Starting capacitor refer to AC electrolytic capacitors or polypropylene and polyester capacitors used to start single-phase asynchronous motors. The function and working principle of the starting capacitor in the washing machine are introduced below.
- Working principle
1.There is a starting auxiliary winding in the stator of the motor, which is 90° apart from the working winding (main winding) in space.
2.The starter auxiliary winding is connected in series with the capacitors, connected to the power supply via the starter switch in parallel with the working winding (main winding), the starting auxiliary winding circuit impedance is capacitive, and the working winding (main winding) impedance is inductive.
3.Therefore, the starting current for starting the auxiliary winding at the start is ahead of the working winding (main winding) by a larger angle.
4.If the capacity of the capacitor is properly matched, the current of the starting secondary winding can lead the current of the working winding (main winding) by 90° to obtain a nearly circular rotating magnetic field.
5.Capacitor starting and running asynchronous motors are characterized by higher starting torque and higher overload capacity, with higher power factor and efficiency. So it is suitable for the working condition of washing machine.
6.When the starting capacitor of the washing machine motor is damaged or the capacity is insufficiently reduced, the terminal voltage of the capacitors will be reduced and the motor cannot be started to rotate. The hand rotation is actually equivalent to a starting torque for the motor, plus the remaining capacity of the capacitors to start the rotation.
The function of the washing machine motor capacitor is mainly to increase the terminal voltage when the motor is started, so that the current of the starting secondary winding leads the current of the working winding (main winding) by 90°, and obtains a nearly circular rotating magnetic field to start the motor to rotate and work normally.