Installation Report
Last week, on July 4th I helped my friend Kyle to convert his swamp cooler. Similar story, he wanted to control it via Nest thermostat. So far I’ve sold a dozen or so boards. And people have been happy with the product so far. This particular scenario was not much different. The only thing I was there to help him out with the installation.
Couple new variables though. I’ve used new revision C on this install. Just to prove to myself that the design works in the new form factor. Also he had AD1C7112 evaporative cooler by Master Cool. The spec claims that the blower motor runs at 16 A which is the theoretical limit of my product. And this particular model has a drain pump. If you check my specs I actually list this model as unsupported one. Simply because my board does not have a drain pump control.
Originally, Kyle was going to replace original control board. It stop working properly. I have a feeling one of the relays failed on the old control board because he was not able to run his cooler at the high speed anymore.
Anyway, my board still can not control drain pump. Maybe I will look at this option in the future. But his old control board can! So, we quickly wired the Smart Swamp Cooler board, jumped the power and the drain signal to the old board. We even hanged old thermostat right there, next to the old controller board. Simply so it can control the drain pump. We ran short section of the thermostat wire from the old thermostat to the old controller board. And reused the thermostat wire running through the house.
The old thermostat was right next to the Nest thermostat. We even had enough wire to reroute it to the Nest.
The whole thermostat wiring was a little confusing. Mostly because Kyle clipped one of the signals earlier that year. So he actually had only 4 signals to work with initially. Eventually we upgraded the cable to 5 signals and that solved all the problems.
At the thermostat he had R, C and W coming from the furnace. Pretty typical setup. We opted out for a single transformer setup. The pictures show wrong setup, I snapped those while we were dealing with 4 conductors instead of 5.
So I removed the jumpers at the Smart Swamp Cooler board. Jumped Rc and Rh and a short red wire at the thermostat. Similar story for the C signal. Jumped Cc and Ch and a short blue wire with a wire nut. Connected those 2 to the R and C signals.
The rest of the wiring was based on the solution F. Once everything was wired, we turned the breaker back on. Ran through the testing sequence on the Nest. And everything was working smoothly.
We had a celebratory beer to celebrate both America’s birthday and the upgraded swamp cooler!
Job well done!
