What will happen if the field of a DC motor opened while running?

What will happen if the field of a DC motor opened while running?

Detailed Solution. For a constant back emf, flux is inversely proportional to the speed of the motor. If field winding is disconnected accidentally, the speed would dangerously increase in order to maintain the back emf of the motor.

What happens with DC shunt motor if field winding gets open during running condition?

As we know, if the field winding of a running shunt motor suddenly breaks open. So, Flux is reduced and speed increase dangerously as flux is inversely proportional to speed.

What will happen if the field of the DC motor is opened accidentally in no load and full load?

The field will be reduced to only to the value of residual flux. The speed will be very high. The parts of motor may even fly apart.

What will happen to the DC motor if we reduce the field current?

With field current cut off, a weak field will exist due to residual magnetism. Therefore, motor will overspeed to maintain back emf. However, torque will decrease in the same proportion. So, motor won’t be able to take load and finally come to a standstill, maybe after causing some damage to the motor.

What is field circuit in DC motor?

A field coil is an electromagnet used to generate a magnetic field in an electro-magnetic machine, typically a rotating electrical machine such as a motor or generator. It consists of a coil of wire through which a current flows.

What happens when a DC motor loses power to its shunt field?

From what I understand the loss of the field current, and thus the field itself, will result in a decrease in back EMF on the armature. This will allow a higher current to flow through the armature, and also cause the motor to speed up.

What will happen if the shunt field winding of a loaded shunt motor accidentally breaks?

Ans: if the shunt field winding of a loaded shunt motor accidentally breaks, the loss of shunt field current would result in stopping of the motor or burn out the armature or fuse.

What will happen if the field circuit breaks down?

Motor runs at dangerously higher speeds before its armature get melt due to higher currents. Originally Answered: What would happen if a field circuit opened during the starting up of a DC motor? The DC Motor does not run then there is no back EMF. Therefore there is no opposing force for input armature current.

What happened if the field flux of a DC motor reduced to half?

But cutting the field voltage (& current) in half will approximately double the speed, because the back emf will be reduced. So, reducing both the armature and field voltages by half will result in approximately constant speed if the motor is only lightly loaded.

What is field circuit?

A general field–circuit coupling mechanism for electromagnetic models is presented. The topological treatment of the circuit allows for a well-defined choice of coupling unknowns and equations, both for couplings of magnetic fields to magnetic circuits and couplings of magnetic fields to electric circuits.

What will happen if the DC shunt motor opened accidentally running on no load has its shunt field winding?