IEC 60947-2:2016/AMD1:2019

IEC 60947-2 ®
Edition 5.0 2019-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
A MENDMENT 1
AM ENDEMENT 1
Low-voltage switchgear and controlgear –
Part 2: Circuit-breakers
Appareillage à basse tension –
Partie 2: Disjoncteurs
IEC 60947-2: 2016-06/AMD1:2019-07(en-fr)

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IEC 60947-2 ®
Edition 5.0 2019-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
A MENDMENT 1
AM ENDEMENT 1
Low-voltage switchgear and controlgear –

Part 2: Circuit-breakers
Appareillage à basse tension –

Partie 2: Disjoncteurs
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.130.20 ISBN 978-2-8322-6997-8

– 2 – IEC 60947-2:2016/AMD1:2019
© IEC 2019
FOREWORD
This amendment has been prepared by subcommittee 121A: Low-voltage switchgear and
controlgear, of IEC technical committee 121: Switchgear and controlgear and their assemblies
for low voltage.
The text of this amendment is based on the following documents:
FDIS Report on voting
121A/286/FDIS 121A/302/RVD
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base publication will
remain unchanged until the stability date indicated on the IEC website under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
_____________
1.1 Scope and object
Replace the existing first paragraph by the following:
This part of IEC 60947 series applies to circuit-breakers, intended to be installed and
operated by instructed or skilled persons, the main contacts of which are intended to be
connected to circuits, the rated voltage of which does not exceed 1 000 V a.c. or 1 500 V d.c.;
it also contains additional requirements for integrally fused circuit-breakers.
th
Replace the 16 existing paragraph by the following:
For certain specific applications (for example traction, rolling mills, marine service,
downstream of variable frequency drives, use in explosive atmospheres), particular or
additional requirements may be necessary.
1.2 Normative references
Replace the existing references to IEC 61000-4-2, IEC 61140, and CISPR 11 by the following
new references:
IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
IEC 61140:2016, Protection against electric shock – Common aspects for installation and
equipment
© IEC 2019
CISPR 11:2015, Industrial, scientific and medical equipment – Radio-frequency disturbance
characteristics – Limits and methods of measurement
CISPR 11:2015/AMD1:2016
Delete the existing references to IEC 60364 (all parts), IEC 61000-3-2, IEC 61000-3-3 and
CISPR 22.
Add the following new normative references to the existing list:
IEC 60228, Conductors of insulated cables
IEC 61545, Connecting devices – Devices for the connection of aluminium conductors in
clamping units of any material and copper conductors in aluminium bodied clamping units
CISPR 32:2015, Electromagnetic compatibility of multimedia equipment – Emission
requirements
Add, after the existing definition 2.22, the following new definition:
2.23
closing release
closing coil
release, energized by a source of voltage, which triggers the closing of the circuit-breaker
Note 1 to entry: A closing release is an auxiliary device of the circuit-breaker, and is different from the "closing
device" mentioned in the figures of Annex A, and in IEC 60947-1, which is part of the test setup and is intended to
establish the short-circuit current.
4.7.1 Types
Renumber existing item "4) other releases." to item "5) other releases.".
Add new item "4) closing release;".
4.7.2 Characteristics
Change existing item 1) to read "1) shunt release and undervoltage release (for opening), and
closing release:", keeping dashed items unchanged.
5.2 Marking
Replace the existing text, including all lettered items, by the following new text and Table 13:
Each circuit-breaker shall be marked in a durable manner; data to be provided and
corresponding locations are indicated in Table 13.

– 4 – IEC 60947-2:2016/AMD1:2019
© IEC 2019
Table 13 – Product information
Item Information Marking
location
1.1 rated current (I ) Visible
n
1.2 Visible
suitability for isolation, if applicable, with the symbol (IEC 60617-S00288:2001-07
combined with IEC 60617-S00219:2001-07)
1.3 indication of the open and closed position with O (IEC 60417-5008;2002-10) and I Visible
(IEC 60417-5007;2002-10) respectively, if symbols are used (see 7.1.6.1 of IEC 60947-
1:2007)
2.1 manufacturer’s name or trade mark Marked
2.2 type designation or catalogue reference Marked
2.3 IEC 60947-2, if the manufacturer claims compliance with the standard Marked
2.4 selectivity category A or B Marked
2.5 rated operational voltage(s) U (see 4.3.2.1 and, where applicable, Annex H) Marked
e
2.6 Marked
unsuitability for IT systems, if applicable, with the symbol (IEC 60417-6363:2016-07)
2.7 rated impulse withstand voltage (U ) Marked
imp
2.8 value (or range) of the rated frequency, and/or the indication "d.c." (or the symbol Marked
(IEC 60417-5031:2002-10))
2.9 rated service short-circuit breaking capacity (I ) at the corresponding rated voltage (U ) Marked
cs e
2.10 rated ultimate short-circuit breaking capacity (I ) at the corresponding rated voltage (U ) Marked
cu e
2.11 rated short-time withstand current (I ), and associated short-time delay, for selectivity Marked
cw
category B
a
2.12 range of the current setting (I ) of the adjustable overload release
Marked
r
a
2.13 range of the rated instantaneous short-circuit current setting (I ), for adjustable releases
Marked
i
2.14 reference temperature for non-compensated thermal releases, if different from 30 °C Marked
2.15 terminals identification, according to 7.1.8.4 of IEC 60947-1:2007 Marked
2.16 line and load terminals, if applicable Marked
2.17 neutral pole terminals, if applicable, by the letter N Marked
2.18 protective earth terminal, where applicable, by the symbol Marked
(IEC 60417-5019:2006-08)
(see 7.1.10.3 of IEC 60947-1:2007)
3.1 rated short-circuit making capacity (I ), if higher than that specified in 4.3.6.1 Literature
cm
3.2 rated insulation voltage (U ), if higher than the maximum rated operational voltage Literature
i
3.3 pollution degree if other than 3 Literature
3.4 conventional enclosed thermal current (I ) if different from the rated current Literature
the
3.5 IP code, where applicable (see Annex C of IEC 60947-1:2007/AMD1:2010) Literature
3.6 minimum enclosure size and ventilation data (if any) to which marked ratings apply Literature
3.7 details of minimum distance between circuit-breaker and earthed metal parts for circuit- Literature
breakers intended for use without enclosures
3.8 suitability for environment A or environment B per Annex J, as applicable Literature
3.9 RMS sensing, if applicable, in accordance with F.4.1.1 Literature
3.10 minimum cable cross-section, if different from Table 9 of IEC 60947-1:2007, for ratings Literature
≤ 20 A according to rated ultimate short-circuit breaking capacity I
cu
3.11 values of tightening torque for the circuit-breaker terminals Literature

© IEC 2019
Item Information Marking
location
3.12 current derating for terminals and connections, if applicable Literature
4.1 for closing releases (see 2.23) and/or motor-operators, rated control circuit voltage, kind of Aux
current and rated frequency for a.c.
4.2 rated control circuit voltage of the shunt release and/or of the under-voltage release (or of Aux
the no-voltage release), kind of current and rated frequency for a.c.
4.3 rated current of indirect over-current releases Aux
4.4 number and type of auxiliary contacts, rated operational currents at the rated operational Aux
voltages, and rated frequency for a.c.
Key
Visible: visible from the front when the circuit-breaker is installed as in service and the actuator is
accessible
Marked: marked on the circuit-breaker
Literature: provided in the manufacturer's literature
Aux: marked on the auxiliaries or on the circuit-breaker, if marking space is sufficient; additionally, data
shall be made available in the manufacturer's literature
a
Where applicable, I and I ranges may be displayed instead of being marked on the circuit-breaker.
r i
5.3 Instructions for installation, operation and maintenance
Replace the existing text by the following new text:
Subclause 5.3 of IEC 60947-1:2007/AMD2:2014 applies with the following addition:
Additional information for the decommissioning and dismantling of the circuit-breaker shall be
provided to the user in the case of a foreseeable hazardous condition, for example due to
stored energy or hazardous substances.
7.1.1 General
Replace the existing text by the following new text:
Subclause 7.1 of IEC 60947-1:2007/AMD1:2010/AMD2:2014 applies with the following
modifications:
The requirements of 7.1.2 of IEC 60947-1:2007/AMD1:2010/AMD2:2014 do not apply to parts
with a mass lower than 2 g (insignificant mass, in accordance with 3.14 of
IEC 60695-2-11:2014). For products containing a plurality of small parts, the total mass of
non-tested parts located in close proximity to each other shall not exceed 10 g. Proximity shall
be based on engineering judgment that takes into consideration the risk of propagation of fire.
Where, in 7.1.2.2 of IEC 60947-1:2007/AMD1:2010/AMD2:2014, the test temperature is to be
specified, the value required by this document for the parts necessary to retain in position
current-carrying parts is:
– 960 °C for the main circuit;
– 850 °C for the other circuits.
7.2.2.3 Main circuit
Replace the existing text by the following new text:

– 6 – IEC 60947-2:2016/AMD1:2019
© IEC 2019
The main circuit of a circuit-breaker, including the over-current releases that may be
associated with it, shall be capable of carrying its rated current I , under the conditions of
n
Clause 8, without the temperature rises exceeding the limits specified in Table 7.
8.3 Type tests
Replace the last existing paragraph by the following new paragraph:
In order to facilitate locating a particular test condition or test, an alphabetical index is given
below, using the terms most likely to be used (not necessarily the exact terms appearing in
the relevant subclause heading).
8.3.1.3 Applicability of sequences according to the relationship between short-circuit
ratings
Replace, in the alphabetical index of tests, in line "Overload releases (verification)", reference
"8.3.4.5" by "8.3.4.6".
a
Table 9 – Overall schema of test sequences
nd
Replace, in test sequence IV row, the existing text of 2 column by the following new text:
b
Circuit-breakers of selectivity category B and circuit-breakers of selectivity category A with
an assigned short-time withstand current (see 4.4)
Table 9b – Applicability of tests or test sequences to 1, 2 and 4-pole circuit-breakers
according to the alternative programme 1 of 8.3.1.4
c
Replace the existing text of the table footnote " " by the following new text:
C
Test at maximum kVA rating (I × corresponding U ).
cu e
Table 9c – Applicability of tests or test sequences to 1, 2 and 3-pole circuit-breakers
according to the alternative programme 2 of 8.3.1.4
c
Replace the existing text of the table footnote " " by the following new text:
C
Test at maximum kVA rating (I × corresponding U ).
cu e
8.3.2.1 General requirements
Replace the existing second paragraph after the note by the following new paragraph:
For the tests in free air concerning overload performance, short-circuit, and short-time
withstand current where applicable, a metallic screen shall be placed on all sides of the
circuit-breaker in accordance with the manufacturer’s instructions. Details, including distances
of the metallic screen from the circuit-breaker, shall be stated in the test report.
Replace the existing fifth paragraph before Table 10 by the following:
The tightening torques to be applied to the terminal screws shall be in accordance with the
manufacturer's instructions (see Table 13, item 3.11).
Table 10 – Number of samples for test
“e”
Replace, in the existing table footnote , “test” by “testing.

© IEC 2019
8.3.2.5 Test conditions for temperature-rise tests
Replace the existing fifth paragraph by the following:
For four-pole circuit-breakers, a test shall first be carried out on the 3-phase poles; for the
neutral pole, the additional single-phase test of 8.3.3.3.4 of IEC 60947-1:2007 applies only
when there is a construction break between the neutral pole and the phase poles (see 7.1.6),
in which case the test current is the rated current of the neutral pole.
8.3.2.6.4.2 Tests on one-, two- and three-pole circuit-breakers
Replace the existing title of this subclause by the following new title:
8.3.2.6.4.2 Common tests on one-, two-, three- and four-pole circuit-breakers
8.3.2.6.4.3 Tests on four-pole circuit-breakers
Replace the existing title of this subclause by the following new title:
8.3.2.6.4.3 Additional tests on four-pole circuit-breakers
Delete the existing first paragraph.
Replace the existing second and third paragraphs by the following new paragraphs:
Additional sequences of operations on one or more new samples, in accordance with
Table 10, shall be carried out on the fourth pole and its adjacent pole, according to test
sequences III or V, as applicable, and test sequence IV if applicable. This requirement applies
even when test sequence III is replaced by test sequence II (I = I ) or test sequence IV is
cu cs
replaced by test sequence VI (I = I ), i.e., additional tests according to test sequence III or
cw cs
V, and test sequence IV, as applicable, are required.
Alternatively, at the request of the manufacturer, these tests may be combined with the tests
of 8.3.2.6.4.2 and made on the same samples, in which case the test in each relevant test
sequence shall comprise
– the test on three adjacent poles,
– the test on the fourth pole and the adjacent pole.
8.3.3.2.2 Short-circuit releases
Replace, in the existing fifth paragraph, third sentence, "indivudal" by "individual".
8.3.3.2.3 Overload releases
a) Instantaneous or definite time-delay releases
Replace, in the existing last paragraph, "(see 8.3.3.2.3)" by "(see 8.3.3.2.1)".
b) Inverse time-delay releases
Replace, in the existing second paragraph, "(see 8.3.3.2.4)" by "(see 8.3.3.2.1)".
Replace, in the existing third paragraph, "see 4.7.3 and 5.2 item b)" by "see 4.7.3 and
Table 13 item 2.14".
8.3.3.4.2.2 Mechanical operation
Replace, in the existing first dashed item, "closing device" with "closing release".

– 8 – IEC 60947-2:2016/AMD1:2019
© IEC 2019
8.3.3.4.3 Operational performance capability without current
th
Replace, in the existing second sentence of the 7 paragraph, "closing devices" with "closing
releases".
8.3.3.4.4 Operational performance capability with current
th
Replace, in the existing second sentence of the 6 paragraph, "closing devices" with "closing
releases".
8.3.3.6.2 Test voltage
Replace the existing first paragraph with the following:
Subclause 8.3.3.4.1, item 4) b), of IEC 60947-1:2007/AMD1:2010 applies.
Delete the existing second paragraph.
8.3.6.5 Test of short-circuit breaking capacity at the maximum short-time withstand
current
Add at the end of the existing last paragraph, the following new sentence:
"; this exception also applies to the test on the fourth pole and the adjacent pole, in
accordance with 8.3.2.6.4.3."
Annex A – Co-ordination between a circuit-breaker and another short-circuit
protective device associated in the same circuit
A.1 General
Add, in last but two existing paragraph, a closing bracket “)” after “2.17.3”.
Figure A.4 – Example of test circuit for conditional short-circuit breaking capacity tests
showing cable connections for a 3-pole circuit-breaker (C )
Replace the existing figure by the following new figure:

© IEC 2019
Replace, the existing first paragraph by the following new text:
Adjustable loads L and R may be located either on the high voltage side or on the low
voltage side of the supply circuit.
Figure A.5 – Example of test circuit for the verification of selectivity
Replace, the existing first paragraph by the following new text:
Adjustable loads L and R may be located either on the high voltage side or on the low
voltage side of the supply circuit.
Annex B – Circuit-breakers incorporating residual current protection
Replace the existing annex by the following new annex:

– 10 – IEC 60947-2:2016/AMD1:2019
© IEC 2019
Annex B
(normative)
Circuit-breakers incorporating residual current protection
B.1 General
B.1.1 Preamble
To provide protection against the effects of electric shock hazards, devices reacting to
residual differential currents are used as protective systems. Such devices are frequently
used in conjunction with or as an integral part of a circuit-breaker to achieve a two-fold goal,
i.e.:
– providing protection of installations against overloads and short-circuit currents;
– providing protection of persons against indirect contact, i.e. hazardous increases of
ground potential due to defective insulation.
NOTE 1 In IEC 61140:2016, the term “protection of persons against indirect contact” is replaced by “fault
protection”.
Residual current devices may also provide additional protection against fire and other
hazards, which may develop as a result of an earth fault of a lasting nature that cannot be
detected by the over-current protective device.
Residual current devices having a rated residual current not exceeding 30 mA are also used
as a means for additional protection against direct contact in the event of failure of the
relevant protective means.
NOTE 2 In IEC 61140:2016, the term “protection of persons against direct contact” is replaced by “basic
protection”.
The requirements for the installation of such devices are specified in various sections of
IEC 60364 series.
This annex includes definitions, additional requirements and tests for circuit-breakers
incorporating residual current protection of type B to cover the use of new electronic
technology in equipment which can result in particular residual currents not covered by the
characteristics of type AC or type A.
NOTE 3 This annex complies with the relevant requirements of IEC 60755.
B.1.2 Scope and object
This annex applies to circuit-breakers providing residual current protection (CBRs). It covers
the requirements for units that concurrently perform residual current detection, compare such
measurements with a preset value and cause the protected circuit to be switched off when
this value is exceeded.
This annex applies to:
• circuit-breakers in accordance with this document, which incorporate the residual current
function as an integrated feature (hereinafter called integral CBRs);
• CBRs consisting of a combination of a residual current device (hereinafter referred to as
r.c. units) and a circuit-breaker in accordance with this document; their combination both
mechanically and electrically, may be carried out either at the factory or in the field by the
user in accordance with the manufacturer's instructions.
This annex covers CBRs of type AC, type A and type B (see B.4.4).

© IEC 2019
This annex applies only to CBRs intended for use in a.c. circuits.
NOTE The neutral current sensing means, if any, can be external to the circuit-breaker or the combination,
depending on the case.
The residual current function of CBRs covered by this annex may or may not be functionally
dependent on line voltage. CBRs depending on an alternative supply source are not covered
by this annex.
This annex does not apply to equipment where the current sensing means (except the neutral
current sensing means) or the processing device are mounted separately from the circuit-
breaker. The requirements for such devices are given in Annex M.
The object of this annex is to state:
a) the specific features of the residual current function;
b) the specific requirements that shall be complied with by the CBR
– under normal circuit conditions;
– under abnormal circuit conditions, whether of a residual current nature or not;
c) the tests that shall be performed to verify compliance with the requirements in b) above,
together with the appropriate test procedures, including tests for electromagnetic
compatibility;
d) the relevant product information.
B.2 Terms and definitions
As a complement to Clause 2 of this document, the following terms and definitions apply:
B.2.1 Terms and definitions relating to currents flowing from live parts to earth
B.2.1.1
earth fault current
current flowing to earth due to an insulation fault
[SOURCE: IEC 60050-442:1998, 442-01-23]
B.2.1.2
earth leakage current
current flowing from the live parts of the installation to earth in the absence of an insulation
fault
[SOURCE: IEC 60050-442:1998, 442-01-24]
B.2.2 Terms and definitions relating to the energization of a CBR
B.2.2.1
energizing quantity
electrical energizing quantity that, alone or in combination with other such quantities, shall be
applied to a CBR to enable it to accomplish its function under specified conditions
B.2.2.2
energizing input-quantity
energizing quantity by which the CBR is activated when it is applied under specified
conditions
Note 1 to entry: These conditions can involve, e.g., the energizing of certain auxiliary elements.

– 12 – IEC 60947-2:2016/AMD1:2019
© IEC 2019
[SOURCE: IEC 60050-442:1998, 442-05-58, modified – In the definition, "residual current
device" has been replaced with "CBR".]
B.2.2.3
residual current
I
∆
vectorial sum of the currents flowing in the main circuit of the CBR, expressed as an r.m.s.
value
[SOURCE: IEC 60050-442:1998, 442-05-19, modified – The definition has been adapted to
apply to CBRs.]
B.2.2.4
residual operating current
I
∆n
value of the residual current which causes the CBR to operate under specified conditions
[SOURCE: IEC 60050-442:1998, 442-05-20, modified – In the definition, "residual current
device" has been replaced with "CBR".]
B.2.2.5
residual non-operating current
I
∆no
value of the residual current at which (and below which) the CBR does not operate under
specified conditions
[SOURCE: IEC 60050-442:1998, 442-05-21, modified – Symbol introduced and, in the
definition, "residual current device" has been replaced with "CBR".]
B.2.3 Terms and definitions relating to the operation and the functions of a CBR
B.2.3.1
circuit-breaker incorporating residual current protection
CBR
circuit-breaker (see 2.1) designed to cause the opening of the contacts when the residual
current attains a given value under specified conditions
B.2.3.2
CBR functionally independent of line voltage
CBR for which the functions of detection and evaluation, and the actuating means of
interruption (see B.2.3.6) do not depend on the line voltage
B.2.3.3
CBR functionally dependent on line voltage
CBR for which the functions of detection and/or evaluation, and/or the actuating means of
interruption (see B.2.3.6) depend on the line voltage
Note 1 to entry: It is understood that the line voltage for detection, evaluation or interruption is applied to the
CBR.
B.2.3.4
detection (of a residual current)
function consisting in sensing the presence of a residual current
Note 1 to entry: This function can be performed, for example, by a transformer integrating the vector sum of the
currents.
[SOURCE: IEC 60050-442:1998, 442-05-24]

© IEC 2019
B.2.3.5
evaluation
function consisting in giving to the CBR the possibility to operate when the detected residual
current exceeds a specified reference value
[SOURCE: IEC 60050-442:1998, 442-05-25, modified – In the term, "(for a residual current)"
has been deleted and in the definition, "residual current device" has been replaced with
"CBR".]
B.2.3.6
interruption
function consisting in bringing automatically the main contacts of the CBR from the closed
position into the open position, thereby interrupting the current(s) flowing through them
[SOURCE: IEC 60050-442:1998, 442-05-26, modified – In the term, "(for a residual current
device)" has been deleted and in the definition, "residual current device" has been replaced
with "CBR".]
B.2.3.7
limiting non-actuating time
maximum delay during which a value of residual current higher than the rated residual non-
operating current can be applied to the CBR without bringing it actually to operate
[SOURCE: IEC 60050-442:1998, 442-05-23, modified – In the definition, "residual current
device" has been replaced with "CBR" and "rated" has been added.]
B.2.3.8
time-delay CBR
CBR specially designed to attain a predetermined value of limiting non-actuating time,
corresponding to a given value of residual current
[SOURCE: IEC 60050-442:1998, 442-05-05, modified – In the definition and the term,
"residual current device" has been replaced with "CBR".]
B.2.3.9
reset-CBR
CBR with an r.c. unit that shall be intentionally reset by a means different from the operating
means of the CBR, following the occurrence of a residual current, before it can be reclosed
B.2.3.10
test device
device simulating a residual current for checking that the CBR operates
B.2.4 Terms and definitions relating to values and ranges of energizing quantities
B.2.4.1
limiting value of the non-operating over-current in the case of a single-phase load
maximum value of a single-phase over-current which, in the absence of a residual current,
can flow through a CBR (whatever the number of poles) without causing it to operate
Note 1 to entry: See B.7.2.7.
B.2.4.2
residual short-circuit making and breaking capacity
value of the a.c. component of a residual prospective short-circuit current which a CBR can
make, carry for its opening time and break under specified conditions of use and behaviour

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© IEC 2019
B.3 Classification
B.3.1 Classification according to the method of operation of the residual current
function
B.3.1.1 CBR functionally independent of line voltage (see B.2.3.2)
B.3.1.2 CBR functionally dependent on line voltage (see B.2.3.3 and B.7.2.12)
B.3.1.2.1 Opening automatically in the case of failure of the line voltage with or
without delay
B.3.1.2.2 Not opening automatically in the case of failure of line voltage
Not opening automatically in the case of failure of the line voltage, but able to trip under
specified conditions in the case of an earth fault arising on failure of the line voltage.
NOTE Classification under this subclause includes CBRs unable to open automatically when no hazardous
situation exists.
B.3.2 Classification according to the possibility of adjusting the residual operating
current
B.3.2.1 CBR with single rated residual operating current
B.3.2.2 CBR with multiple settings of residual operating current
– by fixed steps;
– by continuous variation.
B.3.3 Classification according to time delay of the residual current function
B.3.3.1 CBR without time-delay: non-time-delayed type
B.3.3.2 CBR with time-delay: time-delayed type (see B.2.3.8)
B.3.3.2.1 CBR with non-adjustable time delay
B.3.3.2.2 CBR with adjustable time delay
– by fixed steps;
– by continuous variation.
B.3.4 Classification according to behaviour in presence of a d.c. component
B.3.4.1 CBRs of type AC (see B.4.4.1)
B.3.4.2 CBRs of type A (see B.4.4.2)
B.3.4.3 CBRs of type B (see B.4.4.3)
B.4 Characteristics of CBRs concerning their residual current function
B.4.1 Rated values
B.4.1.1 Rated residual operating current (I )
∆n
The r.m.s. value of a sinusoidal residual operating current (see B.2.2.4) assigned to the CBR
by the manufacturer, at which the CBR shall operate under specified conditions.

© IEC 2019
For a CBR with multiple settings of residual operating current, the highest setting is used to
designate its rating. See, however, Clause B.5 concerning marking.
B.4.1.2 Rated residual non-operating current (I )
∆no
The r.m.s. value of sinusoidal residual non-operating current (see B.2.2.5) assigned to the
CBR by the manufacturer at which the CBR does not operate under specified conditions.
B.4.1.3 Rated residual short-circuit making and breaking capacity (I )
∆m
The r.m.s. value of the a.c. component of the prospective residual short-circuit current (see
B.2.4.2) assigned to the CBR by the manufacturer, which the CBR can make, carry and break
under specified conditions.
B.4.2 Preferred and limiting values
B.4.2.1 Preferred values of rated residual operating current (I )
∆n
Preferred values of rated residual operating current are
0,006 A – 0,01 A – 0,03 A – 0,1 A – 0,3 A – 0,5 A – 1 A – 3 A – 10 A – 30 A
Higher values may be required.
I may be expressed as a percentage of the rated current.
∆n
B.4.2.2 Minimum value of rated residual non-operating current (I )
∆no
The minimum value of rated residual non-operating current is 0,5 I .
∆n
B.4.2.3 Limiting value of non-operating over-current in the case of a single-phase
load
The limiting value of non-operating over-current in the case of a single-phase load shall be in
accordance with B.7.2.7.
B.4.2.4 Operating characteristics
B.4.2.4.1 Non-time-delay type
The operating characteristic for a non-time-delay type is given in Table B.1.
Table B.1 – Operating characteristic in the case of sinusoidal
residual current for non-time-delay type
c a b
I 2 I
Residual current 5 I 10 I
∆n ∆n
∆n ∆n
Maximum break times s 0,3 0,15 0,04 0,04
NOTE These values are derived from IEC 60479-1 and are valid for both 50 Hz and 60 Hz.
a
For CBRs having I ≤ 30 mA, 0,25 A may be used as an alternative to 5 I .
∆n ∆n
b
For CBRs having I ≤ 30 mA, 0,5 A may be used as an alternative to 10 I .
∆n ∆n
c
For CBRs of types A and B, multiplying factors may apply – see B.8.7 and B.8.8.

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© IEC 2019
≤ 30 mA shall be of the non-time-delay type.
CBRs having I
∆n
B.4.2.4.2 Time-delay type
B.4.2.4.2.1 Limiting non-actuating time (see B.2.3.7)
For a time-delay type, the limiting non-actuating time is defined at 2 I and shall be declared
∆n
by the manufacturer.
The minimum limiting non-actuating time is 0,06 s.
The preferred values of limiting non-actuating time are
0,06 s – 0,1 s – 0,2 s – 0,3 s – 0,4 s – 0,5 s – 1 s
B.4.2.4.2.2 Operating characteristics
For CBRs having a limiting non-actuating time of 0,06 s, the operating characteristics is given
in Table B.2.
Table B.2 – Operating characteristics in the case of sinusoidal residual currents,
for time-delay type having a limiting non-actuating time of 0,06 s
a
I 2 I 5 I 10 I
Residual current
∆n ∆n ∆n ∆n
Maximum break time
0,5 0,2 0,15 0,15
s
Limiting non actuating time
- 0,06 - -
s
NOTE These values are derived from IEC 60479-1 and are valid for both 50 Hz and 60 Hz.
a
For CBRs of types A and B, multiplying factors may apply – see B.8.7 and B.8.8

For CBRs having a limiting non-actuati ng time higher than 0,06 s, the manufacturer shall
declare the maximum break time at I , 2 I , 5 I , and 10 I .
∆n ∆n ∆n ∆n
In the case of a CBR having an inverse current/time characteristic, the manufacturer shall
state the residual current/break time characteristic.
B.4.3 Value of the rated residual short-circuit making and breaking capacity (I )
∆m
The minimum value of I is 25 % of I .
∆m cu
Higher values may be tested and declared by the manufacturer.
B.4.4 Operating characteristics in the case of an earth fault current in the presence
or absence of a d.c. component
B.4.4.1 CBR of type AC
A CBR for which tripping is ensured for residual sinusoidal alternating currents, in the
absence of a d.c. component whether suddenly applied or slowly rising.

© IEC 2019
B.4.4.2 CBR of type A
A CBR for which tripping is ensured for residual sinusoidal alternating currents in the
presence of specified residual pulsating direct currents with or without a specified level of
superimposed d.c. (± 6 mA), whether suddenly applied or slowly rising.
B.4.4.3 CBR of type B
A CBR for which tripping is ensured as for type A, and in addition:
– for residual sinusoidal alternating currents up to 1 000 Hz,
– for composite residual currents, whether suddenly applied or slowly rising intended for
circuits supplied between phase and neutral or phase and earthed middle conductor,
– for residual alternating currents superimposed by a smooth direct current of 0,4 times the
rated residual current (I ) or 10 mA whichever is the highest value,
Δn
– for residual pulsating direct currents superimposed by a smooth direct current of 0,4 times
the rated residual current (I ) or 10 mA, whichever is the highest value,
Δn
– for residual direct currents which can result from rectifying circuits, i.e.:
• two-pulse bridge connection line to line for 2-, 3- and 4-pole CBRs,
• three-pulse star connection or six-pulse bridge connection for 3- and 4-pole CBRs,
– for residual smooth direct currents.
B.5 Marking
Each CBR shall be marked as specified in 5.2 and, in addition, in accordance with Table B.3

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© IEC 2019
Table B.3 – Product information
Item Information Marking location
Integral r. c. unit
CBR
B1.1 the operating means of the test device by the letter T (see also B.7.2.6) Visible Visible
operating characteristic in the case of residual currents in the presence or
absence of a d.c. component:
– for CBRs of type AC with the symbol (IEC 60417-6148:2012-01)
– for CBRs of type A with the symbol  (IEC 60417-6149:2012-01)

B1.2 Visible Visible
– for CBRs of type B with the symbol   (IEC 60417-6398:2017-12)

or (IEC 60417-6149:2012-01 + IEC 60417-
6160:2012-04 + IEC 60417-6297:2014-11)
rated residual operating current I
B1.3 Visible Visible
Δn
B2.1 settings of residual operating current, when applicable Marked Marked
limiting non-actuating time at 2 I , for time-delay type, by the symbol Δt
Δn
B2.2 Marked Marked
followed by the limiting non-actuating time
B2.3 Marked Marked
suitability for use with a 3-phase supply only, with the symbol
(IEC 60417-6364:2016-07)
B2.4 rated voltage(s) if different from the rated voltage(s) of the circuit-breaker - Marked
value (or range) of the rated frequency if different from that of the circuit-
B2.5 - Marked
breaker
the indication I ≤ .A (I being the maximum current rating of the circuit-
n n
B2.6
- Marked
breaker with which the r.c. unit may be combined)
B2.7 manufacturer's name or trade mark - Marked
B2.8 type designation or catalog reference - Marked
identification of the circuit-breaker(s) with which the r.c. unit may be
B2.9 assembled, unless incorrect assembly (such as to render the protection - Marked
ineffective) is made impossible by the design;
B2.10 IEC 60947-2 - Marked
rated residual short-circuit making and breaking capacity I if higher than
Δm
B3.1 Literature Literature
25 % of I (see B.4.3)
cu
diagram of connections, including those of the test circuit and, if
B3.2 Literature Literature
applicable, those to the line, for CBRs dependent on the line voltage
value of rated residual non-operating current I if greater than 0,5 I
B3.3 Literature Literature
Δno Δn
Key
Visible: visible from the front when the circuit-breaker is installed as in service and the actuator is
accessible
Marked: marked on the product
Literature: provided in the manufacturer’s literature

© IEC 2019
B.6 Normal service, mounting and transport conditions
Clause 6 applies.
B.7 Design and operating requirements
B.7.1 Design requirements
It shall not be possible to modify the operating characteristic of a CBR except by means which
are specifically provided for setting the rated residual operating current or the definite time
delay.
Changing from one setting to another shall only be possible through a deliberate action, such
as the use of a tool, a password or equivalent means.
CBRs combining an r.c. unit device and a circuit-breaker shall be so designed and built that:
– the coupling system of the r.c. unit and the associated circuit-breaker does not require any
mechanical and/or electrical connection that may adversely affect the installation or result
in injury to the user;
– the addition of the r.c. unit does not adversely affect in any way either the normal
operation or the performance capabilities of the circuit-breaker;
– the r.c. unit does not sustain any permanent damage due to the short-circuit currents
during test sequences.
B.7.2 Operating requirements
B.7.2.1 Operation in the case of a residual current
CBRs shall open automatically in response to any earth leakage current or earth fault current
equal to or exceeding the rated residual operating current for a time exceeding the non-
actuating time.
The operation of CBRs shall be in compliance with the time requirements specified in B.4.2.4.
Compliance shall be checked by the tests of B.8.1.2.
B.7.2.2 Rated residual short-circuit making and breaking capacity (I )
∆m
CBRs shall meet the test requirements of B.8.11.
B.7.2.3 Operational performance capability
CBRs shall comply with the tests of B.8.1.2.1.
B.7.2.4 Effects of environmental conditions
CBRs shall operate satisfactorily, taking into account the effects of environmental conditions.
Compliance is checked by the test of B.8.12.
B.7.2.5 Dielectric properties
CBRs shall withstand the tests of B.8.3.

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B.7.2.6 Test device
CBRs shall be provided with a test device causing the passing through the detecting device of
a current simulating a residual current, in order to allow periodic testing of the ability of the
CBRs to operate.
The test device shall satisfy the tests of B.8.4.
The protective con
...