Why Does The Surge Protector Burn Out?

Surge protectors are important equipment in internal lightning protection. Under the protection of surge protective device, even if the lightning current of tens of kiloamperes invades the internal line, the surge protection device can quickly discharge it to the ground, protecting our safe and efficient use of electricity. However, in recent years, the safety of surge protectors has also become a hot topic. Whether surge protectors are safe and why surge protectors burn out have become the focus. Today, the editor will talk to you about the safety of surge protectors on the issue of why surge protectors burn out.

Lightning current usually has the characteristics of high current and fast speed. Usually, tens of kiloamperes of large current will pass through within tens or hundreds of microseconds. If it is not discharged, it will have a fatal impact on the equipment and human life safety. Surge protectors use varistors or discharge gaps. In normal normal operation, they are equivalent to a very large resistor and do not affect normal operation; when lightning current invades the line, it will quickly conduct, short-circuit the lightning current to the branch and discharge it to the grounding device. So why does the surge protector burn out?

Normally, due to the degradation of the surge protector itself or operational problems, an operating overvoltage is generated, which may cause the varistor to generate a short-circuit current. According to the heat generation formula of electricity R=I²Rt, once the heat reaches a certain level, the surge protector will generate a lot of heat and even catch fire. For this reason, GB 51348-2019 clearly stipulates that surge protectors must be installed with matching backup protectors.