Nec 250.52(a)(6)???

[Eng]

I have a situation where a 225KVA transformer is being installed in a Penthouse with no available Metal water piping or structural metal. I am running out of ideas on how to ground this transformer. I noticed that NEC 250.52(A)(6) states: Other listed grounding electrodes shall be permitted.

In your experience what has "other listed grounding electrodes" qualified as?

Thanks

 

[raider1]

I have a situation where a 225KVA transformer is being installed in a Penthouse with no available Metal water piping or structural metal. I am running out of ideas on how to ground this transformer. I noticed that NEC 250.52(A)(6) states: Other listed grounding electrodes shall be permitted.

In your experience what has "other listed grounding electrodes" qualified as?

Thanks

If you don't have a local water pipe or building steel that qualifies as a grounding electrode close by you will need to run the GEC from the transformer to the closest avaliable electrode that is part of the buildings grounding electrode systyem. You may have to run this GEC quite a ways.

As far as "Other listed grounding electrodes" I really have not seen any.

Chris

 

[tryinghard]

The other listed are forthcoming