Single-stage protective devices

Ideally a surge protection concept should be designed to be multi-stage. This involves the optimum arrangement of components that respond quickly such as suppressor diodes and powerful protective devices such as gas discharge tubes. The gap between these two protection stages is closed by varistors. They take longer to activate than diodes but have a higher discharge capacity.

Single-stage protective devices are only equipped with one component. They are suitable, for example, for the additional protection of long cables from the field, at the building entrance or at the transition between different protection zones. Single-stage protective devices with common mode voltage protection provide protection against surge voltages between the individual signal wires. Versions with normal mode voltage protection provide protection for the wires and ground.