In operation the non rotating stator winding is connected to an alternating current power source. This rotating magnetic field induces the voltage in rotor bars and hence short circuit currents start flowing in the rotor bars.
A Two Pole 75kw 440 V 50 Hz Y Connected Three Phase
3 phase squirrel cage induction motor connection. The three phase induction motor is the most widely used electrical motoralmost 80 of the mechanical power used by industries is provided by three phase induction motors because of its simple and rugged construction low cost good operating characteristics the absence of commutator and good speed regulation. In three phase induction motor the power is transferred from stator to rotor. Nfpa 70 national electrical code table 430250. This rotating magnetic field has a speed which is known as the synchronous speed. Thats why its called squirrel cage induction motor. Squirrel cage induction motor working principle.
An induction motor can therefore be made without electrical connections to the rotor. The voltages listed below are standard rated motor voltages. The alternating current in the stator produces a rotating magnetic field. Induction type squirrel cage and wound rotor amperes synchronous type unity. A squirrel cage induction motor scim is an asynchronous electric motor in which the rotor is made with a short circuited winding in the form of a squirrel cage. Thus at normal supply voltage like in transformers the initial current taken by the primary is very large for a short while.
In a squirrel cage induction motor the starter is used only to decrease the input voltage to the motor so as to decrease the starting current. Induction motor construction the three phase induction electric motor as well as any electric motor consists of two main parts the stator and the rotor. An induction motor or asynchronous motor is an ac electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. This includes induction type and synchronous type three phase alternating current motors. An induction motors rotor can be either wound type or squirrel cage type. Normally we use the motors in industrial drives because they are rugged reliable and economical.
When a 3 phase supply is given to the stator winding it sets up a rotating magnetic field in space. Unlike in dc motors large current at starting is due to the absence of back emfif an induction motor is directly switched on from the supply it takes 5 to 7 times its full. An induction motor is similar to a poly phase transformer whose secondary is short circuited. 3 phase squirrel cage induction motor is one of the most popular types of ac electric motor which achieve the electromechanical energy conversion through stator and squirrel cage rotor by electromagnetic induction. 3 phase dol starter connection three phase. A squirrel cage rotor is the rotating part of the common squirrel cage induction motorit consists of a cylinder of steel laminations with aluminum or copper conductors embedded in its surface.