GROUNDING AND BONDING SDS
- Thread starter manny
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hurk27
Senior Member
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- Portage, Indiana NEC: 2008
Re: GROUNDING AND BONDING SDS
You will creat a parallel path on the neutral and this would be a violation of: 250.30 (1)
Exception No. 1: A bonding jumper at both the source and the first disconnecting means shall be permitted where doing so does not establish a parallel path for the grounded circuit conductor . Where a grounded conductor is used in this manner, it shall not be smaller than the size specified for the bonding jumper but shall not be required to be larger than the ungrounded conductor(s). For the purposes of this exception, connection through the earth shall not be considered as providing a parallel path.
You will creat a parallel path on the neutral and this would be a violation of: 250.30 (1)
Exception No. 1: A bonding jumper at both the source and the first disconnecting means shall be permitted where doing so does not establish a parallel path for the grounded circuit conductor . Where a grounded conductor is used in this manner, it shall not be smaller than the size specified for the bonding jumper but shall not be required to be larger than the ungrounded conductor(s). For the purposes of this exception, connection through the earth shall not be considered as providing a parallel path.
Re: GROUNDING AND BONDING SDS
It looks to me like if you have a non metallic raceway or cable system bonding in both places would be allowed. Metallic raceway systems create a parallel path. Mounting the panel and transformer on a common steel structure would also set up this parallel path even if non metallic conduit was used.
Why would you want to bond in both places?
It looks to me like if you have a non metallic raceway or cable system bonding in both places would be allowed. Metallic raceway systems create a parallel path. Mounting the panel and transformer on a common steel structure would also set up this parallel path even if non metallic conduit was used.
Why would you want to bond in both places?
Re: GROUNDING AND BONDING SDS
As the other two stated you would create a parallel path for load current to flow.
I have seen exception 1 exercised in a couple of circumstances. One is where a transformer was located in one building, and the secondary was feeding an adjacent building where there was no common ground electrode between the two structures. The other application is similar where a generator was located adjacent to the building and not sharing a common electrode.
Basically it is identical to a utility transformer where the utility has it?s own electrode, and the premise has it?s own separate electrode. Earth is the only common path, and is not a good conductor, so the majority of the load current flows on the grounded conductor.
As the other two stated you would create a parallel path for load current to flow.
I have seen exception 1 exercised in a couple of circumstances. One is where a transformer was located in one building, and the secondary was feeding an adjacent building where there was no common ground electrode between the two structures. The other application is similar where a generator was located adjacent to the building and not sharing a common electrode.
Basically it is identical to a utility transformer where the utility has it?s own electrode, and the premise has it?s own separate electrode. Earth is the only common path, and is not a good conductor, so the majority of the load current flows on the grounded conductor.
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