GFP on switch

[Grouch1980]

Hi all,
So for a hotel project i'm working on, the incoming service to the building is 120/208 volts, 3 phase, 4 wire. We have a 2500 amp service switch (@ 120/208 volts) that feeds a 750 KVA step up transformer, thereby stepping up the voltage to 277/480 volts to feed equipment on the roof of the building. The 750 KVA transformer has a secondary disconnect switch (for secondary protection) sized at 1200 amps, with 1200 amp fuses (@ 277/480 volts). My question is, does this 1200 amp secondary switch / fuse need ground fault protection in accordance with section 230.95 of the NEC? I'm being told it does require it... but to me, the 1200 amp switch isn't a service switch... or is it?

Thanks!

 

[iwire]

My question is, does this 1200 amp secondary switch / fuse need ground fault protection in accordance with section 230.95 of the NEC?

No, the secondary side of a customer owned transformer does not require GFP directly per 230.95

I'm being told it does require it... but to me, the 1200 amp switch isn't a service switch... or is it?

I agree with you here, it is not service switch. Direct those that are you citing 230.95 to the definition of service in article 100 and the scope of article 230 found in 230.1



However, article 215 does apply.

ARTICLE 215
Feeders

215.1 Scope. This article covers the installation requirements,
overcurrent protection requirements, minimum size,
and ampacity of conductors for feeders supplying branch circuit
loads.

215.10 Ground-Fault Protection of Equipment. Each
feeder disconnect rated 1000 amperes or more and installed
on solidly grounded wye electrical systems of more than
150 volts to ground, but not exceeding 600 volts phase-tophase,
shall be provided with ground-fault protection of
equipment in accordance with the provisions of 230.95.

Informational Note: For buildings that contain health care
occupancies, see the requirements of 517.17.

Exception No. 1: The provisions of this section shall not
apply to a disconnecting means for a continuous industrial
process where a nonorderly shutdown will introduce additional
or increased hazards.

Exception No. 2: The provisions of this section shall not
apply if ground-fault protection of equipment is provided on
the supply side of the feeder and on the load side of any
transformer supplying the feeder.

So while 230.95 does not directly apply past the service disconnecting means in some cases feeders have to comply with it.

 

[jap]

With that being said a Ground Fault Circuit Breaker might have been a better choice, rather than the "Fused Switch".


JAP>