Kelly, If I read you right you are talking about two different things. The EGC running with the PV DC circuit conductors are just that, EGC's and are sized to the largest PV DC conductor. Applying 690.47D to these conductors is incorrect.
There is a conductor running from the inverters to the main panel however. Some have argued that this conductor is subject to 690.47D, #8 minimum. What size conductor are you using here? There was some discussion that the wire running from the inverter to the main panel is not in fact the DC GEC, but rather a bonding jumper connecting the inverter AC/DC systems to the DC GEC and that this wire need only be sized to the inverter PV AC backfeed breaker. This same conductor also serves at the EGC for everything on up to the array. Mark Frye Berkeley Solar Electric Systems 303 Redbud Way Nevada City, CA 95959 (530) 401-8024 www.berkeleysolar.com -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kelly Keilwitz, Whidbey Sun & Wind Sent: Thursday, June 04, 2009 5:34 PM To: RE Wrenches listserve Subject: [RE-wrenches] FW: 690.47D (revisited) 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 _______________________________________________ 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