I agree Blake - you have to check the specs and consult the mfg. The same is true with combiners, some are rated for continuous duty/full load, and some are not. Lots of large systems out there with 200A combiners connected to 250A OCPDs (and 250A conductors, but that’s another story...).
Brian > On Aug 21, 2019, at 5:20 PM, Blake Gleason <[email protected]> wrote: > > Typically a fused disconnect can only handle 80% of it's nominal current on a > continuous basis. Unfused disconnects are often 100% rated. For example, > see attached Square D bulletin #3110DB0401R0410. > > So, a 100% rated (unfused) 30A disconnect (at least, from Square D) should be > fine here, as long as your OCPD is provided elsewhere (eg, the breaker you > mentioned). > > NEC 690.8(B)(1)(Exception) explicitly allows a 100%-rated device to be used > without multiplying the inverter output current by 125%. > > >> On Wed, Aug 21, 2019 at 3:22 PM Greg <[email protected]> wrote: >> Fellow Wrenches, I'm having a discussion with a utility engineer regarding >> the following situation: >> >> Installing a 6kW inverter that has a full rated output of 25 amps. 80% of >> 30 is 24. That means to me I need to go up to a 40 amp breaker. I'm >> running #8 (continuous load 25 x 1.25 etc.) >> The engineer believes I should use a 60 amp disco since it's on a 40 amp >> breaker. My thinking is I can use a 30 amp disco since it can not produce >> more than 25 amps ever. >> >> Do any of you have a reference that shows what I'm doing is okay? Not okay? >> >> Thanks again, >> Greg Egan >> Remote Power Inc. >> _______________________________________________ >> 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 >> > > > -- > > > > Blake Gleason, PE | Employee-Owner | > Director of Innovation & Technical Excellence > > 510.845.2997 x128 > > Follow us on Facebook, LinkedIn or our website. > > <Square-D-Switch-PV-Bulletin_06-10_100percent_rated.pdf> > _______________________________________________ > 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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