<div dir="auto">The design relies on a relay relaxing upon <span><u>loss</u> of grid voltage</span>. This is fail-safe.</div><div dir="auto"><br></div><div dir="auto">Furthermore, Enphase can be configured to send an email if production is lost so if the system fails as it should, in the no-production state, someone gets notified. <br clear="all"><br clear="all"><div dir="auto"><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><br>William Miller<br>Miller Solar.com<br>805-438-5600<br><a href="http://www.millersolar.com">www.millersolar.com</a><br></div></div></div><div><br></div><div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Tue, Jan 27, 2026 at 9:17 AM Jason Szumlanski via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)"><div dir="ltr"><div dir="ltr"><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I don't like to install anything that isn't failsafe for this purpose, so if it relies on a NC relay opening upon receiving generator voltage, I usually won't consider it because the relay can fail. And if the relay fails, there is no indication of that (other than the adverse effects that might happen).</div></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">That's just my opinion, but I can understand fringe scenarios where there just isn't a way to get the solar connected on the line side. As long as the customer signs off on the risks, I would do it, but cautiously.</div><div><br></div><div><div dir="ltr" class="gmail_signature"><div dir="ltr"><br>Jason Szumlanski<div><span style="font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px;color:rgb(51,51,51)">Principal Solar Designer | Florida Solar Design Group</span><br style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px"><span style="font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px;color:rgb(51,51,51)">NABCEP Certified Solar Professional (PVIP)</span><br style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px"><span style="font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px;color:rgb(51,51,51)">Florida State Certified Solar Contractor CVC56956</span></div><div><font face="Roboto, RobotoDraft, Helvetica, Arial, sans-serif" style="font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;color:rgb(51,51,51)">Florida Certified Electrical Contractor EC13013208</font></div></div></div></div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jan 26, 2026 at 4:41 PM Howard Scot Arey via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)"><div><div dir="auto" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(33,33,33)">Interesting. Somebody else recommended a web-based version of what you did. You were ahead of the times. I might pursue this with the web option...not the radios. Same concept - different technology.</div><div dir="auto" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(33,33,33)"><br></div><div dir="auto" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(33,33,33)">Thank you. </div><div id="m_6088292257297132606m_-2486398253330388193ms-outlook-mobile-body-separator-line" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt" dir="auto"><div dir="auto" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt"><br></div></div><div style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt" id="m_6088292257297132606m_-2486398253330388193ms-outlook-mobile-signature" dir="auto"><div dir="auto" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt"><b style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif">Howard "Scot" Arey</b></div><div dir="auto" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt"><b style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif">Owner, Solar CenTex</b></div><div dir="auto" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt"><br></div><div dir="auto" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt">NABCEP PV Installation Professional</div><div dir="auto" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt">TECL 29755</div><div dir="auto" style="font-family:Aptos,Aptos_MSFontService,-apple-system,Roboto,Arial,Helvetica,sans-serif;font-size:12pt">254-300-1228 </div></div><div dir="auto" id="m_6088292257297132606m_-2486398253330388193mail-editor-reference-message-container"><br><hr style="display:inline-block;width:98%"><div id="m_6088292257297132606m_-2486398253330388193divRplyFwdMsg" style="font-size:11pt"><strong>From:</strong> William Miller <<a href="mailto:william@millersolar.com" target="_blank">william@millersolar.com</a>><br><strong>Sent:</strong> Monday, January 26, 2026 3:28:04 PM<br><strong>To:</strong> RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>><br><strong>Cc:</strong> <a href="mailto:scot.arey@solarcentex.com" target="_blank">scot.arey@solarcentex.com</a> <<a href="mailto:scot.arey@solarcentex.com" target="_blank">scot.arey@solarcentex.com</a>><br><strong>Subject:</strong> RE: [RE-wrenches] Will IQ8 microinverters backfeed a generator during grid interruptions<br></div><br><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">Friends:</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">I had the same problem: Enphase arrays on an outbuilding which was connected to the generator side of a transfer switch. I had no independent power path from the grid to the outbuilding so the Enphase had to be connected to the load side of the transfer switch. When the large generator was powering the facility and the sun was out the generator acted wonky (unstable voltage).</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">My solution was to buy a transceiver set (National Control Devices MlrXR2x). I powered one radio from the grid side of the transfer switch and the other radio controlled a contactor on the remote Enphase feeders. When the grid goes down the contactor opens.</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">The radios were inside of two buildings and the reception was borderline. I augmented the included 900 mHz rubber duckies by replacing them with panel antennas from Pasternak. So far the system is operating as intended.</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">If anyone wants details let me know.</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">William</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">William Miller</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Arial,sans-serif;color:rgb(31,73,125)">Miller Solar</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Arial,sans-serif;color:rgb(31,73,125)"><a href="http://www.millersolar.com/" style="text-decoration:underline;font-family:Arial,sans-serif;color:blue" target="_blank">www.millersolar.com</a></span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Arial,sans-serif;color:rgb(31,73,125)">CA License C-10 77398</span></p></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:14pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p><div><div style="border-width:1pt medium medium;border-style:solid none none;padding:3pt 0in 0in;border-color:rgb(181,196,223) currentcolor currentcolor"><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><b style="font-family:"Times New Roman",serif"><span style="font-size:10pt;font-family:Tahoma,sans-serif">From:</span></b><span style="font-size:10pt;font-family:Tahoma,sans-serif"> RE-wrenches [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" style="text-decoration:underline;font-family:Tahoma,sans-serif;color:blue" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a>] <b style="font-family:Tahoma,sans-serif">On Behalf Of </b>scot.arey--- via RE-wrenches<br><b style="font-family:Tahoma,sans-serif">Sent:</b> Wednesday, January 21, 2026 12:45 PM<br><b style="font-family:Tahoma,sans-serif">To:</b> RE-wrenches<br><b style="font-family:Tahoma,sans-serif">Cc:</b> <a href="mailto:scot.arey@solarcentex.com" style="text-decoration:underline;font-family:Tahoma,sans-serif;color:blue" target="_blank">scot.arey@solarcentex.com</a><br><b style="font-family:Tahoma,sans-serif">Subject:</b> Re: [RE-wrenches] Will IQ8 microinverters backfeed a generator during grid interruptions</span></p></div></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"> </p><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black">Thanks but I'm just trying to grid-tie a small Enphase array without ESS where the point of interconnection is on the customer side of the generator/ATS.<br><br>Trying to use existing wires in place to simplify and lower costs...but the generator is my constraint because I need the PoI to be on line side of the ATS.</span></p></div><div id="m_6088292257297132606m_-2486398253330388193Signature"><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black"> </span></p></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;background:repeat white"><b style="font-family:"Times New Roman",serif"><span style="font-size:11.5pt;font-family:"Segoe UI",sans-serif;color:rgb(36,36,36)">Howard "Scot" Arey</span></b><span style="font-size:11.5pt;font-family:"Segoe UI",sans-serif;color:rgb(36,36,36)"></span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;background:repeat white"><b style="font-family:"Times New Roman",serif"><span style="font-size:11.5pt;font-family:"Segoe UI",sans-serif;color:rgb(36,36,36)">Owner, Solar CenTex</span></b><span style="font-size:11.5pt;font-family:"Segoe UI",sans-serif;color:rgb(36,36,36)"></span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;background:repeat white"><span style="font-size:11.5pt;font-family:"Segoe UI",sans-serif;color:rgb(36,36,36)">254-300-1228 </span></p><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black"> </span></p></div></div><div class="MsoNormal" align="center" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;text-align:center"><hr size="3" width="98%" align="center" style="font-family:"Times New Roman",serif"></div><div id="m_6088292257297132606m_-2486398253330388193divRplyFwdMsg"><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><b style="font-family:"Times New Roman",serif"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:black">From:</span></b><span style="font-size:11pt;font-family:Calibri,sans-serif;color:black"> RE-wrenches <<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" style="text-decoration:underline;font-family:Calibri,sans-serif;color:blue" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a>> on behalf of Jason Szumlanski via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" style="text-decoration:underline;font-family:Calibri,sans-serif;color:blue" target="_blank">re-wrenches@lists.re-wrenches.org</a>><br><b style="font-family:Calibri,sans-serif">Sent:</b> Wednesday, January 21, 2026 2:33 PM<br><b style="font-family:Calibri,sans-serif">To:</b> RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" style="text-decoration:underline;font-family:Calibri,sans-serif;color:blue" target="_blank">re-wrenches@lists.re-wrenches.org</a>><br><b style="font-family:Calibri,sans-serif">Cc:</b> Jason Szumlanski <<a href="mailto:jason@floridasolardesigngroup.com" style="text-decoration:underline;font-family:Calibri,sans-serif;color:blue" target="_blank">jason@floridasolardesigngroup.com</a>><br><b style="font-family:Calibri,sans-serif">Subject:</b> Re: [RE-wrenches] Will IQ8 microinverters backfeed a generator during grid interruptions</span> </p><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"> </p></div></div><div><div><div><div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Arial,sans-serif">I should have also noted that Enphase DOES allow use of a generator with its System Controller 3G, and supposedly the inverter, battery, and generator sources can all power loads simultaneously, so I could be wrong about how the IQ8s work. That said, Enphase has strict pairing specifications and an approved generator list. They seem confident in their ability to limit backfeed to the generator in this scenario.</span></p></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><br clear="all"></p></div><div><div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><br>Jason Szumlanski </p><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:10pt;font-family:Helvetica,sans-serif;color:rgb(51,51,51)">Principal Solar Designer | Florida Solar Design Group<br>NABCEP Certified Solar Professional (PVIP)<br>Florida State Certified Solar Contractor CVC56956</span></p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Helvetica,sans-serif;color:rgb(51,51,51)">Florida Certified Electrical Contractor EC13013208</span></p></div></div></div></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"> </p></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"> </p><div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif">On Wed, Jan 21, 2026 at 3:16 PM William Bryce via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:</p></div><blockquote style="border-width:medium medium medium 1pt;border-style:none none none solid;padding:0in 0in 0in 6pt;margin:5pt 0in 5pt 4.8pt;border-color:currentcolor currentcolor currentcolor rgb(204,204,204)"><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif">If the AC coupled exported energy is more than the generator produced energy, it can destroy the generator controller. </p><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif">That is why most AIO inverters have a relay on the dedicated AC coupling input. It will open the relay if the inverter sees generator power.</p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"> </p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif">The MNP AIO will allow both inputs, but will open the relay if the AC coupled power increases to 20% of the Generator input (firmware dependent).</p><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"> </p></div></div></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"> </p><div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif">On Wed, Jan 21, 2026 at 2:27 PM Jason Szumlanski via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:</p></div><blockquote style="border-width:medium medium medium 1pt;border-style:none none none solid;padding:0in 0in 0in 6pt;margin:5pt 0in 5pt 4.8pt;border-color:currentcolor currentcolor currentcolor rgb(204,204,204)"><div><div><div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Arial,sans-serif">Enphase IQ8 microinverters will absolutely leak some power back to the grid when set to a no-export grid profile. How much, and if that is detrimental to the generator is another question. I suspect if the generator is large enough relative to the PV array, the impact will be nil, but I would not take the risk. </span></p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Arial,sans-serif"> </span></p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Arial,sans-serif">I don't think the fast switching really does the trick in terms of not exporting. That function relies on the consumption CTs connected to the Gateway, which in turn communicates with the microinverters. Aside from the CTs not being totally accurate, I don't see how that communication loop could be fast enough.</span></p></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><br clear="all"></p></div><div><div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><br>Jason Szumlanski </p><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-size:10pt;font-family:Helvetica,sans-serif;color:rgb(51,51,51)">Principal Solar Designer | Florida Solar Design Group<br>NABCEP Certified Solar Professional (PVIP)<br>Florida State Certified Solar Contractor CVC56956</span></p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Helvetica,sans-serif;color:rgb(51,51,51)">Florida Certified Electrical Contractor EC13013208</span></p></div></div></div></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"> </p></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"> </p><div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif">On Wed, Jan 21, 2026 at 12:09 PM scot.arey--- via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:</p></div><blockquote style="border-width:medium medium medium 1pt;border-style:none none none solid;padding:0in 0in 0in 6pt;margin:5pt 0in 5pt 4.8pt;border-color:currentcolor currentcolor currentcolor rgb(204,204,204)"><div><div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black">Good day,</span></p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black"> </span></p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black">I many years ago watched the fast-switching capabilities of the IQ-8 microinverters to produce only what demanded of the MI, and wondered if it might have application in a grid-tied system that is served by a whole-house generator.</span></p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black"> </span></p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black">We have the opportunity to install grid-tied-only array of 24 IQ8 but all the MIs will be on the customer side of an auto-transfer switch and generator. We want to leverage using existing building wiring to carry the solar and all solar sizing meets the 120% rules.</span></p></div><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black"> </span></p></div><div><p class="MsoNormal" style="margin:0in 0in 12pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black">But I know that grid-tied solar on the customer load-side of the transfer switch means no place for full solar power production to flow to when the grid is not available...but then I thought back to that fast switching capability: is there a way to ensure the IQ8 don't backfeed a generator when it is operating for a grid anomaly?<br><br>I suspect the answer is "are you nuts???" but that video of capability got me thinking, "why not?" and if not, how is it - what tells the MI to cease production? - when it is within a full and proper ISC/ESS system design?</span></p></div><div id="m_6088292257297132606m_-2486398253330388193x_m_-2012310686094952153m_-2455509190177091410m_-242233186207474644Signature"><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black"> </span></p></div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;background:repeat white"><b style="font-family:"Times New Roman",serif"><span style="font-size:11.5pt;font-family:"Times New Roman",serif;color:rgb(36,36,36)">Howard "Scot" Arey</span></b><span style="font-size:11.5pt;font-family:"Times New Roman",serif;color:rgb(36,36,36)"></span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;background:repeat white"><b style="font-family:"Times New Roman",serif"><span style="font-size:11.5pt;font-family:"Times New Roman",serif;color:rgb(36,36,36)">Owner, Solar CenTex</span></b><span style="font-size:11.5pt;font-family:"Times New Roman",serif;color:rgb(36,36,36)"></span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;background:repeat white"><span style="font-size:11.5pt;font-family:"Times New Roman",serif;color:rgb(36,36,36)"> </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;background:repeat white"><span style="font-size:11.5pt;font-family:"Times New Roman",serif;color:rgb(36,36,36)">NABCEP PV Installation Professional</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;background:repeat white"><span style="font-size:11.5pt;font-family:"Times New Roman",serif;color:rgb(36,36,36)">TECL 29755</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;background:repeat white"><span style="font-size:11.5pt;font-family:"Times New Roman",serif;color:rgb(36,36,36)">254-300-1228 </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif;background:repeat white"><span style="font-family:Calibri,sans-serif;color:black"><img border="0" src="cid:ii_19c006f10245b16b21" alt="cid:image002.png@01DC8AD7.93B49780" style="width: 105px; max-width: 100%; font-family: Calibri, sans-serif;"></span><span style="font-family:Calibri,sans-serif;color:black"></span></p><div><p class="MsoNormal" style="margin:0in 0in 0.0001pt;font-size:12pt;font-family:"Times New Roman",serif"><span style="font-family:Calibri,sans-serif;color:black"> </span></p></div></div></div><p class="MsoNormal" style="margin:0in 0in 12pt;font-size:12pt;font-family:"Times New Roman",serif">_______________________________________________<br>List sponsored by Redwood Alliance<br><br>Pay optional member dues here: <a href="http://re-wrenches.org" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" target="_blank">http://re-wrenches.org</a><br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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/" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" target="_blank">http://www.members.re-wrenches.org</a></p></div></blockquote></div></div><p class="MsoNormal" style="margin:0in 0in 12pt;font-size:12pt;font-family:"Times New Roman",serif">_______________________________________________<br>List sponsored by Redwood Alliance<br><br>Pay optional member dues here: <a href="http://re-wrenches.org" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" target="_blank">http://re-wrenches.org</a><br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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/" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" target="_blank">http://www.members.re-wrenches.org</a></p></blockquote></div><p class="MsoNormal" style="margin:0in 0in 12pt;font-size:12pt;font-family:"Times New Roman",serif">_______________________________________________<br>List sponsored by Redwood Alliance<br><br>Pay optional member dues here: <a href="http://re-wrenches.org" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" target="_blank">http://re-wrenches.org</a><br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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/" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" 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" style="text-decoration:underline;font-family:"Times New Roman",serif;color:blue" target="_blank">http://www.members.re-wrenches.org</a></p></blockquote></div></div></div></div>
<br></div></div>_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
Pay optional member dues here: <a href="http://re-wrenches.org" rel="noreferrer" 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" rel="noreferrer" 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/" rel="noreferrer" 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" rel="noreferrer" 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" rel="noreferrer" 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" rel="noreferrer" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote></div></div>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
Pay optional member dues here: <a href="http://re-wrenches.org" rel="noreferrer" 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" rel="noreferrer" 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/" rel="noreferrer" 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" rel="noreferrer" 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" rel="noreferrer" 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" rel="noreferrer" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote></div></div>