Do surge protectors work against lightning?

Although surge protectors cannot directly prevent lightning strikes, they can significantly reduce the damage caused by lightning strikes to electrical equipment and circuits. As a specially designed device, it can quickly respond to surge voltage or current in the power grid and effectively absorb transient surge current, thereby protecting electrical equipment and circuits from electromagnetic interference such as surge voltage. However, in areas with frequent lightning activities, surge protectors alone may not be sufficient to fully protect against lightning strikes. Therefore, it is necessary to use them in conjunction with other lightning protection devices such as grounding devices and lightning rods to form a more complete lightning protection system.

1. Working principle and types of surge protectors

Surge protectors work in the following ways:

. ‌Voltage switching type SPD‌: It exhibits high impedance characteristics in the absence of transient overvoltage. Once it senses a lightning transient overvoltage, its impedance will instantly decrease, allowing the lightning current to pass smoothly.

. ‌Voltage limiting type SPD‌: It exhibits high impedance under normal conditions, but as the surge current and voltage gradually increase, its impedance will gradually decrease in a nonlinear manner.

.‌Combined SPD‌: It combines the characteristics of voltage switching and voltage limiting components, and its specific performance depends on the characteristics of the applied voltage‌.

2. Application scenarios and importance of surge protectors

Surge protectors are widely used in various electronic equipment, instruments and communication lines. They are suitable for AC 50/60HZ, rated voltage 220V/380V power supply systems (China), as well as various voltage systems in other countries. It is suitable for residential, tertiary and industrial fields, and can effectively protect power and signal systems from lightning strikes and other transient overvoltage surges‌1

3. Installation and maintenance recommendations for surge protectors

When installing surge protectors, it is necessary to select the appropriate protection level according to the specific environment and purpose, and regularly inspect and maintain them to ensure that they are always in good working condition, thereby minimizing the risk of lightning strikes.

Surge protectors are usually divided into multiple protection levels, including primary, secondary and tertiary protection. The first-level protection is mainly used in the main power distribution cabinet or power supply entrance to prevent strong current shocks caused by direct lightning strikes; the second-level protection is installed in the power distribution cabinet or distribution box to prevent lightning surges from the power system; the third-level protection is installed in front of the terminal equipment to provide fine protection. Correct selection, installation and maintenance are the key to ensuring that the surge protector performs at its best.