IEC 60056:1987

Foreword
Preface
Chapter I: Service conditions, definitions, rating
           construction and design
1 Scope
2 Normal and special service conditions
3 Definitions
3.101 General terms
3.102 Switching devices
3.103 Parts of circuit-breakers
3.104 Operation
3.105 Characteristic quantities of circuit-breakers
3.106 Index of definitions
4 Rating
4.1 Rated voltage
4.2 Rated insulation level
4.3 Rated frequency
4.4 Rated normal current and temperature rise
4.5 Rated short-time withstand current
4.6 Rated peak withstand current
4.7 Rated duration of short-circuit
4.8 Rated supply voltage of closing and opening
        devices and auxiliary circuits
4.9 Rated supply frequency of closing and opening
        devices and auxiliary circuits
4.10 Rated pressures of compressed gas supply for
        operation and for interruption
4.101 Rated short-circuit breaking current
4.102 Rated transient recovery voltage for terminal
        faults
4.103 Rated short-circuit making current
4.104 Rated operating sequence
4.105 Rated characteristics for short-line faults
4.106 Rated out-of-phase breaking current
4.107 Rated line-charging breaking current
4.108 Rated cable-charging breaking current
4.109 Rated single capacitor bank breaking current
4.110 Rated back-to-back capacitor bank breaking
        current
4.111 Rated capacitor bank inrush making current
4.112 Rated small inductive breaking current
4.113 Rated time quantities
4.114 Co-ordination of rated values
5 Design and construction
5.1 Requirements for liquids in circuit-breakers
5.2 Requirements for gases in circuit-breakers
5.3 Earthing of circuit-breakers
5.4 Auxiliary equipment
5.5 Dependent power closing
5.6 Stored energy closing
5.7 Operation of releases
5.8 Low and high pressure interlocking devices
5.9 Nameplates
5.101 Requirements for simultaneity of poles
5.102 General requirement for operation
5.103 Pressure limits of compressed gas for
        interruption in gas blast circuit-breakers
5.104 Vent outlets
Figures 1 to 14
6 Type tests
6.1 Dielectric tests
6.2 Radio interference voltage (r.i.v.) tests
6.3 Temperature-rise tests
6.4 Measurement of the resistance of the main circuit
6.5 Short-time withstand current and peak withstand
        current tests
6.101 Mechanical and environmental tests
6.102 Miscellaneous provisions for making and breaking
        tests
6.103 Test ciruits for short circuit making and
        breaking tests
6.104 Short-circuit test quantities
6.105 Short-circuit test procedure
6.106 Basic short-circuit test-duties
6.107 Critical current tests
6.108 Single-phase short-circuits tests
6.109 Short-line fault tests
6.110 Out-of-phase making and breaking tests
6.111 Capacitive current switching tests
6.112 Magnetizing and small inductive current
        switching tests
7 Routine tests
7.1 Power frequency voltage withstand dry tests
        on the main circuit
7.2 Voltage withstand tests on control and auxiliary
        circuits
7.3 Measurement of the resistance of the main circuit
7.101 Mechanical operating tests
7.102 Design and visual checks
8 Guide to the selection of circuit-breakers for
        service
8.101 General
8.102 Selection of rated values for service conditions
8.103 Selection of rated values for fault conditions
9 Information to be given with enquiries, tenders
        and orders
9.101 Information to be given with enquiries and orders
9.102 Information to be given with tenders
10 Rules for transport, storage, erection and
        maintenance
10.1 Conditions during transport, storage and erection
10.2 Erection
10.3 Maintenance
Figures 15 to 32
Appendix AA - Calculation of transient recovery voltages
        for short-line faults from rated characteristics
Appendix BB - Capacitor bank inrush currents
Appendix CC - Records and reports of type tests for
        making, breaking and short-time current performance
Appendix DD - Determination of short-circuit power factor
Appendix EE - Tightness specifications and tests
Appendix FF - Method of drawing the envelope of the
        prospective transient recovery voltage of a
        circuit and determining the representative
        parameters
Appendix GG - Methods of determining prospective
        transient recovery voltage waves
Appendix HH - Example of a commissioning test programme

Applies to a.c. circuit-breakers designed for indoor or outdoor installation and operation at frequencies up to and including 60 Hz on systems having voltages above 1 000 V. Applies only to three-pole circuit-breakers for use in three-phase systems and single-pole circuit-breakers for use in single-phase systems. Two-pole circuit-breakers for use in single-phase systems are subject to agreement between manufacturer and user.Also applies to the operating devices of circuit-breakers and their auxiliary equipment. However, circuit-breakers with a closing mechanism for dependent manual operation are not covered since a rated short-circuit-making current cannot be specified, and dependent manual operation may be objectionable because of safety considerations.Does not cover circuit-breakers intended for use on motive power units of electrical traction equipment, or circuit-breakers for use with overhead lines which include series capacitors.Replaces IEC 60056-1 to 60056-6.