Double Throw Whole house Fan

Hi all,

I searched the forum and have not found a solution. Wonder if someone here has ideas.

I installed a whole house fan with two speeds. The typical switch is a double-throw switch (meaning high-low-off). Is there any way to get a lutron (ideally caseta) to do this?!

I thought about wiring two side by side on-off switches; one for low and one for high BUT this seems dangerous because it’s possible that both switches could be flipped on and I’m sure that’s not healthy for the fan motor.

Thanks in advance.

Model is Quietcool 2250.
Wiring diagram here: https://quietcoolsystems.com/wp-cont...tion-Guide.pdf

Is it critical that Caseta have the ability to change speeds? If so, this is going to be an uphill battle. If you only wanted to be able to turn on/off, I would install a Caseta switch, with the load going to the common screw of a normal 3way switch. The two traveler wires would go to the high speed and the low speed of the fan. This is essentially the switch you would typically use, except there is no off position, as that would be handled by the Caseta switch. A 3 way switch always sends power from the black common screw to one of the two brass traveler terminals. When you change the position of the switch, it sends power to the other screw. While it would be unfortunate to be unable to control the speed with the app, having a caseta switch and a 3way switch on the wall would likely be fairly intuitive to use.

Hope this helps!

Quote:

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Originally Posted by evankirkhart

Is it critical that Caseta have the ability to change speeds? If so, this is going to be an uphill battle. If you only wanted to be able to turn on/off, I would install a Caseta switch, with the load going to the common screw of a normal 3way switch. The two traveler wires would go to the high speed and the low speed of the fan. This is essentially the switch you would typically use, except there is no off position, as that would be handled by the Caseta switch. A 3 way switch always sends power from the black common screw to one of the two brass traveler terminals. When you change the position of the switch, it sends power to the other screw. While it would be unfortunate to be unable to control the speed with the app, having a caseta switch and a 3way switch on the wall would likely be fairly intuitive to use.

Hope this helps!

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That's a great idea! And to I think its obvious, but to underline it: there's no way for power to be sent to both the high and low speed setting on the fan, right?

Having control of speed via Caseta would be nice, but not critical. Whole House fans are such that you need to be around when operating anyway, it's just nice to have the ability to turn it off via schedule (i.e at night) or via voice (i.e. evening if it's getting too cool). And to attach a Pico for "3-way" control for on-off function from downstairs.

So for a newbie like me, could you elaborate on the wiring diagram? Ignoring grounds, the switch J-box will have three wires coming from the fan black (load-high speed), white (nuetral) and red (load-low speed), and two coming from power black and white. I get that white (neutrals) bypass both switches and get connected to one another. What about the rest?

Thanks

Quote:

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Originally Posted by nkapadia

That's a great idea! And to I think its obvious, but to underline it: there's no way for power to be sent to both the high and low speed setting on the fan, right?
Yes. A 3 way switch takes power from the black screw and sends it to any one of the brass screws, never both.

Having control of speed via Caseta would be nice, but not critical. Whole House fans are such that you need to be around when operating anyway, it's just nice to have the ability to turn it off via schedule (i.e at night) or via voice (i.e. evening if it's getting too cool). And to attach a Pico for "3-way" control for on-off function from downstairs.

So for a newbie like me, could you elaborate on the wiring diagram? Ignoring grounds, the switch J-box will have three wires coming from the fan black (load-high speed), white (nuetral) and red (load-low speed), and two coming from power black and white. I get that white (neutrals) bypass both switches and get connected to one another. What about the rest?

All white neutral wires are connected together. The constant power (feed) wire connects to the black wire on the Caseta switch. The red load wire from the switch connects to the black common terminal of the 3 way switch. Then, the two fan wires connect to the two brass terminals on the 3 way switch. Which fan wire goes to which brass screw is not important for operation, but you may want to make the "down" position on the switch the low speed. This can be done with simple trial and error.



Thanks

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Additional wiring tips (sorry if you already know this and I am insulting your competence, you did say you were a newbie):


Since this project will likely involve a new/enlarged electrical box, try to get the deepest box you can get. Fighting big Caseta switches into a tiny box is a royal pain.

Caseta switches usually have wire pigtails, not screw terminals. When you connect the Caseta switch to the 3 way switch, remember not to try to clamp the stranded wire around the screw terminal. It will either fail immediately or soon after.

Also remember to loop wires around screw terminals clockwise so that the wire is pulled around the screw when it's tightened.

If you use a metal box, don't forget to use a green ground screw to ensure the box is grounded.

Not everyone will agree with me, but I insist on using only high quality wiring devices (hence my preference for Lutron). I would use a commercial style 20 amp switch. You don't have to worry about screw terminals, instead using the back-wire system, among several other advantages. You could save 2 dollars, but if it's worth doing, it's worth overdoing.

Glad I could be of assistance, and feel free to reply with any further questions!

Thanks Evan! That is very helpful. Thanks also for the tips. Nothing's too basic and it never hurts to reiterate good wiring ideas.

I've ordered my Caseta on/off switch. I'll try to post back here when it's done. If this works, you'll have solved something that I've been researching for over a week! And hopefully it'll help others. Currently the only options are the most hideous switches that come with whole house fans or else overpriced SPDT dumb switches.

Thanks again Evan!That worked great. I got it all wired up and working on the Lutron app within a couple hours (including the inevitable issues with existing wiring/wall cavity access and a mishap or two).That was a brilliant solution. Not only is the switch much smarter, it's also miles more attractive than the super ugly ones they sell you for $80+! I hope this helps others as well. Evan's instructions above are pretty clear, but I had drawn up a graphic to use while wiring in the attic and the switchbox if anyone wants it I can post it.Thanks again!

Hi,

Can you post the diagram? Looking at doing the same setup.

Sorry I thought I had posted it. Hope it's still useful to you:https://www.dropbox.com/s/8qrdhpru7m....png?dl=0Edit: Fixed the link

Link just refuses to cooperate:https://www.dropbox.com/s/yzrjljz7wg...20Fan.png?dl=0