Hi.

My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. I want the option to run the fan manually
too, bypassing the thermostat. I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?

Advice appreciated.
Thanks,
Theodore.

millinghill wrote:
Hi.

My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. I want the option to run the fan manually
too, bypassing the thermostat. I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?

Advice appreciated.
Thanks,
Theodore.
Hi,
Jumpering the 'stat with a switch may be the easiest.

On Oct 5, 11:01*am, millinghill wrote:
Hi.

My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. *The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. *I want the option to run the fan manually
too, bypassing the thermostat. *I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?

Advice appreciated.
Thanks,
Theodore.

You need a on-off-on three posiiton aka center off switch. Not sure
if you can get those with decorator toggles. You might have to get a
regular one at radio shack and mount it in a blank faceplate.

You do not need 4 wires from the box to the fan. You only need three,
two hots and a neutral. You can use regular 14/3.

You wamt to wire the neutral the way it is now. One of the two hots
(black if you use 14/3) will connect the way the existing black hot
wire connects. The second hot (red if you use 14/3) would connect to
the connection between the thermostat and the fan motor, bypassing the
thermostat. On the switch side the original supply hot goes to the
center pole. The two hots (balck and red if you use 14/3) to the fan
go to the other two switch poles.

Now when the switch is inteh center position the fan is off. In one
direction the fan is always on in the other direction the fan is only
on if the thermostat calls for it to be on. Test and then label the
faceplate.

On Oct 5, 11:01*am, millinghill wrote:
Hi.

My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. *The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. *I want the option to run the fan manually
too, bypassing the thermostat. *I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?

Advice appreciated.
Thanks,
Theodore.

If you just want "auto/on" a regular light switch will work. If you
want a manual off position, you'll need a SPDT switch with a center-
off position. Not sure if those are available in a light switch
format or if you'd need to use a panel mount toggle and mount it in a
hole drilled in a metal blank cover plate.

(firin' up the google machine)

this will work, although not cheap

http://www.amazon.com/Leviton-1282-M.../dp/B0033PSG5A

personally if you need the center off I would spend the bucks for a
wall switch... UL listings, code compliance, yadda yadda yadda

nate

Jumpering the 'stat with a switch may be the easiest.-

Agreed, but then I'd need two wall switches. Ughh.

On Oct 5, 11:30*am, millinghill wrote:

Who are you quoting here? It's easier to follow a thread if you quote
and provide the proper attribution.

Jumpering the 'stat with a switch may be the easiest.-

Agreed, but then I'd need two wall switches. *Ughh.

Tossing out an idea (that the electrical guru's on this board will
either approve or shoot down in flames) - could you use a lighted
duplex switch?

http://www.marketworks.com/storefron...74452176&c= 0

If so, it's only the one outlet space and the lighted toggles would
tell you at a glance what was controlling the fan.

R

On Oct 5, 10:30*am, millinghill wrote:
Jumpering the 'stat with a switch may be the easiest.-

Agreed, but then I'd need two wall switches. *Ughh.

You can get a double-wall switch, easily at almost any place that
sells electrical parts, like Home Depot.. Instead of one up-down
switch, it has two side-side switches, one above the other in the same
space as a regular switch. The cover plate is just a duplex outlet
cover plate. I put one in our bathroom, the top switch operates the
ceiling light, the lower switch operates the vanity mirror lights.
You would wire it up so one switched hot lead goes thru the
thermostat, the other switched hot lead goes directly to the motor. if
both switches are off, nothing happens. Simple as falling off a log.

On Wed, 5 Oct 2011 08:30:38 -0700 (PDT), millinghill
wrote:

Jumpering the 'stat with a switch may be the easiest.-

Agreed, but then I'd need two wall switches. Ughh.

You can get two toggle switches that fit in a single box. That's what
I have for my roof fan.

I can turn it off when the stat would turn it on, or on when the stat
would turn it off. I use both features. Normally, when I'm using
neither feature, one of the swtiches is Off and one is On so that the
stat controls things. Eventually I got confused which position was
normal, so I drew a line with an indelible marker across both toggles
in their nomarl position.

You would need three conductors from the swtich to the fan/thermostat.

If you're using BX and there's enough room for one more conductor, you
could solder one of the conductors that is in there to two new ones,
and pull the two through the BX that way. In my house, it's about 8
feet with only a small bit of bending, but be sure to allow a few
feeet extra so you don't pull the wires into the BX. Or have a
helper or better yet tie a big knot in the wires.

If romex is legal where you are, and the BX isn't stapled inside the
wall, you could solder the romex to the BX wires and pull the whole
thing through.

On Wed, 5 Oct 2011 08:30:38 -0700 (PDT), millinghill
wrote:

Jumpering the 'stat with a switch may be the easiest.-

Agreed, but then I'd need two wall switches. Ughh.

BTW, how do you expect to do another thing without another swtich?

On Wed, 05 Oct 2011 12:19:33 -0400, micky
wrote:

On Wed, 5 Oct 2011 08:30:38 -0700 (PDT), millinghill
wrote:

Jumpering the 'stat with a switch may be the easiest.-

Agreed, but then I'd need two wall switches. Ughh.

You can get two toggle switches that fit in a single box. That's what
I have for my roof fan.

FTR, there is also non-Decora. Standard switches with the normal big
handle. I think it's a little easier to see what position the swtich
is in when the handle is bigger.

An idea: what if I use a single "three-way switch" and have one hot
leg go to the thermostat, and the other hot leg bypass the thermostat?
The only downside is that it will never be "off" unless I kill the
circuit breaker.
Opinions?

On Oct 5, 1:18*pm, millinghill wrote:

An idea: what if I use a single "three-way switch" and have one hot
leg go to the thermostat, and the other hot leg bypass the thermostat?
The only downside is that it will never be "off" unless I kill the
circuit breaker.
Opinions?

Why would you want to have to turn off the breaker? Isn't there
anything else on that circuit? Using a breaker as a switch is a bad
idea, and running an inexpensive fan constantly is also a bad idea.

What's your issue with a lighted (or not) duplex switch?

R

Why would you want to have to turn off the breaker? *Isn't there
anything else on that circuit? *Using a breaker as a switch is a bad
idea, and running an inexpensive fan constantly is also a bad idea.

What's your issue with a lighted (or not) duplex switch?

R

Exisitng condition is that I can turn fan off with wall switch.
Reality is that it is only running when it is too hot (thermostat) in
the attic.
I would only operate this switch to turn the fan OFF if I need to
service the fan or for some emergency.
I would *never* use a breaker on a regular (or even irregular) basis
as a switch.
I think the duplex switch idea is great and will work fine.
I'm only asking about the three-way switch idea because I have a box
of new ones sitting in the garage right now.

On Oct 5, 1:18*pm, millinghill wrote:
An idea: what if I use a single "three-way switch" and have one hot
leg go to the thermostat, and the other hot leg bypass the thermostat?
The only downside is that it will never be "off" unless I kill the
circuit breaker.
Opinions?

That's fine. I don't have a switch at all on my attic fan. Lots of
them are installed without a switch.

On Oct 5, 1:18*pm, millinghill wrote:
An idea: what if I use a single "three-way switch" and have one hot
leg go to the thermostat, and the other hot leg bypass the thermostat?
The only downside is that it will never be "off" unless I kill the
circuit breaker.
Opinions?

Overkill. You can use a plain old SPDT light switch for the same
purpose. You don't actually need to kill the connection through the
thermostat when you force the fan on manually.

nate

On Wed, 5 Oct 2011 08:01:41 -0700 (PDT), millinghill
wrote:

Hi.

My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. I want the option to run the fan manually
too, bypassing the thermostat. I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?

Advice appreciated.
Thanks,
Theodore.
Use 2 switches. One for On/Off and one for Manual/Automatic is the
simplest way.

My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. I want the option to run the fan manually
too, bypassing the thermostat. I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?


*You could use a combination device with one single pole switch and one
three way switch. The single pole would serve as the on-off and the three
way will change it from thermostat to always on.

http://www.legrand.us/passandseymour...hes/696wg.aspx

I think this combination is also available in Decora style. Go to an
electrical supply company to get one.

On 10/5/2011 2:06 PM, jamesgangnc wrote:
On Oct 5, 1:18 pm, wrote:
An idea: what if I use a single "three-way switch" and have one hot
leg go to the thermostat, and the other hot leg bypass the thermostat?
The only downside is that it will never be "off" unless I kill the
circuit breaker.
Opinions?

That's fine. I don't have a switch at all on my attic fan. Lots of
them are installed without a switch.

EVERYTHING should have an off switch. Back in stone age, we would put
attic fans and lights on switches mounted too high for kids to reach,
right under the scuttle hole. Probably against code now or something.
They were not always ivory levitrons, either, for the fans, Some had a
very industrial toggle or rotator switch- those were probably for the
OTHER kind of attic fan, that sucked hot air out of hallway. Of course,
in some old houses, the hallway and gable fans worked in conjunction.
Thinking back, that might be a lousy idea in a fire- make the entire
house into a chimney. When glowing switches came out, they were very
popular for attic lights, so you could tell off or on without opening
the hatch again.

--
aem sends...

--
aem sends...

On Wed, 5 Oct 2011 11:02:16 -0700 (PDT), millinghill
wrote:

Why would you want to have to turn off the breaker? *Isn't there
anything else on that circuit? *Using a breaker as a switch is a bad
idea, and running an inexpensive fan constantly is also a bad idea.

What's your issue with a lighted (or not) duplex switch?

R

Exisitng condition is that I can turn fan off with wall switch.
Reality is that it is only running when it is too hot (thermostat) in
the attic.

I keep my roof fan off in the spring and the fall, when it's warm
during the day but would otherwise require heat at night (or
tomorrow), so that the attic heats up and it heats my home. It means
I don't have to use the furnace for a couple weeks times two, four
weeks a year.

I would only operate this switch to turn the fan OFF if I need to
service the fan or for some emergency.
I would *never* use a breaker on a regular (or even irregular) basis
as a switch.
I think the duplex switch idea is great and will work fine.
I'm only asking about the three-way switch idea because I have a box
of new ones sitting in the garage right now.

On Wed, 5 Oct 2011 18:15:11 -0400, "John Grabowski"
wrote:

My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. I want the option to run the fan manually
too, bypassing the thermostat. I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?


*You could use a combination device with one single pole switch and one
three way switch. The single pole would serve as the on-off and the three
way will change it from thermostat to always on.

http://www.legrand.us/passandseymour...hes/696wg.aspx

I think this combination is also available in Decora style. Go to an
electrical supply company to get one.


3 way not required. Sw 1 powers the thermostat through the black wire.
Switch 2 powers the fan (fan side of 'stat" through the red wire, from
the black wire at the switch. Sw1 on means the fan is on thermo, Sw1
AND Sw1 on means fan on direct. Sw2 only on, fan is off

On Oct 5, 11:50*pm, wrote:
On Wed, 5 Oct 2011 18:15:11 -0400, "John Grabowski"





wrote:
My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. *The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. *I want the option to run the fan manually
too, bypassing the thermostat. *I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?

*You could use a combination device with one single pole switch and one
three way switch. *The single pole would serve as the on-off and the three
way will change it from thermostat to always on.

http://www.legrand.us/passandseymour...on-devices/sta...

I think this combination is also available in Decora style. *Go to an
electrical supply company to get one.

3 way not required. Sw 1 powers the thermostat through the black wire.
Switch 2 powers the fan (fan side of 'stat" through the red wire, from
the black wire at the switch. Sw1 on means the fan is on thermo, Sw1
AND Sw1 on means fan on direct. Sw2 only on, fan is off- Hide quoted text -

- Show quoted text -

Inquiring minds want to know..... Why does the OP
want to run the attic fan without the attic being hot?
Mine is wired with a switch in series with a thermostat
on the fan, just like his is now. Works fine for me.
Some places it's desirable to have them run for
dehumidification, but for that you wire in a control
that measures temp and humidity.

If he does want the option of running it when it's not
hot, then the SPDT switch is the way to go. It's
simple and won't look like a hack job, which is what
he'll have with two switched, sided by side.

SORRY BUB, THAT IS NOT A SPDT SWITCH, IT IS A DPDT SWITCH.
AND YES WITH A LITTLE REWIRING IT WILL DO THE JOB.
TGITM

On Oct 6, 7:51*am, The Ghost In The Machine
wrote:
SORRY BUB, THAT IS NOT A SPDT SWITCH, IT IS A DPDT SWITCH.
AND YES WITH A LITTLE REWIRING IT WILL DO THE JOB.
TGITM

No, clearly it can be done with a SPDT, center off, switch.
Hot goes to switch pole terminal, one position terminal goes
direct to fan, other position terminal goes to fan thermostat.

On Thu, 6 Oct 2011 04:39:49 -0700 (PDT), "
wrote:

On Oct 5, 11:50*pm, wrote:
On Wed, 5 Oct 2011 18:15:11 -0400, "John Grabowski"





wrote:
My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. *The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. *I want the option to run the fan manually
too, bypassing the thermostat. *I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?

*You could use a combination device with one single pole switch and one
three way switch. *The single pole would serve as the on-off and the three
way will change it from thermostat to always on.

http://www.legrand.us/passandseymour...on-devices/sta...

I think this combination is also available in Decora style. *Go to an
electrical supply company to get one.

3 way not required. Sw 1 powers the thermostat through the black wire.
Switch 2 powers the fan (fan side of 'stat" through the red wire, from
the black wire at the switch. Sw1 on means the fan is on thermo, Sw1
AND Sw1 on means fan on direct. Sw2 only on, fan is off- Hide quoted text -

- Show quoted text -

Inquiring minds want to know..... Why does the OP
want to run the attic fan without the attic being hot?
Mine is wired with a switch in series with a thermostat
on the fan, just like his is now. Works fine for me.
Some places it's desirable to have them run for
dehumidification, but for that you wire in a control
that measures temp and humidity.

Personally, I don't like it when I have no override for things like
this.

If he does want the option of running it when it's not
hot, then the SPDT switch is the way to go. It's
simple and won't look like a hack job, which is what
he'll have with two switched, sided by side.

Yes, those space capsules with 50 switches side by side really look
lke hack jobs.

Inquiring minds want to know..... *Why does the OP
want to run the attic fan without the attic being hot?

Good question.
I am ~considering~ running the attic fan without the attic being hot
due to a COMPLETELY different subject and thread:
http://www.amazon.com/forum/home%20i...x1E8UD38IJPDWU
which suggests via this report by the Army Corps:
http://www.crrel.usace.army.mil/libr.../MP02-5778.pdf
that after you insulate your attic, seal air leaks from conditioned
space below, and install passive ventillation as much as practical,
you may still get an ice dam in the winter simply due to large amount
of snow acting as its own self-insulating blanket (happened to me and
many neighbors last year) and that instead of installing heat wires
etc. on the shingles, the next reasonalbe solution would be to power
ventillate the attic to make sure that the temp stays BELOW freezing
during the time that environmental conditions are favorable for ice
dams to occur (per report).

Like I said, completely different thread and I don't want to hijack
this one. I respectfully suggest we start new thread if folks want to
comment on this aspect.
-OP

On 10/5/2011 1:47 PM, millinghill wrote:
Overkill. You can use a plain old SPDT light switch for the same
purpose. You don't actually need to kill the connection through the
thermostat when you force the fan on manually.

nate

Actually called SPST. SPDT is the same as a 3-way switch.

Oh I get it now: power always on to thermostat switch, and _bypass_
the thermostat with the manual wall switch!
Great. Thanks, Nate and thanks to all others too!!

If the power goes to the fan first (power does not go to the switch then
the fan) you can just change the wiring at the fan.

--
bud--

On Thu, 6 Oct 2011 04:39:49 -0700 (PDT), "
wrote:

On Oct 5, 11:50Â*pm, wrote:
On Wed, 5 Oct 2011 18:15:11 -0400, "John Grabowski"





wrote:
My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. Â*The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. Â*I want the option to run the fan manually
too, bypassing the thermostat. Â*I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?

*You could use a combination device with one single pole switch and one
three way switch. Â*The single pole would serve as the on-off and the three
way will change it from thermostat to always on.

http://www.legrand.us/passandseymour...on-devices/sta...

I think this combination is also available in Decora style. Â*Go to an
electrical supply company to get one.

3 way not required. Sw 1 powers the thermostat through the black wire.
Switch 2 powers the fan (fan side of 'stat" through the red wire, from
the black wire at the switch. Sw1 on means the fan is on thermo, Sw1
AND Sw1 on means fan on direct. Sw2 only on, fan is off- Hide quoted text -

- Show quoted text -

Inquiring minds want to know..... Why does the OP
want to run the attic fan without the attic being hot?
Mine is wired with a switch in series with a thermostat
on the fan, just like his is now. Works fine for me.
Some places it's desirable to have them run for
dehumidification, but for that you wire in a control
that measures temp and humidity.

If he does want the option of running it when it's not
hot, then the SPDT switch is the way to go. It's
simple and won't look like a hack job, which is what
he'll have with two switched, sided by side.
A center off SPDT switch can not be had in a "wall switch"
configuration that looks like a normal house switch so IT will look
like a hack. A double gang switch is an everyday situation -even
triple gang switches are very common. In fact you can buy 2 witches
together in one unit that fit a single box and use a duplex receptacle
plate.

On Thu, 6 Oct 2011 05:57:03 -0700 (PDT), "
wrote:

On Oct 6, 7:51Â*am, The Ghost In The Machine
wrote:
SORRY BUB, THAT IS NOT A SPDT SWITCH, IT IS A DPDT SWITCH.
AND YES WITH A LITTLE REWIRING IT WILL DO THE JOB.
TGITM

No, clearly it can be done with a SPDT, center off, switch.
Hot goes to switch pole terminal, one position terminal goes
direct to fan, other position terminal goes to fan thermostat.
A standard 3 way switch - but it does not give you an OFF option

On 10/5/2011 12:25 PM, micky wrote:
On Wed, 5 Oct 2011 08:30:38 -0700 (PDT), millinghill
wrote:

Jumpering the 'stat with a switch may be the easiest.-

Agreed, but then I'd need two wall switches. Ughh.

BTW, how do you expect to do another thing without another swtich?

What the situation calls for is a single pole, double throw switch with
"Center OFF."

I haven't seen them offered in the form factor of standard 120 volt
toggle switches but I have seen them in the form that mounts in a 1/2"
hole in sheet metal.

BUT "you made me look."

Check out the Levitor 5685-2A. It's a single-pole, double throw,
center off, maintained contact Decora switch.

It might be on the expensive side but with one switch you can choose:
ON, OFF, Thermostat.

for a single switch solution you could use a spdt like the Leviton 1285

On Oct 5, 11:01*am, millinghill wrote:
Hi.

My attic gable fan (http://www.homedepot.com/buy/building-materials/
ceilings-attics/master-flow/power-gable-vent-pg3-1600-cfm-21356.html)
has a thermostat built in that kicks on when it gets too hot up
there. *The fan is powered by a dedicated BX cable that runs up to the
attic, and this cable has a regular wall switch that I can shut on/off
from the 2nd floor hallway. *I want the option to run the fan manually
too, bypassing the thermostat. *I can replace the BX calbe with a
4wire cable (two hot/one neutral/one ground), and have one of the
wires bypass the thermostat.

But, what kind of wall switch would I need to buy that has, basically,
three settings: off, on (for automatic fan operation via thermostat),
and on (for manual operation of fan, bypassing thermostat)?

Advice appreciated.
Thanks,
Theodore.

You will need a Center OFF switch. Hot wire from the panel goes to
common connection on the switch, other two wires dont matter which but
one goes to the normal connection and the other connects to a point
that bypasses the T stat. Mine was wired directly to the breaker
panel, no switch. What I did was wire the switch across the T stat
and I located this switch by the attic entrance so I can turn the fans
on full when I go up there. Switch only selects normal operation or
Bypassed Tsat operation ...OFF/ON is done at the breaker panel.

Jimmie


Jimmie

On Oct 5, 1:18*pm, millinghill wrote:
An idea: what if I use a single "three-way switch" and have one hot
leg go to the thermostat, and the other hot leg bypass the thermostat?
The only downside is that it will never be "off" unless I kill the
circuit breaker.
Opinions?

Thats the way mine is.

Jimmie

On Oct 9, 1:40*pm, JIMMIE wrote:
On Oct 5, 1:18*pm, millinghill wrote:

An idea: what if I use a single "three-way switch" and have one hot
leg go to the thermostat, and the other hot leg bypass the thermostat?
The only downside is that it will never be "off" unless I kill the
circuit breaker.
Opinions?

Thats the way mine is.

Jimmie

Correction No its not, I shouldnt post when half asleep. All you need
is a two way switch connected across the tsat if you use the breaker
for on/off.


Jimmie

On Oct 6, 10:44*am, millinghill wrote:
Inquiring minds want to know..... *Why does the OP
want to run the attic fan without the attic being hot?

Good question.
I am ~considering~ running the attic fan without the attic being hot
due to a COMPLETELY different subject and thread:http://www.amazon.com/forum/home%20i...d_ttp_ef_tft_t...
which suggests via this report by the Army Corps:http://www.crrel.usace.army.mil/libr.../MP02-5778.pdf
that after you insulate your attic, seal air leaks from conditioned
space below, and install passive ventillation as much as practical,
you may still get an ice dam in the winter simply due to large amount
of snow acting as its own self-insulating blanket (happened to me and
many neighbors last year) and that instead of installing heat wires
etc. on the shingles, the next reasonalbe solution would be to power
ventillate the attic to make sure that the temp stays BELOW freezing
during the time that environmental conditions are favorable for ice
dams to occur (per report).

Like I said, completely different thread and I don't want to hijack
this one. *I respectfully suggest we start new thread if folks want to
comment on this aspect.
-OP

Ya know, if you don't have at least one square foot vent opening
for 300 square feet of vented space, you have no warranty on
most shingles, such as Certainteed and Owens-Corning. Verify
warranty details at 1-800-ROOFING.
But putting that aside, the main aim is to get any BTU's that make
it up to the attic to be removed. Problem with your plan is that
a roof fan will also pull conditioned air from within the wall spaces,
causing a net loss in your efforts to keep warm in, cold out.
Also, I've gotten damn tired of dealing with sites with damage
caused by an overheated fan. A lot is depending on an overtemp
sensor supplied by the lowest bidder in China. Those fans get
forgotten about, at the hottest part of the roof, and all the worst
if you turn on the fan and then forget it. Better to put a timer
switch to shunt the t'stat if you feel you really must.
It would be nice to have a remote-reading temperature sensor
in the eaves area, displayed near the timer switch.

On Thu, 06 Oct 2011 20:28:52 -0400, John Gilmer
wrote:

On 10/5/2011 12:25 PM, micky wrote:
On Wed, 5 Oct 2011 08:30:38 -0700 (PDT), millinghill
wrote:

Jumpering the 'stat with a switch may be the easiest.-

Agreed, but then I'd need two wall switches. Ughh.

BTW, how do you expect to do another thing without another swtich?

What the situation calls for is a single pole, double throw switch with
"Center OFF."

You're right!!!

Thanks.

P&M?

I haven't seen them offered in the form factor of standard 120 volt
toggle switches but I have seen them in the form that mounts in a 1/2"
hole in sheet metal.

BUT "you made me look."

Check out the Levitor 5685-2A. It's a single-pole, double throw,
center off, maintained contact Decora switch.

It might be on the expensive side but with one switch you can choose:
ON, OFF, Thermostat.