Relay that will switch 24v?

Hello fellow hubitat users. I am installing a whole home dehumidfication and air exchange system and everything is controlled by bridging the supplied 24v signal to another pin (one to turn on the dehu one to turn on the fan) and I'll need to also control a damper for outside air (another 24v signal the way it looks).

Anyone know of a relay that plugs into mains power (or is powered off 24v?) but has "vin" and "vout" so I can run 24v through it? All of the micro relays use the same power lead to power the device and provide power to the output when switched on.


Aeotech ZW139

Also should mention Insteon Micro modules. There's now a direct driver that will control it via HTTP. You'll need an Insteon hub to use them, but they are really reliable and dual mesh.


Another option is to use a smart plug and attach a 24v power adaptor to it since you mention main power which I assume is 110VAC.

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Nice the ZW139 would even let me have manual switches to control it should I want that level of backup. Not really hot on adding an Insteon hub as I'd have no other use for it...

Thought about the 24v on an outlet but it adds some complexity I'm not a huge fan of to basically replace a humidistat.

Maybe there is a super cool Zwave thermostat with dedicated dehumid and air exchange control ports...

ZBLC15. It's Zigbee. There is a single relay model and a dual relay model. It is powered by house current but switches separate leads that can be AC or DC. Rated for 15 amps house current so it should handle your application. I have one running my attic fan. Works on SmartThings or Hubitat.

Now I’m really upset!
$64 to ship to the UK!
More than the cost of the unit

Shame, it looks like a nice device


Ouch! I didn't see that!

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Evolve LFM-20 works, if you can find them. Isoloate relay, but mains powered. We are using one at our warehouse to turn on and off an evaporative cooler. Z-Wave.

The Qubino Flush 1D will work and it can be powered by 24v:

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Also, I know @ChrisUthe doesn't want Insteon, and that's understandable to not add a hub for one thing (although I've done it many times and will continue), but the Insteon IOLinc also has dry contacts, is powered by mains voltage by just plugging it in and can also sense when contacts have been closed. Has both N/O and N/C contacts.

The Hubitat Insteon direct driver isn't coded for it, but thats on the to do list.

Looks like they have a double that can run on 24v too

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That Dual Relay isn't "dry contact."

One leg of each of the two relays is tied together. Meaning the entire function must be on one circuit. Also it's 24vDC. None of that has to be a problem, it's just this dual one is NOT simply two of the singles in one package.

If the two loads are running from independent 24v sources, two of the singles might be a better choice. Plus, a lot of those types of home appliances work from 24vAC.

Dig in to the details, is my advice. (I'm in the midst of building out a Pool Controller and naturally my first idea was to use those Qubino's. They wouldn't work for me because of the 24DC vs 24vAC. Everything pool related uses 24vAC.)

If you do need fully independent dry contacts, you can use two of these:

Better yet, the dual version:

and just wire them up to the Quibino's. Relay driving a relay ... fun stuff. :smiley:

Yea, I see that csteele, I also see based on this diagram that I'm probably working with 24v AC:

Best just to go with a set of dry contact relays and avoid the worry, though if it suppored 24v AC that would be OK as the supply for both is the same 24v being supplied from the unit.

Can't believe they want $300 for a humidistat to control this thing.

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Yes, if that's a complete schematic, there's nothing to convert the AC into DC on it.

A pair of the Dry Contact Qubino's would do the trick. You have to pair twice, but don't have to "fight" with a parent/child driver.

Wow! Just barely over half that price for an Ecobee lite which has contacts for a humidifier built in. Using my Ecobee 3 that way (which is the same as an Ecobee lite).

How controllable is the ecobee? I have a centralite perl mostly because I just ignore it and constantly change the set point based on various rooms and times. I have no nifty advanced features (single speed fan, no dampers to control etc) but adding a dehumidifier means I need to kick the AC fan on whenever the Dehu kick in, which, if I"m doing all the controlling via hubitat no problem, but relying on the thermostat to be smart enough while I meddle based on other temperature inputs is scary.

I wish I had just relays for the heat & AC, frankly, I don't need the thermostat to maintain a set point, my software can do that.

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If relays is really what you want, probably continue down that path. I don't have anything fancy on our furnace either. It is a two-stage though. Didn't even realize that until we got the Ecobee because our original programable thermostat was only wired up with two wires :joy: When I put in the Ecobee I rewired with CAT 5e wire to the controller so I could fully control the furnace and the humidifier. Ecobee support was super helpful. I described the furnace control board the them and they told me exactly how to wire it. We don't have A/C, but the wiring is there now if we ever do add it (and after this Summer I think we just may).

Ecobee isn't like a Nest. Doesn't try to be smarter than you are. You set schedules and can fiddle with them as you wish. Temporary changes are just that. Schedule resumes and your temporary changes go back to normal. It uses Home and Away schedules if you want, and doesn't if you don't want that.

I like that it can save me some money by not just constantly running a fixed schedule when no one is home and then resumes automatically when we are. Really all I wanted in a thermostat, besides easy to use and remote access. Has all that, but doesn't try think for me. I've had mine for a couple of years. Never touch it other than to turn it off when my wife starts opening the house too soon in the spring and we pay to heat Toronto. Otherwise, I just let it do it's thing. I appreciate the nice extra features like maintenance and filter reminders which I set the schedule for. Then you have the extras like Alexa and Google Home integration and HomeKit if you want that.

Hubitat supported now, so it fits that bill if you're considering it.