|squirrel cage motor
|slip ring motor
|An AC induction motor in which squirrel cage rotor is used is called as squirrel cage motor.
|An AC induction motor in which slip ring rotor is used is called as slip ring motor, it is also known as phase wound motor
|The slots of the rotor are not parallel, but are skewed.
|Rotor have a Cylindrical laminated core with parallel slots and each slot consist one bar.
|Construction is very simple and it is cheap as compared to slip ring induction motor.
|Construction is complicated due to the presence of slip ring and brushes and because of slip ring and brushes the motor is more costly.
|The rotor consists of rotor bars which are permanently shorted with the help of end rings, so it is not possible to add external resistance.
|The rotor is similar to the stator winding. Using slip ring and brushes rotor resistance can be easily added.
|Staring torque is low and cannot be improved.
|Due to the presence of the external resistance high starting torque can be obtained.
|It required Less maintenance.
|Frequent maintenance is required due to the presence of brushes.
|It is the most popular type of AC motor and it is very commonly used in industries because it is very cheap, robust, efficient, and reliable.
|slip ring motor has very little application in industries and they are Rarely used 5% to 10% slip ring motors in industries
|Copper losses is less and hence the efficiency and power factor is high
|Copper losses are high and hence the efficiency and power factor is low.
|Speed control is not possible.
|Speed control is possible by rotor resistance method.
|They are used in lathes, drilling machine, fan, blower printing machines etc.
|They are used where the starting torque is high I.e in hoists, cranes, elevator etc .