Disable leg of gang-trip

CL> Situation: Found out that the home builder had put in AC smoke detectors CL> that weren't gang-trip. I installed new gang-trip ones, and decided to CL> put another in the detached garage. CL> CL> Gang-trip 3-wire type (hot, neutral and trigger). CL> CL> Occasionally, work in the garage (soldering something, starting the lawn CL> tractor etc) will set off the garage alarm which immediately fires up CL> the others... Annoys the rest of the family no end. CL> CL> Suboptimal. CL> CL> Been thinking of putting a switch into the garage alarm's supply feed. CL> CL> Ideally, it'd be a normally-closed timer that when "enabled", it'd CL> disable the garage alarm and gang trip feeding the other alarms until CL> the timer ran out. CL> CL> Has anybody else done something like this? Suggestions? CL> CL> I could put a double-pole switch in (to cut the hot and neutral), or CL> even a single-pole (just cutting the hot should work), but these CL> are battery backup units, so I suspect that wouldn't work... CL> CL> So maybe the best I can do is disable the gang-trip with a switch. CL> Are there any cheap "normally closed" mechanical timers?
The heat detector suggested by others is probably a better idea but if for some reason you prefer to use the smoke detector how about something like a bathroom fan timer (60 minute?) powering a SPDT relay? You smoke detector is wired to the NC terminals. When you're about to make smoke turn the timer on, which pulls in the relay contacts, opening the circuit. At the end of the timer cycle the power to the relay is cut off, automatically resetting your smoke detector. Probably need to pull the battery in the garage smoke detector else it will scream, but that might cause the others to chirp.
- barry.martinATthesafebbs.zeppole.com
* Butt softly....the wind through yonder pants seat breaks.....
RoseReader 2.52 P003186
The Safe BBS Bettendorf, IA 563-359-1971
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