Overvoltage Protection

A surge protector protects electrical and electronic devices from excessive electrical voltages. Surges can have various causes.

  • Lightning strikes (lightning electromagnetic pulse)
  • Sudden drop in load / increase in load
  • Switching operations (switching electromagnetic pulse)
  • Electrostatic discharges (electrostatic discharge)

There is a three-stage concept for protection against overvoltages.

Stage 1

A coarse protection (SPD type 1, Surge Protection Device) protects against high-energy disturbances. For example, it prevents lightning from entering the line to be protected. It is designed to limit the residual voltage to 1300 to 6000 V.

Stage 2

A medium protection (SPD type 2) is usually located in floor distributors. It is designed to limit the overvoltages to 600 to 2000 V.

Stage 3

Fine protection (SPD type 3) is the protection of sockets and connectors.

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