This part of IEC 61643 is a test specification for metal oxide varistors (MOV), which are used
for applications up to 1 000 V AC or 1 500 V DC in power line, or telecommunication, or
signalling circuits. They are designed to protect apparatus or personnel, or both, from high
transient voltages.
This specification applies to MOVs having two electrodes and hybrid overvoltage protection
components. This specification also does not apply to mountings and their effect on the
MOV’s characteristics. Characteristics given apply solely to the MOV mounted only in the
ways described for the tests.