SmartThings Community

Whole House Fan With RIB Relay SPDT Question

(Tristan Colborg) #1

Hey community have a question on my switch option to control my whole house fan. I used to have it set up using the Enerwave Dual Relay Switch Module (this guy here) but unfortunately I think the start load of the whole house fan killed the switch. So now I am looking for another option to wire this back up and get it smart again, hate having to walk to the switch.

Here is the wiring diagram for the unit.

51%20PM

Question I have is if I am using this RIB Relay what is the best way to hook this up using actual switches?
Can I use 2 separate Zooz On/Off switches with the Low/On hooked up to one of the paddles, and then the High Speed hooked to the other Paddle? If I understand it correctly the RIB relay we have the coil activated only allowing the High motor to be running with this set up, and therefore avoid having both loads running to the motor at the same time. Is that correct? Sorry just want to make sure I understand it correctly.

Thanks everyone!

(Allan) #2

Wouldn’t it make more sense to have one switch control high or low (on = high, off = low) and the other switch control on and off?

(Tristan Colborg) #3

Yeah that was what I wanted I guess I just don’t know how the switches would work like that. Would I just wire the two smart switches exactly how the wiring diagram is? I assumed both switches would need power all the time to keep them connected to the hub.

(Allan) #4

I would have to think about it more but one switch would do the master on/off then the other switch would control the relay, which would be fed power from the main switch. You need the relay so it can supply power whether the switch is on or off (high and low).

I can draw something up if you need.

(Tristan Colborg) #5

Okay so would you pigtail the load to both switches then? The part I’m confused by. Because technically in the diagram from manufacture the on/off switch supplies power to the low on the other switch when the on/off is turned on. Then when you click the low/high switch it’s rerouting the power to the high speed on the motor. That’s why I think you’d have to run the low to one switch and the high to the other, otherwise I don’t know how you would Supply power to both switches without the low fan wanting to run.

(Allan) #6

No, give me a couple hours and I’ll throw up a picture. You have to be able to switch the low and high, if you have the low off one switch the high off the other switch there’s a potential of turning on both switches and probably burning up your motor. That’s where the relay comes in.

(Allan) #7

NOTE: I am not a electrician (by trade) although I have rewired and done a lot of renovations.

So first switch is master on/off. Second switch is just turning on and off the relay you listed. The relay has a common and a normally open and a normally closed. So when the second switch is OFF the relay will be in the normally closed position which is low speed. If the second switch is on the relay will switch the normally open side on (turning off the other) and be in high speed. This way there is no possibility of powering both at once. Switch 1 will always act as a master. Grounds not shows.

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(Tristan Colborg) #8

So just to make sure I understand correctly. Both switches are going to get power from the incoming line. The load on the on/off switch will be connected to the common on the relay to control the low speed of the fan. The second switch will be used to initiate the high speed of the fan and connected to the coil of the relay to trip the normally open circuit on the relay. So could I just use two regular on/off smart switches then?

Thanks again for your help.

(Allan) #9

Yes. Otherwise your second switch would become a “dumb” switch (if it didn’t always have power).

Technically it will “power” either low or high. Its the common power supply to the fan.

Yup. Again technically the second switch is just flipping the relay which is diverting power from the first switch to low or high speed

Yes but make sure the master on off is rated for the power of the fan. The low/high technically doesn’t since its just switching the relay but I assume you want them to match.

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(Tristan Colborg) #10

Awesome thanks for the clarification. Have you used the Zooz switches? I have only used the GE units before.

(Allan) #11

No, I’ve only used the GE ones also…got like 30 in my house currently. Electric motors are inductive loads so make sure whatever you go with is capable of a inductive load at the amperage the motor needs to start. The ZooZ ZEN21 doesn’t list inductive or motors as supported, the GE 14291 does say it supports up to a 1/2 HP motor. Keep that in mind.

Or you could add another relay that can handle the power load off of switch 1 and make this even more complicated. :slight_smile:

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