IEC 61557-6:2019

IEC 61557-6 ®
Edition 3.0 2019-07
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Electrical safety in low voltage distribution systems up to 1 000 V a.c. and
1 500 V d.c. – Equipment for testing, measuring or monitoring of protective
measures –
Part 6: Effectiveness of residual current devices (RCD) in TT, TN and IT systems

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IEC 61557-6 ®
Edition 3.0 2019-07
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Electrical safety in low voltage distribution systems up to 1 000 V a.c. and

1 500 V d.c. – Equipment for testing, measuring or monitoring of protective

measures –
Part 6: Effectiveness of residual current devices (RCD) in TT, TN and IT systems

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.220.20; 29.080.01; 29.240.01 ISBN 978-2-8322-7236-7

– 2 – IEC 61557-6:2019 RLV © IEC 2019
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Requirements . 7
4.1 General . 7
4.2 Tests Functions . 7
4.2.1 Tripping tests Measurement of trip current . 7
4.2.2 Non-tripping tests functions . 8
4.2.3 Fault voltage indication . 8
4.2.4 Measurement of trip time . 10
4.3 Measurement with indicators . 10
4.4 Test with rated residual operating current . 10
4.5 Fault voltages exceeding U . 10
L
4.6 Overvoltage . 10
5 Marking and operating instructions . 11
5.1 Marking . 11
5.2 Explicit indication of the waveform of the testing current . 11
5.3 Operating instructions . 11
6 Tests . 12
6.1 General . 12
6.2 Operating uncertainty . 12
6.3 Fault voltage . 13
6.4 Testing the connection to voltages higher than nominal voltage . 13
6.5 Overvoltage . 14
Annex A (normative) Measuring equipment for residual current protective devices
(RCDs) of type B .
Annex A (informative) Applicable tripping tests (time and current) for different types of
RCDs . 17
Bibliography . 18

Table 1 – Calculation of operating uncertainty . 13
Table A.1 – Tripping tests for different types of RCD . 17

Table 1 – Calculation of operating uncertainty . 13
Table A.1 – Tripping tests for different types of RCD . 17

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL SAFETY IN LOW VOLTAGE DISTRIBUTION SYSTEMS UP TO
1 000 V AC AND 1 500 V DC – EQUIPMENT FOR TESTING, MEASURING
OR MONITORING OF PROTECTIVE MEASURES –

Part 6: Effectiveness of residual current devices (RCD)
in TT, TN and IT systems
FOREWORD
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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– 4 – IEC 61557-6:2019 RLV © IEC 2019
International Standard IEC 61557-6 has been prepared by IEC technical committee 85:
Measuring equipment for electrical and electromagnetic quantities.
This third edition cancels and replaces the second edition published in 2007. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) addition of requirements for testing a new type of RCD;
b) addition of requirements for type B RCDs (former Annex B);
c) addition of new Annex B on recommended tripping times;
d) alignment of the structure with that of the whole IEC 61557 series.
The text of this International Standard is based on the following documents:
FDIS Report on voting
85/ 684/FDIS 85/ 697/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
This International Standard is to be used in conjunction with IEC 61557-1:2019.
A list of all parts in the IEC 61557 series, published under the general title Electrical safety in
low voltage distribution systems up to 1 000 V AC and 1 500 V DC – Equipment for testing,
measuring or monitoring of protective measures, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

ELECTRICAL SAFETY IN LOW VOLTAGE DISTRIBUTION SYSTEMS UP TO
1 000 V AC AND 1 500 V DC – EQUIPMENT FOR TESTING, MEASURING
OR MONITORING OF PROTECTIVE MEASURES –

Part 6: Effectiveness of residual current devices (RCD)
in TT, TN and IT systems
1 Scope
This part of IEC 61557 specifies the requirements for measuring equipment applied to the
testing of the effectiveness of protective measures by regular disconnections of residual
current protective devices (RCD) in TT, TN and IT systems.
This part of IEC 61557 specifies the requirements applicable to measuring equipment for
testing the effectiveness of protective measures of residual current devices (RCD) installed in
TT, TN and IT systems.
It is not the purpose of this document to verify the RCD according to their product standards.
NOTE Applicable tripping tests for time and current of RCD are listed in Annex A, Table A.1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC/TR 60755, General requirements for residual current operated protective devices
IEC 60947-2, Low-voltage switchgear and controlgear – Part 2: Circuit-breakers
IEC 61008 (all parts), Residual current operated circuit-breakers without integral overcurrent
protection for household and similar uses (RCCBs)
IEC 61009 (all parts), Residual current operated circuit-breakers with integral overcurrent
protection for household and similar uses (RCBOs)
IEC 61010-1:20012010, Safety requirements for electrical equipment for measurement,
control, and laboratory use – Part 1: General requirements
IEC 61010-1:2010/AMD1:2016
IEC 61010-2-030:2017, Safety requirements for electrical equipment for measurement, control,
and laboratory use – Part 2-030: Particular requirements for equipment having testing or
measuring circuits
IEC 61010-031, Safety requirements for electrical equipment for measurement, control and
laboratory use – Part 031: Safety requirements for hand-held and hand-manipulated probe
assemblies for electrical test and measurement
__________
A consolidated version of this publication exists, comprising IEC 61010-1:2010 and
IEC 61010-1:2010/AMD1:2016.
– 6 – IEC 61557-6:2019 RLV © IEC 2019
IEC 61557-1:20072019, Electrical safety in low voltage distribution systems up to 1 000 V AC
and 1 500 V DC – Equipment for testing, measuring or monitoring of protective measures – Part 1:
General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61557-1 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
earth fault current
I∆
current flowing to earth due to an insulation fault
[SOURCE: IEC 60050-442:1998, 442-01-23]
3.2
residual current
I
∆
RMS value of the vector sum of the currents flowing through the main circuit of the residual
current device
[SOURCE: IEC 60050-442:1998, 442-05-19, modified – in alignment with the use in this
document. The symbol has been modified.]
3.3
rated residual operating current
I
∆n
fault current for which the residual current protective device is designed
3.4
residual operating current
I
a
fault current at which the residual current protective device is activated
value of residual current which causes the residual current device to operate under specified
conditions
[SOURCE: IEC 60050-442:1998, 442-05-20, modified – The symbol has been added.]
3.5
total earthing resistance
R
A
resistance between the main earthing terminal and the earth
2)
[IEV 826-04-03 ]
__________
2)
IEC 60050-826:1982, International Electrotechnical Vocabulary – Part 826: Electrical installations of buildings
(withdrawn and superseded by IEC 60050-826:2004, International Electrotechnical Vocabulary – Part 826:
Electrical installations, in which this definition no longer appears).

3.5
leakage current
electric current in an unwanted conductive path to earth under normal operating conditions
[SOURCE: IEC 60050-195:1998, 195-05-15, modified – "to earth" has been added and the
deprecated term "earth current" omitted.]
3.6
test resistance
R
p
resistance by means of which a fault current for test purposes is produced
3.7
resistance to earth
resistance to ground, US
real part of the impedance to earth
[SOURCE: IEC 60050-195:1998, 195-01-18]
4 Requirements
The following requirements as well as those given in IEC 61557-1 shall apply.
4.1 General
In addition to the requirements of IEC 61557-1:2019, Clause 4, the requirements of Clause 4
of this document shall apply.
Test leads and test probes used with this measuring equipment shall fulfil the requirements
of IEC 61010-031.
Equipment intended for making measurements on distribution systems shall, at the minimum,
be rated for measurement category III in accordance with IEC 61010-2-030.
Equipment intended for making measurements on electrical equipment shall, at the minimum,
be rated for measurement category II in accordance with IEC 61010-2-030.
4.2 Tests Functions
4.2.1 Tripping tests Measurement of trip current
The measuring equipment shall be capable of indicating that if and when the residual
operating current of the protective device is less than or equal to the rated residual operating
current.
The tests shall be carried out with a sinusoidal, or mains-derived quasi sinusoidal test current.
The operating uncertainty of the calibrated test currents, determined in accordance with
Table 1, shall not exceed 0 % to +10 % of the rated residual current with the rated residual
operating current as fiducial value determined in accordance with Table 1 (the rated residual
operating current) +10 %.
The operating uncertainty of measurement of the residual operating current, determined in
accordance with Table 1, shall not exceed ±10 % of the rated residual operating current as
fiducial value determined in accordance with Table 1.

– 8 – IEC 61557-6:2019 RLV © IEC 2019
If the measuring equipment is provided for the purpose of testing residual current protective
devices (RCD) of 30 mA or below, installed for supplementary protection, the measuring
equipment shall be capable of providing a test of 5 times the rated residual operating current.
The test period shall be limited to 40 ms. When measuring the trip time, this limit of test
period need not be applied so long as the fault voltage remains below the touch voltage limit.
If the measuring equipment is capable of producing half-wave test currents, testing of residual
current protective devices (RCDs) Type A may alternatively be carried out using half-wave
test currents according to the IEC 61008 and IEC 61009 series, IEC 60947-2 and IEC/TR
60755 testing of pulse current sensitive RCDs may alternatively be carried out using half-
wave test currents. In this case, test equipment shall be able to test in both polarities.
If the measuring equipment includes a test intended to be applied to residual current devices
(RCD) type B, the test current shall be an increasing smooth direct residual current.
NOTE A smooth direct current is a current with less than 10 % AC ripple (peak to peak).
If the test current increases linearly, the rate of increase shall not be greater than 2 times I
Δn
in 5 s. If the test current increases in steps, the increase per step shall not be more than
2 times I /30 and the rate of increase shall not be greater than 2 times I in 5 s.
Δn Δn
It shall be possible to test with both polarities of the test current. The operating uncertainty of
the measurement of the residual current shall not exceed ±10 % of the rated residual
operating current and the operating uncertainty of the maximum value of the increasing test
current shall not exceed (2 times the rated residual operating current) +10 %.
4.2.2 Non-tripping tests functions
When a test at 50 % or less of the rated residual operating current is included to test the
reliability immunity of the RCD to nuisance tripping, the minimum test period for general type
RCDs shall be 0,3 s and for type S RCDs, it shall be 0,5 s. The protective device shall not
open operate.
When a non-trip test at 50 % or less of the rated residual operating current is included, the
operating uncertainty of the calibrated test current shall not exceed be in the range between
0 % and −10 % of the specified non-tripping test current in accordance with Table 1.
NOTE If the purpose of the test is to evaluate other parameters (e.g. fault voltage) the
minimum test period may be shorter but not less than one cycle of the rated frequency.
4.2.3 Fault voltage indication
The measuring equipment shall be capable of indicating whether the fault voltage at the rated
residual operating current of the protective device is less than or equal to the conventional
touch voltage limit. The test may be carried out with or without a probe.
NOTE Indication can may be provided by displaying the value of the fault voltage or by the
use of other clear indicators.
4.2.1 If a fault voltage is displayed or indicated for the residual operating current and not for
the rated residual current, this shall be indicated in the display or on the measuring equipment,
or calculated according to the following formulae.
The following condition shall be fulfilled:
I
∆
U ≤ U ∗
F L
I
∆N
where
U is the conventional touch voltage limit.
L
4.2.2 The operating uncertainty during the measurement of the fault voltage shall not exceed
0 % to +20 % with the conventional touch voltage limit as fiducial value, determined in
accordance with Table 1.
NOTE The internal resistance of the voltage measuring equipment should be at least 0,7 kΩ/V of the full-scale
value of the measurement range. The influence of the voltage measurement on the measurement of the fault
current should be taken into consideration.
4.3 The measuring equipment shall be capable of measuring the trip time of residual current
protective devices at the rated residual operating current or shall be capable of indicating the
compliance with the maximum allowed trip time.
When measuring the trip time, the operating uncertainty shall not exceed ± 10 % with the
maximum permissible trip time as fiducial value and the influence quantities according to
Table 1.
4.4 On measuring equipment with indicators, the switching value of the indicators shall be the
conventional true value for the calculation of uncertainties, provided nothing to the contrary is
stated.
4.5 The operating uncertainty applies under the rated operating conditions stated in
IEC 61557-1 and the following:
– the protective conductor is free from extraneous voltages;
– the system voltage remains constant during the measurement;
– the circuit following the residual current protective device carries no leakage current;
– the system voltage is within 85 % to 110 % of the nominal system voltage for which the
equipment has been designed;
– the resistance of the probes is within the limits stated by the manufacturer;
– sinusoidal test current.
If the value of the fault voltage or the indication for the fault current (shown on a display or
otherwise indicated) show the value for the residual current and not for the rated residual
operating current, this shall be indicated on the display or on the measuring equipment.
Otherwise the fault voltage shall be calculated according to Equation 1:
I
a
UU≤×
(1)
F L I
Δn
where
U  is the fault voltage;
F
U  is the conventional touch voltage limit;
L
I is the rated residual operating current;
∆n
I  is the residual operating current.
a
The operating uncertainty of the fault voltage measurement, determined in accordance with
Table 1, shall be in the range of 0 % and +20 % with the conventional touch voltage limit as
fiducial value.
– 10 – IEC 61557-6:2019 RLV © IEC 2019
The internal resistance of the voltage measuring equipment should be at least 0,7 kΩ/V of the
full-scale value of the measurement range. The influence of the voltage measurement on the
measurement of the fault current should be taken into consideration.
4.2.4 Measurement of trip time
The measuring equipment shall be capable of measuring the trip time of residual current
devices (RCD) at the rated residual operating current or shall be capable of indicating the
compliance with the maximum permissible trip time. As a minimum, the test equipment shall
include a test with a sinusoidal test current.
When measuring the trip time, the operating uncertainty shall not exceed ±10 % with the
maximum permissible trip time as fiducial value and the influence quantities according
to Table 1.
If trip times are measured with different waveforms, the manufacturer should provide guidance
on the interpretation of the results in the operating instructions.
4.3 Measurement with indicators
On measuring equipment with indicators, the threshold value of the indicators shall be the
value for the calculation of uncertainties.
4.4 Test with rated residual operating current
When testing with the rated residual operating current, the following conditions shall be met:
– the test current shall be switched on during a zero crossing;
– the starting phase of the test current shall be indicated to the user;
– the test period shall be limited to the maximum allowed trip time of the residual current
protective device (RCD) under test. When measuring the trip time, these limits of the test
periods need not be applied.
4.5 Fault voltages exceeding U
L
Prevention of danger by due to fault voltages exceeding 50 V U within the system under test
L
shall be ensured during measurements. This can be achieved as follows:
– automatic disconnection in accordance with IEC 61010-1:2010/AMD1:2016, Figure 12,
when fault voltages with a magnitude >50 V > U occur;
L
– use of test resistances R adjustable in steps, or continuously, in such a manner that the
p
test is started with a resistance that permits a maximum current of 3,5 mA to flow when all
parallel-connected circuits are included. An unambiguous detection shall be ensured, for
example by means of a voltmeter, as to determine whether this test resistance can be
varied without producing a hazardous fault voltage.
If the measuring equipment indicates the value of the voltage at its measuring terminals, it
shall also indicate if the system voltage exists and if the live conductor is exchanged with the
protective conductor.
4.6 Overvoltage
The user shall not be exposed to danger and the equipment shall not be damaged when the
measuring equipment is connected for at least 10 min to 120 % of the nominal voltage of the
distribution system for which the measuring equipment has been designed. Protective devices
shall not be activated.
The user shall not be exposed to danger and the measuring equipment shall not be damaged
when the measuring equipment is accidentally connected for at least 1 min with up to 173 %
of its rated voltage to earth. Protective devices may be activated.
5 Marking and operating instructions
5.1 Marking
In addition to the marking in accordance with IEC 61557-1:2019, 5.1 and 5.2, the following
information shall be provided on the measuring equipment.
The rated residual operating current or rated residual operating currents of the residual
current device (RCD) for which the measuring equipment has been designed shall be marked.
The maximum voltage to earth and the rated measuring category shall be marked.
5.2 Explicit indication of the waveform of the testing current
The measuring equipment shall contain the indication that in the case of a half wave testing
current or DC testing current, the tripping test shall be carried out in both directions (see
Annex A for tripping test for different types of RCD). Where there is insufficient space, the
warning symbol according to IEC 61010-1:2010, Table 1 symbol 14 shall be marked adjacent
to the RCD function or a warning shall be given on the display.
5.3 Operating instructions
In addition to IEC 61557-1:2019, 5.3, the operating instructions shall state include the
following information.
– Where the measuring circuit has no probe and if a possible voltage present between the
protective conductor and earth will influence the measurements, a warning must shall be
included.
– Where the measuring circuit uses the N-conductor as a probe, a warning shall be given to
test the connection between the neutral point of the distribution system and earth before
the test is started; a possible voltage between the N-conductor and the earth may
influence the measurements.
– A warning that leakage currents in the circuit following the residual current protection
device (RCD) may influence the measurements.
– Where the fault voltage is indicated by the test equipment, a clear statement shall be
given as to whether the voltage relates to the rated residual operating current or to the
residual operating current of the protective device. If applicable, a note to fulfil the
conditions of 4.2.3 shall also be included.
– A statement that the earth electrode resistance of a measuring circuit with a probe shall
not exceed a value to be stated by the manufacturer.
– A warning, that when using a probe, the potential fields of other earthing installations may
influence the measurement.
– A warning that special conditions in residual current protective devices (RCD) of a
particular design, for example of type S (selective and resistance resistant to impulse
currents) shall be taken into consideration.
– A warning that equipment, which is connected downstream of a in the circuit following the
residual current protective device (RCD) may cause a considerable extension of the
operating time. Examples of such equipment might be connected capacitors or running
motors.
– 12 – IEC 61557-6:2019 RLV © IEC 2019
6 Tests
The following tests in addition to those required according to IEC 61557-1 shall be executed.
6.1 General
In addition to IEC 61557-1:2019, Clause 6, the tests in Clause 6 of this document shall be
performed.
These tests shall be carried out performed at all rated residual operating currents and in
addition at 50 % and 500 % of the rated residual operating current, if applicable.
The test circuit shall be adapted to test both at the limits of the fault voltage for which the
equipment is designed and at the appropriate total earthing resistance R = R for each
A Amax
range.
The test circuit shall be adapted to each test method employed. The manufacturer's data shall
be heeded observed.
NOTE The maximum earthing resistance is derived from:
U
L
R =
A
max
I
Δn
where
U is the conventional touch voltage limit;
L
I is the rated residual operating current.
∆n
6.2 Operating uncertainty
The operating uncertainty applies under the rated operating conditions stated in IEC 61557-1
and the following:
– the voltage on the protective conductor relative to earth or N shall be below 1 V RMS;
– the system voltage remains stable within ±1 V during the measurement;
– the circuit following the residual current device (RCD) carries a negligible leakage current;
– the system voltage is within 85 % to 110 % of the nominal system voltage for which the
equipment has been designed;
– the resistance of the probes is within the limits stated by the manufacturer.
The operating uncertainty shall be determined in accordance with Table 1. In this process, the
intrinsic uncertainty shall be determined under the following reference conditions:
– nominal voltage of the distribution system;
– nominal frequency of the distribution system;
– reference temperature (23 ± 2) °C;
– reference position in accordance with the manufacturer's statement;
– protective conductor free from extraneous voltages;
– 100 Ω resistance of the auxiliary earth electrode in a TT system.

Table 1 – Calculation of operating uncertainty
Intrinsic uncertainty or Reference conditions or Designation Requirements or Type of
influence quantity specified operating range code test in accordance test
with the relevant
parts of IEC 61557
Intrinsic uncertainty Reference conditions A Part 6, 6.1 R
6.2
Position Reference position ±90° E Part 1, 4.2 R
IEC 61557-1:2019,
4.2
Supply voltage At the limits stated by the E Part 1, 4.2, 4.3 R
manufacturer IEC 61557-1:2019,
4.2, 4.3
Temperature 0 °C and 35 °C E Part 1, 4.2 T
IEC 61557-1:2019,
4.2
Resistance of the probes Within the limits stated by the E Part 6, 4.5 T
manufacturer
6.3
System voltage 85 % to 110 % of the nominal E Part 6, 4.5 T
voltage IEC 61557-6:2019,
6.3
Operating uncertainty Part 6, 4.1 R
2 2
Part 6, 4.2
BA=±+ E
∑ i
i
Part 6, 4.3
6.2
Key
B
B % =±×100 %


F
A = intrinsic uncertainty
E E = variations
n
i
R = routine test
T = type test
F = fiducial value
The operating uncertainty evaluated according to Table 1 shall not exceed the limits specified
in 4.1, 4.2, 4.3 and 4.4.
6.3 Fault voltage
When measuring the fault voltage, compliance with the permissible operating uncertainty shall
be tested for measurements with and without a probe.
Compliance with 4.5 shall be tested in all ranges.
Compliance with the conditions for the internal resistance in accordance with 4.2.3 shall be
tested in all measurement ranges (type test).
6.4 Testing the connection to voltages higher than nominal voltage
Compliance with the requirements under 4.6 and 4.7 4.5 shall be tested (routine test).
6.5 The overload protection in accordance with 4.8 and 4.9 shall be tested (type test).
6.6 Compliance with the tests in this clause shall be recorded.

– 14 – IEC 61557-6:2019 RLV © IEC 2019
6.5 Overvoltage
The permissible overload in accordance with the requirements of 4.5 and 4.6 shall be tested
(type test).
Annex A
(normative)
Measuring equipment for residual current protective
devices (RCDs) of type B
A.1 Scope
This annex specifies requirements for measuring equipment for testing the effectiveness of
protective measures with disconnection by residual current protective devices (RCD) of type B.
A.2 Requirements
The following requirements as well as those given in IEC 61557-1 shall apply.
A.2.1 In addition to the verification of the residual operating current with sinusoidal- or half-
wave test current, for testing a residual current protective device (RCD) of type B, it shall be
verified, that the operating current with a smooth direct residual current, is smaller or equal to
2 times the rated residual operating current I If the value of the operating current is to be
..
∆N
evaluated, a continuously increasing smooth direct test current starting with 0,2 times the
rated residual current I shall be applied.
∆N
NOTE A smooth direct current is a current with less than 10 % a.c. ripple (peak-to-peak).
A.2.2 If the test current increases linearly, the increase shall not be greater than 2 times I in
∆N
5 s. If the test current increases in steps, the increase per step shall not be more than 2 times
I /30 and the increase shall not be greater than 2 times I in 5 s.
∆N ∆N
A.2.3 It shall be possible to perform verifications with smooth direct residual current in both
directions of the test current.
A.2.4 The operating uncertainty for the measurement of the residual operating current shall
not exceed ±10 % of the rated residual operating current and shall comply with the values
given in Table 1 of this standard.
A.2.5 The operating uncertainty according to 4.2 of IEC 61557-1 under rated operating
conditions shall apply and the following:
– the protective conductor is free from extraneous voltages;
– the system voltage remains constant during the measurement;
– the circuit following the residual current protective device carries no leakage current;
– the system voltage is within 85 % to 110 % of the nominal system voltage for which the
equipment has been designed;
– the resistance of the probes is within the limits stated by the manufacturer;
– smooth direct current.
A.2.6 It is to be ensured that the measurements do not pose any risks within the system under
test by fault voltages exceeding 120 V d.c.
This may be achieved by:
– automatic disconnection in accordance with Figure 1 of IEC 61010-1, if the fault voltage
exceeds 120 V d.c.;
– 16 – IEC 61557-6:2019 RLV © IEC 2019
– the use of test resistors RP, which are fixed or adjustable and where the test starts with a
resistance which limits the test current to a maximum current of 15 mA d.c., included are
parallel measuring circuits.
It must be clearly ascertainable, that the test resistance may be reduced, without producing a
dangerous voltage, for example with the indication of the fault voltage.
A.3 Marking and operating instructions
In addition to the marking in accordance with IEC 61557-1 and this standard, the following
information shall be provided on the measuring equipment.
A.3.1 Explicit indication, that the measuring device is suitable for testing residual current
protective devices (RCD) of type B.
A.3.2 The measuring equipment shall contain the indication that residual current protective
devices (RCD) of type B shall be tested in both current directions.
Where there is insufficient space, the warning symbol No. 14 according IEC 61010-1 shall be
marked adjacent to the RCD function or a warning shall be given on the display.
A.4 Tests
The tests according to IEC 61557-1 and this standard apply.

Annex A
(informative)
Applicable tripping tests (time and current) for different types of RCDs
Table A.1 – Tripping tests for different types of RCD
AC sinusoidal test AC half wave test current Rising smooth direct
RCD type
current (pulsating direct test current) test current
AC x n/a n/a
A x x n/a
F x x n/a
B x x x
B+ x x x
NOTE 1 The limits for trip times can be found in IEC 60364-4-41 or in national standards.
NOTE 2 Type B+ is defined in some national standards.

– 18 – IEC 61557-6:2019 RLV © IEC 2019
Bibliography
IEC 60050-195:1998, International Electrotechnical Vocabulary (IEV) – Part 195: Earthing and
protection against electric shock
IEC 60050-442:1998, International Electrotechnical Vocabulary (IEV) – Part 442: Electrical
accessories
IEC 60359:2001, Electrical and electronic measurement equipment – Expression of
performance
IEC 60364-4-41, Low-voltage electrical installations – Part 4-41: Protection for safety –
Protection against electric shock
IEC 61008-1:2002, Residual current operated circuit-breakers without integral overcurrent
protection for household and similar uses (RCCBs) – Part 1: General rules
IEC 61009-1:2006, Residual current operated circuit-breakers with integral overcurrent
protection for household and similar uses (RCBOs) – Part 1: General rules

–––––––––––
IEC 61557-6 ®
Edition 3.0 2019-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical safety in low voltage distribution systems up to 1 000 V a.c. and
1 500 V d.c. – Equipment for testing, measuring or monitoring of protective
measures –
Part 6: Effectiveness of residual current devices (RCD) in TT, TN and IT systems

Sécurité électrique dans les réseaux de distribution basse tension au plus
égale à 1 000 V c.a. et 1 500 V c.c. – Dispositifs de contrôle, de mesure ou
de surveillance de mesures de protection –
Partie 6: Efficacité des dispositifs à courant différentiel résiduel (DDR)
dans les réseaux TT, TN et IT
– 2 – IEC 61557-6:2019 © IEC 2019
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Requirements . 6
4.1 General . 6
4.2 Functions . 7
4.2.1 Measurement of trip current . 7
4.2.2 Non-tripping functions . 7
4.2.3 Fault voltage indication . 8
4.2.4 Measurement of trip time . 8
4.3 Measurement with indicators . 8
4.4 Test with rated residual operating current . 9
4.5 Fault voltages exceeding U . 9
L
4.6 Overvoltage .
...