Varistor FAQ

1. What does a varistor mean?

A: Refers to the voltage across the varistor at the specified temperature and DC (typically 1 mA or 0.1 mA).

2. What is the reason for protecting the varistor?

answer:

(1) Distinguish between power protection, signal lines, and varistor for data line protection. They must meet the requirements of different technical standards.

(2) According to the difference of the continuous working voltage applied to the varistor, the varistor across the power line can be divided into two types of AC or DC, and the varistor under these two voltage stresses. The aging characteristics are different.

(3) According to the abnormal overvoltage characteristics of the varistor, the varistor can be divided into three types: surge suppression type, high power type and high energy type.

3. How is the varistor damaged?

answer:

(1) aging failure, manifested as an increase in leakage current, and the varistor voltage drops significantly until it is zero;

(2) Transient overvoltage damage;

(3) The number of overvoltage protections;

(4) ambient operating temperature;

(5) Whether the varistor is squeezed;

(6) Whether to pass the quality certification;

(7) The surge energy is too large and exceeds the absorbed power;

(8) insufficient pressure resistance;

(9) current and surge are too large, etc.

4. How to classify varistor?

Answer: According to the abnormal overvoltage characteristics of the varistor, the varistor can be divided into three types: surge suppression type, high power type and high energy type.

5. What should I pay attention to when using varistor?

(1) It is forbidden to beat or heavy pressure;

(2) Preserved in a dust-free, dry environment;

(3) Do not allow the current and energy flowing into the varistor to exceed its rated value;

(4) Do not place flammable substances near the varistor;

(5) The varistor may cause other problems due to the effect of the impedance of its capacitor on high frequency applications;

(6) Direct exposure to the sun or the ambient temperature next to the heater may exceed the operating temperature that the varistor can withstand;

(7) When soldering, please be careful not to melt the solder joints and resin of the varistor;

(8) If the varistor is applied to a high-voltage line similar to thunder, it is recommended to install the varistor on the 220v power line.