Note the use of film capacitors

With the rapid development of technology, film capacitors have gradually replaced aluminum electrolytic capacitors, and Xiaobian has also said this reason. So as a technician, what do we need to pay attention to when using film capacitors?

1) The rated voltage of the film capacitor must be consistent with the voltage of the local grid. For some grids with excessive voltage or harmonics, due to higher harmonics, especially the third, fifth and seventh harmonics, the energy is large. The hazard is also strong. When configuring, measures should be taken to avoid and isolate it.

2) Pay attention to the operating environment temperature. Excessive operating temperature will lead to an increase in the electrochemical reaction of the film capacitor, which will affect the heat dissipation during self-healing, which will lead to self-healing failure or shortened service life. Therefore, when installing the film capacitor, avoid the heat source and improve the heat dissipation and ventilation. surroundings.

3) The capacitor cabinet should be equipped with reasonable protection devices:

1. Adjust the appropriate delay and discharge time. The input and cut capacitor banks must be equipped with a limited current and discharge device. Because the internal resistance of the film capacitor is small, the inrush current may be up to 10,000 amps. In order to prevent the newly-input capacitor from being discharged by the capacitor placed on the side, a current-limiting protection device should be provided; in order to ensure the safety of the operation and maintenance of the film capacitor , a discharge device must be provided;

2. The cutting procedure should follow the principle of first casting first, then cutting after cutting;

3. To prevent frequent switching, the capacitor bank must retain sufficient capacity as a base array when it is cut.

After reading the above points, I believe that everyone will pay more attention to the use of film capacitors in the future.