SparkFun Forums

[bab264]

Hello - I'm brand new here and I'm hoping this is the best place to post a question I can't find an answer to anywhere on the 'net... but I may admittedly be looking in the wrong places.

I have a whole house fan (tamarack hv1000) that requires the use of an SPST switch. The fan itself needs to constantly have power, as when the switch is thrown off, it needs power to close its insulating doors.

When I purchased the fan, I didn't realize it constantly needed power. My plan was to connect the fan to my home security / automation system via a zigbee outlet controller, so that I could operate it in the same way I operate other lighting and devices in my house.

So my question is - is there any device or method anyone can think of that would allow me to connect or simulate an SPST switch to the outlet controller, so that when the outlet controller is turned on, the SPST switch is thrown on, thus turning on the fan -- and when the outlet controller is turned off, the SPST switch is thrown off?

Thanks!

[Ross Robotics]

Bypass the SPST switch. Don't need to have 2 switches.. As long as it's switched somehow, just take out the SPST..

[bab264]

I'm sure this is a novice's question, but how would I bypass the SPST switch? The instructions indicate that an SPST switch is required based on the wiring from the fan... how would I wire it otherwise and to what type of switch?

Remember that my goal is to use an on/off outlet controller (more specifically, a Centralite 4255050-RZHA), whereby when the outlet controller is turned on, it causes the switch to be on. Because the fan needs a constant source of power, I can't use the outlet controller to directly control power to the fan itself.

[Ross Robotics]

Think you need to do some more research on what it takes to turn off and on the fan. If I have time later, I may look up your fan and see how it operates, but that job should really fall to you. Are you using 110V or 225V? Why can't you use the outlet controller to control the fan? Thinking you could take out the SPST and wire it up like it's always on, then use the controlled outlet to supply the power to the fan.

[bab264]

Thanks for the feedback. I did try to do some research on how to do this, but I couldn't find an answer - admittedly because I might be looking in the wrong places though.

The fan runs off of 110. I can't use the outlet controller to supply power to the fan, because when you turn the fan off via the switch, the entire unit still needs power to close the insulating doors...

Switch goes on - insulating doors open, and then fan begins to run. Switch goes off, fan stops and then insulating doors close. The doors are powered by a motor.

If I simply have the switch on all of the time and then try to remove power from the unit to turn it off, the insulating doors will never close, as the motor won't have power.

[Ross Robotics]

You could replace the SPST with a relay at the correct rating. But the relay would need to be on a delay to give enough time for the doors to open and close. Which this would require another circuit either via your remote or some source from the outlet.

Hopefully, I will have enough time tonight to study the controller and fan and see if I can come up with some ideas.

[bab264]

If it's helpful, wiring information can be found on page 3 if the installation manual, here: http://www.efi.org/sites/default/files/5502-1631.pdf.

[DanV]

It looks as though all you need is the remote controller to handle the Black wire.
Since the Red wire is supposed to be always on, it supplies power for the doors to open / close automatically when you energize (or de-energize) the Black wire.

The wiring instructions say that the fan motor is controlled internally.

[bab264]

I have the version that comes without a remote controller, although I can purchase it if needed.

My goal is to control the fan though through my home automation system, not via a separate remote control... although I will ultimately do that if there's no creative way around the problem.

I'm attempting to essentially find a way to energize/de-energize the black wire through use of an on/off outlet controller, instead of a traditional SPST switch. I figured there would be some device that would turn an SPST switch on/off when the outlet controller was turned on or off, but can't find an easy solution... my apologies if I'm doing a poor job of explaining this.

[n1ist]

You are looking for a relay with a 120V coil and SPST contacts (though one with SPDT contacts will work; just ignore the extra contact) to replace the switch. Current rating on the contacts should be at least a few amps (the fan draws about 1A, but there's likely a startup surge. Keep in mind that you are working with line voltage; there are both safety issues and electrical code issues you have to deal with. I would use a RIBU1C relay; it will mount directly to the electrical box on the fan. The only issue is that I don't know of a code-compliant way of connecting the coil of the relay to the home automation outlet as you can't use a flexible cord, and can't there is no plug rated to fit on romex. From an electrical point of view, a regular linecord would work, but wouldn't be ok with NEC. If your home-automation system has light switch or hardwired controllers, that would work instead and be compliant.

/mike

[bab264]

Thanks! There is a hard-wired light switch relay (manual http://216.92.42.133/pdf/products/HA_Relay_Install.pdf) that works with my home automation system - thinking that this would be suitable... can you confirm? If it is, I think I'll end up purchasing that along with the RIBU1C relay and then bring in an electrician to make sure it's all done according to code.

[n1ist]

I believe it should work, and you would not need the RIB as it provides a switched hot.

Looking at the data sheets, I would connect it as follows:
Line white to relay white and fan white
Line black to relay black and fan red
relay red to fan black
Line green or bare to relay green and fan ground screw.

/mike

[bab264]

Thanks mike - to confirm, this setup will provide a constant source of power to the fan, even when the light switch relay is turned off?

If so, I'm wondering why the fan manufacturer suggested that only an SPST switch would work...

Sorry for the novice questions... I just want to make sure I'm headed down the right path.