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--></style></head><body lang="EN-US" link="blue" vlink="purple"><div class="WordSection1"><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a">Hi Dana,</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a">This is still a confusing issue, I agree. This article helps a bit:</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a"><a href="http://www.nmsu.edu/~tdi/pdf-resources/IAEI%20Mar_Apr%202012.pdf">http://www.nmsu.edu/~tdi/pdf-resources/IAEI%20Mar_Apr%202012.pdf</a></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a">If you look in a SMA TL inverter installation manual, for example, they only mention equipment grounds – there is no reference to a GEC that I can find. The 2014 code doesn’t seem to have clear wording on not requiring a GEC to me but Rebekah’s recap below is spot on. Luckily it is widely accepted in our neck of the woods that TL inverters don’t need GECs. </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a">I’m not familiar with the Solectria TL product. It sounds like it will be best to call them if you need to install one of their inverters. </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a">Best, </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a">August</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#44546a"> </span></p><div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> RE-wrenches [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Dana Brandt<br><b>Sent:</b> Monday, November 03, 2014 12:06 PM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] Code reference request</span></p></div><p class="MsoNormal"> </p><div><div><div><p class="MsoNormal" style="margin-bottom:12.0pt">I think I'm a bit confused on this point. I can't seem to find the code that specifically exempts the GEC requirement for inverters of ungrounded PV systems. The only exception I can find is only for AC PV modules (2014 NEC 690.47 (C) ). </p></div><p class="MsoNormal" style="margin-bottom:12.0pt">I just looked in the installation manual for Solectria's new TL inverters and found this:<br>"Per NEC 690.47, a GEC must be installed, and the Grounding Electrode Terminal (GET) conductor must be sized in accordance with NEC article 250.166."</p></div><div><p class="MsoNormal">What am I missing?<br><br>Thanks,</p></div><div><div><div><div><p class="MsoNormal"><br clear="all"></p><div><div><div><p class="MsoNormal">Dana<br><br>Dana Brandt<br>Ecotech Energy Systems, LLC<br><a href="http://www.ecotechenergy.com" target="_blank">www.ecotechenergy.com</a><br><a href="mailto:dana@ecotechenergy.com" target="_blank">dana@ecotechenergy.com</a><br>360.318.7646</p></div></div></div><p class="MsoNormal"> </p><div><p class="MsoNormal">On Tue, Oct 28, 2014 at 11:30 AM, Rebekah Hren <<a href="mailto:rebekah.hren@o2energies.com" target="_blank">rebekah.hren@o2energies.com</a>> wrote:</p><div><p class="MsoNormal">If you are on 2014:</p><div><p class="MsoNormal"> 690.47(B) </p><div><div><div><p><span style="font-size:10.0pt;font-family:"Times","serif"">An ac equipment grounding system shall be permitted </span></p></div></div><div><div><p><span style="font-size:10.0pt;font-family:"Times","serif"">to be used for equipment grounding of inverters and other </span></p></div></div><div><div><p><span style="font-size:10.0pt;font-family:"Times","serif"">equipment <b>and for the ground-fault detection reference for </b></span></p></div></div></div><div><p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Times","serif"">ungrounded PV systems.</span></b></p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">and 690.47(C)(3) </p></div></div><div><div><div><div><p><b><span style="font-size:10.0pt;font-family:"Times","serif"">For ungrounded systems, this conductor shall be sized in accordance with 250.122 </span></b><span style="font-size:10.0pt;font-family:"Times","serif"">and shall</span></p></div></div><div><div><p><span style="font-size:10.0pt;font-family:"Times","serif"">not be required to be larger than the largest ungrounded </span></p></div></div><div><div><p><span style="font-size:10.0pt;font-family:"Times","serif"">phase conductor. </span></p></div></div></div></div></div><div><div><div><p class="MsoNormal"> </p><div><p class="MsoNormal">On Tue, Oct 28, 2014 at 2:22 PM, Gary Willett <<a href="mailto:Gary@icarussolarservices.com" target="_blank">Gary@icarussolarservices.com</a>> wrote:</p><p class="MsoNormal">Kirk:<br><br>A DC grounding electrode conductor (GEC) is not required for inverters that do NOT have a ground reference for the PV+ and PV- conductor(s) from the PV array.<br><br>A GEC is not required if the string inverter is one of the new TL (transformerless) types. Also, this applies to micro-inverters such as the new Enphase M250 and later versions of the M215.<br><br>Where this applies, only a properly sized equipment grounding conductor (EGC) is required.<br><br>The EGC is sized according to [NEC 690.45] and can be a minimum of #14AWG when not exposed to damage, or #6AWG when exposed to potential damage.<br><br>Regards,<br><br>Gary Willett PE<br>Icarus Engineering LLC</p><div><div><p class="MsoNormal"><br><br>On 10/28/14, 12:53 PM, Kirk wrote:</p><p class="MsoNormal" style="margin-bottom:12.0pt">Hi,<br>I'm on a jobsite without my code book. Could someone tell me where in the code ungrounded systems do not require the inverter GEC? Basically my onsite electrician doesn't believe me. Thanks.<br><br>Kirk Herander<br>VSE<br>_______________________________________________<br>List sponsored by Redwood Alliance<br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">RE-wrenches@lists.re-wrenches.org</a><br><br>Change listserver email address & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>List-Archive: <a href="http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html" target="_blank">http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm" target="_blank">www.re-wrenches.org/etiquette.htm</a><br><br>Check out or update participant bios:<br><a href="http://www.members.re-wrenches.org" target="_blank">www.members.re-wrenches.org</a></p><p class="MsoNormal" style="margin-bottom:12.0pt"><br>_______________________________________________<br>List sponsored by Redwood Alliance<br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">RE-wrenches@lists.re-wrenches.org</a><br><br>Change listserver email address & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>List-Archive: <a href="http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html" target="_blank">http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm" target="_blank">www.re-wrenches.org/etiquette.htm</a><br><br>Check out or update participant bios:<br><a href="http://www.members.re-wrenches.org" target="_blank">www.members.re-wrenches.org</a></p></div></div></div><p class="MsoNormal"><br><br clear="all"></p><div><p class="MsoNormal"> </p></div></div></div><p class="MsoNormal"><span style="color:#888888">-- </span></p><div><p class="MsoNormal"><span style="color:#888888">Tel: <a href="tel:336.266.8800" target="_blank">336.266.8800</a><br><a href="http://o2energies.com/" target="_blank">http://o2energies.com/</a><br>Project Engineer<br>NABCEP Certified PV Installation Professional™ 091209-85<br>NC Licensed Electrical Contractor<br><br>This message, together with any attachments, is intended only for the named recipient(s). 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