Definitions for "AC Motor"
Alternating current motor that operates with a power source where the voltage alternates or changes in magnitude and direction 60 times per second. The rate of change is expressed as 60 Hertz (Hz). In some countries, the motor changes 50 times per second
a completely different kind of load and won't work right with the square wave your UPS is putting out when on battery power
AC Motors may be operated at a constant speed, without variable speed control, or may be furnished with a variable frequency controller for variable speed control. Variable speed AC Motors generally provide a 10:1 drive turndown ratio, typically for powering a feeder.