How about a relay powered by the AC grid with SPDT contact configuration. Use normally closed contacts to close a circuit turning on a lamp or other device powered off the backup AC power. When the AC grid goes down, the relay de-energizes and closes the normally closed contacts thereby turning on the indicator device.
Richard On Thu, Feb 27, 2025 at 9:18 AM Nicholas Ponzio via RE-wrenches < re-wrenches@lists.re-wrenches.org> wrote: > Dear Esteemed Wrenches, > > This issue arises periodically, and I'm hopeful someone in the group has > devised a cost-effective, low-power solution. > > For a whole-home backup system, how can we best alert homeowners that they > are operating on battery power? These homeowners do not use smartphones and > won't receive push notifications. Is there a simple solution to activate a > single light or audible alarm exclusively when the grid is down? This > particular instance involves a FranklinWH system, but the same challenge > applies to any battery with a whole-home backup and "instant-on" transfer > switch. > > Thank you in advance for your insights. > > Sincerely, > Nicholas Ponzio > Building Energy > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > 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 > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > >
_______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org 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 There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
