I hate to disappoint anyone shopping for an evap cooler motor, but it’s impossible to answer questions like what the best one is. This depends absolutely entirely upon the piece of equipment, the cooler it uses and the application this equipment is designed for. So, you would have to go through quite the list of different applications, models of equipment for said applications and so forth to make solid, intuitive suggestions that would be entirely open to interpretation.
However, I feel that when searching for the best evaporative cooler motor, the best way to find it is to have some understanding of how electric motors work, and understanding of why they fail, and therefore, a solid understanding about what aspects of the cooler may or may not speed up the degradation of any given motor.
An electric motor is actually a pretty simple device, it just isn’t entirely obvious in how it works unless you already are aware of electromagnetism. Electromagnetism, central to how an evap cooler motor functions, is the interaction between electricity and magnetic fields. For example, everyone is familiar with the idea of an electromagnet, in other words, a far more powerful magnet due to current being passed through it. Well, current can also cause resistance against magnetic fields, and this is where work can be performed by an electric motor. A spitting camshaft is lined with magnetic material, and a stationary copper coil wraps around the shaft, but it doesn’t make contact. When current is passed through the coil, the magnets are repelled by the electrical field produced, thus creating spin.
As we said, it’s pretty simple on a fundamental level. However, there is a lot of deep science, competitive science in the industry at that, as far as materials, voltages and so forth they can produce better motors, specific types of motors and ones that have higher power or better longevity. You see, motors tend to malfunction over time due to one of 3 reasons. They may overheat, even in a cold environment, from a lot of use. Resistance of any sort is achieved by converting voltage or magnetic properties into heat, so motors get hot. Heat can reduce the conductive ability of materials as well as damage the magnetic alignment of materials, thus eventually making the motor unable to function.
Moisture is another thing that can really mess up even the best evaporative cooler motor. Given that coolers tend to produce a lot of condensation and moisture, you need the best housing possible and the most moisture-resistant evap cooler motor can find. Shopping online will save you a ton of money on this due to licensed resellers not having to worry about shelf space nor deal with the ridiculous markups of manufacturers or the overhead of a brick-and-mortar location. Ultimately, you will get your cooler and therefore the rest of your equipment back up and running far faster and far less expensively if you take this approach in shopping for your components.