For film capacitors, most people don't know much about them. For example, they are often asked a question: Do film capacitors have certification standards and marks? Come and introduce us today.

Are there certification standards and marks for film capacitors?

Film capacitors generally do not have certification. This is not because manufacturers are unwilling to certify capacitors, but because there are no relevant standards.

Which capacitors need to pass safety certification?

1. X safety capacitor.

Commonly used X safety capacitors are X1 capacitors and X2 capacitors. This kind of capacitor is generally used between the neutral wire and the live wire of the power supply to suppress the electromagnetic interference of the power supply. It must be certified, and this is mandatory.

X safety capacitors generally need to pass the certifications of CQC in China, ENEC in the European Union, and UL in the United States. These three are the most important. Of course, there are some certifications such as KC Korean certification and VDE German certification, but they are not as important as the first three. so big.

2. Y safety capacitor.

The so-called Y safety capacitors are common Y1 capacitors and Y2 capacitors. Y capacitors are capacitors that are connected between the two lines of the power line and the ground (L-E, N-E), and generally appear in pairs. Based on the limitation of the leakage current, the value of the Y capacitor should not be too large. Generally, the X capacitor is uF level, and the Y capacitor is nF level. The X capacitor suppresses differential mode interference, and the Y capacitor suppresses common mode interference.

Varistors also need safety certification

The varistor is not a capacitor, it is a resistor, and it also needs safety certification.

The biggest advantage of the varistor is that when the threshold value of the varistor itself is greater than the voltage given by the outside, the current flow value in the circuit is very small, and its own valve will be equivalent to a valve that cannot work. When the voltage increases When it is large, the resistance value in the circuit decreases, and the current increases, which ultimately reduces the influence of the voltage on the circuit. Through this function, we can protect the circuit in the varistor and prevent the circuit from being affected by the voltage, so that the value of the voltage will not change too much.