'02 NEC - SE Rating on ATS?

[Keri_WW]

Per the '02 NEC, am I required to have a service entrance rated disconnecting means between a generator and an ATS? I only have an '05 code and need specific code sections if you guys know them.

Thanks!! :grin: :grin:
Keri

 

[pete m.]

Per the '02 NEC, am I required to have a service entrance rated disconnecting means between a generator and an ATS?Keri

The NEC would not prohibit a disconnect ahead of the ATS but it also doesn't require one unless the ATS was not SUSE (suitable for use as service equipment) rated. You might look at 230.66. Whatever means you use to disconnect the service conductors would need to be SUSE rated.

Pete

 

[tryinghard]

Per the '02 NEC, am I required to have a service entrance rated disconnecting means between a generator and an ATS?...Keri

No, unless these are the service, if so a service disconnect is required as per 230.70 and if the ATS is identified "suitable for use as service equipment", 230.66 & 230.70(C).

Otherwise the circuit feeding the ATS will provide short-circuit & ground-fault protection and the ATS is the disconnect to and from the generator source.

 

[Keri_WW]

I guess the first question should have been, is this ATS considered service entrance equipment? My thinking was that the generator was on the same level as a service xfmr, in that it was the source of power for the building. Is this correct thinking?

 

[tryinghard]

I guess the first question should have been, is this ATS considered service entrance equipment?

Only if labeled "service equipment/rated"

My thinking was that the generator was on the same level as a service xfmr, in that it was the source of power for the building. Is this correct thinking?

Maybe but not likely, is there currently a utility company serving this building?

If the generator supplies the whole building it will be considered the same as a "separately derived system" even if the neutral is not switched. It will not be considered a service unless it is owned by the service utility (not likely), it will simply be considered another source supply. In this fashion it will feed not serve. Again the short-circuit & ground-fault protection for the feeders will be on the supplies (either commercial - from utility served distribution - and or generator supply).