Clarification - it's square root of 3, not 2, and if the Inverter Output Current is specified on a datasheet for a 3-phase inverter, it would already have the factor applied and that is the rating used to apply to 1.25x factor.
For example, Sunny Tripower 12,000 has a inverter output rating of: 12000 / 480 / sqrt(3) = 14.43 (listed as 14.5). Multiply the number of inverters times 14.5 times 1.25 to get the combined OCPD and wire rating required. On Sat, Oct 24, 2015 at 8:39 AM, Glenn Burt <glenn.b...@glbcc.com> wrote: > Two things, > Combined OCPD sizing is based on the output current of the inverters, not > the individual OCPD values. > And in most 3 phase systems you will have a square root of 2 to factor > into your calculations. > > Sincerely, > Glenn Burt > Sent from my 'smart' phone so please excuse grammar and typos. > ------------------------------ > From: Allen Frishman <amfr...@aeonsolar.com> > Sent: 10/24/2015 7:50 > To: RE-wrenches <re-wrenches@lists.re-wrenches.org> > Subject: [RE-wrenches] Combined Inverter Fuse sizing > > Wrencher's, > Quick question regarding sizing the fuse for a combined group of > inverters. If I have six 10KW three phase inverters each with a max AC > current of 30A they each require a 3 pole 40 A breaker. If I then take > the combined output of the AC combiner panel I see two possible options for > sizing the combined fuse size. > > 6 inverters x 40A breakers each = 240A so I need to use a 250A fuse > 6 Inverters x 30A max output each = 180A x 1.25 = 225A Fuse > > Seems like both are acceptable options since all wire will be protected. > > All feedback is appreciated. > > *Al Frishman* > AeonSolar > > *(917) 699-6641 <%28917%29%20699-6641> - cell* > *(888) 460-2867 <%28888%29%20460-2867>* > *www.aeonsolar.com <http://www.aeonsolar.com/>* > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > >
_______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org