What is Stalling in Induction motor and how to protect motor during Stalling?

Due to the mechanical problem in the motor or due to high overloading during starting of motor induction motor fails to start. This condition where the motor fails to start is called Stalling and it is undesirable as motor draws heavy currents. Therefore motor should be immediately isolated from the supply.

Instantaneous over-current relay is employed to protect the motor against Stalling.