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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:14.0pt;font-family:"Century Gothic","sans-serif"'>Seriously I have never heard of 99% eff. under load with a transformer. Anyone else heard of this kind of eff. factor?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif"'><o:p> </o:p></span></p><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Century Gothic","sans-serif"'>Dana Orzel<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Century Gothic","sans-serif"'>Great Solar Works, Inc<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Century Gothic","sans-serif"'>E - dana@solarwork.com<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Century Gothic","sans-serif"'>V - 970.626.5253<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Century Gothic","sans-serif"'>F - 970.626.4140<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Century Gothic","sans-serif"'>C - 970.209.4076<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Century Gothic","sans-serif"'>web - www.solarwork.com<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Century Gothic","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Century Gothic","sans-serif"'>"Responsible Technologies for Responsible People since 1988"</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Century Gothic","sans-serif"'>Do not ever believe anything, but seriously trust through action.<o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif"'><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 style='margin-left:.5in'><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>Mark Frye<br><b>Sent:</b> Monday, July 25, 2011 9:11 AM<br><b>To:</b> 'RE-wrenches'<br><b>Subject:</b> Re: [RE-wrenches] Efficient step up, down transformers<o:p></o:p></span></p></div></div><p class=MsoNormal style='margin-left:.5in'><o:p> </o:p></p><p class=MsoNormal style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>Lars,</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p><p class=MsoNormal style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>Scary stuff. I worked with a system similar to this and went with big wire.</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p><p class=MsoNormal style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>The problem with xfrms is that you can either have low standby losses and good efficency at load or vis-a-versa, but you can't really have both. </span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p><p class=MsoNormal style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>Were the xfrms specifically wound for 120x480 conversion? If not, it is possible that the coil taps are connected in a manner that is not efficient.</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p><div><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>That being said, 15.6 A @ 120V sound like an awefully large number. Perhaps you have a bad connection at one of your pull boxes.</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>I would be happy to stop by and take a look at the xfrm spec etc. with you.</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><br></span><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Mark Frye</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <br></span><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Berkeley Solar Electric Systems</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <br></span><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>303 Redbud Way</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <br></span><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Nevada City, CA 95959</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <br></span><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>(530) 401-8024</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <br><a href="http://www.berkeleysolar.com/"><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>www.berkeleysolar.com</span></a></span><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> </span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p></div><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><div class=MsoNormal align=center style='margin-left:.5in;text-align:center'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><hr size=3 width="100%" align=center></span></div><p class=MsoNormal style='mso-margin-top-alt:0in;margin-right:0in;margin-bottom:12.0pt;margin-left:.5in'><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>lars Ortegren<br><b>Sent:</b> Monday, July 25, 2011 7:43 AM<br><b>To:</b> re-wrenches@lists.re-wrenches.org<br><b>Subject:</b> [RE-wrenches] Efficient step up, down transformers</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p><p class=MsoNormal style='margin-left:.5in'>Wrenches,<o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'> I recently installed three “ultra -efficient” step up-down transformers on an off grid micro grid project with a 1500’ wire run. The grid is powered by a an old SW4024(120v) output, stepped up to 480v, and stepped down to 240v at two locations. I was told by the manufacturer that they were “99% efficient under a full load”, but upon firing up the system, I found a NO LOAD AMPEREAGE OF 15.6 amps!!! Needless to say, a completely unworkable situation for an off grid scenario, as the 840ah battery would be drained in a couple of hours before anything was turned on. I’m wondering if anyone out there has either found off grid friendly step up-down transformers, or if I’m just screwed and need to pull parallel 4/0 runs (probably the price of a new car) to fix the problem. HELP!<o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'><o:p> </o:p></p><p class=MsoNormal style='margin-left:.5in'><b><i>Lars Ortegren<o:p></o:p></i></b></p><p class=MsoNormal style='margin-left:.5in'><o:p> </o:p></p><p class=MsoNormal style='margin-left:.5in'><span style='font-family:"Bodoni MT"'>Director of Operations<o:p></o:p></span></p><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Berlin Sans FB";color:#002060'>California Solar Electric Company<o:p></o:p></span></p><p class=MsoNormal style='margin-left:.5in'>10141 Evening Star Drive, Suite 6<o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'>Grass Valley, CA 95945<o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'><o:p> </o:p></p><p class=MsoNormal style='margin-left:.5in'>Phone : (530)274-3671<o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'>Fax: (530)274-7518<o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'><o:p> </o:p></p></div></body></html>