<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I think the issue is that some installers are wanting the supplementary electrode for the array tied to the building grounding system in two places. I saw this in BIll Brooks seminar too, but then he said it wasn't necessary. Basically the EGC system already ties both electrodes together as required, and a 2nd conductor directly between the two electrodes can create a lightning loop.<div>If the electrodes would be close together, you can actually drop the array electrode, and tie straight to the building electrode. But if it is on the other side of the building for instance, some have run 2 conductors, 1) the already required EGC through the AC conduit, and then 2) a separate GEC on the outside of the building that connects the electrodes a 2nd time. </div><div><br></div><div>This would be the same logic as bonding your electrode of your house to your neighbor's house: it's not necessary ( they're already bonded through the services) and it can cause trouble, especially with lightning.</div><div>Even my new ground impedance tester only works, if each grounding electrode is bonded once (and only once) to the rest of the grounding system. </div><div>It's a key point of lighting protection in multiple electrode grounding systems too: never create loops in your grounding system. </div><div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>R. Walters</div><div><a href="mailto:ray@solarray.com">ray@solarray.com</a></div><div>Solar Engineer</div><div><br class="khtml-block-placeholder"></div><div><br class="khtml-block-placeholder"></div><br class="Apple-interchange-newline"></span>
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<br><div><div>On Aug 23, 2010, at 9:27 AM, Matt Lafferty wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div lang="EN-US" link="blue" vlink="purple"><div dir="ltr" align="left"><span class="328123715-23082010"><font color="#0000ff" size="2" face="Arial">Hi Jason,</font></span></div><div dir="ltr" align="left"><span class="328123715-23082010"><font color="#0000ff" size="2" face="Arial"></font></span> </div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010">I'm a little confused about your intention.<span class="Apple-converted-space"> </span></span></font><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010">I think you might be making this harder than it needs to be. Everything you need is right there in 2008 NEC 690.47(C).</span></font></div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010"></span></font> </div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010">Where are you tying into the building AC distribution system? Get your GEC the same place the existing AC distribution system at your point of interconnection is bonded.<span class="Apple-converted-space"> </span></span></font><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010">If the grounding electrode conductor for the point of interconnection is building steel (like the delta-wye transformer scenario described in your original post), source your GEC there.</span></font></div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010"></span></font> </div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010">Your AC & DC grounding system(s) must be bonded together per<font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010"> 690.47(C)(1).<span class="Apple-converted-space"> </span></span></font>For "normal" interactive, non-backup systems, I use a common ground bus for both AC & DC (690.47(C)(5). I size it and any bonding jumpers as the smaller of #8 CU or whatever 690.47(C)(2) & 690.47(C)(7) comes out to.<span class="Apple-converted-space"> </span></span></font><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010">My common GEC originates at the AC interconnection per 690.47(C)(6) & 690.47(C)(8). I run the common GEC to and thru the inverter(s) and out to the array thru the raceway system.</span></font></div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010"></span></font> </div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010"></span></font><span class="328123715-23082010"><div><font face="Arial"><font color="#0000ff"><font size="2">NOTE: Once you are on the <span class="328123715-23082010">array</span><span class="Apple-converted-space"> </span>side of the inverter(s), the GEC is a<span class="328123715-23082010"><span class="Apple-converted-space"> </span>DC</span> equipment ground. <span class="328123715-23082010">I size it not smaller than #8 and large enough to carry any unintentional system currents safely to ground based on the DC configuration. This may result in multiple ground conductors running thru different conduits. Every pipe (AC & DC) gets a ground wire in my systems. DC raceways should also be bonded to the GEC (meyers-hub, ground-bushing, etc.). AC raceways on the load side of an OCP do not require this provision by code, but it doesn't hurt to go ahead and do it anyway.</span></font></font></font></div><div><font color="#0000ff" size="2" face="Arial"></font> </div></span></div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010">690.47(D) is for equipment grounding.<span class="Apple-converted-space"> </span><span class="328123715-23082010">This is a separate issue from the system GECs described in 690.47(C). I consider it to be "enhanced" or "bonus" equipment grounding. </span></span></font><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010"><u><strong>In addition</strong></u><span class="Apple-converted-space"> </span>to the requirements of 690.47(C), you must<span class="Apple-converted-space"> </span><strong><u>ALSO</u></strong><span class="Apple-converted-space"> </span>bond your rack to the building steel and make sure the steel is properly bonded to earth,<span class="Apple-converted-space"> </span><em>OR</em> run a separate ground conductor from the rack to a grounding electrode. Either way, this becomes another grounding electrode system that you need to bond to your 690.47(C) GEC system. If you are bonding all your equipment correctly, this<span class="Apple-converted-space"> </span><em>should</em><span class="Apple-converted-space"> </span>happen via the equipment grounding conductor(s) mentioned in the NOTE above.</span></font></div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010"></span></font> </div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010">I hope this helps clarify it for you.</span></font></div><div><font color="#0000ff" size="2" face="Arial"><span class="328123715-23082010"></span></font> </div><div><strong><i><span style="font-family: 'Monotype Corsiva'; ">Matt Lafferty</span></i></strong></div><div class="Section1"><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: Arial; font-size: 10pt; "><a href="mailto:gilligan06@gmail.com" style="color: blue; text-decoration: underline; ">gilligan06@gmail.com</a></span></div></div><div><font size="2" face="Arial"></font> </div><div><font size="2" face="Arial"></font> </div><br><div dir="ltr" lang="en-us" class="OutlookMessageHeader" align="left"><hr tabindex="-1"><font size="2" face="Tahoma"><b>From:</b><span class="Apple-converted-space"> </span><a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" style="color: blue; text-decoration: underline; ">re-wrenches-bounces@lists.re-wrenches.org</a><span class="Apple-converted-space"> </span>[mailto:re-wrenches-bounces@lists.re-wrenches.org]<span class="Apple-converted-space"> </span><b>On Behalf Of<span class="Apple-converted-space"> </span></b>Jason Szrom<br><b>Sent:</b><span class="Apple-converted-space"> </span>Monday, August 23, 2010 6:41 AM<br><b>To:</b><span class="Apple-converted-space"> </span>RE-wrenches<br><b>Subject:</b><span class="Apple-converted-space"> </span>Re: [RE-wrenches] PV GEC to the same point as the utilityservice GEC?<br></font><br></div><div></div><div class="WordSection1" style="page: WordSection1; "><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); ">Matt,<o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); ">Thanks for the reply. I should have clarified, but I am talking about a standard grid-tied, non-backup system.<o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); ">I’m still not quite sure I have any solid code sections to back up my assumption that it is OK to tie the inverter GEC to the nearest steel, rather than running all the way back to the water main (where the utility service entrance GEC is tied).<o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); ">If we have an inverter mounted on a roof, are you saying we can or cannot go to the closest building steel with the GEC? 690.47(C)(6) sounds like we have to go back to the water main. While 690.47(D) sounds like we are supposed to tie to the nearest building steel (“Grounding electrodes shall be installed… as close as practicable to the location of roof-mounted photovoltaic arrays”).<o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); ">Thanks for any clarifications,<o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><b><span style="color: rgb(36, 64, 97); font-size: 12pt; ">Jason M. Szrom, PE<o:p></o:p></span></b></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(36, 64, 97); font-size: 12pt; ">Engineer<o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(36, 64, 97); ">Solar Energy Systems, LLC<o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(36, 64, 97); ">718-389-1545 x13<o:p></o:p></span></div></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div><div style="border-bottom-width: medium; border-bottom-style: none; border-bottom-color: initial; border-left-width: medium; border-left-style: none; border-left-color: initial; padding-bottom: 0in; padding-left: 0in; padding-right: 0in; border-top-color: rgb(181, 196, 223); border-top-width: 1pt; border-top-style: solid; border-right-width: medium; border-right-style: none; border-right-color: initial; padding-top: 3pt; "><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><b><span style="font-family: Tahoma, sans-serif; font-size: 10pt; ">From:</span></b><span style="font-family: Tahoma, sans-serif; font-size: 10pt; "><span class="Apple-converted-space"> </span><a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" style="color: blue; text-decoration: underline; ">re-wrenches-bounces@lists.re-wrenches.org</a><span class="Apple-converted-space"> </span>[mailto:re-wrenches-bounces@lists.re-wrenches.org]<span class="Apple-converted-space"> </span><b>On Behalf Of<span class="Apple-converted-space"> </span></b>Matt Lafferty<br><b>Sent:</b><span class="Apple-converted-space"> </span>Thursday, August 19, 2010 2:01 PM<br><b>To:</b><span class="Apple-converted-space"> </span>'RE-wrenches'<br><b>Subject:</b><span class="Apple-converted-space"> </span>Re: [RE-wrenches] PV GEC to the same point as the utility service GEC?<o:p></o:p></span></div></div></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><o:p> </o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: Arial, sans-serif; color: blue; font-size: 10pt; ">Good questions, Jason.</span><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "> <o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: Arial, sans-serif; color: blue; font-size: 10pt; ">No. Yes (2008 NEC 690.47(C) & (D)).</span><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "> <o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: Arial, sans-serif; color: blue; font-size: 10pt; ">Alternative considerations that might result in a "maybe": Does the system in question have storage (i.e. batteries)? Is your POCC on a Delta system? (your hi-rise example says Wye... But if it is directly tied to a Delta system, you might gotta run back to basement.)</span><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "> <o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: Arial, sans-serif; color: blue; font-size: 10pt; ">If you are talking about a standard, grid-tied, non-backup system, and the AC distribution between your tie-in and the utility is suitably sized for the PV, you should hit the GE system where your AC system is getting it's neutral bond. (Closest steel OK for PV grounding electrode.) Equipment ground, same thing. Be sure to run an equipment grounding conductor from the inverter to the array (i.e. don't just bond the rack to building steel).</span><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "> <o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: Arial, sans-serif; color: blue; font-size: 10pt; ">Regarding your Additional Info items:</span><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: Arial, sans-serif; color: blue; font-size: 10pt; ">1. Yep.</span><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: Arial, sans-serif; color: blue; font-size: 10pt; ">2. Some people on this list and in the AHJ community would argue that the AC side of the inverter in this case IS a separately derived system in all cases (I'm not among that bunch). Either way, the output of your entire system is going thru the building's AC distribution system. ESPECIALLY if you are on the secondary of a WYE xfrmer, you can and SHOULD source your PV GEC where the xfrmer neutral is bonded.</span><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: Arial, sans-serif; color: blue; font-size: 10pt; ">3. You are right. The various provisions of 690.47(C) allow/require this. In particular, (C)5 & 6.</span><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "> <o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: Arial, sans-serif; color: blue; font-size: 10pt; ">The underlying principle that counts here is, "Get your GEC where your AC source gets its system ground."</span><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "> <o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><strong><i><span style="font-family: 'Monotype Corsiva'; font-size: 12pt; ">Matt "I'm no building inspector" Lafferty</span></i></strong><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p> </o:p></span></div><div class="MsoNormal" align="center" style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; font-family: Calibri, sans-serif; font-size: 11pt; text-align: center; "><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><hr align="center" size="2" width="100%"></span></div><p class="MsoNormal" style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 12pt; "><b><span style="font-family: Tahoma, sans-serif; font-size: 10pt; ">From:</span></b><span style="font-family: Tahoma, sans-serif; font-size: 10pt; "><span class="Apple-converted-space"> </span><a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" style="color: blue; text-decoration: underline; ">re-wrenches-bounces@lists.re-wrenches.org</a><span class="Apple-converted-space"> </span>[mailto:re-wrenches-bounces@lists.re-wrenches.org]<span class="Apple-converted-space"> </span><b>On Behalf Of<span class="Apple-converted-space"> </span></b>Jason Szrom<br><b>Sent:</b><span class="Apple-converted-space"> </span>Thursday, August 19, 2010 7:38 AM<br><b>To:</b><span class="Apple-converted-space"> </span><a href="mailto:re-wrenches@lists.re-wrenches.org" style="color: blue; text-decoration: underline; ">re-wrenches@lists.re-wrenches.org</a><br><b>Subject:</b><span class="Apple-converted-space"> </span>[RE-wrenches] PV GEC to the same point as the utility service GEC?</span><span style="font-family: 'Times New Roman', serif; font-size: 12pt; "><o:p></o:p></span></p><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; ">Wrenches,<o:p></o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><o:p> </o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; ">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?<o:p></o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><o:p> </o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; ">Additional info:<o:p></o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0.5in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; text-indent: -0.25in; ">1.<span style="font-family: 'Times New Roman', serif; font-size: 7pt; "> <span class="Apple-converted-space"> </span></span>The DC side of the inverter is a separately derived system and therefore needs a GEC to a ground electrode.<o:p></o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0.5in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; text-indent: -0.25in; ">2.<span style="font-family: 'Times New Roman', serif; font-size: 7pt; "> <span class="Apple-converted-space"> </span></span>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.<o:p></o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0.5in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; text-indent: -0.25in; ">3.<span style="font-family: 'Times New Roman', serif; font-size: 7pt; "> <span class="Apple-converted-space"> </span></span>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.<o:p></o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><o:p> </o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; ">Thanks for any input,<o:p></o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; ">Jason<o:p></o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><o:p> </o:p></div><div style="font-family: Calibri, sans-serif; margin-left: 0in; font-size: 11pt; margin-right: 0in; margin-top: 0in; margin-bottom: 0pt; "><b><span style="color: rgb(36, 64, 97); font-size: 12pt; ">Jason M. 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