In-wall timer and switch controlling bathroom fan

[JimC622911]

I'm wiring a bathroom remodel, with a wall switch for an overhead fan. I find I need to place a timer in the circuit for house venting reasons-- I'll need to run it several times a day to vent the house. A friend's house has a similar set up, with both an Intermatic (E1020) mechanical in-wall timer and a standard switch. BOTH seem to control the fan independently and I can't figure out how this wired. It doesn't seem to be standard 3 way wiring-- the switch isn't a

3-way switch and, if the timer turns the fan on, flipping the wall switch doesn't turn it off. As far as I can tell there is a 12/3 or 14/3 connection between the switch and the timer. The fan will go on via either the timer (it has both a push button and the motorized rotating dial) or the switch, and when it is on via whatever device, manipulating the other doesn't turn it off. How to wire this?

[Scott]

The switches would have to be in parallel with one another to make it work the way you descibe.

JimC622911 wrote: :: I'm wiring a bathroom remodel, with a wall switch for an overhead :: fan. I find I need to place a timer in the circuit for house :: venting reasons-- I'll need to run it several times a day to vent :: the house. A friend's house has a similar set up, with both an :: Intermatic (E1020) mechanical in-wall timer and a standard switch. :: BOTH seem to control the fan independently and I can't figure out :: how this wired. It doesn't seem to be standard 3 way wiring-- the :: switch isn't a 3-way switch and, if the timer turns the fan on, :: flipping the wall switch doesn't turn it off. As far as I can tell :: there is a 12/3 or 14/3 connection between the switch and the timer. :: The fan will go on via either the timer (it has both a push button :: and the motorized rotating dial) or the switch, and when it is on :: via whatever device, manipulating the other doesn't turn it off. :: How to wire this?

[Doug]

[e-mail] (JimC622911) wrote in news: [e-mail]:

I have a fan wired this way but I did it with a 3 way switch. If you don't use a 3 way switch and wire it in parallel then you end up with voltage on the output of the timer when the non-timer switch is on. I don't know if this is a problem or not but I didn't like it so I used a 3 way switch. The wiring is pretty simple. Common terminal of the 3 way to fan hot, 1 traveller terminal to the hot output of the timer and the other traveller terminal to constant hot.

In the parallel setup you'd just wirenut the output of the timer, the output of a switch connected to constant hot and the fan hot together. Again, I don't know about the safety of this. Odds are it's fine but I didn't want to risk it when there was a simple and safe alternative.

Doug