[RE-wrenches] PV GEC to the same point as the utility service GEC?

Jason Szrom jszrom at solaresystems.com
Thu Aug 19 07:38:01 PDT 2010


Wrenches,

Questions:  Does the PV GEC have to be bonded to the ground electrode system at the same point as the utility service equipment GEC? Is there a code section to back this up?

Additional info:

1.       The DC side of the inverter is a separately derived system and therefore needs a GEC to a ground electrode.

2.       The AC side of the inverter is not a separately derived system therefore 250.30(A)(7) does not apply. This section states that AC separately derived systems should be grounded to the nearest ground electrode (building steel in many cases) and therefore does not need to be bonded to the same point as the utility service GEC.

3.       My thought process is this:  The PV GEC can be bonded to the nearest ground electrode as long as this electrode is tied to the same ground electrode as the utility service electrode, forming one complete 'ground electrode system'. My opinion is that this setup is analogous to this example which is regularly seen in the field.  High rise building with structural steel bonded to water main with utility service GEC bonded as well. Delta-wye step-down transformer on an upper level with the derived neutral on the secondary bonded to closest building steel. Yet there is still an equipment grounding connection to both the primary and secondary sides of the transformer. This implies that it is OK and even preferable to tie the PV GEC to the nearest ground electrode,  but I can't find any evidence or section in the code that confirms or denies this.

Thanks for any input,
Jason

Jason M. Szrom, PE
Engineer

Solar Energy Systems, LLC
1205 Manhattan Ave
Suite 1210
Brooklyn, NY 11222

718-389-1545 x13
www.solarEsystems.com<http://www.solaresystems.com/>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20100819/555cdd03/attachment-0002.html>


More information about the RE-wrenches mailing list