the meter (in most typical self contained metering applications) is still a part of the service conductors and all grounding/bonding ahead of the service disconnecting means is done to the grounded conductor (neutral in most cases). NEC also requires a bonding jumper at the service disconnecting means and separate grounded and equipment grounding conductors beyond that point.
 
midamericairon said:
I have been having a conversation with the local power company over bonding the neutral and the ground in the main breaker panel of a residence.
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You haven't said where the Service Disconnect is located. Is it inside the "main breaker panel", as you call it? Or is it part of the meter, or separate from both the meter and the "main breaker panel"?
 
midamericairon said:
The power company is requiring us to bond the neutral and the ground in the meter base attached to the house.
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That is a typical installation here in the southeast.
midamericairon said:
By doing this, should the main breaker panel be treated as a sub-panel and the neutral bus and ground bus be isolated?
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No, the separation takes place after the service disconnect.

midamericairon said:
The power companies argument is, by having the main breaker panel neutral and ground bonded it is creating a parallel path to ground. I tend to agree with them on this issue.
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Sounds like your POCO has a good understanding of the way things work, be thankful, many don't.

Roger
 
As mentioned neutral is usually already bonded to the cabinet in a meter socket, and even in combination meter/mains/loadcenters.

They only thing that may need to be done is connect to a grounding electrode - though most POCO will already have a rod at any structure they provided.
 
midamericairon said:
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The power companies argument is, by having the main breaker panel neutral and ground bonded it is creating a parallel path to ground. I tend to agree with them on this issue.
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roger said:
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Sounds like your POCO has a good understanding of the way things work, be thankful, many don't.
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+1​

A parallel grounded [neutral] conductor pathway on noncurrent-carrying metal parts on the POCO-side of the main disconnecting means has long been considered as permitted and not objectionable current. Those that feel it is install nonmetallic raceway between enclosures. I've not seen nor heard of any AHJ that requires it, though.

FWIW, the main bonding jumper is always located in the main disconnecting means enclosure(s) regardless of being bonded elsewhere on the POCO side. Bonding elsewhere on the consumer side is, in almost all cases, a Code violation.
 
I believe you can bond neutral to ground at following location
1. Service conductors
2. Meter panel
3. At the service disconnect

Mike has Video on this on YT.
 
roy167 said:
I believe you can bond neutral to ground at following location
1. Service conductors
2. Meter panel
3. At the service disconnect

Mike has Video on this on YT.
Click to expand...

First off you bond the "grounded conductor", which most of the time is also the "neutral conductor" but not always.

Second, ahead of and including the service disconnecting means, anything that needs bonded gets bonded to the "grounded conductor", this alone covers all three of the items you mentioned.

Third, there is separately derived systems, those can be bonded at the source or at the first disconnecting means, usually one or the other but not both.

Fourth, welcome to the forum.
 
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