What is the use of a capacitor in a fan?


A capacitor in a fan is used to create a phase difference between the current flowing to the motor’s start and run windings, facilitating the motor’s rotation and providing the necessary torque.

What is the use of a capacitor in a fan?
What is the use of a capacitor in a fan?


The capacitor in a fan serves to create a phase shift in the current supplied to the start and run windings of the motor. This phase difference is essential for the motor’s proper operation. When the fan is turned on, the capacitor briefly delays the current to the start winding, creating a rotating magnetic field. This rotation kick-starts the motor, and once it’s running, the capacitor continues to adjust the current to ensure efficient operation, providing the required torque.


Q: Why does a fan have a capacitor?

A: The capacitor creates a phase difference in the motor windings, enabling motor rotation and providing necessary torque.

Q: What happens if a fan capacitor fails?

A: A failed capacitor can lead to the fan motor not starting or humming without rotation.

Q: Are capacitors used in all types of fans?

A: Capacitors are commonly used in ceiling fans and some other types for motor operation.

Q: How does a capacitor help in starting a fan motor?

A: The capacitor introduces a delay in the current to the start winding, initiating motor rotation.

Q: Can a fan operate without a capacitor?

A: Some fans use other starting mechanisms, but capacitors are common for efficient motor operation.

Q: What are the signs of a faulty fan capacitor?

A: Symptoms include motor humming without starting, slow starting, or the fan not starting at all.

Q: Are there different types of capacitors in fans?

A: Fans may use different capacitor types, such as electrolytic or motor-run capacitors.

Q: Can a capacitor be replaced in a fan?

A: Yes, a faulty capacitor can be replaced to restore normal fan operation.

Q: How long do fan capacitors typically last?

A: Capacitor lifespan varies, but they may last around 10-15 years with normal usage.

Q: Do all fan motors require capacitors?

A: No, some fan motors use alternative starting methods, but capacitors are common for efficiency.