Marco, 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.
This Solar Pro article might help: http://solarprofessional.com/articles/design-installation/ungrounded-pv-power-systems-in-the-nec/page/0/9 Best, August *August Goers* Luminalt Energy Corporation o: 415.641.4000 m: 415.559.1525 www.luminalt.com On Thu, Oct 23, 2014 at 2:29 PM, Marco Mangelsdorf <[email protected]> wrote: > Yet again this “PV wire” thing rears its head. > > > > 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. > > > > 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. > > > > So I’m thinking, why pay the extra expense for the double-insulated wire > when single-insulated wire may suffice. > > > > Anyone know of anything written somewhere that requires the use of > double-insulated conductors in TL DC circuits? > > > > Thanks, > > marco > > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > >
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