Can my motor be variable speed?
“The speed of any AC motor is dependent on the applied frequency. However, some AC motors are just not suitable for variable speed operation. Single-phase motors (for reasons I won’t go into here. Mostly it has to do with how single-phase motors START. Once they’re running, change the frequency, change the speed.) are just not good candidates. There are some tricks you can play (reduce the applied voltage enough, and the motor WILL slow down, but it’ll run hotter), but generally single-phase applications are fixed-speed.”