SOLUTION

Belted slip ring induction motors are employed for the operation of Jaw Crushers.

• Starting torque is directly proportional to the rotor resistance of an induction motor.
• In the SLIP RING induction motor the ends of the rotor windings are externally connected by a variable rheostat (resistance is varied in order to give it proper starting and running current).
• So more the resistance, more the torque. When we add resistance to the rotor the torque is high, the slip is high and the current is reduced.
• Therefore slip ring induction motor is used for providing high starting torque.
• Belted slip ring induction motor is almost invariably used as, very often, the motor has to start against the heavy load or a stuck crusher.