The speed regulation of a motor is defined as the speed change from full load to the zero load condition and is expressed as a percentage of the rated speed value, ie the difference between the unladen engine speed and engine speed with load. The synchronous motor speed is deliberate by the rotational speed of the rotating field, which depends on the number of poles of the motor and the frequency of the network, in hertz.
If the speed of a motor is kept constant for different loads, it means that the motor has a good speed regulation. The nominal speed is the speed (RPM) of the motor hose assembly running at nominal power, under rated voltage and frequency. The rated speed will depend on the slip and the synchronous speed. The nominal speed, called slip, is the difference between the speed of the rotor and the speed of the rotating field in the stator or synchronous speed. When the motor load is zero (empty), the rotor rotates practically with the synchronous rotation. Slipping softens with increasing engine rated power.