Configuration Principles And Selection Points Of Surge Protectors

If the distance between the incoming line terminal's surge protective device and the protected equipment is greater than 30m, a second surge protector with a current capacity of 8kA should be installed as close to the protected equipment as possible.

When selecting an SPD, care should be taken to ensure it will not burn out due to power frequency overvoltage. This is because SPDs protect against transient overvoltages (in the μs range), while power frequency overvoltages are transient overvoltages (in the millisecond range). The energy of power frequency overvoltages is hundreds of times greater than that of transient overvoltages. Therefore, an SPD with a higher power frequency operating voltage should be selected.

SPD Protection: Each level of the SPD should be protected by a circuit breaker or fuse. The current-interrupting capacity of the protector should be greater than the maximum short-circuit current at that location.

In addition, when selecting a surge protection device, considerations should include: a fast response time, service life, price, maintainability, current capacity, and moisture resistance.