I just put an attic fan in and just wired it direct for now.
I want to put a 3 position switch on it. [off, on, automatic]
The fan has the adjustable thermostat that turns it on when the attic
is hot-- but sometimes I might want to bypass that. [In winter it will
be off; in summer after a few hot days, if it cools off at night I
want it to run all night.]
I thought this would be an easy thing to pick up, but neither of the
borg's I've visited have anything that looks workable. Before I
wander down to our local electrical supply place, is there some reason
this is a bad idea? [and is electric supply my next best bet-- or an
The switch you want is a single pole- double throw, with center off
position. They are commonly found in the small bat type, but fairly hard to
find in a standard toggle type. The electrical supply would be your best
bet. Another way to do this is install a double gang box with one single
pole switch and one three way switch. Run the power first through the single
pole, which will give you the "off" run from the single pole to the common
of the three way, and one wire off a traveler to the fan direct and the
other to the thermostat
I'd be mildly surprised if a real electrical supply shop didn't have
an appropriate switch, but if not, you can always use a combination
of 2: A spdt switch that swaps between auto- and allways-on, and
a regular spst on/off feeding power to that.
Thanks for the correct terminology . [I had to look up 'bat type' - I
was thinking about the flying mammal, not the baseball tool. Now it
I had pictured a knob type switch-- but now that I have the
terminology I'll give the electrical supply a try & see what they
Using a gang box & a 3-way is an interesting idea but space is tight &
I'll do some searching for the SPDT switch before I go that route.
Thanks to all of you for the suggestions--
On Thu, 9 Jun 2005 17:00:24 -0400, "RBM" <rbm2(remove
What Wayne is showing you is probably why those switches aren't readily
available. If you use the bat type, get double pole double throw- center off
and put jumpers across the three positions to double the amperage capacity
of the switch
The question that comes to mind is why you would want to do this at
all. The purpose of these fans is to provide extra ventilation when
it's very hot. What's the purpose of burning electricity to keep it
running all night after the attic has cooled off? You can just set
the thermostat somewhere lower. The attic insulation handles the bulk
of the heat issue and should have no problem once the attic is below
100 or so. At that point, it's more likely you;re spending more money
running the fan than you save on cooling. Plus, these fans, especially
if there is insufficient intake, can acually pull conditioned air out
of the house through holes around electrical outlets, recessed lights,
In my part of the world [upstate NY] it *usually* cools off enough at
night that sucking ambient air into the house will replace the use of
a window AC-- and closing up the windows in the AM will hold the
coolness all day. Right now I'm just opening the attic door to
make it a whole-house vent overnight, but I'll be putting a closeable
vent between the upstairs and attic at some point.
We spend a lot more money heating-- and in the winter if the attic
gets to 150 degrees on a couple days I'd like to leave the heat right
there. So turning it right off for the winter makes sense.
Having the ability to make the adjustments in the hallway rather than
going up to the attic to make them makes them all the more likely to
If I were in the south with central air it probably wouldn't be worth
the effort, but where I am the attic fan replaces AC most of the time.
[Past week is an exception- it has stayed muggy around the clock so
automatic would be the way to go this week.]
Is it acceptable (NEC-wise) to use a bat type switch at 120 VAC? If
so, how would one mount it in a standard electrical box?
BTW, I did find one online vendor that sold a toggle-type switch for
It's perfectly legal,like any other switch it has to be rated for the
voltage and amperage/ HP that it's used for. They come standard with multi
speed whole house fans. The switch mounts to a cover plate which mounts to
You are making it too hard. Just put in a double
box and use two regular switches. The first is
power on/off. The second is automatic/manual.
The cost is the box, two 39cent switches, and
another piece of romex for the third wire you
need. I did this long ago for my attic fan
because I wanted more control. While you are
screwing around with this and if the original fan
was direct wired, you might want to rewire so that
it is easily pluged in and unpluged. I did that
also because I needed to remove the fan for
repairs before I finally figured out that the
solution was replacing the original crappy fiber
washers (thrust) with nylon washers.
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