<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; ">Fellow wrenches,<DIV><BR class="khtml-block-placeholder"></DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>I have been following the AC coupling discussions with interest, and now have a site where this would make a lot of sense. One question remains that I have not been able to answer by reading the archives I have found. Since the AC circuit from the batteryless UI inverter actually passes through the backup inverter before landing eventually in the main panel, does the backup inverter have to have the same listings required of UI inverters for interconnection(UL and IEEE)? For example, in Outback's white paper, they show the backup inverter as an off grid unit in one drawing, and grid-tie unit in another. Do both scenarios meet the code, as the generation (PV) is connected to a listed UI inverter? Have any of you run into trouble with AHJs when installing these AC coupled systems for battery back up in grid tied residences?</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Thanks,</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><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; "><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Jim Grundy</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">NABCEP Certified Solar PV Installer</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px">Vermont Solar Specialist Plumber PS-279</P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Elemental Energy, Inc.</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">1750 Clark Rd</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">E. Montpelier, VT<SPAN class="Apple-converted-space"> </SPAN><SPAN class="Apple-converted-space"> <SPAN class="Apple-converted-space"> </SPAN></SPAN>05651</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">802-476-3441 (p)</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">802-476-5680 (f )</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">802-272-8933 (c)</FONT></P><BR class="Apple-interchange-newline"></SPAN> </DIV><BR></DIV></BODY></HTML>