Marc, High or low battery cut-out on a battery based inverter is lights out. There is usually a warning period that becomes a fault. I still think this is crazy for offgrid unless it is a very large system 20+KW of battery inverters in a microgrid type mindset with onsight knowledgeable people. Also lots of DC coupled solar.
Forgive me if I have missed something here as I have installed about 20 gensets for my California wildfire residents last month. Good Luck. Dave Angelini Offgrid Solar "we go where powerlines don't" http://members.sti.net/offgridsolar/ e-mail offgridso...@sti.net text 209 813 0060 On Sun, 3 Nov 2019 09:38:51 -0800, Mark Frye <ma...@berkeleysolar.com> wrote: > Hi William, > > Thanks, you bring up issues that are important to me here. > > In particular, my situation is that the GT inverter is inter-tied a > couple sub panels upstream of where I want to put the BB inverter. The > distance is long, so I am looking for a solution where I don't have to > run a cable between the two. > > In general, I do wonder about using AC line voltage rise to take the Gt > inverters off line. The main goal is to prevent excess voltage at the > battery, so monitoring battery voltage is most direct, and there are > simple solutions for that. > > Is AC line voltage a suitable metric for achieving the same goal? > > Here is where I could use Wrench knowledge to confirm my thinking, that > being: > > - With excess energy in the system, the charger moves it into the > battery, raising it's voltage until it reaches it high charging voltage > set point > > - Once the battery reaches it's high voltage set point, the charger > stops putting energy into the battery > > - With no other place to put the excess energy, the AC voltage rises > > Am I getting this right, the reason to disconnect AC coupled inverters > when the battery if full is not to prevent the batteries from being > overcharged, but rather to prevent the AC line from becoming unstable? > > I am hoping this is correct and that with $200 of industrial grade > devices from Digikey I can implement a robust control that will > disconnect the GT inverters before the AC line goes so high that the BB > inverter faults. > > Mark > > > > _______________________________________________ > 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
