Kelly, If I understand your situation, the AHJ is allowing you to use the existing grounding electrode/s as the (new for 2008) required array electrode, rather than adding an additional electrode closer to the array.
He does want an additional GROUNDING ELECTRODE CONDUCTOR, sized appropriately, and, of course, run separately from the array circuit conductors, directly from the array to the existing electrode. If this is the case, it makes sense. You dont want to depend on your EQUIPMENT GROUNDING CONDUCTOR, run with your circuit conductors, to carry energy from a lightning strike, for instance. Take that energy (renewable but undesired) to EARTH / GROUND as directly as possible. Hope this helps. Dick Solarwind Electric Bradford, VT --- You wrote: All, This issue was discussed here about a year ago, before most jurisdictions had adopted the 2008 Code and AHJ's started interpreting it. Our current situation is a residential, roof-mounted PV array, with not an extraordinary distance to the existing AC GEC. The AHJ has NOT required the "additional PV" GE, but IS requiring the extra GEC from the array to the AC/DC GE, on the grounds of (690.47D) "The dc grounding electrode conductor shall be sized according to 250.166" (i.e. #8 min). We have the standard EGC inside the conduit, running with the PV DC circuit conductors. Is there any "grounds" for this requirement? What are your AHJ's requiring? Thanks, Kelly Keilwitz, P.E. Whidbey Sun & Wind, LLC Renewable Energy Systems NABCEP Certified PV Installer WA Electrical Administrator #KEILWKM923RB 987 Wanamaker Rd. Coupeville, WA, 98239 360.678.7131 sunw...@whidbeysunwind.com WA Electrical Contractor #WHIDBSW920MS WA General Contractor #WHIDBSW946M1 --- end of quote --- _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org 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
