Bob,
Evaporative coolers (swamp) are the norm here in Tucson and I guess I've wired a few. We use a Midwest box which has a 4 wire motor receptacle for the 2 speed motor with a time delay Fusestat for each speed. It also has a standard duplex for the pump protected by a 1.25 to 1.6 amp fusestat. We mount the Midwest box on a stand and feed it from below with Emt. Then we run cords and plugs into the cooler and connect them to the coolers interior J box which has rubber receptacles for the motor and pump. I have never seen a 120V unit on a circuit bigger than 20 amps, even some of the 10,000 CFM units which are 1-1/3HP. However, many of the larger units are run on 240V. Pumps are available as well that run on 240.
The Midwest boxes have been required by city code for more than twenty years after many fires from unprotected motors and pumps as most people run them 24/7 all summer even when they are not home.
After many times being helped on this forum I am thrilled to be able to make a worthwhile contribution.
Brian in Sunny Arizona
