We also go to the utility side as a rule. We have only one exception. A 60kW Solectria inverter is tied into a building system that is supported by a 1 MW generator. It's a university heating plant where it was clearly shown the base load was far larger than the 60kw solar PV system, even when the plant was at "idle". The facility had a building management system with historical 15min usage data to support this.
Unless you have hard data that your solar inverter will never ever meet the buildings real-time demand, tie into the grid side. This is best practice to the best of my knowledge. With Regards, Daniel Young, NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90 NABCEP Certified Solar Heating InstallerTM: Cert #SH031409-13 -----Original Message----- From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Aaron Mandelkorn Sent: Tuesday, October 28, 2014 11:20 AM To: RE-wrenches Subject: Re: [RE-wrenches] Interconnection with Generator I always connect to the utility side of the transfer switch. Since the transfer switch is a listed electrical enclosure it is the best option I have used. Aaron Aaron Mandelkorn Owner/Solar Specialist Renewable Energy Outfitters 719-221-5249 970-596-3744 www.reosolar.com reoso...@gmail.com > On Oct 28, 2014, at 8:48 AM, Corey Shalanski <cshalan...@joule-energy.com> wrote: > > Wrenches, > > We frequently encounter residences with backup generators. The question that arises: how should the PV system be interconnected? > > I have searched the archives and found some good information about this subject, but nothing definitive. I have fallen into the habit of broadly proclaiming that the PV system *must* be interconnected on the "utility" side of the transfer switch - in order to prevent backfeeding into the generator and thereby eliminate unintentional equipment damage. Is this concern justified? If so, should this be an absolute rule or would it depend on the generator make/model? > > Thanks for any insights. > > -- > Corey Shalanski > Joule Energy > New Orleans, LA > _______________________________________________ > 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 ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2247 / Virus Database: 4031/7967 - Release Date: 10/28/14 ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2247 / Virus Database: 4031/7967 - Release Date: 10/28/14 _______________________________________________ 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