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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Keith,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I think if you search the archives you will find a bunch of information on this subject. The general consensus, I believe, was to not try to back feed a generator. Make your point of interconnection ahead of the generator transfer switch. Often this means a supply side connection is easier if the home is already wired for a whole house generator. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I seriously doubt you will have a big impact on fuel consumption, even if you are able to run the PV system and generator in parallel operation. The PV to generator size ratio would need to be sufficiently small for this to work. You certainly don’t want to attempt to operate a 10kW inverter output in parallel with a 5kW generator, for example. If I understand it right, the generator would overspeed and the inverter(s) would lose sync.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Anyway, if you don’t want to replace expensive generator control boards if it doesn’t work, just isolate the systems altogether. I’ve never tried it… too chicken, or maybe too smart… </span><span style='font-size:11.0pt;font-family:Wingdings;color:#1F497D'>J</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Jason Szumlanski<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Fafco Solar</span><span style='font-size:4.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p></div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> re-wrenches-bounces@lists.re-wrenches.org [mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Keith Cronin<br><b>Sent:</b> Wednesday, July 20, 2011 3:05 PM<br><b>To:</b> RE-Wrenches<br><b>Subject:</b> [RE-wrenches] Generator-Transfer Switch-Solar<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>Wrenches<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>With the advent of micros on the scene and the potential for using a generator on an on-grid property, are any of you using a transfer switch to isolate the genny and use the PV to feed the genny to reduce fuel consumption?<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>Are there issues with frequency and voltage?<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>How are the utilities looking at these types of installations? Favorable?<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>Would you use 2 transfer switches- one ahead of the other- to completely isolate the property or circuit panel to ensure there is no chance of a backfeed?<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>Is it just better to keep things isolated as two separate systems?<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt;background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>Regards,<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>Keith<o:p></o:p></span></p></div></div></div></body></html>