Hi Larry. We did this recently. We settled on a Square D 60A 600VDC disconnect feeding a Midnite Solar Transfer switch with 60A, 300VDC breakers. We put an engraved placard on the transfer switch instructing the customer to turn off the disconnect first then to operate the transfer switch and when the transfer either way is completed to turn on the disconnect again. . It could have worked without the disconnect but we felt that it was probably an abundance of caution to operate the transfer switch with PV disconnected. Our application was switching from a Grundfos pump in the summer to a Fronius inverter in fall and the reverse in spring. . This was a seasonal transfer instead of daily transfer. Certainly not automated. But relatively fool proof and safe. Good luck.
Sunny Regards, Kirpal Khalsa Oregon LRT#25 NABCEP Certified PV Installation Professional Oregon Solarworks LLC www.oregonsolarworks.com 541-299-0402 On Thu, Feb 16, 2017 at 4:24 PM, Roy Rakobitsch <[email protected]> wrote: > Arcing would only happen when disconnecting pump during sunny periods, why > not disconnect at dusk? Connecting pump will not arc due to soft start. Not > sure about that particular charge controller, but some controllers can use > Aux relay logic to do this upon full SOC. The Midnite Classic comes to > mind. Swithcing can be done with contactor. > Just a thought. > > > Roy Rakobitsch > NABCEP Certified Small Wind Installer® > Certified Advanced Tower Climbing, Safety & Rescue > Wind/PV Design Engineer > Windsine LLC > 631-514-4166 <(631)%20514-4166> > www.windsine.org > > On Feb 16, 2017 4:24 PM, "Starlight Solar Power Systems" < > [email protected]> wrote: > >> Hello Wrenches, >> >> A customer has 3250 Watt PV array @ 139Voc. The PV controller is Magnum >> PT100. He wants to install a Grundfos SQFlex pump and be able to switch the >> DC from the PV controller to run the pump directly. He would like to switch >> midday after the battery (48V) is at a high SoC. >> >> I’m looking for a switching arrangement to do this without arcing since >> it will be used a few times each week. Any have a recommendation? >> >> Thank you, >> >> Larry Crutcher >> Starlight Solar Power Systems >> >> >> >> >> >> >> >> _______________________________________________ >> 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/re >> [email protected]/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: [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]. > org/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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