Which of the following motor will have a relatively higher power factor?
Right Answer is:
Capacitor run motor
Capacitor Run Motor
- In this motor, the capacitor that is connected in series with the auxiliary winding is not cut out after starting and is left in the circuit all the time. That is the capacitor is used for starting and remains in the circuit during the running conditions.
- This motor is similar to the capacitor start motor except that there is no centrifugal switch.
- The capacitor value is chosen to obtain a nearly 90° phase shift between the currents of main and auxiliary windings around full-load speed.
- This simplifies the construction and decreases the cost because the centrifugal switch is not needed. The power factor, torque pulsation, and efficiency are also improved because the motor runs as a two-phase motor. The motor will run more quickly.
- Capacitor Run Motor has relatively higher power factor.
Performance and characteristics:- Starting torque is lower about 50 to 100% of full load torque. Power factor is improved may be about unity. Efficiency is improved to about 75%. It is usually used in fans, room coolers, portable tools, and other domestic and commercial electrical appliances.
The main advantages of capacitor run motor are:
- Higher power factor,
- Increased overload capacity of the motor,
- Higher efficiency, and
- Noiseless running of motor.