0
The starting torque is low because this type of motor requires an additional way of ensuring that it starts rotating the right way. It is not economical to give this additional mechanism the capacity to deliver the full load torque.
Wiki User
∙ 9y ago
Add your answer:
Earn +20 pts
How starting torque of an induction motor can be increased?
For a single phase motor, this can be done by connecting a capacitor in series with the starting windings. For three phase motors, this can be done by connecting starting resistors in the stator windings at starting. This reduces the stator current and hence it's flux density. Thus the rotor will have less opposition starting to rotate. Hence, the torque has increased.
What type of motor is used in centrifugal pump?
3 Phase induction motor because it produce high torque at starting
Will a single-phase Induction motor run on one winding once it has been started?
A single-phase induction motor has a main winding and a starting winding. When the motor has run up to normal speed the starting winding can be switched out, but for small motors this is not usually worth the trouble.
Why a pure single phase induction motor does not have starting torque but has running torque?
A single-phase induction motor can be considered as running on two oppositely-rotating magnetic fields. In normal running just below synchronous speed, the slip is perhaps 0.05 on one of these rotating fields and 1.95 on the other. The first field supplies the major part of the torque. When the motor is stationary with power supplied, both fields have a slip of 1 and they produce contrary torques so the motor remains stalled. If the motor is spun in one direction, the slip becomes unbalanced and there is a net torque from the direction with the least slip, so the motor runs up in that direction.
How do you check single phase motor winding?
Single phase motor winding is often checked just by listening to the noise that the motor is making. An experienced person can tell if the motor is working at single phase or double phase.
What are the advantages of three phase motor over the single phase motor?
A 3-phase motor produces a steady torque that does not pulsate. A 3-phase motor starts turning in the right direction when switched on without the need for a separate starting winding.
How starting torque of an induction motor can be increased?
For a single phase motor, this can be done by connecting a capacitor in series with the starting windings. For three phase motors, this can be done by connecting starting resistors in the stator windings at starting. This reduces the stator current and hence it's flux density. Thus the rotor will have less opposition starting to rotate. Hence, the torque has increased.
Why capacitor is used in ceiling fan?
Capacitor helps a motor generate a starting torque. once the torque is produced and motor rotates capacitor acts as a current path. technically capacitor creates a phase difference.
Why use clutch plate in single phase motor?
induction motors have very little starting torque as the motor come up to speed it reduces the torque load until it gets near synchronous speed
What is a 3 phase torque?
It is a short-hand description of the torque from a 3-phase motor. By the nature of 3-phase electricity, a motor using it gives a constant torque, unlike a single-phase motor which gives a torque that pulsates at twice the supply frequency. Usually that does not matter because there is enough inertia in the rotating parts to mask the effect.
What are the uses of single phase or three phase motor?
torque load, generation load, power correction load
What is phase 3?
It is a short-hand description of the torque from a 3-phase motor. By the nature of 3-phase electricity, a motor using it gives a constant torque, unlike a single-phase motor which gives a torque that pulsates at twice the supply frequency. Usually that does not matter because there is enough inertia in the rotating parts to mask the effect.
What is a 3 phase?
It is a short-hand description of the torque from a 3-phase motor. By the nature of 3-phase electricity, a motor using it gives a constant torque, unlike a single-phase motor which gives a torque that pulsates at twice the supply frequency. Usually that does not matter because there is enough inertia in the rotating parts to mask the effect.
How you determine the starting and running winding of a capacitor start single phase motor?
I think the resistance value of starting winding is less than the running winding of the single phase motor
Performance curve of a single phase induction motor?
The performance curve can be a graph of torque versus speed. The torque is zero at zero speed and also at the synchronous speed. Normally an induction motor operates at 90-97% of the synchronous speed, where the slip is between 10% and 3%. In this region the torque is proportional to the slip. As the torque is increased the speed falls until the motor stalls and the speed drops to zero. Below the stalling speed the torque rises between zero speed and the stalling speed. Because the torque is 0 at 0, a single-phase induction motor needs a separate starting winding fed by a starting capacitor to produce a little positive torque that starts the motor.
What are the advantages of single phase induction motor?
the torque requirement of single phase induction motor is less,and it is use for low power applications upto 1 to 10 kw.like in fans,mixiers
What type of motor is used in centrifugal pump?
3 Phase induction motor because it produce high torque at starting
