David, Jeff, Chris, et al, Thanks for the ideas on my remote relay query.
As it turns out cutting power to the subpanel is not an option. On first pass, I thought the ideas for adjusting the generator output seemed like simple and cheap answers to a regular problem we run into (Automatic Transfer Switches engaging a backup generator when the grid goes down). Certainly, even in normal circumstances, the chance of the inverter connecting to the generator is less than likely. However, the risk of blowing out the generator regulator or worse is something we want to avoid. Even if we adjust the voltage or frequency window so that the inverter will definitely not connect, there is no guarantee that a generator service person will not readjust them in the future as they might if they are being conscientious. It also gets us into touching something we'd just as soon not get into whenever avoidable. Usually we do a main tap on the line side of the ATS, but in many cases this is not the most convenient or plausible solution, as in this case. For anyone interested, as it turns out, I did find a power line control solution that will hopefully work well for this situation as well as other circumstances where we need to control something across a space that running control wires is difficult or not possible, but there are existing electrical conductors. www.automatedoutlet.com The products that I will use in this scenario are: http://www.automatedoutlet.com/Home/UPB-Plug-in-Modules/SA-UMA-E-W http://www.automatedoutlet.com/Home/UPB-Plug-in-Modules/SA-UMI32W http://www.automatedoutlet.com/Home/Relay-Modules-Timers/ELK-9200 They gave me wholesale pricing very easily. I will followup with a review of the products once I use them if anyone is interested. Howie -- Howie Michaelson NABCEP Certified Solar PV Installer™ Catamount Solar, LLC Renewable Energy Systems Sales and Service VT Solar Electric & Hot Water Incentive Partner http://www.CatamountSolar.com 802-272-0004 On Sun, December 9, 2012 10:08 pm, David Katz wrote: > Howie, > You could set the generator frequency to 61 Hz, then the grid tie inverter > will not operate or you could set the generator output voltage to 260 vac > and have the same result. > David Katz > > Sent from my HTC smartphone on the Now Network from Sprint! > > > ----- Reply message ----- > From: "Howie Michaelson" <ho...@suncatchervt.com> > To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org> > Subject: [RE-wrenches] Remote relay options > Date: Wed, Dec 5, 2012 7:31 am > > > > Hi All, > > I am looking for options for controlling a disconnecting relay for a > grid-tied inverter. It is a PVI5000 so 30 amp 240vAC. I need to > disconnect it when the backup generator gets kicked on by the Automatic > Transfer Switch when the grid goes down. The array is on a garage that is > several hundred feet from the house and service entrance and ATS and > digging in a control wire for that distance won't work. So I need a way > to sense that the generator is putting out power and then control a > contactor which would disconnect the inverter from the subpanel. I've > looked for wireless and powerline control options but I can't seem to put > together the pieces. > > Any ideas of the most cost effective and reliable approach? > > Thanks, > Howie > -- > Howie Michaelson > NABCEP Certified Solar PV Installer™ > > Catamount Solar, LLC > Renewable Energy Systems Sales and Service > VT Solar Electric & Hot Water Incentive Partner > http://www.CatamountSolar.com > 802-272-0004 > > > > > > _______________________________________________ > 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<http://www.re-wrenches.org/etiquette.htm> > > Check out participant bios: > www.members.re-wrenches.org<http://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
