<html><body><span style="font-family:Verdana; color:#000; font-size:10pt;"><div>In ungrounded systems the PV wire requirement is to be used the whole DC circuit, so that is all the way to the inverter. 690.35 (D) is pretty clear . Because it is ungrounded the protection is the PV wire's fire rating and you don't get that with thhn/thwn.</div><div>And of course Red for positive and black for negative. </div><div>Most building departments have not pick up on this yet. But they will. </div><div><br></div><div></div><div>Aram</div><div><br></div><div><br></div><div><br></div><div></div>
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Subject: Re: [RE-wrenches] double insulated wire<br>
From: Will White <<a href="mailto:William.White@realgoods.com">William.White@realgoods.com</a>><br>
Date: Fri, June 28, 2013 10:23 am<br>
To: RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>><br>
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</style> <div class="WordSection1"> <div class="MsoNormal" style="font-size:12pt;">We use PV Wire which is double insulated on the roof in free air and regular THHN/TNWN for the run from the junction box back to the inverter (using no white or gray wires of course).<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;">Thanks,<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;">Will<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;"><a target="_blank" name="_top"></a><u><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:#0F243E">__________________________________________________________________________________________<o:p></o:p></span></u></div> <div class="MsoNormal" style="font-size:12pt;"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:#0F243E">Will White<o:p></o:p></span></div> <div class="MsoNormal" style="font-size:12pt;"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:#0F243E">Regional Field Operations Manager – New England<o:p></o:p></span></div> <div class="MsoNormal" style="font-size:12pt;"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:#0F243E"><o:p> </o:p></span></div> <div class="MsoNormal" style="font-size:12pt;"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:#0F243E">Real Goods Solar<o:p></o:p></span></div> <div class="MsoNormal" style="font-size:12pt;"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:#0F243E">64 Main St.<o:p></o:p></span></div> <div class="MsoNormal" style="font-size:12pt;"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:#0F243E">Montpelier, VT 05602<o:p></o:p></span></div> <div class="MsoNormal" style="font-size:12pt;"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:#0F243E">Tel: (802) 223-7804<o:p></o:p></span></div> <div class="MsoNormal" style="font-size:12pt;"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:#0F243E">Cell: (802) 234-3167<o:p></o:p></span></div> <div class="MsoNormal" style="font-size:12pt;"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:#0F243E"><a target="_blank" href="http://www.realgoodssolar.com/"><span style="color:blue">www.realgoodssolar.com</span></a><o:p></o:p></span></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div> <div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in"> <div class="MsoNormal" style="font-size:12pt;"><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""> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a> [<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Marco Mangelsdorf<br> <b>Sent:</b> Friday, June 28, 2013 1:10 PM<br> <b>To:</b> 'RE-wrenches'<br> <b>Subject:</b> [RE-wrenches] double insulated wire<o:p></o:p></span></div> </div> </div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;">I’m kinda confused. With more transformerless inverters on the market (e.g., SMA and Power-One), it’s not clear to me if double insulated wiring needs to be used all the way from each series string to their respective inverter.<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;">We’ve been installing the P1 3-6 kW TL inverters and there’s no apparent mention of needing to use such conductors, yet I remember needing to do so when I installed a number of the 8, 9 and 10 kW SMA TL inverters.<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;">Thanks,<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;">marco<o:p></o:p></div> </div> <hr>_______________________________________________<br>
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