This standard specifies the activity requirements for electrically biased differential relays. Relays of this category belong to a subgroup of specific relays using more than one input energy supply [as specified in IEC 60255-6, Part 6 (Relays using more than one input energy supply)]. The above relay characteristics are implemented differently depending on the manufacturer. This standard applies to relays designed to detect faults in alternators, motors, and transformers. It does not apply to relays designed for busbar protection or to differential relays for the protection of transmission lines. This standard covers biased differential relays and relays where, for example, the limiting ratio increases with increasing through-current. In individual cases, additional requirements are specified in the individual national standards. These standards carry out type tests. This standard applies only to relays in new conditions. In case of inconsistency between this item standard and an individual standard, the requirements of the individual standard shall take precedence.?
KS C IEC 60255-13-A:2014 history
2019KS C IEC 60255-13-A-2019 Electrical relays — Part 13: Biased(percentage) differential relays
2014KS C IEC 60255-13-A:2014 Electrical relays — Part 13: Biased(percentage) differential relays