IEC 61643-12:2008

Applies to surge protective devices (SPD's) used to protect, under specific conditions, electrical systems and equipment against various overvoltage and impulse curents (e.g. lightning, switching surges).Information is provided on equipment to be protected, system characteristics, insulation levels, overvoltages, methods of installation,location,co-ordination and failure modes of SPD's, as well as equipment failure consequences.

IEC 61643-12:2020 describes the principles for the selection, operation, location and coordination of SPDs to be connected to 50/60 Hz AC power circuits, and equipment rated up to 1 000 V RMS. These devices contain at least one non-linear component and are intended to limit surge voltages and divert surge currents. NOTE 1 Additional requirements for special applications are also applicable, If required. NOTE 2 IEC 60364 and IEC 62305-4 are also applicable. NOTE 3 This standard deal only with SPDs and not with surge protection components (SPC) integrated inside equipment. This third edition cancels and replaces the second edition published in 2008. This edition constitutes a technical revision. NOTE The following differing practice of a less permanent nature exists in the USA: In the USA, SPDs tested to Class I tests are not required. This exception applies to the entire document. This edition includes the following significant technical changes with respect to the previous edition: a) Scope: Deleted reference to 1 500 V dc b) Added or revised some definitions c) Added new clause 4 on Need for protection d) Added new information on disconnecting devices e) Revised Characteristics of SPD f) Revised List of parameters for SPD selection g) Added new information on Measured Limiting Voltage e) Added or revised some Annexes