IEC 61009-1:2024

IEC 61009-1 ®
Edition 4.0 2024-11
INTERNATIONAL
STANDARD
Residual current operated circuit-breakers with integral overcurrent protection
for household and similar uses (RCBOs) –
Part 1: General rules
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IEC 61009-1 ®
Edition 4.0 2024-11
INTERNATIONAL
STANDARD
Residual current operated circuit-breakers with integral overcurrent protection

for household and similar uses (RCBOs) –

Part 1: General rules
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.50  ISBN 978-2-8327-0011-2

– 2 – IEC 61009-1:2024 © IEC 2024
CONTENTS
FOREWORD . 10
INTRODUCTION . 12
1 Scope . 13
2 Normative references . 15
3 Terms and definitions . 16
4 Classification . 16
4.1 According to the supply conditions . 16
4.1.1 RCBO operating correctly on the occurrence of residual current . 16
4.1.2 RCBO with 2 or 4 current paths operating correctly on the occurrence of
residual current within the voltage range of 1,1 U and 85 V . 17
e
4.1.3 RCBO according to 4.1.2 fitted with a functional earth (FE) and able to
continue to provide protection when supplied from just one phase and
FE . 17
4.1.4 RCBO with 3 current paths operating correctly on the occurrence of
residual current within the voltage range of 1,1 U and 0,7 U . 17
e e
4.1.5 RCBO operating correctly on the occurrence of residual current within
the voltage range 1,1 U and U . 17
e x
4.1.6 RCBO according to 4.1.5, however reclosing automatically after
restoration of the supply voltage . 17
4.2 According to the possibility of adjusting the residual operating current . 17
4.3 According to their operation in response to the type of residual current . 17
4.4 According to time-delay (in the presence of a residual current) . 18
4.5 According to the protection against external influences . 18
4.6 According to the method of mounting . 18
4.7 According to the method of connection . 18
4.8 According to the type of terminals . 18
4.9 According to the number of poles and current paths . 18
4.10 According to the instantaneous tripping current . 19
4.11 According to the I t characteristics . 19
5 Characteristics of RCBOs . 19
5.1 Summary of characteristics . 19
5.2 Rated quantities and other characteristics . 20
5.2.1 Rated voltages . 20
5.2.2 Rated current (I ) . 20
n
5.2.3 Rated frequency . 20
5.2.4 Rated short-circuit capacity (I ) . 20
cn
5.2.5 Rated residual operating current (I ) . 20
Δn
5.2.6 Rated residual non-operating current (I ) . 21
Δno
5.2.7 Rated residual making and breaking capacity (I ) . 21
Δm
5.2.8 Void . 21
5.2.9 Void . 21
5.2.10 Operating characteristics in response to the type of residual current . 21
5.2.11 RCBO type S . 21
5.3 Standard and preferred values . 21
5.3.1 Standard values of rated operational voltage (U ) . 21
e
5.3.2 Preferred values of rated current (I ) . 21
n
5.3.3 Standard values of rated residual operating current (I ) . 21
Δn
5.3.4 Standard value of residual non-operating current (I ) . 22
Δno
5.3.5 Preferred values of rated frequency . 22
5.3.6 Standard values of rated impulse withstand voltage (U ) . 22
imp
5.3.7 Standard limit values of break time and non-actuating time for RCBO of
type AC and A . 22
5.3.8 Void . 22
5.3.9 Void . 22
5.3.10 Void . 22
5.3.11 Minimum value of the rated residual making and breaking capacity

(I ) . 22
Δm
5.3.12 Void . 22
5.3.13 Void . 22
5.3.14 Values of rated short-circuit capacity . 22
5.3.15 Standard ranges of overcurrent instantaneous tripping . 23
6 Marking and other product information . 23
7 Standard conditions for operation in service and for installation . 24
7.1 Standard conditions . 24
7.2 Conditions of installation . 24
7.3 Pollution degree . 24
8 Requirements for construction and operation . 24
8.1 Mechanical design . 24
8.1.1 General . 24
8.1.2 Mechanism . 25
8.1.3 Clearances, creepage distances and solid insulation . 26
8.1.4 Screws, current-carrying parts and connections . 27
8.1.5 Terminals for external conductors . 28
8.1.6 Non-interchangeability . 30
8.2 Protection against electric shock . 30
8.3 Dielectric properties and isolating capability . 31
8.4 Temperature-rise . 31
8.4.1 General . 31
8.4.2 Temperature-rise limits . 31
8.4.3 Ambient air temperature . 31
8.5 Operating characteristics . 31
8.5.1 General . 31
8.5.2 Operation in response to the type of residual current . 31
8.5.3 Operation in presence of a residual current equal to or greater than I . 32
Δn
8.5.4 Operation under overcurrent conditions . 32
8.6 Mechanical and electrical endurance . 33
8.7 Performance at short-circuit currents . 33
8.8 Resistance to mechanical shock and impact . 33
8.9 Resistance to heat . 33
8.10 Resistance to abnormal heat and to fire . 34
8.11 Test device . 34
8.12 Void . 34
8.13 Void . 34

– 4 – IEC 61009-1:2024 © IEC 2024
8.14 Behaviour of RCBOs in the event of current surges caused by impulse
voltages . 34
8.15 Reliability . 35
8.16 Electromagnetic compatibility (EMC) . 35
8.17 Resistance to temporary overvoltages (TOV) . 35
9 Tests . 35
9.1 General . 35
9.2 Test conditions . 35
9.3 Test of indelibility of marking . 36
9.4 Test of reliability of screws, current-carrying parts and connections . 37
9.5 Test of reliability of screw-type terminals for external copper conductors . 37
9.6 Verification of protection against electric shock . 39
9.7 Test of dielectric properties . 39
9.7.1 Resistance to humidity . 39
9.7.2 Insulation resistance of the main circuit . 40
9.7.3 Dielectric strength of the main circuit . 41
9.7.4 Insulation resistance and dielectric strength of auxiliary circuits. 41
9.7.5 Secondary circuit of detection transformers . 42
9.7.6 Capability of control circuits connected to the main circuit to withstand
high DC voltages due to insulation measurements . 42
9.7.7 Verification of impulse withstand voltages . 42
9.8 Test of temperature-rise . 44
9.8.1 Ambient air temperature . 44
9.8.2 Test procedure . 44
9.8.3 Measurement of the temperature of parts . 45
9.8.4 Temperature-rise of a part . 45
9.9 Verification of the operating characteristics . 45
9.9.1 Verification of the operating characteristics under residual current
conditions . 45
9.9.2 Verification of the operating characteristic under overcurrent conditions . 45
9.10 Verification of mechanical and electrical endurance . 47
9.10.1 General test conditions . 47
9.10.2 Test procedure . 47
9.10.3 Condition of the RCBO after test . 48
9.11 Short-circuit tests . 48
9.11.1 General conditions for test . 48
9.11.2 Test circuit for short-circuit performance . 49
9.11.3 Values of test quantities . 50
9.11.4 Tolerances on test quantities . 50
9.11.5 Power factor of the test circuit . 50
9.11.6 Measurement and verification of I t and of the peak current (I ) . 50
p
9.11.7 Calibration of the test circuit . 51
9.11.8 Interpretation of records . 51
9.11.9 Condition of the RCBO for test. 51
9.11.10 Behaviour of the RCBO during short-circuit tests . 52
9.11.11 Test procedure . 53
9.11.12 Verification of the RCBO after short-circuit test . 56
9.11.13 Verification of the rated residual making and breaking capacity (I ) . 56
Δm
9.12 Verification of resistance to mechanical shock and impact . 57

9.12.1 Mechanical shock . 57
9.12.2 Mechanical impact . 58
9.13 Test of resistance to heat . 60
9.13.1 Test on complete RCBOs . 60
9.13.2 Ball pressure test . 61
9.14 Test of resistance to abnormal heat and to fire . 62
9.15 Verification of the trip-free mechanism . 63
9.16 Verification of the operation of the test device at the limits of rated
operational voltage . 63
9.17 Void . 63
9.18 Void . 63
9.19 Verification of the behaviour of RCBOs in the event of current surges caused
by impulse voltages . 63
9.19.1 Current surge test for all RCBOs (0,5 µs/100 kHz ring wave test) . 63
9.19.2 Verification of the behaviour at surge currents up to 3 000 A (8/20 µs
surge current test) . 64
9.20 Verification of reliability . 65
9.20.1 Climatic test. 65
9.20.2 Test with temperature of 40 °C . 66
9.21 Verification of withstand against ageing . 67
9.22 Electromagnetic compatibility (EMC) . 67
9.23 Test of resistance to rusting . 67
9.24 Verification of the behaviour of the RCBO under temporary overvoltage

(TOV) conditions . 68
9.24.1 General . 68
9.24.2 TOV test for all RCBOs . 68
9.24.3 Additional tests for RCBOs with a terminal intended to be connected to
the PE . 68
9.24.4 Verification after the tests . 68
Annex A (normative) Test sequence and number of samples to be submitted for
certification purposes . 99
Annex B (normative) Determination of clearances and creepage distances . 100
B.1 General . 100
B.2 Creepage distances where more than one material is used . 100
B.3 Creepage distances split by floating conductive part . 100
B.4 Measurement of creepage distances and clearances . 100
Annex C (normative) Arrangement for the detection of the emission of ionized gases

during short-circuit tests . 105
Annex D (normative) Routine tests . 108
D.1 General . 108
D.2 Tripping test . 108
D.3 Dielectric strength test . 108
D.4 Performance of the test device . 108
Annex E (informative) Methods for determination of short-circuit power-factor . 109
E.1 General . 109
E.2 Method I – Determination from DC components . 109
E.3 Method II – Determination with pilot generator . 110
Annex F (informative) Co-ordination under short-circuit conditions between an RCBO
and another short-circuit protective device (SCPD) associated in the same circuit . 111
F.1 General . 111

– 6 – IEC 61009-1:2024 © IEC 2024
F.2 Overview. 112
F.3 General requirements for the co-ordination of an RCBO with another SCPD . 112
F.3.1 General consideration . 112
F.3.2 Take-over current . 112
F.3.3 Behaviour of C in association with another SCPD . 112
F.4 Type and characteristics of the associated SCPD . 112
F.5 Verification of selectivity . 113
F.6 Verification of back-up protection . 113
F.6.1 Determination of the take-over current . 113
F.6.2 Verification of back-up protection . 114
F.6.3 Tests for verification of back-up protection . 114
F.6.4 Results to be obtained . 115
Annex G (normative) Additional requirements and tests for RCBOs consisting of a
circuit-breaker and a residual current unit designed for assembly on site . 119
G.1 General . 119
G.2 Marking and other product information . 119
G.2.1 Manufacturer's name or trade mark . 119
G.2.2 Marking . 119
G.2.3 Instructions for assembly and operation . 120
G.3 Constructional requirements . 120
G.3.1 General . 120
G.3.2 Degree of protection . 120
G.3.3 Mechanical requirements . 121
G.3.4 Electrical compatibility . 121
G.4 Type tests and verifications . 121
G.4.1 Tests on circuit-breakers . 121
G.4.2 Tests on RC units . 121
G.4.3 Tests on assembled circuit-breaker and RC unit (RCBO) . 121
G.4.4 Verification of marking and constructional requirements of RCBOs . 121
G.5 Routine tests on the RC unit . 122
Annex H (informative) Examples of terminal designs . 123
Annex I (informative) Correspondence between ISO and AWG copper conductors . 126
Annex J (informative) Follow-up testing program for RCBOs . 127
J.1 General . 127
J.2 Follow-up testing program . 127
J.2.1 General . 127
J.2.2 Quarterly follow-up testing program . 127
J.2.3 Annual follow-up testing program . 127
J.2.4 Sampling procedure . 128
Bibliography . 131

Figure 1 – Standard test finger . 81
Figure 2 – Void . 82
Figure 3 – Void . 82
Figure 4 – Void . 82
Figure 5 – Typical diagram for all short circuit tests except for the verification of the
suitability in IT systems . 83
Figure 6 – Typical diagram for the verification of the suitability in IT systems . 84

Figure 7 – Detail of impedances Z, Z and Z . 84
1 2
Figure 8 – Mechanical shock test apparatus . 85
Figure 9 – Mechanical impact test apparatus . 86
Figure 10 – Striking element for pendulum impact test apparatus. 87
Figure 11 – Mounting support for sample for mechanical impact test. 88
Figure 12 – Example of mounting an unenclosed or flush-type RCBO for mechanical
impact test . 89
Figure 13 – Example of mounting of panel mounting type RCBO for the mechanical
impact test . 90
Figure 14 – Application of force for mechanical test of rail mounted RCBO . 91
Figure 15 – Ball-pressure test apparatus. 91
Figure 16 – Current ring wave 0,5 µs/100 kHz . 92
Figure 17 – Test circuit for the ring wave test on RCBOs . 92
Figure 18 – Surge current impulse 8/20 µs . 93
Figure 19 – Test circuit for the surge current test of RCBOs . 93
Figure 20 – Stabilizing period for reliability test . 94
Figure 21 – Reliability test cycle . 95
Figure 22 – Void . 95
Figure 23 – Example of records for short-circuit tests . 96
Figure 24 – Test circuit for the verification of the behaviour under temporary over
voltage (TOV) conditions for RCBOs with a terminal intended to be connected
to the PE . 97
Figure 25 – Void . 97
Figure 26 – Void . 97
Figure 27 – Diagrammatic representation for glow-wire test . 98
Figure B.1 – Measuring creepage distances and clearances: Example 1 . 101
Figure B.2 – Measuring creepage distances and clearances: Example 2 . 101
Figure B.3 – Measuring creepage distances and clearances: Example 3 . 101
Figure B.4 – Measuring creepage distances and clearances: Example 4 . 102
Figure B.5 – Measuring creepage distances and clearances: Example 5 . 102
Figure B.6 – Measuring creepage distances and clearances: Example 6 . 102
Figure B.7 – Measuring creepage distances and clearances: Example 7 . 103
Figure B.8 – Measuring creepage distances and clearances: Example 8 . 103
Figure B.9 – Measuring creepage distances and clearances: Example 9 . 103
Figure B.10 – Measuring creepage distances and clearances: Example 10 . 104
Figure B.11 – Measuring creepage distances and clearances: Example 11 . 104
Figure C.1 – Example of test arrangement . 106
Figure C.2 – Grid . 107
Figure C.3 – Grid circuit . 107
Figure F.1 – Overcurrent co-ordination between an RCBO and a fuse or back-up
protection by a fuse – Operating characteristics . 116
Figure F.2 – Total selectivity . 117
Figure F.3 – Back-up protection – Operating characteristics . 118
Figure H.1 – Examples of pillar terminals . 123

– 8 – IEC 61009-1:2024 © IEC 2024
Figure H.2 – Examples of screw terminals and stud terminals . 124
Figure H.3 – Examples of saddle terminals . 125
Figure H.4 – Examples of lug terminals . 125

Table 1 – Marking . 69
Table 2 – Void . 70
Table 3 – Void . 70
Table 4 – Void . 70
Table 5 – Void . 70
Table 6 – Void . 70
Table 7 – Void . 70
Table 8 – Void . 70
Table 9 – Void . 70
Table 10 – Void . 70
Table 11 – Standard limit values of break time and non-actuating time for alternating
residual currents (RMS values) for type AC and A . 70
Table 12 – Standard maximum values of break time for half-wave residual currents

(RMS values) for type A . 70
Table 13 – Void . 71
Table 14 – Tripping current limits . 71
Table 15 – Void . 71
Table 16 – Void . 71
Table 17 – Void . 71
Table 18 – Void . 71
Table 19 – Rated impulse withstand voltage as a function of the nominal voltage of the
installation . 71
Table 20 – Minimum clearances and creepage distances . 72
Table 21 – Test voltage of auxiliary circuits . 73
Table 22 – Test voltage for verification of rated impulse withstand voltage. 73
Table 23 – Test voltage for verifying the suitability for isolation, with reference to the rated
impulse withstand voltage of the RCBO and the altitude where the test is carried out . 74
Table 24 – Connectable cross-sections of copper conductors for screw-type terminals . 74
Table 25 – Test copper conductors corresponding to the rated currents . 74
Table 26 – Screw thread diameters and applied torques . 75
Table 27 – Pulling forces . 75
Table 28 – Temperature-rise values . 75
Table 29 – Power factor ranges of the test circuit . 76
Table 30 – Withstand values and duration of temporary overvoltages . 76
Table 31 – Void . 76
Table 32 – Void . 76
Table 33 – Void . 76
Table 34 – Void . 76
Table 35 – Void . 76
Table 36 – Void . 76

Table 37 – Standard values of rated short circuit capacity. 76
Table 38 – Ranges of overcurrent instantaneous tripping . 77
Table 39 – Time-current operating characteristics . 77
Table 40 – List of short-circuit tests . 77
Table 41 – Ratio between service short-circuit capacity (I ) and rated short-circuit
cs
capacity (I ) – (factor k) . 78
cn
Table 42 – Test procedure for I in the case of single- and two-pole RCBOs . 78
cs
Table 43 – Test procedure for I in the case of three- and four-pole RCBOs . 78
cs
Table 44 – Test procedure for I . 78
cn
Table 45 – Void . 78
Table 46 – Standard values of rated operational voltage . 79
Table 47 – Values of influencing quantities . 80
Table J.1 – Test sequences during follow-up inspections . 128
Table J.2 – Number of samples to be tested . 130

– 10 – IEC 61009-1:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RESIDUAL CURRENT OPERATED CIRCUIT-BREAKERS
WITH INTEGRAL OVERCURRENT PROTECTION
FOR HOUSEHOLD AND SIMILAR USES (RCBOs) –

Part 1: General rules
FOREWORD
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