If you are doing it on the AC side, a Generac transfer switch has the capability and is designed to do this. It's easy to rig an interface as I discussed privately with Bill.
On Fri, Nov 29, 2019 at 1:29 AM Jerry Shafer <jerrysgarag...@gmail.com> wrote: > Wrenches > Need to be careful here to use something that has the interrupt KVA rating > required to prevent an arc in the event of an under load opening with the > switch proper AIC rating 10,000 or more, last thing I think you want is to > have that kind of liability on products that are not designed for that type > of use. But thats just me. > NABCEP PV Inspector > California Solar contractor > Jerry > > On Mon, Nov 25, 2019 at 8:52 PM Bill Hennessy <b...@berkssolar.com> wrote: > >> hi folks-- >> >> We're installing a grid-tied, battery backup system on a farm where the >> service entrance is on a pole in the yard. At the single-phase, 240v, >> service entrance, there are two main breaker subpanels--one going to the >> house and one to the barn. The buildings are each about 100 feet away from >> the pole in opposite directions. The PV/battery system is located in the >> barn. When utility power is lost and the battery backup kicks in, we are >> looking for a way to bypass the house subpanel at the pole so it won't >> backfeed the grid. >> >> When the grid drops out, we need to tie the backup power coming from the >> barn to the line going to the house. We're thinking an automatic transfer >> switch installed at the pole will do the job, but the transfer switches >> seem to have built in delays to work with starting a generator. The >> switch does not have to be service entrance rated. >> >> It looks like the Asco 300 series has time delay adjustments, but it is >> pricey and has a seven-week lead time. (Thank-you PG&E) >> >> The battery backup system will switch over in milliseconds and we were >> hoping to find something similar for the transfer operation at the pole. >> We're >> looking for something simple--hopefully a basic transfer switch that will >> quickly switch and drop out when grid power is restored. >> >> Would appreciate any thoughts or suggestions. >> >> regards, bill >> >> Bill Hennessy >> Berks Solar, LLC >> 371 Centennial Rd >> Mertztown, PA 19539 >> >> o 610 682 4300 >> c 484 560 4666 >> NABCEP certified installer >> PA contractor #44411 >> www.berkssolar.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 > > -- Chris Mason Solar systems designer Generac Generators Industrial technician Comet Systems Ltd DBA Comet Solar Anguilla Cell 264.235.5670 WhatsApp 264.235.5670 Skype: netconcepts www.cometsolar.com <http://www.cometenergysystems.com/>
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