Squirrel Cage induction Motor

Slip Ring Induction Motor

The construction of squirrel cage inductionConstruction of slip ring induction simple and rugged.

Construction of slip ring induction motors needs slip rings, brushes, short-circuiting device, etc

This type of motor has less overhang and better space factor in slots.

These motors have the highest overhang and poor space factor in slots.

Cost and maintenance are less.

The cost is more.

Higher efficiency (in case of machines, notdesigned for high starting torque)

Low efficiency and more copper losses.

Small copper losses and better power factor.

Poor power factor and can be improved at the start.

The cooling factor is better because of its bare end rings and the availability of more space for rotor fans.

The cooling factor is not quite efficient.

These motors have better speed regulation, simple starting and low staring torque with high starting current

Poor speed regulation when operated with external resistances in the rotor circuit. The motor needs slip rings, brush gear, short-circuting device and starting resistors etc