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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Also using Drakes solution, you bypass the issue with the inverter \u201cvoltage drop\u201d causing it to go out of spec in high production times (a 5% voltage drop would really mean that the inverter would see the grid as being 5% higher than it really is when producing at full power, potentially causing a high grid voltage fault). You can then allow for more than 1% voltage drop over that distance without risking the system shutting down. You change an operational requirement constraint into a pure power production vs cost of wire issue. It might be that going with smaller wire is less expensive that the extra energy you would generate from that 1% better voltage drop.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Also you said 11.4kW inverter with 240V 1ph, which makes me think SolarEdge. If that\u2019s true then your situation just got a even better. I believe they will communicate to optimizers up to 1000\u2019 (I don\u2019t like operating at the edge of a systems spec, but might be the best option here). But they operate at the same, higher voltage under power producing conditions. That only helps your power loss issues. You can run the numbers, but you usually lose about 1/2ish total annual energy compared to the calculated %voltage drop on the DC lines. So if you have the wire run designed for 5% drop at peak power, you\u2019d really only lose roughly 2-3% total energy per year.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>With Regards,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Daniel Young, <o:p></o:p></p><p class=MsoNormal>NABCEP Certified PV Installation Professional<sup>TM</sup>: Cert #031508-90<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> RE-wrenches <re-wrenches-bounces@lists.re-wrenches.org> <b>On Behalf Of </b>drake.chamberlin@redwoodalliance.org<br><b>Sent:</b> Monday, September 17, 2018 1:50 PM<br><b>To:</b> RE-wrenches <re-wrenches@lists.re-wrenches.org><br><b>Subject:</b> Re: [RE-wrenches] Step-up/Step-down Transformer question<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>Another option would be to locate the inverters near the grid and run the DC at as high a voltage as possible. Have a separate run of wire for each of the 5 inverters. If you ran the DC at 500 V, an 11.4 kW inverter would only draw 22.8. A. Use 2/0 AL for a little over 1% VD at full power. <br><br><o:p></o:p></span></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><br>----- Original Message -----<o:p></o:p></span></p><div id=origionalMessageFromField><div><p class=MsoNormal style='background:#E4E4E4'><b><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>From:<o:p></o:p></span></b></p></div><p class=MsoNormal style='background:#E4E4E4'><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>"RE-wrenches" <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>><o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><o:p> </o:p></span></p><div id=origionalMessageToField><p class=MsoNormal><b><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>To:<o:p></o:p></span></b></p></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>"RE-wrenches" <<a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a>><o:p></o:p></span></p><div id=origionalMessageSentField><p class=MsoNormal><b><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>Cc:<o:p></o:p></span></b></p></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><o:p> </o:p></span></p><div><p class=MsoNormal><b><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>Sent:<o:p></o:p></span></b></p></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>Mon, 17 Sep 2018 09:42:01 -0700<o:p></o:p></span></p><div id=origionalMessageSubjectField><p class=MsoNormal><b><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>Subject:<o:p></o:p></span></b></p></div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>[RE-wrenches] Step-up/Step-down Transformer question<br><br><o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Helvetica",sans-serif'>Wrenches,</span><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Helvetica",sans-serif'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Helvetica",sans-serif'>We have a PV array situated about 900' from the POI (240V 1PH). We initially spec'd (5) 11.4kW inverters and the combined output would be 238A. The wire size required for this current over that distance is cost prohibitive.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Helvetica",sans-serif'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Helvetica",sans-serif'>A solution was to use a single 50kW 3 phase inverter at the array and then convert it to 240V... somehow? Is anyone familiar with how to go about doing this? My thought was to have a step down transformer at the POI and pull off two legs to get 240V. Is this even a thing?<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Helvetica",sans-serif'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Helvetica",sans-serif'>The other, more expensive option is to use a step up transformer at the array and a step down at the POI to get us a smaller wire size.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Helvetica",sans-serif'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.5pt;font-family:"Helvetica",sans-serif'>Thanks for any input.<o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><br clear=all><o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><o:p> </o:p></span></p></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>-- <o:p></o:p></span></p><div><div><div><div><div><div><div><div><div><div><div><div><div><p class=MsoNormal><b><u><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif;color:#0B5394;background:white'>Loren Ortiz Commercial PV Designer</span></u></b><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><o:p> </o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif;color:#0B5394;background:white'> </span></b><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif;color:#0B5394;background:white'> <a href="mailto:lorenzo@cal-solar.com">loren@cal-solar.com</a><b> (530) 274-3671</b></span><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'> <o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><o:p> </o:p></span></p></div></div></div></div></div></div></div></div></div></div></div></div></div></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><b><span style='font-size:9.5pt;font-family:"Arial",sans-serif;color:#999999;background:white'>Showroom located at: 149 E Main St. Grass Valley, CA 95945</span></b><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'><o:p></o:p></span></p></blockquote></div></body></html>