Advantages of Squirrel-Cage Induction Motors

The advantages of squirrel-cage motors compared with the slip ring induction motors are given below

(i) They are more robust and cheaper
(ii) Comparatively they have  higher efficiency and power factor
(iii) Since the risk of sparking is eliminated by the absence of slip rings and brushes, they are explosion-proof.

Advantages of Slip ring Induction Motors

The advantages of the wound rotor (Slip ring) Induction motors compared with the squirrel-cage motors are given below

(i) They have very high starting torque
(ii) They have very low starting current
(iii) They have a means of varying speed by use of external rotor resistance.