# Why is it dangerous to lose the field of a shunt motor?

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If the field current is reduced the magnetic field will drop causing the back EMF voltage to drop. This increase in the drive voltage to the armature will cause the motor to speed up until the back EMF is once again at its previous level.

## What will happen if the field of the DC shunt motor is accidentally removed?

Answer: n d.c shunt motor if field winding supply is removed the motor back emf will drop to zero, hence the armature will draw more current to make up the emf. this results in blowing up of fuse.

## What effect would the loss of field current have on a DC motor?

Assuming the DC motor is driving a load at a constant torque, the removal of field current will result in lower torque produced by the motor and its speed will go lower and its armature current will increase due to lower back-EMF.

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

What will happen if the d.c. shunt motor opened accidentally running on no-load has its shunt field winding? 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 would happen if the field of DC shunt motor is opened * 1 point?

WHY: we know that E=K*phi*w in DC machines, so when the field is open or if=0, the generated flux (phi) is going to be zero, and for the given E, the speed is derived from E/0, so, the developed speed would be infinity. So, due to motor inertia the motor speeds up.

## When load is removed motor will run at the highest speed?

Answer : When load is removed, series motor will run at the highest speed.

## What is the principle of shunt?

A shunt motor (known as a shunt wound DC motor) is a type of DC motor which is self-excited and has the field windings that are connected in parallel to the armature winding of the motor. As these two parts are connected in parallel, the armature and field windings are exposed to the same supply voltage.

## What are the advantages of DC shunt motor?

• The power supply of the DC motor is any way cheap.
• Shunt would motor able to runs at a predetermined speed.
• The speed of a dc shunt motor is sufficiently constant.
• Direct current machines can use for heavy industrial applications where the torque and speed wider range.

## Can the speed of shunt motor be reduced by varying field resistance?

Because the voltage drop across the armature varies, this results in the speed of the motor changing. The motor would now be classified as a varying speed rather than a constant speed motor. More precisely, it remains an adjustable, varying speed motor. The operator can adjust the speed by changing armature resistance.

## Which motor has the poorest speed control?

Which of the following DC motor has the poorest speed control? Explanation: DC series motor at no load condition gives infinite speed ideally. Practically it will damage all the armature circuit. Thus, as the load is reduced speed of the motor will go on increasing rapidly.

## What will happen when DC shunt motor is started with load?

If the same machine is run as a motor it takes a line current of 20A from 220V supply. … Answer : With the increase in load on a d.c. shunt motor, speed of the motor reduces slightly.

## What will happen if the shunt field is open during running?

Explanation: If shunt field is suddenly opened, flux due to shunt field will become 0. As, net flux is equal to shunt field flux – series field flux, the direction of flux will be reversed and thus motor will run in opposite directions.

## What happens if the field winding of a running shunt motor suddenly breaks open?

Concept of DC shunt motor:

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.

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## What happens to a shunt motor when the starting torque required is too high?

Properly functioning control circuitry will detect a lack of synchronization and secure the motor. If the control circuitry fails and the motor fails to reach synchronous speed, the damper windings will literally melt resulting in a very expensive repair.