n asynchronous motors, the frequency of the rotating field created in the air gap and the rotation frequency of the rotor are not the same. These motors are called asynchronous for this reason. The frequency of the rotating field in the air gap depends on the motor’s feed frequency and the number of poles and does not change with the motor’s load, but the rotation frequency of the rotor varies according to the load. As the load increases in the motor operation area, the motor rotation speed decreases, and the motor rotation speed increases as the load decreases. The motor rotation speed is the highest in idle mode. The motor rotation speed of the asynchronous motor in the motor operation area cannot exceed the rotation speed of the rotating field. The rotation speed of the rotating field is calculated as follows: