IEC TR 62271-306:2012

FOREWORD
1 General
2 Evolution of IEC standards for high-voltage
   circuit-breaker
3 Classification of circuit-breakers
4 Insulation levels and dielectric tests
5 Rated normal current and temperature rise
6 Transient recovery voltage
7 Short-line faults
8 Out-of-phase switching
9 Switching of capacitive currents
10 Gas tightness
11 Miscellaneous provisions for breaking tests
12 Rated and test frequency
13 Terminal faults
14 Double earth fault
15 Transport, storage, installation, operation and maintenance
16 Inductive load switching
Annex A (informative) - Consideration of d.c. time constant
        of the rated short-circuit current in the application of
        high-voltage circuit-breakers
Annex B (informative) - Interruption of currents with
        delayed zero crossings
Annex C (informative) - Parallel switching
Annex D (informative) - Application of current limiting reactors
Annex E (informative) - Explanatory notes on the revision of
        TRVs for circuit-breakers of rated voltages higher
        than 1 kV and less than 100 kV
Annex F (informative) - Current and test-duty combination
        for capacitive current switching tests
Annex G (informative) - Grading capacitors
Annex H (informative) - Circuit-breakers with opening resistors
Annex I (informative) - Circuit-breaker history
Bibliography

IEC/TR 62271-306:2012(E) is applicable to a.c. circuit-breakers designed for indoor or outdoor installation and for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above 1 000 V. This technical report addresses utility, consultant and industrial engineers who specify and apply high-voltage circuit-breakers, circuit-breaker development engineers, engineers in testing stations, and engineers who participate in standardization. It is intended to provide background information concerning the facts and figures in the standards and provide a basis for specification for high-voltage circuit-breakers. Thus, its scope will cover the explanation, interpretation and application of IEC 62271-100 and IEC 62271-1 as well as related standards and technical reports with respect to high-voltage circuit-breakers.