Views: 0 Author: Site Editor Publish Time: 2026-02-27 Origin: Site
There are many things to consider when selecting film capacitors. For example, the selection of rated voltage is crucial. If the rated voltage is too low, the capacitor is easily damaged during use. What happens if a film capacitor is over-voltaged?
1. First, understand what the rated voltage of a film capacitor is.
Most film capacitors have many parameters printed on them, among which the voltage printed is its rated voltage.
Definition of rated voltage: The rated voltage of a capacitor refers to the voltage that ensures the capacitor can work continuously for a long time without being broken down under specified temperature conditions.
2. What is the breakdown voltage of a film capacitor?
This is easy to understand. The breakdown voltage is the limit voltage of a capacitor. If this voltage is exceeded, the dielectric inside the capacitor will break down.
Normal film capacitors have a margin in their rated voltage:
For example, the KYET series CBB22 224J630V film capacitor has a rated voltage of 630V. What is its breakdown voltage?
KYET's film capacitors have a margin of 1.6 to 1.8 times the rated voltage. That is to say, although they are labeled as 630V, they can actually withstand voltages of 1008V to 1134V. If the voltage exceeds this, the capacitor is easily damaged.
Do all film capacitors have a voltage tolerance margin of 1.6 times?
It is generally accepted in the industry that film capacitors have a voltage tolerance margin of 1.6 to 1.8 times. Even if a qualified film capacitor experiences an overvoltage, as long as the overvoltage is not too large, it will not be damaged, but the lifespan of the film capacitor will be shorter.
Special reminder: Due to price wars, some film capacitor manufacturers not only have very low voltage tolerance margins, but some have even been found to be using low-voltage capacitors to impersonate high-voltage capacitors. For example, they may be using 400V film capacitors to impersonate 630V capacitors. If such inferior film capacitors exceed these limits, they will quickly become damaged.
