If I use the Hu361 (unfused) it has the 30 amp rating, the 80% reduction only applies if I use fuses per the continuous operation derating for overcurrent devices. The switch is not a conductor or overcurrent device. If I use the H361 (fused) then the 80% derate applies, (24 amps) and if I use the double break I am limited to 18 amps in all cases.
Darryl Correct? --- On Sat, 6/27/09, Phil Undercuffler <solarp...@gmail.com> wrote: > From: Phil Undercuffler <solarp...@gmail.com> > Subject: Re: [RE-wrenches] fronius IG Plus practical engineering WAA??? > To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org> > Date: Saturday, June 27, 2009, 10:47 PM > They added a special listing, where > they were able to expand the range of their heavy duty > switch when used in PV direct applications. The special PV > listing doesn't void the standard wiring methods, > however. You can still run the full 30 amps (24 * 1.25) > through two poles series connected, or you can bring > multiple subarrays through each of the poles, each with a > lower individual Isc limit but with an aggregate higher > current capacity. > > This really becomes handy on the larger 60 and > 100A disconnects. Suddenly, a 3 pole 100A disconnect can > be used for three large subarrays to a central inverter, > which saves considerably on BOS costs. Also, be aware that > (the last I looked) the special listing doesn't apply to > their 200A and larger disconnects. > > > > Phil Undercuffler > > -------- > > > > > > On Sat, Jun 27, 2009 at 9:22 PM, > Darryl Thayer <daryl_so...@yahoo.com> > wrote: > > > > Again this is FMI for my information, Did not Square D > change there rating for PV systems? > > Darryl > > > > --- On Fri, 6/26/09, Phil Undercuffler <solarp...@gmail.com> > wrote: > > > > > From: Phil Undercuffler <solarp...@gmail.com> > > > Subject: Re: [RE-wrenches] fronius IG Plus practical > engineering WAA??? > > <snip> > > > > > > This confirmed my understanding > > > that the limiting factor > > > on the 30A switch > > > > > > in a photovoltaic applications is > > > not 30A * 0.8. The limiting factor > > > is 18A > > > > > > per pole or 11.5A Isc per pole. > > > > > > <unsnip> > > > > > > > > > > > > To clarify – the 18A per pole / > > > 11.5A Isc per pole only > > > applies if you are using the limited listing for PV > > > applications, with one > > > string or subarray per pole. If you > > > wire > > > the HU361RB disconnect with two poles connected in > series, > > > then you may run the > > > switch at 100% of its rating. > > > > > > > > > > > > Therefore, you can stuff up to 24 > > > amps Isc (24 * 1.25 = > > > 30) through a single disconnect if the poles are wired > in > > > series, or you can > > > run 3 subarrays each with no more than 11.5A per pole > if > > > wired in > > > parallel. > > > > > > > > > > > > Sometimes it’s good to have > > > options. > > > > > > > > > > > > > > > > > > > > > > > > Phil Undercuffler > > > > > > Director, Battery-based and > > > Off-grid > > > > > > Distribution Sales Group > > > > > > Conergy > > > > > > Our World Is Full of Energy > > > > > > 1730 > > > Camino Carlos Rey Suite 103 > > > > > > Santa > > > Fe, NM 87507 > > > > > > p.undercuff...@conergy.us > > > > > > Direct > > > | > > > 505.216.3841 > > > > > > Toll Free | 888.396.6611 x4841 > > > > > > Fax | 505.473.3830 > > > > > > www.conergy.us > > > > > > > > > > > > -----Inline Attachment Follows----- > > > > > > _______________________________________________ > > > List sponsored by Home Power magazine > > > > > > List Address: RE-wrenches@lists.re-wrenches.org > > > > > > Options & settings: > > > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > > > > > List-Archive: > > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > > > > > List rules & etiquette: > > > www.re-wrenches.org/etiquette.htm > > > > > > Check out participant bios: > > > www.members.re-wrenches.org > > > > > > > > > > > > > > _______________________________________________ > > List sponsored by Home Power magazine > > > > List Address: RE-wrenches@lists.re-wrenches.org > > > > Options & settings: > > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > > > List rules & etiquette: > > www.re-wrenches.org/etiquette.htm > > > > Check out participant bios: > > www.members.re-wrenches.org > > > > > > > -----Inline Attachment Follows----- > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org