CBB capacitor failure and solution

CBB capacitors, polypropylene capacitors. It has excellent high-frequency insulation performance. The capacitance and loss are independent of frequency in a large frequency range. The change with temperature is small, and the dielectric strength increases with temperature, which is difficult to obtain with other dielectric materials. High temperature resistance and low absorption coefficient. Any kind of capacitor will encounter the same problem, that is, there is a failure problem in use, what is the reason for CBB capacitor failure, how to solve the failure reason. There are several reasons for failure analysis of CBB capacitors:

1. Capacitor seal is not enough, water vapor enters to cause oxidation, and the pressure is reduced.

Once there is a problem with the sealing of the capacitor, the withstand voltage of the capacitor must drop. This is a common problem of the capacitor, and the CBB capacitor is also unavoidable.

2. Long-term instantaneous current is too large, the voltage is too high, internal discharge self-healing leads to capacity decline

If the current is too large, it exceeds the inherent capacity range of the CBB capacitor, causing damage inside it. In the long run, the internal discharge self-healing leads to a decrease in capacity.

3. Long-term high-load work, evaporation of metal plating leads to capacity reduction

If the CBB capacitor is in a high-load working state for a long time, its internal damage will be inevitable, especially the evaporation of the metal plating, which will cause the capacity of the CBB capacitor to continuously decrease.

How to solve the CBB capacitor failure, the following methods can be used:

1. Purchasing qualified brand CBB capacitor manufacturer

Brand CBB capacitor manufacturers produce products with relatively reliable quality, and their design is strictly designed and checked. Under normal circumstances, there is no problem of sealing.

2. According to the working environment selected capacitor

If the capacitor is working in an environment where the current is too long in a long-term transient, then we must take this factor into consideration when selecting the capacitor. For example, the safety capacitor X2 is generally nominally 275VAC, but in fact, the 1KV can be withstand the transient test. of.

3. Parallel reasonable varistor

The use of parallel varistor to prevent the surge voltage is too high, it is said that this method is more effective, there are conditions to reduce the instantaneous current, generally within the allowable range, series resistance.