IEC 61008-1:2024

IEC 61008-1 ®
Edition 4.0 2024-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Residual current operated circuit-breakers without integral overcurrent
protection for household and similar uses (RCCBs) –
Part 1: General rules
Interrupteurs automatiques à courant différentiel résiduel sans dispositif de
protection contre les surintensités incorporé pour usages domestiques et
analogues (ID) –
Partie 1: Règles générales
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IEC 61008-1 ®
Edition 4.0 2024-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Residual current operated circuit-breakers without integral overcurrent

protection for household and similar uses (RCCBs) –

Part 1: General rules
Interrupteurs automatiques à courant différentiel résiduel sans dispositif de

protection contre les surintensités incorporé pour usages domestiques et

analogues (ID) –
Partie 1: Règles générales
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.120.50  ISBN 978-2-8327-0007-5

– 2 – IEC 61008-1:2024 © IEC 2024
CONTENTS
FOREWORD . 9
INTRODUCTION . 11
1 Scope . 12
2 Normative references . 13
3 Terms and definitions . 14
4 Classification . 15
4.1 According to the supply conditions . 15
4.1.1 RCCB operating correctly on the occurrence of residual current . 15
4.1.2 RCCB 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 . 15
e
4.1.3 RCCB 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 . 15
4.1.4 RCCB with 3 current paths operating correctly on the occurrence of
residual current within the voltage range of 1,1 U and 0,7 U . 15
e e
4.1.5 RCCB operating correctly on the occurrence of residual current within
the voltage range 1,1 U and U . 16
e x
4.1.6 RCCB according to 4.1.5, however reclosing automatically after
restoration of the supply voltage . 16
4.2 According to the possibility of adjusting the residual operating current . 16
4.2.1 RCCB with a single value of rated residual operating current . 16
4.2.2 RCCB with multiple settings of residual operating current by fixed steps . 16
4.3 According to their operation in response to the type of residual current . 16
4.3.1 RCCB of type AC . 16
4.3.2 RCCB of type A . 16
4.4 According to time-delay (in the presence of a residual current) . 16
4.4.1 RCCB without time-delay: type for general use . 16
4.4.2 RCCB with time-delay: type S for selectivity . 16
4.5 According to the protection against external influences . 16
4.5.1 Enclosed-type RCCB (not requiring an appropriate enclosure) . 16
4.5.2 Unenclosed-type RCCB (for use with an appropriate enclosure) . 16
4.6 According to the method of mounting . 16
4.6.1 Surface-type RCCB . 16
4.6.2 Flush-type RCCB . 16
4.6.3 Panel board type RCCB, also referred to as distribution board type . 16
4.7 According to the method of connection . 16
4.7.1 RCCB for which the electrical connections are not associated with the
mechanical mounting . 16
4.7.2 RCCB for which the electrical connections are associated with the
mechanical mounting . 16
4.8 According to the type of terminals . 17
4.8.1 RCCB with screw-type terminals for copper conductors . 17
4.8.2 RCCB with screwless type terminals for copper conductors . 17
4.8.3 RCCB with flat quick-connect terminals for copper conductors . 17
4.8.4 RCCB with screw-type terminals for aluminium conductors . 17
4.9 According to the number of poles and current paths . 17
4.9.1 Single-pole RCCB with two current paths . 17
4.9.2 Two-pole RCCB . 17

4.9.3 Three-pole RCCB . 17
4.9.4 Three-pole RCCB with four current paths . 17
4.9.5 Four-pole RCCB . 17
5 Characteristics of RCCBs . 17
5.1 Summary of characteristics . 17
5.2 Rated quantities and other characteristics . 18
5.2.1 Rated voltages . 18
5.2.2 Rated current (I ) . 18
n
5.2.3 Rated frequency . 18
5.2.4 Rated making and breaking capacity (I ) . 18
m
5.2.5 Rated residual operating current (I ) . 18
Δn
5.2.6 Rated residual non-operating current (I ) . 18
Δno
5.2.7 Rated residual making and breaking capacity (I ) . 18
Δm
5.2.8 Rated conditional short-circuit current (I ) . 19
nc
5.2.9 Rated conditional residual short-circuit current (I ) . 19
Δc
5.2.10 Operating characteristics in response to the type of residual current . 19
5.2.11 RCCB type S . 19
5.3 Standard and preferred values . 19
5.3.1 Standard values of rated operational voltage (U ) . 19
e
5.3.2 Preferred values of rated current (I ) . 19
n
5.3.3 Standard values of rated residual operating current (I ) . 19
Δn
5.3.4 Standard value of residual non-operating current (I ) . 20
Δno
5.3.5 Preferred values of rated frequency . 20
5.3.6 Standard values of rated impulse withstand voltage (U ) . 20
imp
5.3.7 Standard limit values of break time and non-actuating time for RCCB of
type AC and A . 20
5.3.8 Standard minimum value of non-operating overcurrent in the case of a

load through an RCCB with two current paths . 20
5.3.9 Standard minimum value of the non-operating overcurrent in the case of
a single-phase load through a three-pole or four-pole RCCB . 20
5.3.10 Standard minimum value of the rated making and breaking capacity
(I ) . 20
m
5.3.11 Standard minimum value of the rated residual making and breaking

capacity (I ) . 20
Δm
5.3.12 Standard and preferred values of the rated conditional short-circuit
current (I ). 21
nc
5.3.13 Standard values of the rated conditional residual short-circuit current
(I ) . 21
Δc
6 Marking and other product information . 21
7 Standard conditions for operation in service and for installation . 22
7.1 Standard conditions . 22
7.2 Conditions of installation . 22
7.3 Pollution degree . 22
8 Requirements for construction and operation . 23
8.1 Mechanical design . 23
8.1.1 General . 23
8.1.2 Mechanism . 23

– 4 – IEC 61008-1:2024 © IEC 2024
8.1.3 Clearances, creepage distances and solid insulation . 25
8.1.4 Screws, current-carrying parts and connections . 26
8.1.5 Terminals for external conductors . 27
8.2 Protection against electric shock . 28
8.3 Dielectric properties and isolating capability . 29
8.4 Temperature-rise . 29
8.4.1 General . 29
8.4.2 Temperature-rise limits . 29
8.4.3 Ambient air temperature . 30
8.5 Operating characteristics . 30
8.5.1 General . 30
8.5.2 Operation in response to the type of residual current . 30
8.5.3 Operation in presence of a residual current equal to or greater than I . 30
Δn
8.6 Mechanical and electrical endurance . 30
8.7 Performance at short-circuit currents . 31
8.8 Resistance to mechanical shock and impact . 31
8.9 Resistance to heat . 31
8.10 Resistance to abnormal heat and to fire . 31
8.11 Test device . 31
8.12 Void . 32
8.13 Behaviour of RCCBs in the event of overcurrent in the main circuit . 32
8.14 Behaviour of RCCBs in the event of current surges caused by impulse
voltages . 32
8.15 Reliability . 32
8.16 Electromagnetic compatibility (EMC) . 32
8.17 Resistance to temporary overvoltages (TOV) . 33
9 Tests . 33
9.1 General . 33
9.2 Test conditions . 33
9.3 Test of indelibility of marking . 34
9.4 Test of reliability of screws, current-carrying parts and connections . 34
9.5 Test of reliability of screw-type terminals for external copper conductors . 35
9.6 Verification of protection against electric shock . 36
9.7 Test of dielectric properties . 37
9.7.1 Resistance to humidity . 37
9.7.2 Insulation resistance of the main circuit . 38
9.7.3 Dielectric strength of the main circuit . 38
9.7.4 Insulation resistance and dielectric strength of auxiliary circuits. 39
9.7.5 Secondary circuit of detection transformers . 40
9.7.6 Capability of control circuits connected to the main circuit to withstand
high DC voltages due to insulation measurements . 40
9.7.7 Verification of impulse withstand voltages . 40
9.8 Test of temperature-rise . 42
9.8.1 Ambient air temperature . 42
9.8.2 Test procedure . 42
9.8.3 Measurement of the temperature of parts . 42
9.8.4 Temperature-rise of a part . 42
9.9 Verification of the operating characteristics . 42
9.10 Verification of mechanical and electrical endurance . 43

9.10.1 General test conditions . 43
9.10.2 Test procedure . 43
9.10.3 Condition of the RCCB after test . 44
9.11 Verification of the behaviour of the RCCB under short-circuit conditions . 44
9.11.1 List of the short-circuit tests . 44
9.11.2 Short-circuit tests . 44
9.12 Verification of resistance to mechanical shock and impact . 51
9.12.1 Mechanical shock . 51
9.12.2 Mechanical impact . 51
9.13 Test of resistance to heat . 54
9.13.1 Test on complete RCCB . 54
9.13.2 Ball pressure test . 54
9.14 Test of resistance to abnormal heat and to fire . 55
9.15 Verification of the trip-free mechanism . 56
9.16 Verification of the operation of the test device at the limits of rated
operational voltage . 56
9.17 Void . 57
9.18 Verification of the behaviour of RCCBs in the event of overcurrent in the
main circuit . 57
9.19 Verification of the behaviour of RCCBs in the event of current surges caused
by impulse voltages . 57
9.19.1 Current surge test for all RCCBs (0,5 µs/100 kHz ring wave test) . 57
9.19.2 Verification of the behaviour at surge currents up to 3 000 A (8/20 µs

surge current test) . 58
9.20 Verification of reliability . 59
9.20.1 Climatic test. 59
9.20.2 Test with temperature of 40 °C . 60
9.21 Verification of withstand against ageing . 61
9.22 Electromagnetic compatibility (EMC) . 61
9.23 Test of resistance to rusting . 61
9.24 Verification of the behaviour of the RCCB under temporary overvoltage
(TOV) conditions . 62
9.24.1 General . 62
9.24.2 TOV test for all RCCBs . 62
9.24.3 Additional tests for RCCBs with a terminal intended to be connected to

the PE . 62
9.24.4 Verification after the tests . 62
Annex A (normative) Test sequence and number of samples to be submitted for
certification purposes . 93
Annex B (normative) Determination of clearances and creepage distances . 94
B.1 General . 94
B.2 Orientation and location of a creepage distance . 94
B.3 Creepage distances where more than one material is used . 94
B.4 Creepage distances split by floating conductive part . 94
B.5 Measurement of creepage distances and clearances . 94
Annex C (normative) Arrangement for the detection of the emission of ionized gases
during short-circuit tests . 99
Annex D (normative) Routine tests . 102
D.1 General . 102
D.2 Tripping test . 102

– 6 – IEC 61008-1:2024 © IEC 2024
D.3 Dielectric strength test . 102
D.4 Performance of the test device . 102
Annex E (informative) Methods for determination of short-circuit power-factor . 103
E.1 General . 103
E.2 Method I – Determination from DC components . 103
E.3 Method II – Determination with pilot generator . 104
Annex F (informative/normative) Void . 105
Annex G (informative/normative) Void . 106
Annex H (informative) Examples of terminal designs . 107
Annex I (informative) Correspondence between ISO and AWG copper conductors . 110
Annex J (informative) Follow-up testing program for RCCBs . 111
J.1 General . 111
J.2 Follow-up testing program . 111
J.2.1 General . 111
J.2.2 Quarterly follow-up testing program . 111
J.2.3 Annual follow-up testing program . 111
J.2.4 Sampling procedure . 112
Annex K (informative) SCPDs for short-circuit tests . 115
K.1 Introductory remark . 115
K.2 Silver wires . 115
K.3 Fuses. 116
K.4 Other means . 116
Bibliography . 117

Figure 1 – Standard test finger . 74
Figure 2 – Void . 75
Figure 3 – Void . 75
Figure 4 – Void . 75
Figure 5 – Typical diagram for all short circuit tests except for the verification of the
suitability in IT systems . 76
Figure 6 – Typical diagram for the verification of the suitability in IT systems . 77
Figure 7 – Detail of impedances Z, Z and Z . 77
1 2
Figure 8 – Mechanical shock test apparatus . 78
Figure 9 – Mechanical impact test apparatus . 79
Figure 10 – Striking element for pendulum impact test apparatus. 80
Figure 11 – Mounting support for sample for mechanical impact test. 81
Figure 12 – Example of mounting an unenclosed or flush-type RCCB for mechanical

impact test . 82
Figure 13 – Example of mounting of panel mounting type RCCB for the mechanical
impact test . 83
Figure 14 – Application of force for mechanical test of rail mounted RCCB . 84
Figure 15 – Ball-pressure test apparatus. 84
Figure 16 – Current ring wave 0,5 µs/100 kHz . 85
Figure 17 – Test circuit for the ring wave test on RCCBs . 85
Figure 18 – Surge current impulse 8/20 µs . 86
Figure 19 – Test circuit for the surge current test of RCCBs . 86

Figure 20 – Stabilizing period for reliability test . 87
Figure 21 – Reliability test cycle . 88
Figure 22 – Void . 88
Figure 23 – Example of records for short-circuit tests . 89
Figure 24 – Test circuit for the verification of the behaviour under temporary
overvoltage (TOV) conditions for RCCBs with a terminal intended to be connected to
the PE . 90
Figure 25 – Test apparatus for the verification of the minimum I t and I values to be
p
withstood by the RCCB . 91
Figure 26 – Void . 91
Figure 27 – Diagrammatic representation for glow-wire test . 92
Figure B.1 – Measuring creepage distances and clearances: Example 1 . 95
Figure B.2 – Measuring creepage distances and clearances: Example 2 . 95
Figure B.3 – Measuring creepage distances and clearances: Example 3 . 95
Figure B.4 – Measuring creepage distances and clearances: Example 4 . 96
Figure B.5 – Measuring creepage distances and clearances: Example 5 . 96
Figure B.6 – Measuring creepage distances and clearances: Example 6 . 96
Figure B.7 – Measuring creepage distances and clearances: Example 7 . 97
Figure B.8 – Measuring creepage distances and clearances: Example 8 . 97
Figure B.9 – Measuring creepage distances and clearances: Example 9 . 97
Figure B.10 – Measuring creepage distances and clearances: Example 10 . 98
Figure B.11 – Measuring creepage distances and clearances: Example 11 . 98
Figure C.1 – Example of test arrangement . 100
Figure C.2 – Grid . 101
Figure C.3 – Grid circuit . 101
Figure H.1 – Examples of pillar terminals . 107
Figure H.2 – Examples of screw terminals and stud terminals . 108
Figure H.3 – Examples of saddle terminals . 109
Figure H.4 – Examples of lug terminals . 109

Table 1 – Marking . 63
Table 2 – Void . 64
Table 3 – Void . 64
Table 4 – Void . 64
Table 5 – Void . 64
Table 6 – Void . 64
Table 7 – Void . 64
Table 8 – Void . 64
Table 9 – Void . 64
Table 10 – Void . 64
Table 11 – Standard limit values of break time and non-actuating time for alternating
residual currents (RMS values) for type AC and A . 64
Table 12 – Standard maximum values of break time for half-wave residual currents

(RMS values) for type A . 64

– 8 – IEC 61008-1:2024 © IEC 2024
Table 13 – Void . 65
Table 14 – Tripping current limits . 65
Table 15 – Void . 65
Table 16 – Void . 65
Table 17 – Void . 65
Table 18 – Void . 65
Table 19 – Rated impulse withstand voltage as a function of the nominal voltage of the
installation . 65
Table 20 – Minimum clearances and creepage distances . 66
Table 21 – Test voltage of auxiliary circuits . 68
Table 22 – Test voltage for verification of rated impulse withstand voltage. 68
Table 23 – Test voltage for verifying the suitability for isolation, with reference to the rated
impulse withstand voltage of the RCCB and the altitude where the test is carried out . 68
Table 24 – Connectable cross-sections of copper conductors for screw-type terminals . 69
Table 25 – Test copper conductors corresponding to the rated currents . 69
Table 26 – Screw thread diameters and applied torques . 69
Table 27 – Pulling forces . 70
Table 28 – Temperature-rise values . 70
Table 29 – Power factor ranges of the test circuit . 70
Table 30 – Withstand values and duration of temporary overvoltages . 70
Table 31 – Void . 71
Table 32 – Void . 71
Table 33 – Void . 71
Table 34 – Void . 71
Table 35 – Tests to be made to verify the behaviour of RCCBs under short-circuit
conditions . 71
Table 36 – Minimum values of I t and I . 71
p
Table 37 – Void . 72
Table 38 – Void . 72
Table 39 – Void . 72
Table 40 – Void . 72
Table 41 – Void . 72
Table 42 – Void . 72
Table 43 – Void . 72
Table 44 – Void . 72
Table 45 – Void . 72
Table 46 – Standard values of rated operational voltage . 72
Table 47 – Values of influencing quantities . 73
Table J.1 – Test sequences during follow-up inspections . 112
Table J.2 – Number of samples to be tested . 114
Table K.1 – Indication of silver wire diameters as a function of rated currents and
short-circuit currents . 115

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RESIDUAL CURRENT OPERATED CIRCUIT-BREAKERS
WITHOUT INTEGRAL OVERCURRENT PROTECTION
FOR HOUSEHOLD AND SIMILAR USES (RCCBS) –

Part 1: General rules
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
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