What will happen when the field of a DC shunt motor gets opened while the motor is running?
What will happen when the field of a DC shunt motor gets opened while the motor is running?
Right Answer is:
The motor will attain dangerous high speed
SOLUTION
- In a DC shunt motor, if we cut the supply for the field winding, the speed would dangerously increase in order to maintain the back emf of the motor.
- In the case of DC motors Speed ∝ Back emf(Eb)/flux(φ).
- So if flux drops to ZERO theoretically speed will tend to infinity and practically it will damage the windings of the motor.