separately derived system grounding

[sevlander]

When grounding a separately derived system, specifically a 480/208-120 transformer, is building steel adequate if the main service has met all grounding and bonding requirements? Do any other bonds at the transformer location need to be installed?

 

[dnbob]

Re: separately derived system grounding

If the building steel is effectively grounded, then yes it is acceptable. 250.104 a4exeption (NEC 2002)

 

[sandsnow]

Re: separately derived system grounding

Going to bldg steel covers you on having an electrode.
If present in the area served by the XFMR, you have to bond the CW system

edit oops: Unless the CW is already bonded to the bldg steel

[ December 22, 2005, 06:04 PM: Message edited by: sandsnow ]