David, Thanks for the early posts re. your experimentation and to Allan for reposting them. I have used a single switch in an off/on mode for AC coupled regulation where flooded batteries are used. On the AGM setups, which are a better battery in my opinion for AC coupling, I use the Morningstar relay driver and resistive heating elements to bleed progressively more power from the GTI to mimic 3 stage charging. When float stage is achieved I use a switch with both time and voltage input capability to shut down the GTI completely. This setup seems to work as we haven't had battery issues come up yet and a couple of these systems have been through a couple of weeks of off grid operation due to ice storms wrecking the local grid. I have followed this thread with interest and was glad for the repost and subsequent discussion. Cheers, Nathan Jones
On Tue, Nov 22, 2011 11:06 AM CST David Katz wrote: >Nathan, >I use an SW for backup in AC coupling. I use one of the auxiliary 1 amp relays >to activate a larger relay on the AC output of the grid tie inverter to break >the Ac connection when the batteries reach full charge voltage. This is I >simple but crude pwm charge control merthod. When the AC breaks, the grid tie >inverter goes off for 5 minutes. The loads operate on the Sw, pulling the >battery down, which closes the relay and the cycle repeats. >David Katz > >----- Original Message ----- >From: Nathan Jones [mailto:solardud...@yahoo.com] >Sent: Tuesday, November 22, 2011 07:10 AM >To: re-wrenches@lists.re-wrenches.org <re-wrenches@lists.re-wrenches.org> >Subject: Re: [RE-wrenches] Convert Grid Tie SW4048 to Backup System; Add New >Inverter, AC Coupled > >Bill, >I believe Allans post indirectly answered my question. While he did not >specifically state the SW could be used in an AC coupled arrangement, I >believe it was implied. Since the listing issue, as I understand it, was due >to failure to drop out of sell mode in a certain set of circumstances and >never had anything to do with the behavior of the inverter in any of its >"incoming AC only" settings as far as disconnecting there should not be any >question as to its suitability for AC coupling there. The only question would >be how they would react and manage backfed AC from a GTI in event of a grid >failure. That question is unknown to me and has not been specifically answered >yet. Any one have an answer to that? >Nathan Jones >Power Source Solar >Springfield, Mo >R >417-827-0738 >On Tue, Nov 22, 2011 6:08 AM CST Bill Loesch wrote: > >> >>Fellow Wrenches, >> >>Didn't Jim Duncan provide the impetus for the delisting and hasn't he >>provided a comprehensive discussion here (or some other linked location) >>before? >>Does anyone have an answer to Nathan's question of 20 November 11? >> >>Bill Loesch >> >>----- Original Message ----- >>From: "William Miller" <will...@millersolar.com> >>To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org> >>Sent: Sunday, November 20, 2011 1:12 PM >>Subject: Re: [RE-wrenches] Convert Grid Tie SW4048 to Backup System; Add New >>Inverter, AC Coupled >> >> >>> Joel: >>> >>> I don't belive it was an NEC thing, it was a UL/ETL consideration. This >>> relates to the NEC only in that it is required to use listed equipment. >>> >>> William Miller >>> >>> >>> At 09:21 AM 11/20/2011, you wrote: >>> >Where in the NEC is the requirement for the GTI interface? >>> >>> _______________________________________________ >>> 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 >>> >> >>_______________________________________________ >>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 >> > >_______________________________________________ >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 > >_______________________________________________ >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 > _______________________________________________ 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
