How to suppress lightning overvoltage in industrial servo systems?

Suppressing overvoltages caused by direct or induced lightning strikes on servo systems requires multi-level integrated protection. The Eintraelectronics suppression scheme is as follows:

Level 1 (Building entrance): Using a 10/350μs waveform switching SPD (e.g., spark gap based) to discharge most of the energy from a direct lightning strike.

Level 2 (Distribution cabinet): Using an 8/20μs waveform voltage-limiting SPD (e.g., varistor 14D series) to further limit residual voltage.

Level 3 (Equipment entrance): Installing coordinated MOVs (e.g., 14D511K) and TVS (e.g., SM8K series) at the servo drive input for fine protection.

Sufficient line distance (typically >10m) must be maintained between each level, or energy coordination must be achieved through decoupling inductors. Simultaneously, all metal conduits, cable trays, and equipment enclosures must be equipotentially connected to the same grounding system. Through this multi-level protection, lightning overvoltages of tens of thousands of volts can be limited to below the insulation withstand level of the servo equipment (typically <4kV), protecting it from damage.