Speed of an operating electrical motor with load is lower than the synchronous speed (no load) of the motor.
Synchronous and approximate speed (rpm) at rated load for small and medium motors operating at 60 hz and 50 hz:
|Approximate Electrical Motor Speed (rpm)|
|No. Poles||Speed with Rated Load||Synchronous Speed (no Load)|
|60 hz||50 hz||60 hz||50 hz|