AS/NZS 3947.1:1998

1 - AS/NZS 3947.1:1998 LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR - GENERAL RULES
4 - PREFACE
8 - CONTENTS
11 - 1 General
11 - 1.1 Scope and object
12 - 1.2 Normative references
14 - 2 Definitions
18 - 2.1 General terms
18 - 2.1.1 switchgear and controlgear:
18 - 2.1.2 switchgear:
18 - 2.1.3 controlgear:
19 - 2.1.4 over-current:
19 - 2.1.5 short circuit:
19 - 2.1.6 short-circuit current:
19 - 2.1.7 overload:
19 - 2.1.8 overload current:
19 - 2.1.9 ambient air temperature:
19 - 2.1.10 conductive part:
19 - 2.1.11 exposed conductive part:
19 - 2.1.12 extraneous conductive part:
19 - 2.1.13 live part:
19 - 2.1.14 protective conductor (symbol PE):
19 - 2.1.15 neutral conductor (symbol N):
20 - 2.1.16 enclosure:
20 - 2.1.17 integral enclosure:
20 - 2.1.18 utilization category
20 - 2.1.19 isolation (isolating function):
20 - 2.1.20 electric shock:
20 - 2.2 Switching devices
20 - 2.2.1 switching device:
20 - 2.2.2 mechanical switching device:
20 - 2.2.3 semiconductor switching device:
20 - 2.2.4 fuse:
20 - 2.2.5 fuse-link:
20 - 2.2.6 fuse-element:
20 - 2.2.7 fuse-combination unit:
21 - 2.2.8 disconnector:
21 - 2.2.9 switch
21 - 2.2.10 switch-disconnector:
21 - 2.2.11 circuit-breaker:
21 - 2.2.12 contactor
21 - 2.2.13 semiconductor contactor
21 - 2.2.14 contactor relay:
21 - 2.2.15 starter:
21 - 2.2.16 control circuit device:
21 - 2.2.17 control switch
21 - 2.2.18 pilot switch:
22 - 2.2.19 push-button:
22 - 2.2.20 terminal block:
22 - 2.2.21 short-circuit protective device (SCPD):
22 - 2.2.22 surge arrester:
22 - 2.3 Parts of switching devices
22 - 2.3.1 pole of a switching device:
22 - 2.3.2 main circuit
22 - 2.3.3 control circuit
22 - 2.3.4 auxiliary circuit
22 - 2.3.5 contact
22 - 2.3.6 contact piece:
22 - 2.3.7 main contact:
22 - 2.3.8 arcing contact:
23 - 2.3.9 control contact:
23 - 2.3.10 auxiliary contact:
23 - 2.3.11 auxiliary switch
23 - 2.3.12 “a” contact - make contact:
23 - 2.3.13 “b” contact - break contact:
23 - 2.3.14 relay (electrical):
23 - 2.3.15 release
23 - 2.3.16 actuating system
23 - 2.3.17 actuator:
23 - 2.3.18 position indicating device:
23 - 2.3.19 indicator light:
23 - 2.3.20 anti-pumping device:
23 - 2.3.21 interlocking device:
23 - 2.3.22 terminal:
24 - 2.3.23 screw-type terminal:
24 - 2.3.24 screwless-type terminal:
24 - 2.3.25 clamping unit:
24 - 2.3.26 unprepared conductor:
24 - 2.3.27 prepared conductor:
24 - 2.4 Operation of switching devices
24 - 2.4.1 operation
24 - 2.4.2 operating cycle
24 - 2.4.3 operating sequence
24 - 2.4.4 manual control:
24 - 2.4.5 automatic control:
24 - 2.4.6 local control:
24 - 2.4.7 remote control:
24 - 2.4.8 closing operation
25 - 2.4.9 opening operation
25 - 2.4.10 positive opening operation
25 - 2.4.11 positively driven operation:
25 - 2.4.12 dependent manual operation
25 - 2.4.13 dependent power operation
25 - 2.4.14 stored energy operation
25 - 2.4.15 independent manual operation
25 - 2.4.16 independent power operation
25 - 2.4.17 actuating force (moment):
25 - 2.4.18 restoring force (moment):
25 - 2.4.19 travel
26 - 2.4.20 closed position
26 - 2.4.21 open position
26 - 2.4.22 tripping
26 - 2.4.23 trip-free mechanical switching device:
26 - 2.4.24 instantaneous relay or release:
26 - 2.4.25 over-current relay or release:
26 - 2.4.26 definite time-delay over-current relay or release:
26 - 2.4.27 inverse time-delay over-current relay or release:
26 - 2.4.28 direct over-current relay or release:
26 - 2.4.29 indirect over-current relay or release:
26 - 2.4.30 overload relay or release:
26 - 2.4.31 thermal overload relay or release:
27 - 2.4.32 magnetic overload relay or release:
27 - 2.4.33 shunt release:
27 - 2.4.34 under-voltage relay or release:
27 - 2.4.35 reverse current relay or release
27 - 2.4.36 operating current
27 - 2.4.37 current-setting
27 - 2.4.38 current setting range
27 - 2.5 Characteristic quantities
27 - 2.5.1 nominal value:
27 - 2.5.2 limiting value:
27 - 2.5.3 rated value:
27 - 2.5.4 rating:
27 - 2.5.5 prospective current
28 - 2.5.6 prospective peak current:
28 - 2.5.7 prospective symmetrical current (of an a.c. circuit):
28 - 2.5.8 maximum prospective peak current (of an a.c. circuit):
28 - 2.5.9 prospective making current (for a pole of a switching device):
28 - 2.5.10 prospective breaking current (for a pole of a switching device or a fuse):
28 - 2.5.11 breaking current (of a switching device or a fuse):
28 - 2.5.12 breaking capacity (of a switching device or a fuse):
28 - 2.5.13 making capacity (of a switching device):
29 - 2.5.14 short-circuit breaking capacity:
29 - 2.5.15 short-circuit making capacity:
29 - 2.5.16 critical load current:
29 - 2.5.17 critical short-circuit current:
29 - 2.5.18 Joule integral
29 - 2.5.19 cut-off current - let-through current:
29 - 2.5.20 time-current characteristic:
29 - 2.5.21 cut-off (current) characteristic - let-through (current) characteristic:
29 - 2.5.22 over-current protective co-ordination of over-current protective devices:
29 - 2.5.23 over-current discrimination:
30 - 2.5.24 back-up protection:
30 - 2.5.25 take-over current:
30 - 2.5.26 short-time delay:
30 - 2.5.27 short-time withstand current:
30 - 2.5.28 peak withstand current:
30 - 2.5.29 conditional short-circuit current (of a circuit or a switching device):
30 - 2.5.30 conventional non-tripping current (of an over-current relay or release):
30 - 2.5.31 conventional tripping current (of an over-current relay or release):
30 - 2.5.32 applied voltage (for a switching device):
30 - 2.5.33 recovery voltage:
31 - 2.5.34 transient recovery voltage (abbreviation TRV):
31 - 2.5.35 power-frequency recovery voltage:
31 - 2.5.36 d.c. steady-state recovery voltage:
31 - 2.5.37 prospective transient recovery voltage (of a circuit):
31 - 2.5.38 peak arc voltage (of a mechanical switching device):
31 - 2.5.39 opening time (of a mechanical switching device):
31 - 2.5.40 arcing time (of a pole or a fuse):
31 - 2.5.41 arcing time (of a multipole switching device):
31 - 2.5.42 break time:
31 - 2.5.43 make time:
31 - 2.5.44 closing time:
31 - 2.5.45 make-break time:
32 - 2.5.46 clearance:
32 - 2.5.47 clearance between poles:
32 - 2.5.48 clearance to earth:
32 - 2.5.49 clearance between open contacts (gap):
32 - 2.5.50 isolating distance (of a pole of a mechanical switching device):
32 - 2.5.51 creepage distance:
32 - 2.5.52 working voltage:
32 - 2.5.53 temporary overvoltage:
32 - 2.5.54 transient overvoltages:
32 - 2.5.55 impulse withstand voltage:
32 - 2.5.56 power-frequency withstand voltage:
33 - 2.5.57 pollution:
33 - 2.5.58 pollution degree (of environmental conditions):
33 - 2.5.59 micro-environment (of a clearance or creepage distance):
33 - 2.5.60 overvoltage category (of a circuit or within an electrical system):
33 - 2.5.61 co-ordination of insulation:
33 - 2.5.62 homogeneous (uniform) field:
33 - 2.5.63 inhomogeneous (non-uniform) field:
33 - 2.5.64 tracking:
33 - 2.5.65 comparative tracking index (CTI):
34 - 2.6 Tests
34 - 2.6.1 type test:
34 - 2.6.2 routine test:
34 - 2.6.3 sampling test:
34 - 2.6.4 special test:
34 - 3 Classification
35 - 4 Characteristics
36 - 4.1 General
36 - 4.2 Type of equipment
36 - 4.3 Rated and limiting values for the main circuit
36 - 4.3.1 Rated voltages
37 - 4.3.2 Currents
38 - 4.3.3 Rated frequency
39 - 4.3.4 Rated duties
40 - 4.3.5 Normal load and overload characteristics
41 - 4.3.6 Short-circuit characteristics
42 - 4.4 Utilization category
42 - 4.5 Control circuits
42 - 4.5.1 Electrical control circuits
43 - 4.5.2 Air-supply control circuits (pneumatic or electro-pneumatic)
43 - 4.6 Auxiliary circuits
43 - 4.7 Relays and releases
44 - 4.8 Co-ordination with short-circuit protective devices (SCPD)
44 - 4.9 Switching overvoltages
44 - 5 Product information
44 - 5.1 Nature of information
45 - 5.2 Marking
45 - 5.3 Instructions for installation, operation and maintenance
46 - 6 Normal service, mounting and transport conditions
46 - 6.1 Normal service conditions
46 - 6.1.1 Ambient air temperature
46 - 6.1.2 Altitude
46 - 6.1.3 Atmospheric conditions
47 - 6.1.4 Shock and vibration
48 - 6.2 Conditions during transport and storage
48 - 6.3 Mounting
48 - 7 Constructional and performance requirements
48 - 7.1 Constructional requirements
48 - 7.1.1 Materials
49 - 7.1.2 Current-carrying parts and their connections
49 - 7.1.3 Clearances and creepage distances
49 - 7.1.4 Actuator
50 - 7.1.5 Indication of the contact position
50 - 7.1.6 Additional constructional requirements for equipment suitable for isolation
51 - 7.1.7 Terminals
52 - 7.1.8 Additional requirements for equipment provided with a neutral pole
52 - 7.1.9 Provisions for protective earthing
53 - 7.1.10 Enclosures for equipment
54 - 7.1.11 Degrees of protection of enclosed equipment
54 - 7.1.12 Conduit pull-out, torque and bending with metallic conduits
54 - 7.2 Performance requirements
54 - 7.2.1 Operating conditions
56 - 7.2.2 Temperature-rise
57 - 7.2.3 Dielectric properties
59 - 7.2.4 Ability to make, carry and break currents under no-load, normal load and overload conditions
60 - 7.2.5 Ability to make, carry and break short-circuit currents
61 - 7.2.6 Switching overvoltages
61 - 7.2.7 Leakage currents of equipment suitable for isolation
61 - 7.3 Electromagnetic compatibility (EMC)
61 - 7.3.1 General
62 - 7.3.2 Immunity
62 - 7.3.3 Emission
63 - 8 Tests
63 - 8.1 Kinds of test
63 - 8.1.1 General
63 - 8.1.2 Type tests
64 - 8.1.3 Routine tests
64 - 8.1.4 Sampling tests
64 - 8.2 Compliance with constructional requirements
64 - 8.2.1 Materials
65 - 8.2.2 Equipment
65 - 8.2.3 Enclosures for equipment
65 - 8.2.4 Mechanical properties of terminals
68 - 8.2.5 Verification of the effectiveness of indication of the main contact position of equipment suitable for isolation
69 - 8.2.6 Test for verification of clamping units transmitting contact pressure through insulating materials other than ceramics
70 - 8.2.7 Conduit pull-out test, torque test and bending test with metallic conduits
71 - 8.3 Performance
71 - 8.3.1 Test sequences
71 - 8.3.2 General test conditions
74 - 8.3.3 Performance under no-load, normal load and overload conditions
83 - 8.3.4 Performance under short-circuit conditions
89 - 8.4 Tests for EMC
89 - 8.4.1 Immunity
89 - 8.4.2 Emission
118 - Annex A - Examples of utilization categories for low-voltage switchgear and controlgear
119 - Annex B - Suitability of the equipment when conditions for operation in service differ from the normal conditions
119 - B.1 Examples of conditions differing from normal
119 - B.2 Connections with other apparatus
119 - B.3 Auxiliary contacts
119 - B.4 Special applications
120 - Annex C - Degrees of protection of enclosed equipment
120 - Introduction
120 - C.1 Scope
120 - C.2 Object
120 - C.3 Definitions
120 - C.4 Designation
120 - C.5 Degrees of protection against access to hazardous parts and against ingress of solid foreign objects indicated by the first
121 - C.6 Degrees of protection against ingress of water indicated by the second characteristic numeral
121 - C.7 Degrees of protection against access to hazardous parts indicated by the additional letter
121 - C.8 Supplementary letters
121 - C.9 Examples of designations with IP Code
121 - C.10 Marking
121 - C.11 General requirements for tests
122 - C.12 Tests for protection against access to hazardous parts indicated by the first characteristic numeral
122 - C.13 Tests for protection against ingress of solid foreign objects indicated by the first characteristic numeral
122 - C.14 Tests for protection against water indicated by second characteristic numeral
123 - C.15 Tests for protection against access to hazardous parts indicated by additional letter
123 - C.16 Summary of responsibilities of relevant technical committees
127 - Annex D - Examples of terminals.
133 - Annex E - Description of a method for adjusting the load circuit
135 - Annex F - Determination of short-circuit power-factor or time-constant
135 - F.1 Determination of short-circuit power-factor
136 - F.2 Determination of short-circuit time-constant (oscillographic method)
137 - Annex G - Measurement of creepage distances and clearances
137 - G.1 Basic principles
137 - G.2 Use of ribs
142 - Annex H - Correlation between the nominal voltage of the supply system and the rated impulse withstand voltage of equipment
145 - Annex J - Items subject to agreement between manufacturer and user
146 - Annex K - Power-frequency dielectric tests
146 - K.1 General
146 - K.2 Power-frequency test as type test for verification of dielectric properties
149 - K.3 Power-frequency tests for verification of dielectric withstand after switching test with current or short-circuit test
150 - K.4 Verification of dielectric withstand after humidity treatment
150 - K.5 Power-frequency tests for verification of dielectric withstand during routine tests
151 - Annex L - Terminal marking and distinctive number
151 - L.1 General
151 - L.2 Terminal marking of impedances (alphanumerical)
153 - L.3 Terminal marking of contact elements for switching devices with two positions (numerical)
155 - L.4 Terminal marking of overload protection devices
156 - L.5 Distinctive number
157 - Annex M - Flammability test
157 - M.1 Hot wire ignition test
158 - M.2 Arc ignition test

Applies to switchgear and controlgear intended to be connected to circuits, the rated voltage of which does not exceed 1000 volt a.c. or 1500 volt d.c. This Standard is identical with and has been reproduced from IEC 60947-1:1996.

This standard applies, when required by the relevant product standard, to switchgear and controlgear hereinafter referred to as "equipment" and intended to be connected to circuits, the rated voltage of which does not exceed 1000 V a.c. or 1500 V d.c. It does not apply to low-voltage switchgear and controlgear assemblies which are dealt with in IEC 439.NOTE - In certain clauses or subclauses of this standard, the equipment covered by this standard is also referred to as "device", to be consistent with the text of such clauses or subclauses. The object of this standard is to state those general rules and requirements which are common to low-voltage equipment as defined in 1.1, including for example:- definitions;- characteristics;- information supplied with the equipment;- normal service, mounting and transport conditions;- constructional and performance requirements;- verification of characteristics and performance.

First published in Australia as AS 3650-1988.
Revised and redesignated AS 3947.1-1993.
Jointly revised and designated AS/NZS 3947.1:1998.