AS 1930-1976

1 - AS 1930-1976 CIRCUIT-BREAKERS FOR DISTRIBUTION CIRCUITS
4 - PREFACE
6 - CONTENTS
8 - SECTION 1. SCOPE AND OBJECT
8 - 1.1 SCOPE.
8 - 1.2 OBJECT.
10 - SECTION 2. DEFINITIONS
10 - 2.0 APPLICATION.
10 - 2.1 DEVICES.
10 - 2.1.1 Switching device
10 - 2.1.2 Mechanical switching device
10 - 2.1.3 Fuse
10 - 2.1.4 Circuit-breaker
10 - 2.1.5 Integrally-fused circuit-breaker
10 - 2.2 GENERAL TERMS.
10 - 2.2.1 Overcurrent
10 - 2.2.2 Overload
10 - 2.2.3 Interlocking device
10 - 2.2.4 Anti-pumping device
10 - 2.2.5 Main circuit
11 - 2.2.6 Control circuit
11 - 2.2.7 Auxiliary circuit
11 - 2.2.8 Pole
11 - 2.2.9 Closed position
11 - 2.2.10 Open position
11 - 2.2.11 Ambient air temperature
11 - 2.2.12 Operation
11 - 2.2.13 Operating cycle
11 - 2.2.14 Operating sequence
11 - 2.2.15 Short-circuit current
12 - 2.3 CONSTRUCTIONAL ELEMENTS.
12 - 2.3.1 Main contact
12 - 2.3.2 Arcing contact
12 - 2.3.3 Control contact
12 - 2.3.4 Auxiliary contact
12 - 2.3.5 ‘a’ contact
12 - 2.3.6 ‘b’ contact
12 - 2.3.7 Release
12 - 2.3.8 Instantaneous release
12 - 2.3.9 Making-current release
12 - 2.3.10 Overcurrent release
12 - 2.3.11 Definite time-delay overcurrent release
12 - 2.3.12 Inverse time-delay overcurrent release
13 - 2.3.13 Direct overcurrent release
13 - 2.3.14 Indirect overcurrent release
13 - 2.3.15 Overload release
13 - 2.3.16 Thermal overload release
13 - 2.3.17 Reverse current release
13 - 2.3.18 Shunt release
13 - 2.3.19 Undervoltage release
13 - 2.3.20 Conductive part
13 - 2.3.21 Exposed conductive part
13 - 2.4 CONDITIONS OF OPERATION.
13 - 2.4.1 Closing operation
13 - 2.4.2 Opening operation
13 - 2.4.3 Dependent manual operation
13 - 2.4.4 Dependent power operation
14 - 2.4.5 Stored energy operation
14 - 2.4.6 Independent manual operation
14 - 2.4.7 Fixed trip circuit-breaker
14 - 2.4.8 Trip-free circuit-breaker
14 - 2.4.9 Circuit-breaker with lockout-preventing closing
14 - 2.4.10 Connected position (service position)
14 - 2.4.11 Disconnected position (isolated position)
14 - 2.4.12 Test position
14 - 2.5 CHARACTERISTIC QUANTITIES.
14 - 2.5.1 Rated value
15 - 2.5.2 Prospective current
15 - 2.5.3 Prospective peak current
15 - 2.5.4 Maximum prospective peak current
15 - 2.5.5 Prospective breaking current
15 - 2.5.6 Prospective symmetrical breaking current (a. c. circuits)
15 - 2.5.7 Making capacity
15 - 2.5.8 Breaking current
15 - 2.5.9 Breaking capacity
15 - 2.5.10 Short circuit making (or breaking) capacity
15 - 2.5.11 Short-time withstand current
16 - 2.5.12 Peak withstand current
16 - 2.5.13 Applied voltage
16 - 2.5.14 Recovery voltage
16 - 2.5.15 Opening time
16 - 2.5.16 Arcing time.
17 - 2.5.17 Critical breaking current
17 - 2.5.18 Break-time
17 - 2.5.19 Make-time
17 - 2.5.20 Make-break time
17 - 2.5.21 Current setting
17 - 2.5.22 Current setting range
17 - 2.5.23 Take-over current
17 - 2.5.24 Conventional non-tripping current
17 - 2.5.25 Conventional tripping current
17 - 2.5.26 Clearance
18 - 2.5.27 Creepage distance
19 - SECTION 3. CLASSIFICATION
19 - 3.1 DESIGNATION ACCORDING TO THE METHOD OF CONTROL OF THE CLOSING OPERATION
19 - 3.2 DESIGNATION ACCORDING TO THE INTERRUPTING MEDIUM.
19 - 3.3 GROUPING ACCORDING TO THEIR ARRANGEMENT.
19 - 3.4 DISTINCTION ACCORDING TO DEGREEOF PROTECTION PROVIDED BY THE ENCLOSURE
20 - SECTION 4. CHARACTERISTICS
20 - 4.1 SUMMARY OF CHARACTERISTICS.
20 - 4.2 TYPE OF CIRCUIT-BREAKER.
20 - 4.3 RATED QUANTITIES.
20 - 4.3.1 General.
20 - 4.3.2 Rated Voltage.
21 - 4.3.3 Rated Currents.
21 - 4.3.4 Rated Frequency.
21 - 4.3.5 Rated Duty.
22 - 4.3.6 Rated Short-circuit Making and Breaking Capacities and Rated Short-time Withstand Current.
24 - 4.3.7 Short-circuit Performance Categories.
24 - 4.4 CONTROL CIRCUITS AND AIR-SUPPLY SYSTEMS
24 - 4.4.1 General.
24 - 4.4.2 Control Circuits.
26 - 4.4.3 Air-supply Systems.
26 - 4.5 TYPES AND CHARACTERISTICS OF RELEASES.
26 - 4.5.1 Types.
26 - 4.5.2 Characteristics.
27 - 4.5.3 Current Setting of Overcurrent Releases.
27 - 4.5.4 Time Setting of Overcurrent Releases.
28 - 4.6 AUXILIARY SWITCHES.
29 - SECTION 5. INFORMATION REGARDING THE CIRCUIT-BREAKER
29 - 5.1 ESSENTIAL MARKING ON NAMEPLATES.
29 - 5.2 OTHER INFORMATION.
29 - 5.3 LOCATION OF NAMEPLATE.
29 - 5.4 MARKING OF TERMINALS FOR EXTERNAL CONDUCTORS.
30 - 5.4.1 Avoidance of Damage to Cable Insulation by Excessive Temperature.
30 - 5.4.2 Warning Label or Tag.
31 - SECTION 6. STANDARD CONDITIONS OF OPERATION IN SERVICE
31 - 6.1 STANDARD SERVICE CONDITIONS.
31 - 6.2 SHAPE AND SYMMETRY OF VOLTAGES AND CURRENTS.
32 - SECTION 7. CONDITIONS FOR CONSTRUCTION
32 - 7.1 MECHANICAL DESIGN.
32 - 7.1.1 General Requirements.
32 - 7.1.2 Clearances and Creepage Distances.
32 - 7.1.3 Terminals.
33 - 7.2 ENCLOSURES.
33 - 7.2.1 Mechanical Details.
33 - 7.2.2 Insulation.
34 - 7.3 TEMPERATURE RISE.
34 - 7.3.1 Results to be Obtained.
34 - 7.3.2 Ambient Air Temperature.
34 - 7.3.3 Main Circuit.
34 - 7.3.4 Control Circuits.
35 - 7.3.5 Auxiliary Circuits.
35 - 7.4 DIELECTRIC PROPERTIES.
36 - 7.5 MECHANICAL AND ELECTRICAL ENDURANCES.
37 - 7.6 OVERLOAD PERFORMANCE.
37 - 7.7 OPERATING CONDITIONS.
37 - 7.7.1 Closing.
39 - 7.7.2 Opening.
41 - SECTION 8. TESTS
41 - 8.1 TESTING.
41 - 8.2 VERIFICATION OF THE CHARACTERISTICS OF CIRCUIT-BREAKERS.
41 - 8.2.1 Type Tests.
41 - 8.2.2 Routine Tests.
41 - 8.3 TYPE TESTS.
41 - 8.3.1 General.
42 - 8.3.2 Verification of Temperature-rise Limits.
47 - 8.3.3 Verification of Dielectric Properties.
49 - 8.3.4 Verification of Rated Short-circuit Making and Breaking Capacities.
62 - 8.3.5 Verification of the Ability to Carry Rated Short-time Withstand Current.
63 - 8.3.6 Verification of Mechanical Operation and of Mechanical and Electrical Endurances.
65 - 8.3.7 Verification of Overload Performance.
67 - 8.3.8 Verification of Operating Limits and Characteristics of Over-current Opening Releases.
69 - 8.4 ROUTINE TESTS.
69 - 8.4.1 Mechanical Operation Tests.
69 - 8.4.2 Calibration of Releases.
69 - 8.4.3 Dielectric Tests.
71 - SECTION 9. ADDITIONAL REQUIREMENTS FOR INTEGRALLY-FUSED CIRCUIT-BREAKERS
71 - 9.1 SCOPE AND OBJECT.
71 - 9.1.1 Scope.
71 - 9.1.2 Object.
71 - 9.2 GENERAL REQUIREMENTS FOR COORDINATION OF THE CIRCUIT-BREAKER WITH ITS FUSES.
71 - 9.2.1 Behaviour of the Circuit-breaker Alone.
71 - 9.2.2 Behaviour of the Composite Unit.
71 - 9.3 TYPE AND CHARACTERISTICS OF THE COORDINATED FUSES.
72 - 9.4 CHARACTERISTICS OF INTEGRALLY-FUSED CIRCUIT-BREAKERS.
72 - 9.5 VERIFICATION OF THE REQUIREMENTS FOR COORDINATION.
72 - 9.5.1 Verification of the Take-over Current.
72 - 9.5.2 Verification of the Behaviour of the Composite Unit.
73 - 9.5.3 Test Currents.
73 - 9.5.4 Test Procedure.
73 - 9.5.5 Results to be Obtained.
75 - APPENDIX A - DETERMINATION OF SHORT-CIRCUIT POWER FACTOR OR TIME-CONSTANT
75 - A1 INTRODUCTION.
75 - A2 DETERMINATION OF SHORT-CIRCUIT POWER FACTOR.
75 - A2.1 Method I- Determination from D.C. Component.
76 - A2.2 Method II - Determination with Pilot Generator.
76 - A2.3 Method III-Determination from Circuit Constants before Test.
76 - A3 DETERMINATION OF SHORT-CIRCUIT TIME-CONSTANT
77 - APPENDIX B - INFORMATION TO BE GIVEN BY THE PURCHASER
77 - B1 GENERAL.
77 - B2 PARTICULARS OF SYSTEM.
77 - B3 AMBIENT AIR TEMPERATURE.
77 - B4 ALTITUDE.
77 - B5 ATMOSPHERIC CONDITIONS.
77 - B6 CONDITIONS OF INSTALLATION.
77 - B7 CONNECTIONS WITH OTHER APPARATUS.
77 - B8 CHARACTERISTICS OF CIRCUIT-BREAKER.
79 - APPENDIX C - ITEMS SUBJECT TO AGREEMENT BETWEEN THE PURCHASER AND THE MANUFACTURER
80 - APPENDIX D - CLEARANCES AND CREEPAGE DISTANCES FOR CIRCUIT-BREAKERS
80 - D1 INTRODUCTION.
80 - D2 SURFACE OF INSULATING PARTS.
80 - D3 CONDUCTING PARTS.
80 - D4 CLEARANCES AND CREEPAGE DISTANCES TO BE MAINTAINED.
81 - APPENDIX E - COORDINATION OF CIRCUIT-BREAKERS WITH SEPARATE FUSES ASSOCIATED IN THE SAME CIRCUIT
81 - INTRODUCTION.
81 - E1 SCOPE.
81 - E2. OBJECT.
82 - E3 GENERAL REQUIREMENTS FOR COORDINATION OF A CIRCUIT-BREAKER WITH ITS ASSOCIATED FUSE OR FUSES.
82 - E3.1 Take-over Current.
82 - E3.2 Behaviour of the Circuit-breaker in Association With its Fuses.
82 - E4 TYPE AND CHARACTERISTICS OF THE ASSOCIATED FUSES.
82 - E5 METHODS FOR VERIFICATION OF THE COORDINATION.
82 - E5.1 Determination of the Take-over Current.
82 - E5.2 Verification of the Behaviour of the Circuit-breaker.
83 - E5.3 Current for Verification of Correct Coordination.
83 - E5.4 Results to be Obtained.

Applies to both air-break and oil-break circuit-breakers and to their operating devices and auxiliary equipment. It deals with ratings, classification, mechanical and electrical design and construction, performance, testing and marking. Additional requirements for integrally fused circuit-breakers are included. Appendices include information to be given by the purchaser, items subject to agreement, and coordination of circuit-breakers with separate fuses.

This standard applies to circuit-breakers, the main contacts of which are intended to be connected to circuits the rated voltage of which does not exceed 1000 V a.c. or 1200 V d.c. It also contains additional requirements for integrally-fused circuit-breakers.It does not apply to single and multipole-(a) moulded case air circuit-breakers (see AS C411); (b) miniature overcurrent circuit-breakers (see AS 3111 );(c) circuit-breakers having short-circuit performance category P-1 (see IEC Publication 157-1); and(d) circuit-breakers intended for installation in rail or road vehicles or in aircraft.NOTES:1. Circuit-breakers which are dealt with in this standard may be provided with devices for automatic opening under predetermined conditions other than those of overcurrent and undervoltage, e.g. reversal of power or current. This standard does not deal with the verification of operation under such predetermined conditions.2. Circuit-breakers when applied to marine use or to the protection of generators may also be required to comply with requirements not included in this standard.3. Oil-immersed circuit-breakers to be used in explosive atmospheres will be subject to additional requirements. (See AS ...., Oil-immersed Electrical Equipment for Explosive Atmospheres.*)