Response Time of Surge Protective Devices Employing Spark Gap Technology

The transient behavior of commercially available low-voltage surge protective devices (SPDs) is experimentally investigated by employing standard lightning and switching impulse voltages. The response time of an SPD that integrates a triggered spark gap between the power lines and earth is on focus; a novel definition of the response time is proposed. Surprisingly, the experimentally derived response time varies beyond the upper limit declared by the SPD manufacturer. This work stresses the need for an update of international standards to incorporate a definition of the response time of SPDs covering a wide range of transients.