Rotor Motors in Short Circuit

The shorted rotor name is given because of the type of rotor used, which is considered the most common in the industry. Some basic particulars need to be understood when it comes to electrical commands. Generally, the squirrel cage-type rotor induction motor consists of two parts, by the stator, which is the electric motor magnetic circuit, generally of the grooved type, in which are installed the coils which with the proper connection, generate the rotating magnetic field. The rotor has a winding formed by copper or aluminum bars short-circuited at the ends. The current in the rotor circuit is induced by the action of the rotating field of the stator.

In this way, the induction motor in operation means that the magnetic field made in the rotor circuit will chase the rotating field of the stator. In the case of the motor being energized, it works as a transformer with the secondary one in short circuit, requiring from the electrical network a current greater than nominal, reaching up to eight times its value. High starting currents cause unpleasant situations, requiring cable sizes with larger diameters than expected.