Views: 9 Author: Site Editor Publish Time: 2022-11-02 Origin: Site
A single-phase motor with a slightly larger power is generally equipped with two capacitors, that is, a starting electrical appliance and a running capacitor. Before the 70s, the single-phase motor used more than one capacitor, which was the starting capacitor. After the motor is started, the centrifugal switch opens the capacitor twice, and only the main winding works at this time. The secondary winding is idle.
In order to improve the working efficiency of single-phase motors, dual-capacitor single-phase motors appeared after 70 years.
What is the reason for the burnout of the starting capacitor of a single-phase motor? I will only talk about the reason why the startup capacitor is burned out.
Generally, the startup capacitor is not easy to burn out because its working time is very short. It is only thrown away by the centrifugal switch at the moment of starting, and there is no current through the starting capacitor, so it is not easy to burn out. Not easy to burn out does not mean that it will not be burnt out.
What is the reason for burning out the startup capacitor?
(一) Capacitors with low withstand voltage or poor quality, choose capacitors with a withstand voltage of 500V.
(二) When the centrifugal switch is turned off, an arc is often generated. It is very likely that the switch cannot be turned off after the motor is started, and the capacitor has always flowed through. It is easy to burn out the secondary winding of the motor and the starting capacitor within a period of time.
(三) The capacity of the selected capacitor is too small, and the starting current is greater than the allowable value of the capacitor.
(四) The motor is chamfered or the bearing is damaged, it is difficult for the motor to start the centrifugal switch and it is difficult to reach the disconnected speed within a period of time, and the starting power is easy to burn out.
The above are my personal opinions on why the startup capacitor is burned out.