EVS-EN IEC 62146-1:2026

This part of IEC 62146 includes generalities of capacitors used on alternating current circuit breakers and introduces specifications for grading capacitors. Regarding grading capacitors, their function is to control the voltage distribution across the individual interrupter units of a multi-break circuit-breaker.
Capacitors can also be used in parallel to the interrupter unit on single break circuit-breakers to modify the Transient Recovery Voltage (TRV). This TRV capacitor application is covered by IEC 62146-2:2023.
Capacitors for high-voltage alternating circuit breakers are sub-components for the circuit breaker and are specified in accordance with the circuit-breaker specifications according to IEC 62271-1, IEC 62271-100, and if applicable to IEC 62271-203.
This document applies to grading capacitors falling into one or both of the following categories for:
− mounting on air-insulated circuit-breakers.
− mounting on enclosed circuit-breakers (for example immersed in insulating gas, in oil, etc.).
The testing for each of the above applications is in some cases different.
The object of this document is:
− to define uniform rules regarding performances, testing and rating;
− to define specific safety rules;
− to provide a guidance for installation and operation.
NOTE CIGRÉ TB-368 presents a study about the operating environment of voltage grading capacitors applied to high-voltage circuit-breakers (see [2]1).
This document does not apply to capacitors not directly associated with high-voltage alternating current circuit-breakers.