IEC 62962:2019

IEC 62962 ®
Edition 1.0 2019-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Particular requirements for load-shedding equipment (LSE)

Exigences spécifiques pour les délesteurs (LSE)

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IEC 62962 ®
Edition 1.0 2019-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Particular requirements for load-shedding equipment (LSE)

Exigences spécifiques pour les délesteurs (LSE)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.015; 29.020 ISBN 978-2-8322-7385-2

– 2 – IEC 62962:2019  IEC 2019
CONTENTS
FOREWORD . 9
INTRODUCTION . 11
1 Scope . 12
2 Normative references . 13
3 Terms and definitions . 14
4 General requirements . 22
4.1 General . 22
4.2 Architecture . 23
4.3 Standard conditions for operation in service . 24
5 General remarks on tests . 25
5.1 Environmental conditions . 25
5.1.1 General . 25
5.1.2 Ambient temperature range in normal use. 25
5.1.3 Relative humidity . 25
5.1.4 Altitude . 25
5.2 General testing procedure and samples . 26
6 Ratings . 27
6.1 Rated values . 27
6.1.1 Rated operational voltages . 27
6.1.2 Rated insulation voltage . 27
6.1.3 Rated impulse voltage . 27
6.1.4 Maximum value of rated current . 27
6.1.5 Preferred rated current values (I ) . 27
n
6.1.6 Minimum value of rated making and breaking capacity (I ) . 28
RMS
6.1.7 Rated frequency . 28
6.1.8 Rated conditional short-circuit current . 28
6.1.9 Preferred rated load-shedding current (power) values (I L , P L ) . 28
n s n s
6.2 Time-current characteristic for LSEs monitoring the current . 28
6.2.1 LSE operating principle . 28
6.2.2 Current limits (I L ) . 30
n s
6.2.3 Minimum switch OFF-time . 30
6.2.4 Reclosing conditions . 31
6.3 Time-power characteristic . 32
6.4 LSE shedding sequence . 32
7 Classification . 33
7.1 General . 33
7.2 According to the LSE functional category . 33
7.3 According to the switching means . 34
7.4 According to the possibility of adjusting the rated load-shedding current(s)
(or power) . 34
7.5 According to the shedding sequence . 34
7.6 According to the design . 34
7.6.1 Stand-alone LSE with internal or external sensors or measuring units . 34
7.6.2 LSE with external sensor . 34
7.6.3 Combined LSE (or assembled LSE) . 34
7.7 According to the method of mounting . 34

7.8 According to the type of terminals . 34
7.9 According to the contact openings . 34
7.10 According to the protection against external influences . 35
7.11 According to the number of poles . 35
7.12 According to the type of monitored parameters . 35
8 Markings and information . 35
8.1 General . 35
8.2 Test of markings . 36
9 Protection against electric shock . 36
9.1 General . 36
9.2 Test for protection against electric shock . 37
10 Terminals for external copper conductors . 40
10.1 General . 40
10.2 Terminals with screw clamping for external copper conductors . 40
10.2.1 General . 40
10.2.2 Conductor fitting . 46
10.2.3 Mechanical strength of terminals . 46
10.2.4 Resistance to corrosion of terminals . 46
10.2.5 Clamping effects on conductors . 46
10.2.6 Clamping reliability of terminals . 47
10.2.7 Clamping length of terminals . 48
10.2.8 Reliability of terminals . 49
10.2.9 Accidental loosening of earthing terminals . 49
10.2.10 Resistance to corrosion of earthing terminals . 49
10.2.11 Additional requirements for the design of pillar terminals . 50
10.2.12 Additional requirements for the design of lug terminals . 50
10.2.13 Additional requirements for terminals for the connection of external
conductors . 50
10.3 Screwless terminals for external copper conductors . 50
10.3.1 General . 50
10.3.2 Conductor fittings . 50
10.3.3 Connection of conductors . 51
10.3.4 Type of material . 51
10.3.5 Conductors clamping . 51
10.3.6 Operation of terminals . 51
10.3.7 Multi conductor terminals . 52
10.3.8 Introduction of conductors . 52
10.3.9 Fixing of terminals . 52
10.3.10 Mechanical strength. 52
10.3.11 Electrical and thermal stress resistance . 54
10.3.12 Mechanical reliability . 56
11 Constructional requirements . 59
11.1 General . 59
11.2 Mechanical requirements for insulating means . 59
11.3 Installation requirements . 59
11.4 Fixing of covers, cover plates and actuating members . 62
11.4.1 General . 62
11.4.2 Fixings based on screws or rivets . 63

– 4 – IEC 62962:2019  IEC 2019
11.4.3 Fixings which may be removed by applying a force perpendicular to the
surfaces . 63
11.4.4 Fixings which may be removed using a tool . 63
11.5 Attachment of knobs . 64
11.6 Mounting means . 64
11.7 Accessories . 64
12 Mechanism and operating means . 64
12.1 General . 64
12.2 Indication of the position . 65
12.3 Rest position . 65
12.4 Making and breaking . 65
12.5 Action of the mechanism without cover or cover plate . 65
12.6 Fixings and removal of operating means . 65
12.7 Locking . 66
12.8 Status indicators . 66
13 Resistance to ageing and humidity . 66
13.1 Resistance to ageing . 66
13.2 Resistance to humidity . 67
14 Insulation resistance and dielectric strength . 67
14.1 General . 67
14.2 Insulation resistance of the main circuit . 67
14.3 Dielectric strength of main circuits . 68
14.4 Insulation resistance and dielectric strength of other circuits . 70
14.5 Verification of impulse withstand voltages (across clearances and through
solid insulations) . 71
14.5.1 General testing procedure . 71
14.5.2 Verification of clearances with the impulse withstand voltage tests . 72
15 Temperature rise . 72
15.1 General . 72
15.2 Test setup . 73
15.3 Test procedure . 74
16 Making and breaking capacity . 76
17 Normal operation . 76
17.1 Functional tests: disconnection and reclosing . 76
17.1.1 General . 76
17.1.2 Disconnection tests . 77
17.1.3 Reclosing tests . 78
17.1.4 Load-shedding sequence(s) tests . 79
17.1.5 Remotely controlled LSE and LSE with connection to other external
equipment. 79
17.2 Endurance test . 79
18 Mechanical strength . 80
18.1 General . 80
18.2 Pendulum hammer test . 81
18.3 Covers, cover plates or actuating members – Accessibility to live parts . 89
18.3.1 General . 89
18.3.2 Verification of the non-removal of covers, cover plates or actuating
members . 89
18.3.3 Verification of the removal of covers, cover plates or actuating members. 89

18.4 Covers, cover plates or actuating members – Accessibility to non-earthed
metal parts separated from live parts . 90
18.5 Covers, cover plates or actuating members – Accessibility to insulating
parts, earthed metal parts, the live parts of SELV ≤ 25 V AC or metal parts
separated from live parts . 90
18.6 Covers, cover plates or actuating members – Application of gauges . 90
18.7 Grooves, holes and reverse tapers . 92
18.8 Rail mounted LSEs . 93
19 Resistance to heat . 94
19.1 General . 94
19.2 Basic heating test . 94
19.3 Ball-pressure test on parts of insulating material necessary to retain current-
carrying parts and parts of the earthing circuit in position . 95
19.4 Ball-pressure test on parts of insulating material not necessary to retain
current-carrying parts and parts of the earthing circuit in position. 95
20 Screws, current carrying capacity and connections . 95
20.1 General . 95
20.2 Correct insertion of screws . 96
20.3 Contact pressure of electrical connections . 97
20.4 Screws and rivets used both as electrical and mechanical connections . 97
20.5 Material of current-carrying parts . 97
20.6 Thread-forming and thread-cutting screws . 98
21 Creepage distances, clearances and distances through sealing compound . 98
21.1 General . 98
21.2 Measurements . 98
21.3 Insulating compound . 99
22 Resistance of insulating material to abnormal heat and fire . 101
22.1 General . 101
22.2 Glow-wire test . 101
23 Resistance to rusting . 103
24 EMC requirements . 104
24.1 General . 104
24.2 Immunity . 104
24.2.1 General . 104
24.2.2 Voltage dips and short interruptions . 105
24.2.3 Surge immunity test for 1,2/50 wave impulses . 105
24.2.4 Electrical fast transient/burst test . 106
24.2.5 Electrostatic discharge test . 106
24.2.6 Radiated electromagnetic field test . 107
24.2.7 Radio-frequency voltage test . 107
24.2.8 Power-frequency magnetic field test . 108
24.3 Emission . 108
24.3.1 General . 108
24.3.2 Low-frequency emission . 108
24.3.3 Radio-frequency emission . 108
25 Coordination with short-circuit devices . 108
25.1 General requirements for coordination . 108
25.2 Testing conditions . 108
25.2.1 Test circuit . 108

– 6 – IEC 62962:2019  IEC 2019
25.2.2 Tolerances on test quantities . 112
25.2.3 Power factor of the test circuit . 112
25.2.4 Power frequency recovery voltage . 113
25.2.5 Calibration of the test circuit . 113
25.2.6 Sequence of operations . 113
25.3 Tests of coordination between the LSE and the SCPD . 113
25.3.1 General . 113
25.3.2 Verification of the coordination at the rated conditional short-circuit
current (I ). 114
nc
25.3.3 Verification at the instantaneous tripping of the SCPD . 114
25.3.4 Condition of the LSE during and after tests . 114
26 Tests under abnormal conditions . 114
26.1 General . 114
26.2 Tests under fault conditions . 115
26.3 Overload tests . 116
27 Components . 116
27.1 Fuses. 117
27.2 Capacitors . 117
27.3 Resistors . 118
27.4 Automatic protective devices (other than fuses) . 118
27.4.1 General . 118
27.4.2 Cut-outs . 118
27.4.3 Automatic protective devices . 120
27.5 Transformers . 120
Annex A (normative) Test sequences and number of specimens . 121
Annex B (informative) Correspondence between ISO and AWG copper conductors . 123
Annex C (normative) Determination of clearances and creepage distances . 124
C.1 General . 124
C.2 Orientation and location of a creepage distance . 124
C.3 Creepage distances where more than one material is used . 124
C.4 Creepage distances split by floating conductive part . 124
C.5 Measurement of creepage distances and clearances . 124
Annex D (normative) Arrangement for the detection of the emission of ionized gases
during short-circuit tests . 128
Bibliography . 131

Figure 1 – Energy efficiency management system . 11
Figure 2 – LSE general architecture . 24
Figure 3 – Time-current characteristic of a Class A LSE . 29
Figure 4 – Joined test finger (test probe B according to IEC 61032:1997) . 38
Figure 5 – Test pin for checking the protection against electric shock . 40
Figure 6 – Terminals with stirrup . 41
Figure 7 – Pillar terminals . 41
Figure 8 – Screw terminals and stud terminals . 43
Figure 9 – Saddle terminals . 44
Figure 10 – Lug terminals . 45
Figure 11 – Test apparatus for checking damage to conductors . 54

Figure 12 – Information for deflection test . 57
Figure 13 – Determination of the direction of the forces to be applied . 61
Figure 14 – Direction for the conductor pull of 30 N for 1 min . 62
Figure 15 – Pendulum impact test apparatus . 82
Figure 16 – Pendulum impact test apparatus (striking element) . 83
Figure 17 – Mounting support of specimens . 84
Figure 18 – Mounting block for a flush type LSE . 85
Figure 19 – Example of mounting support of a panel board type LSE . 86
Figure 20 – Example of mounting support for a rear fixed LSE . 87
Figure 21 – Gauge (thickness: about 2 mm) for the verification of the outline of covers,
cover-plates or actuating members . 90
Figure 22 – Example of application of the gauge of Figure 21 on covers fixed without
screws on a mounting surface or supporting surface . 91
Figure 23 – Examples of applications of the gauge of Figure 21 . 92
Figure 24 – Gauge for verification of grooves, holes and reverse tapers . 93
Figure 25 – Sketch showing the direction of application of the gauge of Figure 24 . 93
Figure 26 – Application of forces on a rail-mounted LSE . 94
Figure 27 – Ball-pressure test apparatus. 95
Figure 28 – Thread-cutting screw . 96
Figure 29 – Thread-forming screw . 96
Figure 30 – Diagrammatic representation . 102
Figure 31 – Typical diagram for all coordination tests . 110
Figure 32 – Detail of impedances Z and Z . 110
Figure C.1 – Example 1 . 125
Figure C.2 – Example 2 . 125
Figure C.3 – Example 3 . 125
Figure C.4 – Example 4 . 126
Figure C.5 – Example 5 . 126
Figure C.6 – Example 6 . 126
Figure C.7 – Example 7 . 127
Figure D.1 – Test arrangement . 129
Figure D.2 – Grid . 130
Figure D.3 – Grid circuit . 130

Table 1 – Cross-sectional areas (S) of test copper conductors corresponding to the
rated currents . 26
Table 2 – Rated impulse voltage as a function of the nominal voltage of the installation . 27
Table 3 – Load-shedding classes . 30
Table 4 – Disconnecting time . 31
Table 5 – Load-shedding classes . 32
Table 6 – Disconnecting time . 32
Table 7 – Load-shedding functional categories . 33
Table 8 – Marking and position of marking . 35

– 8 – IEC 62962:2019  IEC 2019
Table 9 – Relationship between rated currents and connectable cross-sectional areas
of copper conductors . 39
Table 10 – Dimensions and tightening torque of pillar terminals . 42
Table 11 – Dimensions and tightening torque for screw and stud terminals . 44
Table 12 – Dimensions and tightening torque for saddle terminals . 45
Table 13 – Dimensions and tightening torque for lug terminals. 45
Table 14 – Tightening torque for the verification of the mechanical strength of screw-

type terminals . 47
Table 15 – Test values for pulling out test . 48
Table 16 – Relationship between rated currents and connectable cross-sectional areas
of copper conductors for screwless terminals . 51
Table 17 – Test values for flexion and pull out for copper conductors . 53
Table 18 – Test current for the verification of electrical and thermal stresses in normal
use of screwless terminals . 55
Table 19 – Cross-sectional areas of rigid copper conductors for deflection test of

screwless terminals . 58
Table 20 – Deflection test forces . 58
Table 21 – Forces to be applied to covers, cover-plates or actuating members whose
fixing is not dependent on screws . 63
Table 22 – Test voltage, points of application and minimum values of insulating
resistance for the verification of dielectric strength . 69
Table 23 – Test voltages of auxiliary circuits . 71
Table 24 – Test voltage for verification of impulse withstand voltage . 72
Table 25 – Temperature-rise test currents and cross-sectional areas of copper
conductors . 73
Table 26 – Permissible temperature rise values (based on Table 3 of IEC 60065:2001) . 75
Table 27 – Number of operations for normal operation test . 80
Table 28 – Height of fall for impact test . 88
Table 29 – Minimum clearances and creepage distances . 100
Table 30 – Immunity tests (overview) . 104
Table 31 – Voltage dip and short-interruption test values . 105
Table 32 – Surge immunity test voltages . 106
Table 33 – Fast transient test values . 106
Table 34 – Minimum values of I t and I . 111
p
Table 35 – Power factors for short-circuit tests . 112
Table 36 – Capacitors . 118
Table A.1 – Specimen for tests . 122
Table B.1 – Correspondence between ISO and AWG copper conductors . 123

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PARTICULAR REQUIREMENTS FOR
LOAD-SHEDDING EQUIPMENT (LSE)
FOREWORD
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