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--></style></head><body lang="EN-US" link="blue" vlink="purple"><div class="WordSection1"><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Friends:</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">I have an installation of 12 Enphase IQ inverters that is downstream from a generator transfer switch. During power outages the generator will run poorly when the Enphase is on and the sun is shining. The problems go away when the Enphase is shut off. No surprises about this.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">The Enphase is installed on a barn about 150 conduit feet from the generator transfer switch. My plan is to create a low voltage signal when the generator is running and send it to a coil on a contactor in the barn. Said contactor will disconnect the 12 micro-inverters.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">There is existing one 26 AWG pairs of a Cat 6 cable running between the buildings. I have found a two pole, 30A contactor that draws 7 watts on the coil. The voltage drop calcs on 150 feet of 26 AWG wire shows a 24 volt signal will not cause excessive voltage drop (~4%).</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Here is where I am uncertain: Should I run 24 volts AC or DC? My concern about DC is if there are any damp connections, electrolysis will occur that might erode the 26 AWG conductors. We’ve all seen powder where copper used to be. Is AC less susceptible to electrolysis? My research has turned up no pertinent conclusions.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Thanks in advance.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">William Miller</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">Miller Solar</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">17395 Oak Road, Atascadero, CA 93422</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">805-438-5600</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif""><a href="http://www.millersolar.com/">www.millersolar.com</a></span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">CA Lic. 773985</span></p><p class="MsoNormal"> </p><p class="MsoNormal"> </p></div></body></html>