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??

3way (DPDT) timer switches
 

Jack wrote:
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??

Not really, you need two SPST switches but connected in parallel. I
must say that logical as it seems, I've never heard of such a
hookup.... any reasons why it wouldn't be feasible/safe/according to
code? You'd definitely want to hook them up to the same breaker, for
safety when you "turn the power off" to work on them........

3way (DPDT) timer switches
 

Jack wrote:
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??

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

Then either switch can turn it ON.


Mark

3way (DPDT) timer switches
 

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.


On Oct 10, 1:03 pm, "Jack" wrote:
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??

3way (DPDT) timer switches
 

Jack wrote:
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??


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.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison

3way (DPDT) timer switches
 

On 10 Oct 2006 10:12:53 -0700, "z" wrote:


Jack wrote:
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??

Not really, you need two SPST switches but connected in parallel. I
must say that logical as it seems, I've never heard of such a
hookup.... any reasons why it wouldn't be feasible/safe/according to
code? You'd definitely want to hook them up to the same breaker, for
safety when you "turn the power off" to work on them........


Well, in order to work, that means that the vents to the
two bathrooms have to be interconnected, which isn't
a good idea.

3way (DPDT) timer switches
 

Well, in order to work, that means that the vents to the
two bathrooms have to be interconnected, which isn't
a good idea.

Why is it not a good idea... batrooms are back to back.. both hoses
take air out of bathroom.. go into a fan unit in the attic and it blows
the air out the top of the roof.. not understanding the problme with
that.. what am I missing. .

3way (DPDT) timer switches
 

Why is it not a good idea... batrooms are back to back.. both hoses
take air out of bathroom.. go into a fan unit in the attic and it blows
the air out the top of the roof.. not understanding the problme with
that.. what am I missing. .


I don't know for sure, it's just on my list of things not to do.

I think it has to do with creating a connection between the
bathrooms, allowing noise and odors to travel between them,
and letting one bathroom, (the one with the open door, and
hence low resistance) provide all the air the fan can draw,
so that the other (with the stench, closed door, and high
resistance) keeps it's oderiferous gasses, but that's all guesswork.

--Goedjn

3way (DPDT) timer switches
 

According to Tom Horne, Electrician :

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.

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).
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

3way (DPDT) timer switches
 

Goedjn wrote:
Why is it not a good idea... batrooms are back to back.. both hoses
take air out of bathroom.. go into a fan unit in the attic and it blows
the air out the top of the roof.. not understanding the problme with
that.. what am I missing. .


I don't know for sure, it's just on my list of things not to do.

I think it has to do with creating a connection between the
bathrooms, allowing noise and odors to travel between them,
and letting one bathroom, (the one with the open door, and
hence low resistance) provide all the air the fan can draw,
so that the other (with the stench, closed door, and high
resistance) keeps it's oderiferous gasses, but that's all guesswork.

--Goedjn

I dunnit... when I bought the house, found one b-room vented outside
but one b-room vented into the attic, so just Y-connected it into the
duct because I hate to punch holes in my house, and I noticed that both
fans had flapper door dampers built in to produce at least some
isolation from each other, and from backflow from the outside. And yes,
I do feel some backflow of warm humid air from one b-room into the
other (mostly when it's cold enough to feel such a thing) but it's not
like a detectible draft from a fan and doesn't bring the humidity in
the recipient room up much at all; and I don't detect any stench
because my poop smells like a mountain meadow. Although I did pick up a
couple of cheap plastic flapper dampers last time I was at HD to
install some time to see if it makes any difference over the built in
ones.