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Posted By: ken m sub panel grounding - 10/02/01 08:08 PM
i know this is a particularly worn out question. however, would someone please tell me the code book location that pertains to why a 4 wire feeder is needed for a sub panel that is fed either from the load side of the meter or is fed from a breaker located within the main panel? the local inspectors are looking for backup (reference) when the meter box and the main panel are not located back-to-back and a 4 wire is needed. thx for any help. ken m
Posted By: Nick Re: sub panel grounding - 10/02/01 08:37 PM
250-24(a)(5)
"LOAD SIDE GROUNDING CONNECTIONS. A grounding connection shall not be made to any grounded circuit conductor on the load side of the service disconnecting means except as otherwise permitted in this article."
This is assuming your Main Bonding Jumper is located in the meter enclosure. [Linked Image]
Posted By: resqcapt19 Re: sub panel grounding - 10/02/01 09:02 PM
Nick,
It has nothing to do with the location of the main bonding jumper. If there is no service disconnect between the meter and the panel a 4 wire conenction is not required. The grounded conductor can be used to bond anything on the line side of the service disconenct and within the service disconnect enclosure. The 4 wire feeders are only required on the load side of the service disconnecting means.

Don(resqcapt19)
Posted By: Nick Re: sub panel grounding - 10/02/01 09:19 PM
Your right! [Linked Image]
Posted By: Joe Tedesco Re: sub panel grounding - 10/02/01 11:25 PM
See Section 384-20 for the refrence that includes the answer to the question. The NECH also gives a good explanation as to the reason for the isolated neutral in that sub panel.
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