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#77637 - 06/29/01 05:15 PM transformer grounding
dom Offline
Junior Member

Registered: 06/29/01
Posts: 8
When installing a 75kva dry type transformer,
(480delta-120/208wye) If using a water pipe as a ground electrode, does it need to be supplemented by another electrode? Would an equipment ground installed with the primary circuit feeding the transformer qualify as a supplementary ground electrode? thanks

2014 / 2011 NEC & Related Books and Study Guides
#77638 - 06/29/01 05:28 PM Re: transformer grounding
sparky Offline

Registered: 10/18/00
Posts: 5545
Hi dom!


a start..

#77639 - 06/30/01 04:19 PM Re: transformer grounding
resqcapt19 Offline

Registered: 11/10/00
Posts: 2209
Loc: IL
If the transformer feeder originates in the building service equipment, you can install the GEC in with the feeder conducotrs. See the exception in 250-30(a)(3).

#77640 - 07/02/01 05:24 PM Re: transformer grounding
dom Offline
Junior Member

Registered: 06/29/01
Posts: 8
Is there a different requirement for the ground electrode for the main switchgear(250-50) and a ground electrode at a transformer fed from a subpanel in the same system?(250-30(b)(2).- 250-30(a)(3).


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