Under normal circumstances, the service life of film capacitors is definitely very long. As long as the selection is correct and the use is correct, it is definitely not an electronic component that is easily damaged on the circuit. However, due to various reasons, the film capacitors used in some circuits are often damaged. What are the reasons for capacitor damage?

1. The voltage in the circuit is too high, causing the film capacitor to be broken down.

The most important parameter of the film capacitor is the rated working voltage. If the voltage on the circuit is too high, it will far exceed the rated working voltage of the film capacitor. Under the action of such a high voltage, a strong partial discharge and internal discharge will occur inside the film capacitor. Dielectric damage can even lead to capacitor breakdown.

Secondly, it is also possible to buy inferior film capacitors with low voltage pretending to be high voltage. Due to the serious price war in the market now, some manufacturers will choose to use low withstand voltage capacitors as high withstand voltage capacitors in order to make their capacitors more price-competitive. This will lead to the problem of insufficient actual withstand voltage of the capacitors. It is prone to breakdown of the film capacitor due to excessive voltage.

2. Caused by excessive temperature.

Film capacitors have their rated operating temperature. For example, the maximum temperature resistance of CBB is 105°C (special reminder: there are still a large number of low-quality CBB capacitors on the market with a maximum temperature resistance of only 85°C), and the maximum temperature resistance of CL capacitors is 120°C ( The highest temperature resistance of inferior products is 105℃). If the film capacitor is operated at a temperature higher than its maximum allowable temperature for a long time, the thermal aging of the capacitor will be accelerated, and the life of the capacitor will be significantly shorter. On the other hand, in the installation and use of capacitors, special attention should be paid to the ventilation, heat dissipation and radiation problems of the capacitor in actual use conditions, so that the heat generated by the capacitor in operation can be dissipated in time, which can extend the service life of the film capacitor .

3. It is caused by the purchase of inferior film capacitors.

Now the industry is too chaotic. In order to fight the price war, the quality of capacitors of some manufacturers has completely lost the bottom line. They use the worst materials and the production process can save money. The design life of this kind of capacitor is only about one year. If you buy Inferior film capacitors are also easily damaged.