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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal>Hi again wrenches. Have a customer looking for a LG Resu 10 “B” battery in good working order. Wants to add it to his current Resu 10 for additional storage.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thx<o:p></o:p></p><p class=MsoNormal>Peter Giroux<o:p></o:p></p><p class=MsoNormal>ASAE<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> RE-wrenches <re-wrenches-bounces@lists.re-wrenches.org> <b>On Behalf Of </b>Peter Giroux via RE-wrenches<br><b>Sent:</b> Monday, December 26, 2022 9:40 AM<br><b>To:</b> cwarfel@entech-engineering.com; 'RE-wrenches' <re-wrenches@lists.re-wrenches.org><br><b>Cc:</b> pgiroux@mindspring.com<br><b>Subject:</b> Re: [RE-wrenches] Utility transformer limitations<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Morning all. Just got a call from a customer with a radian and fortress battery that caught fire. Has anyone had any issues with either unit?? We have numerous systems with combos of both and no issues. System has been in place for well over a year, climate controlled garage and system has worked well. Did a BMS board replacement earlier this year.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> Any and all help appreciated.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thank you<o:p></o:p></p><p class=MsoNormal>Peter Giroux<o:p></o:p></p><p class=MsoNormal>ASAE<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> RE-wrenches <<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>> <b>On Behalf Of </b>Christopher Warfel via RE-wrenches<br><b>Sent:</b> Monday, December 26, 2022 8:17 AM<br><b>To:</b> <a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a><br><b>Cc:</b> Christopher Warfel <<a href="mailto:cwarfel@entech-engineering.com">cwarfel@entech-engineering.com</a>><br><b>Subject:</b> Re: [RE-wrenches] Utility transformer limitations<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><p><span style='font-size:13.5pt'>Wouldn't the microinverters shut down if the voltage rose? They wouldn't be able to raise voltage about PUC/DPU limits I would think. They would shut down on high voltage. I am saying this because of an experience this fall where our infamous Block Island Power Company raised the taps on a local xfmr due to their "secret heat pump program" that was dragging down local voltage. They claimed solar was a burden, but were quiet on the load building program they embarked upon without any disclosure. When the cooling loads disappeared, the voltage went above our grid tied systems set points and they shut down. We told the utility they had a high voltage problem and they adjusted the taps. Of course they did not acknowledge or thank us. It seems our little coop which is now head from a guy from the Vermont Electric Coop is taking an old utility approach instead of cooperation, integration and maximization of performance and economics. </span><o:p></o:p></p><p><span style='font-size:13.5pt'>I'd think you be able to ask how the supply can raise the voltage when there is so much diversified load on the same device. Electricians have to do a diversity calculation, and I know a utility has to conduct them as part of these studies. Worse case of no load and all generation is such a low probability that to design for it, when/if it occurred, is not a danger and of no material consequence makes little sense. But, we've been dealing with that ever since this person arrived in our neck of the woods.</span><o:p></o:p></p><p><o:p> </o:p></p><p><span style='font-size:13.5pt'>Chris Warfel </span><o:p></o:p></p><p><o:p> </o:p></p><p><o:p> </o:p></p><div><p class=MsoNormal>On 12/25/2022 5:21 PM, Garrison via RE-wrenches wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal>Hi William,<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>One possible path forward would be to ask the utility co what AC inverter capacity would be allowed. Maybe the solution would be to unplug a micro or two if you are just over the limit. Even better, maybe they would allow you set an export limit on the micros you have installed.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I had a recent situation where a 40kW DC system had exceeded a utility transformer by only 2kW AC, so a simple redesign avoided an $8k invoice from the utility. The utility was not transparent about this option at first and only made it clear after some persistence.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Good luck,<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Garrison Riegel<o:p></o:p></p></div><div><p class=MsoNormal>Celestar Solar<o:p></o:p></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal style='margin-bottom:12.0pt'>On Dec 25, 2022, at 3:14 PM, Darryl Thayer via RE-wrenches <a href="mailto:re-wrenches@lists.re-wrenches.org"><re-wrenches@lists.re-wrenches.org></a> wrote:<o:p></o:p></p></blockquote></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal> <o:p></o:p></p><div><div><p class=MsoNormal><span style='font-size:18.0pt;font-family:"Times New Roman",serif'>It is common practice for the utility to overload the transformer a lot for the potential load. They expect no one will use their service at maximum, furthermore, they expect non coincidence of loads. Look at the transformer most have a label as to the kW or the unit, and the utility should give you that number along with the impedance. Note I have had area engineers not understand that solar reduces the load on the transformer. They have two concerns, you will overload and you will raise the voltage to other customers. Overload is ridiculous; the transformer must be at least 20 kW if a 15 kW concern is valid. However, raising the voltage is not. If all the customers shut off their power, the voltage would rise to the inverter limit,and/or feed current back on the distribution line raising up/downstream customers voltage. I have had this problem, on three occasions discussions with the utility upper engineering, not local engineer, i prevailed, one case I did not. In one cast utility allowed connection and put a voltage monitor on secondary voltage, then later allowed permanent connection.. Good luck <o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Sun, Dec 25, 2022 at 1:16 PM William Miller via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'><div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'>Wrenched:</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'>Merry Christmas to those of you that observe such traditions, or substitute the winter festivity of your choice.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'>I helped a previous employee install an Enphase IQ8 system on his home. He applied for the utility approval concurrently with his building permit The day he got his final inspection the utility contacted him and claimed "The aggregate generation exceeds the identified transformer rating" and refused him a Permission to Operate letter.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'>Adding up the service ratings of the homes on his secondary we get about 336 kW of potential consumption. Adding the grid-tied systems on his secondary we get about 16.5 kW. How is it that the back-feed exceeds the transformer rating?</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'>I would appreciate any insight on how to consider this situation and how to fight it.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'>Sincerely,</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'>William Miller</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Verdana",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Arial",sans-serif'>Miller Solar</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Arial",sans-serif'>17395 Oak Road, Atascadero, CA 93422</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Arial",sans-serif'>805-438-5600</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Arial",sans-serif'><a href="http://www.millersolar.com/" target="_blank">www.millersolar.com</a></span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Arial",sans-serif'>CA Lic. 773985</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt'>_______________________________________________<br>List sponsored by Redwood Alliance<br><br>Pay optional member dues here: <a href="http://re-wrenches.org" target="_blank">http://re-wrenches.org</a><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>There are two list archives for searching. When one doesn't work, try the other:<br><a href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/" target="_blank">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br><a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm" target="_blank">http://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">http://www.members.re-wrenches.org</a><o:p></o:p></p></div></blockquote></div><p class=MsoNormal style='margin-bottom:12.0pt'>_______________________________________________<br>List sponsored by Redwood Alliance<br><br>Pay optional member dues here: <a href="http://re-wrenches.org">http://re-wrenches.org</a><br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">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">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>There are two list archives for searching. When one doesn't work, try the other:<br><a href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br><a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm">http://www.re-wrenches.org/etiquette.htm</a><br><br>Check out or update participant bios:<br><a href="http://www.members.re-wrenches.org">http://www.members.re-wrenches.org</a><o:p></o:p></p></div></blockquote><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><pre>_______________________________________________<o:p></o:p></pre><pre>List sponsored by Redwood Alliance<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Pay optional member dues here: <a href="http://re-wrenches.org">http://re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Change listserver email address & settings:<o:p></o:p></pre><pre><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>There are two list archives for searching. When one doesn't work, try the other:<o:p></o:p></pre><pre><a href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><o:p></o:p></pre><pre><a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>List rules & etiquette:<o:p></o:p></pre><pre><a href="http://www.re-wrenches.org/etiquette.htm">http://www.re-wrenches.org/etiquette.htm</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Check out or update participant bios:<o:p></o:p></pre><pre><a href="http://www.members.re-wrenches.org">http://www.members.re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre></blockquote><div><p class=MsoNormal>-- <o:p></o:p></p><div><div><div><div><div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-family:"PMingLiU-ExtB",serif'> Christopher Warfel</span><br><span style='font-family:"PMingLiU-ExtB",serif'> ENTECH Engineering, Inc.</span><br><span style='font-family:"PMingLiU-ExtB",serif'>PO Box 871, Block Island, RI 02807</span><br><span style='font-family:"PMingLiU-ExtB",serif'> 401-466-8978</span><br><a href="http://entech-engineering.com/"><span style='font-family:"PMingLiU-ExtB",serif;text-decoration:none'><img border=0 width=274 height=121 style='width:2.8541in;height:1.2604in' id="Picture_x0020_1" src="cid:image001.jpg@01D91941.A1052D60"></span></a><o:p></o:p></p></div></div></div></div></div></div></div></body></html>