Kent, Jason, or anyone else Would you a have a simple one-line you could share for wiring the inverter on the utility side of the transfer switch?
Thank you. Larry Liesner Wirewiz Westport, CT Phone: 203-644-2404 Fax: 203-557-0556 wire...@gmail.com www.wire-wiz.com On Mar 26, 2011, at 6:04 PM, Jason Szumlanski wrote: > We’ve explored this strategy many times due to all of the whole house and > critical load generators in Florida. We’ve stayed away from the contactor > solution because of the potential for the NC contactor failing to open, > keeping the inverters “online” when transferred to generator power. While > unlikely, this is a possibility that must be considered. > > The other issue presented here is that the inverters will shut down every > time the generator exercises. > > The only sure-fire way seems to be wiring the inverter on the utility side of > the transfer switch, as Kent said. > > Jason Szumlanski > Fafco Solar > > > From: re-wrenches-boun...@lists.re-wrenches.org > [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg > Sent: Saturday, March 26, 2011 5:56 PM > To: RE-wrenches > Subject: Re: [RE-wrenches] Generator and Enphase > > Mark, > > I agree it is best to wire the inverters on the utility side of the transfer > switch. When that isn't easy, a normally closed contactor that is opened by > generator voltage, will isolate the inverters from the generator and allow > automatic return to utility operation when the generator is off. > > Kent Osterberg > Blue Mountain Solar > > > > Mark Frye wrote: > Eric, > > I do not have direct experience with this but have been exploring the issue > for a project I am currently doing. > > My response will be to take the trouble to interconnect the Enphase inverters > on the line side of the tranfer switch so that the inverters can never be > connected to the generator. > > Here are the reasons why: > > 1 - Enphase states that any such application is considered an "off-grid" > application which voids their warrenty. As I am installing under the > California CSI program, I am required to provide a 10 year manufacture > equipment warranty so I cannot afford to install the inverters in a > dis-allowed manner. > > 2 - Enphase states that the waveform of the generator may be "clean" enough > such that the inverter may attempt to syncornize and connect to it as if it > were the utility. If this were to happen Enphase believes the inverters will > ruin the generator regulator before the generator ruin the inverter. I don't > want to be the one to run the experiment to find out which would be which. > > 3 - I considered a contactor on the output of the inverters, such that the > inverters would isolated by a loss of line voltage, requiring some form of > reset. Ulitmately my customer agreed with me that this was an undesirable > constraint on the operation of an otherwise reliable grid-tied system and it > was not clear that this would satify the warranty issue. > > Mark Frye > Berkeley Solar Electric Systems > 303 Redbud Way > Nevada City, CA 95959 > (530) 401-8024 > www.berkeleysolar.com > > > From: re-wrenches-boun...@lists.re-wrenches.org > [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Eric Thomas > Sent: Saturday, March 26, 2011 2:09 PM > To: re-wrenches@lists.re-wrenches.org > Subject: [RE-wrenches] Generator and Enphase > > I have a customer with a "30A Mechanically Interlocked Breaker" for their > generator feed at the main panel. My question is: If the home power is > transferred from utility to generator power, will the backfed PV see the > generator as grid power and sync up and produce? This is a nice Honda > Generator so the power should be fairly clean. Any experiences are > appreciated. > > Take Care, > > > Eric Thomas > Solar Epiphany LLC > (206) 919-3014 > www.solarepiphany.com > > > _______________________________________________ > 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 >
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