SPD

1. What Is An Surge Protection Device？

A surge protector is an electrical protection device specifically designed to limit transient overvoltages and dissipate surge currents in electrical circuits.

Its main function is to protect sensitive electrical equipment from damage caused by surge impacts resulting from lightning strikes, power grid fluctuations, and equipment startup and shutdown.

2.How Surge Protection Device Work ？

When the grid voltage remains stable within the rated range, the surge protector is in a high-impedance state, approximating an open circuit, resulting in no power loss and not affecting the normal operation of the power distribution system.

When the system encounters transient overvoltage (surge) caused by lightning induction, grid fluctuations, or the starting and stopping of large equipment, the surge protector quickly switches to a low-impedance conducting state, rapidly discharging the surge current through the grounding circuit, while simultaneously clamping the voltage across the protected equipment within a safe threshold to prevent damage to precision components due to overvoltage breakdown.

After the surge fault is eliminated and the grid voltage returns to its rated value, the surge protector automatically resets to the high-impedance state, entering the next monitoring and standby mode.
It should be noted that surge protectors only work against transient overvoltage and do not provide overload or short-circuit protection.

Therefore, in actual power distribution systems, they must be used in conjunction with devices such as circuit breakers to achieve comprehensive circuit protection.

3.Advantages of Surge Protective Devices (SPD)

The core advantages of a Surge Protective Device (SPD) are as follows: it provides strong protection for electrical equipment to avoid direct damage; ensures the stability of the electrical system and reduces the risk of faults; cuts down economic losses and optimizes cost input; has a wide range of applicable scenarios and strong compatibility; features extremely fast response speed with no “delay” in protection; and operates in a fully automatic mode, requiring no manual activation or reset.

4.Application Scenarios of Surge Protective Devices (SPD)

The application scenarios of Surge Protective Devices (SPD) cover all fields including civil scenarios, commercial scenarios, industrial scenarios, and special public facilities.

The core logic is: as long as there is a risk of “sudden overvoltage (surge)” in a circuit and the downstream equipment is voltage-sensitive or of high value, an SPD needs to be configured.