Thanks Dave, that is definitely helpful. I was thinking that all inverters should be considered as one system, but I realize now that is not the case from a code perspective when sizing the GEC. It makes sense that the individual inverter should be the extent of the "system," as there are many different configuration possibilities and the Code cannot be rewritten for each one.
Thanks again, Garrison Garrison Riegel Project Manager Solar Service Inc [p] 847-677-0950 [f] 847-647-9360 www.solarserviceinc.com NABCEP Certified Solar PV and Thermal InstallerT -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dave Click Sent: Wednesday, July 25, 2012 9:32 AM To: RE-wrenches Subject: Re: [RE-wrenches] DC GEC Sizing Issue - Water Main GE Garrison, In this case, the "largest conductor supplied by the system" is quoted from 250.166(B) and note that "the system" refers to the "dc system": ** 250.166 Size of the Direct-Current Grounding Electrode Conductor. The size of the grounding electrode conductor for a *dc system* shall be as specified in 250.166(A) and (B), except as permitted by 250.166(C) through (E). (B) Not Smaller Than the Largest Conductor. Where the *dc system* is other than as in 250.166(A), the grounding electrode conductor shall not be smaller than the largest conductor supplied by the system, and not smaller than 8 AWG copper or 6 AWG aluminum. ** As for the suitability of a water pipe as a "pipe electrode" it's not something I've done personally. After further research it seems like the water pipe probably fits not as 250.52(A)(5) but as (A)(1). So if you're going to building steel or a water pipe, 250.166(B) is applicable and so 8 AWG Cu should be acceptable for this connection. Hope that clarifies! DKC _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
