In the event that the electric motor rotates at a speed other than the synchronous speed, ie different from the speed of the rotating field, the rotor winding shall cut off or interrupt the magnetic field lines of the field and, according to the laws of electromagnetism, Induced currents. Therefore, it can be stated that the greater the load, the greater the torque needed to be able to drive it. To obtain a larger torque, the velocity difference must be greater, so that the induced currents and the produced fields are larger.
This way, as the load increases, the engine speed will decrease. When the load is zero, ie no-load motor T113076, the rotor will rotate virtually with synchronous rotation. The main difference between the speed of the motor, represented by n, and the synchronous speed, represented by ns, is called slip, which can be expressed in revolutions per minute, or rpm, as a fraction of the synchronous speed. Nominal speed consists of the speed, rpm, of the motor operating at nominal power, at rated voltage and frequency, depending on the slip and the synchronous speed.