3way (DPDT) timer switches

Anyone have source for a timer switch that can be turned on/off from 2 locations?

I have a bathroom fan mounted in attic that services 2 bathrooms, would like a timer in each bathroom that would only allow it to run for short time, especially because it is very quiet, so it could be easily forgotten about.

I believe that would be a DPDT timer switch??

Reply to
Jack
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sounds like you just need to wire two ordinary SPST switches in PARALLEL.

Then either switch can turn it ON.

Mark

Reply to
Mark

If you wire two spring wound timers in parallel, then the fan will run for the longer of the two settings. Since each turns on the fan for what the user thinks is the right amount of time the longer time of the two serves the purpose, no real need to shutoff the other switch. If they are wired in parallel then you can use inexpensive SPST timers with 14-2 wire 9no need for a neutral to the timers as they are spring wound). The wiring runs are easier since its just direct from each timer to the fan, no looping between bathrooms. The Intermatic units are about $10 at the Borgs and fit both Decora and regular wall plates.

Reply to
Howard

Such switches are available but they are bulky and somewhat pricey. Mount a relay or contactor at the fan that is turned on by a timer relay. Set the timer relay for whatever length of time you feel is appropriate. The timer relay is started by a momentary contact switch that can be located in each bathroom served.

Reply to
Tom Horne, Electrician

According to Tom Horne, Electrician :

The drawback to this is that the timer duration is fixed at the controller, rather than the switches. I suspect you'd have to assemble it out of gear that isn't normally intended for end-user/consumer use, and may require some creative carving (eg: mounting thread-mount momentary switches in holes drilled in blank face plates, or industrial momentary switches, or industrial time delay relays, or Radio Shack components (not necessarily code-rated for the purpose) etc).

A simpler, likely less expensive approach would be two ordinary timers as suggested elsewhere, with the switched legs tied together at the fan power lead. The fan goes on just as long as the "last timer" says to.

You'd have to be careful with this - both timers would _have_ to be on the same circuit, and it would probably be safest to use timers that have mechanical relay contacts rather than fully electronic.

[I personally prefer fully mechanical "windup" timers for fan timer applications.] [Momentary switches as you suggest would probably ALSO have to be on the same circuit. Or some hackery with X10 or whatever...]

That said - do you think hooking two timers (or ordinary switches for that matter) in parallel like this is code-legal?

I suspect it's legal, because it's almost identical to an ordinary three way setup triggering a timer (which might be confusing, but it should be legal).

Reply to
Chris Lewis

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