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Posted By: Roger Generator OCPD listed for service entrance - 01/22/04 02:19 AM
Opinions with code references please.

Optional Standby Generator with 600 amp breaker in onboard enclosure, Service Rated and Listed by special order.

Generator is SDS and sits 50' from entrance into mech room where another switch is installed adjacent to Normal power MDP.

Does anybody know of a reason per any codes that there should be a Service Rated Switch installed closer to the building, or that the interior switch should be located nearest point of entrance per 230.70(A)(1).

Also with this Service Disconnect located at the Generator, wouldn't we be meeting 230.72(B)?

Roger
I'm stumped!
Can't help at all.
Doesn't the feeder usually go directly from main switch in the generator to the tansfer switch?
Roger,
Is the generator in the same building as the MDP?
Don
Posted By: Roger Re: Generator OCPD listed for service entrance - 01/22/04 10:50 PM
Hello Russ and Don.

Don the generator sits outside the building and is feeding a UPS in a computer room. (this is at a university and backs up the network campus wide)

The state inspector, who I've not spoke with yet, left the job with out inspecting the installation saying or implying the generator disconnect (enclosed breaker) could not be used for the service disconnect even though it is listed as such.

Roger
Roger,
If the generator is at a second building then wouldn't 225.31 require a disconnect at the main building located per 225.32? Or does this installation meet Exception #1 to 225.32?
Don
The generator is not a service as per the 2002 NEC.
Service (Article 100). The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served.

This installation falls under 225.30(A)(4)

I believe as Don has stated that the exception #1 to 225.32 would make the described installation compliant with the NEC. The switch still has to follow 225.36 Suitable for Service Equipment.

Pierre
For most AHJs the conditions of maintenance and supervision that would fulfill the exception is full time on site electrical staff.
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Tom H
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