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</o:shapelayout></xml><![endif]--></head><body bgcolor=white 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'>It has been my experience that if Sunpower modules are installed contrary to their manufacturer recommended positive ground configuration, that in a short time you will only be generating a few watts. I have seen this in more than one instance when the array was mis-wired and the negative was the grounded conductor.<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'>Fortunately reversing the wiring allows the static charge to bleed of in a couple of weeks, and the strings returned to their expected production values.<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 would recommend against trying to use them intentionally in this fashion.<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'>-Glenn<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><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";color:windowtext'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> re-wrenches-bounces@lists.re-wrenches.org [mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Allan Sindelar<br><b>Sent:</b> Friday, November 19, 2010 10:08 AM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> [RE-wrenches] Positive-ground question re Sunpower<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'>Wrenches:<br>This has been addressed before in a slightly different context, so a short answer is enough. Can a Sunpower module be used successfully in a negative-grounded low-voltage system?<br><br>The situation: Mark in our Taos office sent me the following: <span style='color:#1F497D'>"We have an old time friend and customer. [John] and his wife used to help us on various installations years ago. They're both retired now and living on fixed limited income. About two months ago, we sold them a replacement battery bank of golf carts. They have a small off grid system with a few hundred watts of PV. Recently, [John's wife] was put on an oxygen machine for a heart condition. The machine consumes somewhere around 800 Watt-hours per day. Their system can't keep up now without running the generator most every day. I was wondering about a couple blem/cosmetic damaged panels that PosE has at their shop in Santa Fe. I'm not sure yet whether the best solution would be to upgrade their existing system, or perhaps a separate system for the O2 machine. Either way, if there is a way to help them with the equipment, then I'd be happy to donate my time to help [John] do an upgrade. If there is some way we can help them out, it would be a good thing. They're just a couple of really good people who've helped a lot of others out in their lifetime. Now they're the ones in need, and I'm just trying to find a way to help them."<br><br>We have two Sunpower 215s with cosmetic damage that can't be sold. </span>I think that one or both can be used here, but are just somewhat less efficient if negative grounded. <br><br>What's the straight scoop here, please?<br>Thanks,<br>Allan<o:p></o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt'><a href="mailto:Allan@positiveenergysolar.com" target="_blank"><span class=il>Allan</span>@positiveenergysolar.com</a><br>NABCEP Certified Photovoltaic Installer<br>EE98J Journeyman Electrician<br><b>Positive Energy, Inc.</b><br>3201 Calle Marie<br>Santa Fe, New Mexico 87507<br><b>505 424-1112</b><br><a href="http://www.positiveenergysolar.com/" target="_blank">www.positiveenergysolar.com</a></span><o:p></o:p></p></div></div></div></body></html>