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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Esteemed Wrenches,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>We are having a hard time finding a source of PV Wire with a 1000V rating that will fit into a two-hole 1/2" strain relief. It seems that all of the wire brands that are “double-insulated” just have too large of a diameter to get two of them though a 1/2" strain relief, needed since most common combiners have 1/2" knockouts for wire entry. However, we have found a source of single-insulated wire that is UL Listed and bears the “PV Wire” marking.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I’ve always been under the assumption that “double-insulated wire” was necessary when using transformerless grid-tie inverters, as it is with power tools that only have two-prong plugs on them. However I can’t find that specific language in the Code. It just says “must be marked as PV Wire”. I also found this quote about PV Wire from John Wiles (underlining mine):<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>“The thickness is specified and there may be <u>one or two layers</u> of insulation. The insulation must pass an accelerated UV test of 720 hours and will be<o:p></o:p></p><p class=MsoNormal>marked “Sunlight Resistant.” PV cable/PV wire also has smoke and flame-retardants and may be used inside conduit inside buildings. In the U.S., it should<o:p></o:p></p><p class=MsoNormal><u>not be called a ‘double-insulated cable’</u> as that is a purely European term.”<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>This appears to mean that double-insulation is not required for transformerless (non-isolated) inverters; just that it needs to be marked as “PV Wire”. Can anyone here confirm, hopefully with documentation, that actually having “double-insulation” is not required when using non-isolated inverters?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:12.0pt'>Brian Teitelbaum <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>AEE Solar<o:p></o:p></span></p></div></body></html>