UNE-EN IEC 62271-104:2021

This part of IEC 62271 is applicable to three-pole alternating current switches for rated voltages higher than 52 kV, having making and breaking current ratings, for indoor and outdoor installations, and for rated frequencies up to and including 60 Hz.

This standard is also applicable to the operating devices of these switches and to their auxiliary equipment.

NOTE 1 Switches for gas insulated switchgear are covered by this standard.

NOTE 2 Switches having a disconnecting function and called switch-disconnectors are also covered by IEC 62271-102.

NOTE 3 Earthing switches are not covered by this standard. Earthing switches forming an integral part of a switch are covered by IEC 62271-102.

The main object of this standard is to establish requirements for switches used in transmission and distribution systems. General-purpose switches for this application are designed to comply with the following service applications:

carrying rated normal current continuously;

carrying short-circuit currents for a specified time;

switching of mainly active loads;

switching of no-load transformers;

switching of the charging current of unloaded cables, overhead lines or busbars;

switching of closed-loop circuits;

making short-circuit currents.

A further object of this standard is to establish requirements for limited-purpose and special- purpose switches used in transmission and distribution systems.

Limited-purpose switches comply with one or more of the service applications indicated above.

Special-purpose switches may comply with one or more of the service applications indicated above and, in addition, are suitable for one or more of the following applications:

switching single capacitor banks;

switching back-to-back capacitor banks;

switching shunt reactors including secondary or tertiary reactors switched from the primary side of the transformer;

applications requiring an increased number of operating cycles;

switching under earth fault conditions in non-effectively earthed neutral systems.