# Grounding and Bonding



## ablyss (Feb 8, 2014)

Dominick said:


> So im installing a small single phase !5kva Liebert UPS tomorrow. Im trying to be clear on bonding my raceway which feeds my disconnect. Is a UPS which feeds a !00 amp single phase panel a separately derived system? This UPS does not have a built in transformer. Thanks for any help!



Maybe 250.30(A)(6) Exception No. 2 is what you're looking for:


> A grounding electrode conductor shall not be required for a system that supplies Class 1, Class 2, or Class 3 circuit and is derived from a transformer rated not more than 1000 volt-amperes, provided the system grounded conductor is bonded to the transformer frame or enclosure by a jumper sized in accordance with 250.30(A)(1)


I'm thinking you do need to run a separate grounding electrode as your 5KVA exceeds the 1KVA limit.


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## Dominick (Apr 18, 2011)

I will be running a ground wire to building steel which qualifies as a grounding electrode. My question is since my neutral is not switched do I still need a grounding bushing on my raceway entering my disconnect.


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## brian john (Mar 11, 2007)

Is there in internal bypass with a neutral, if so then it is not a separately derived system.


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## Dominick (Apr 18, 2011)

There is a bypass on the unit, so with that being said it does't need the grounding bushing since its not service equipment or a separately derived system?


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