<div dir="ltr">Marco,<div><br></div><div>For a standard 600 volt non-isolated (transformerless) inverter based systems, you just need to make sure that your array source circuit conductors have a "photovoltaic or PV wire" rating. You can also switch to standard THWN-2 once you get into conduit. </div><div><br></div><div>This Solar Pro article might help:</div><div><br></div><div><a href="http://solarprofessional.com/articles/design-installation/ungrounded-pv-power-systems-in-the-nec/page/0/9">http://solarprofessional.com/articles/design-installation/ungrounded-pv-power-systems-in-the-nec/page/0/9</a><br></div><div><br></div><div>Best,</div><div><br></div><div>August</div></div><div class="gmail_extra"><br clear="all"><div><div dir="ltr"><p><b><span style="font-size:9.0pt;font-family:"Century Gothic","sans-serif"">August Goers</span></b></p><p><span style="font-size:8.0pt;font-family:"Century Gothic","sans-serif"">Luminalt Energy Corporation</span></p><p><span style="font-size:8.0pt;font-family:"Century Gothic","sans-serif"">o: 415.641.4000</span></p><p><span style="font-size:8.0pt;font-family:"Century Gothic","sans-serif"">m: 415.559.1525</span></p>

<p><span style="font-size:8.0pt;font-family:"Century Gothic","sans-serif""><a href="http://www.luminalt.com" target="_blank">www.luminalt.com</a></span></p>

<p> </p></div></div>
<br><div class="gmail_quote">On Thu, Oct 23, 2014 at 2:29 PM, Marco Mangelsdorf <span dir="ltr"><<a href="mailto:marco@pvthawaii.com" target="_blank">marco@pvthawaii.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">








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<p class="MsoNormal">Yet again this “PV wire” thing rears its head.<u></u><u></u></p>

<p class="MsoNormal"><u></u> <u></u></p>

<p class="MsoNormal">For our PV systems using transformerless (TL) inverters, our
standard practice has been to use double-insulated conductors for all DC
circuits coming into the TL inverter(s), which we believe represents the best
practice.<u></u><u></u></p>

<p class="MsoNormal"><u></u> <u></u></p>

<p class="MsoNormal">However, there doesn’t appear to be any requirement stated
in the code that states the need to use double-insulated conductors for DC
circuits and TL inverters.<u></u><u></u></p>

<p class="MsoNormal"><u></u> <u></u></p>

<p class="MsoNormal">So I’m thinking, why pay the extra expense for the
double-insulated wire when single-insulated wire may suffice.<u></u><u></u></p>

<p class="MsoNormal"><u></u> <u></u></p>

<p class="MsoNormal">Anyone know of anything written somewhere that requires the
use of double-insulated conductors in TL DC circuits?<u></u><u></u></p>

<p class="MsoNormal"><u></u> <u></u></p>

<p class="MsoNormal">Thanks,<u></u><u></u></p>

<p class="MsoNormal">marco<span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><u></u><u></u></span></p>

<p class="MsoNormal"><u></u> <u></u></p>

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