Evaporative (Swamp) Cooler Control /w White Rabbit Thermostat Converter

I am trying to control my evaporate cooler from my vera. I think I have it figured out, but would really like to know if anyone else is doing this too. Otherwise, I hope this information helps someone else. I will update if and when I have everything hooked up.

I have a Trane Z-wave Thermostat which is currently hooked up to my furnace. I run my swamp cooler from a simple wall switch - completely manually. For those of you who aren’t familiar with swamp coolers they are typically controlled with line voltage. You have a fan which can be off/low/hi and a pump which can be off or on. I suppose you need three relays, although you don’t want to make sure the high and low fan relays can’t be active at the same time.

Most thermostats for these operate at line voltage as well. I’m considering buying a White Rabbit Cooler Controller which lets you use a normal thermostat to control an evaporation cooler. Online I see two packages: The 21D28-3 and the 21D28-6. These packages come with the relay control box (8A18Z-2) and cheap thermostats. The 21D28-3 is obsolete, but the only difference seems to be the included thermostat so that is the one I’m buying (it is also about $40 cheaper).

The 8A18Z-2 box has lines for R (24v power??), pump relay (W), fan speed relay (Y), and a fan timer relay (G). I think the included thermostats let the pump run for 60 seconds before starting the fan which is nice. I’m assuming this is all easy to hook up to my Trane thermostat. I’m not sure if I will have to disconnect the furnace but that isn’t a big deal, because there is normally at least a three week gap between when I run the cooler and the heater.

This is exactly what I want to do (do you live in New Mexico, by chance?). I have the Trane TZEMT043AB32MAA thermostat. Any success?

I do! Probably one of the places where people still use these these things.

I picked up this guy a few months ago:


But I haven’t had a chance to hook it all up yet. I think it should work fine. I’ll probably get to it in the next month or so.

Just ordered mine… look forward to setting it up in the next month or so myself! Please let me know when you have yours connected or if you run into any problems.

Wondering if anyone set this up yet and got everything to work? The summer is coming and we will be using our coolers before we know it. I wan t to automate my evaporative cooler and want to know if this approach worked.

Not yet for me, it’s almost getting too hot now… I should be doing it in the next couple of weeks.

I haven’t set it up either… still sitting in my garage but I’ll probably be hooking it up in the next few weeks as well.

It is officially hot outside and its time to get our coolers running to protect from the heat. Did anyone get this worked out? I’m interested in hearing your experiences.

I wanted to share my attempt and failure. I have tried to connect a z wave stat to my current masterstat cc2000a low voltage setup for my cooler. I tried replacing my current master cool stat in the house with a 2gig t30 wave stat. I connected the 24v lead to the RC on the z wave stat, pump lead to the the cool, fan lead to the fan and the com lead to the com but the moment I turn it on it blows the 500ma fuse in the master stat low voltage box. I have tried to turn the fan on only but it still blows the fuse.

Open to suggestions or hearing of another’s experience.

Here is a picture of the low voltage box with the thermostat wires and fuse that is blowing.

Bump because its hot.

I assume your existing thermostat was used for a winter heater.

Most thermostats are capable of separate Heat and Cool transformers … but they default to a common transformer.

When you hooked up your swamp cooler to the thermostat … using the RC … there is usually a jumper (or switch) on the thermostat that needs to be removed to have independent transformers for heat and cool. You will need to get the instructions for you thermostat.

For now try disconnecting the R (or RH) wire that goes to your heater.

Thank you for the response. I did remove the jumper and it still blew the fuse. Has anyone else gotten something to work?

Does it blow the fuse right away ?

Try running the swam cooler manually …
Disconnect the thermostat wires at the Swamp Cooler …
Jumper R to G to turn on the fan …
Jumper R to Y to turn on the pump …
Does it still blow the the fuse ?

If manual operation works OK, then there are couple of possibilities:

  1. Wires are shorted (White and Any other)
  2. You removed the wrong jumper (for RH and RC)
  3. The two units are fighting each other … Should not be a problem if the jumper is removed.

Reconnect Swamp Cooler wires, but disconnect the White wire from the Swam Cooler at the Thermostat and the Swamp Cooler.
Check to make sure the white and any other wire (Red, Green, Yellow) are not shorted.
If not … remove the HEATING wires at the thermostat … reconnect all Swamp cooler wiring and try again … (For now put the jumper back in.).

If everything works this way …

Put the heat wires back on … Remove the Jumper, Leave one of the White wires off at a time … It should only need one (From the heater or Swamp Cooler, which one depends on if the thermostat powers itself from RC or RH when the jumper is removed).

Was this issue ever resolved?

I would also like to have z-wave thermostat control of a swamp cooler. But, from the few threads available, it appears there may not be a working solution.