IEC 61557-10:2024

IEC 61557-10 ®
Edition 3.0 2024-10
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
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 10: Combined measuring equipment for testing, measuring and monitoring
of protective measures
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IEC 61557-10 ®
Edition 3.0 2024-10
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
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 10: Combined measuring equipment for testing, measuring and monitoring
of protective measures
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.220.20; 29.080.01; 29.240.01 ISBN 978-2-8322-9833-6
– 2 – IEC 61557-10:2024 CMV © IEC 2024
CONTENTS
FOREWORD .3
1 Scope .5
2 Normative references .5
3 Terms and definitions .6
4 Requirements .6
4.1 General .6
4.2 Extraneous overvoltage withstand capability .7
4.3 Performance after application of extraneous overvoltage .7
5 Marking and operating instructions .8
5.1 General .8
5.2 Marking and Pictogram .8
6 Tests .9
Bibliography . 10
List of comments . 11

Figure 1 – Maximum distribution system voltage marking.8
Figure 2 – Example of a pictogram for a 500V AC system .9

Table 1 – Extraneous overvoltage withstand capability .6

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 10: Combined measuring equipment for testing, measuring or and
monitoring of protective measures

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,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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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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shall not be held responsible for identifying any or all such patent rights.
This commented version (CMV) of the official standard IEC 61557-10:2024 edition 3.0
allows the user to identify the changes made to the previous IEC 61557-10:2013
edition 2.0. Furthermore, comments from IEC TC 85 experts are provided to explain the
reasons of the most relevant changes, or to clarify any part of the content.
A vertical bar appears in the margin wherever a change has been made. Additions are in
green text, deletions are in strikethrough red text. Experts' comments are identified by a
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comment.
This publication contains the CMV and the official standard. The full list of comments is
available at the end of the CMV.

– 4 – IEC 61557-10:2024 CMV © IEC 2024
IEC 61557-10 has been prepared by IEC technical committee TC85: Measuring equipment for
electrical and electromagnetic quantities. It is an International Standard.
This third edition cancels and replaces the second edition published in 2013. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) The scope has been updated to include the combination of measuring functions covered by
the IEC 61557 series with those not covered by the IEC 61557 series.
b) Reasonably foreseeable misuse is now considered.
c) An exemption has been added for terminals that can only be accessed by use of a tool.
d) Table 1 has been updated for clarification.
e) The voltage source used for the overload test takes into account the expected short-circuit
currents for measurement categories in accordance with IEC 61010-2-030:2017.
The text of this International Standard is based on the following documents:
Draft Report on voting
85/887/CDV 85/914/RVC
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
This International Standard is to be used in conjunction with IEC 61557-1:2019.
A list of all parts of 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 webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
IMPORTANT – The "colour inside" logo on the cover page of this document 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 10: Combined measuring equipment for testing, measuring or and
monitoring of protective measures

1 Scope
This part of IEC 61557 specifies the requirements for combined measuring equipment that
combines several measuring functions or methods of testing, measuring or monitoring, that are
in accordance with the respective parts of IEC 61557, into one piece of apparatus.
Measuring equipment which combines measuring functions or methods of testing, measuring
or monitoring covered by the respective parts of IEC 61557 with those not covered by the
respective parts of IEC 61557 is also within the scope of this document. 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 61557-1:2019, 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
IEC 61557-2, 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 2:
Insulation resistance
IEC 61557-3, 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 3:
Loop impedance
IEC 61557-4, 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 4:
Resistance of earth connection and equipotential bonding
IEC 61557-5, 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 5:
Resistance to earth
IEC 61557-6, 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
IEC 61557-7, 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 7:
Phase sequence
– 6 – IEC 61557-10:2024 CMV © IEC 2024
IEC 61010-2-030:20102023, Safety requirements for electrical equipment for measurement,
control, and laboratory use – Part 2-030: Particular requirements for equipment having testing
and or measuring circuits
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61557-1, IEC 61557-2,
IEC 61557-3, IEC 61557-4, IEC 61557-5, IEC 61557-6, IEC 61557-7 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
combined measuring equipment
equipment device that combines, into one piece of apparatus, several measuring functions or
methods of testing, measuring or monitoring, some or all of which are in accordance with other
parts of IEC 61557
3.2
extraneous overvoltage
voltage applied to the measurement terminals of the combined measuring equipment to test the
overvoltage withstand capability
4 Requirements
4.1 General
4.1.1 The following requirements in addition to those given in all relevant parts of IEC 61557
shall apply.
4.1.2 No hazard shall arise for the user when the highest extraneous overvoltage according
to the respective parts of this document (see Table 1) is accidentally applied to each
combination of tests and measurement terminals with every combination of function and range
settings, even though some of these functions are not themselves covered by IEC 61557
Parts 2 to Parts 7.
4.1.3 Terminals that are clearly identifiable as not test or measurement terminals and that
will not retain the terminals of specified probes or accessories need not be tested.
The duration time shall be the longest possible indicated in the respective parts of
IEC 61557.
In addition to the requirements of IEC 61557-1:2019, Clause 4 and all respective parts, the
requirements of Clause 4 shall apply.
Under normal conditions and in cases of reasonably foreseeable misuse, no hazard shall arise
when: 2
• the maximum rated voltage or current of a measuring circuit terminal, or
• the maximum extraneous overvoltage according to the respective parts of IEC 61557 (see
Table 1)
is applied to that terminal or to any other compatible terminal, with any combination of function
and range settings.
If the measuring device bears a marking or a pictogram in accordance with 5.2, the extraneous
overvoltage can be reduced to 1,1 times of the maximum expected line to line voltage.
4.2 Extraneous overvoltage withstand capability
Terminals that are clearly not of similar types and that will not retain the connectors of the probe
assembly or the accessory do not need to be tested.
Terminals that can only be accessed by use of a tool do not need to meet the requirements of
this clause 3. The duration time shall be the longest possible indicated in the respective parts
of IEC 61557.
Table 1 – Extraneous overvoltage withstand capability
Part of IEC 61557
2 3 4 5 6 7
Insulation Loop Protective Earth RCD Phase
bonding resistance sequence
AC extraneous 1,2 × U 1,2 × U 1,2 × U 1,2 × U 1,2 × U 1,2 × U
N O O O O O
overvoltage
10 s continuous continuous continuous continuous continuous
and duration
and
time and
1,1 x phase- 1,1 x phase-
to-phase to-phase
line-to-line line-to-line
voltage voltage
1 min 1 min
DC extraneous 1,2 × U Not Not Not Not Not
N
overvoltage applicable applicable applicable applicable
applicable 4
10 s
and duration
time
NOTE 1 U is the voltage referenced to earth (see IEC 61557-1:2007 2019, 3.3a).
O
NOTE 2 U is the nominal output voltage (see IEC 61557-1:20072019, 3.1 and IEC 61557-2:2007 , 3.1)
N
NOTE 3 RCD is residual current device

4.3 Performance after application of extraneous overvoltage
If parts of the combined measuring equipment are defective after the extraneous overvoltage is
applied, the defect shall be clearly indicated. Indications and displayed values shall not lead to
erroneous interpretations of safe or unsafe situations or conditions. The indication shall be
visible to the user when the instrument is in the normal position.
When the extraneous overvoltage is applied, protective components or protective circuits within
the measuring equipment may be activated. The activation of protective these components or
circuits in equipment for measuring or testing insulation resistance in accordance with
IEC 61557-2 shall be clearly indicated if the operation of the equipment is impaired. The
indication shall be visible to the user when the instrument is in the normal position. Indications
and displayed values shall not lead to erroneous interpretations of safe or unsafe situations or
conditions.
IEC 61557-1:2007, 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 1: General requirements
IEC 61557-2:2007, 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 2: Insulation resistance

– 8 – IEC 61557-10:2024 CMV © IEC 2024
Protective components or circuits shall have sufficient voltage rating and current-breakability
breaking capacity for the expected overload current condition.
5 Marking and operating instructions
5.1 General
The requirements specified in the respective parts of IEC 61557 shall apply.
In addition to IEC 61557-1:2019, Clause 5, and all other respective parts, the following
information shall be provided on the combined measuring equipment.
If the requirements of 5.2 are applicable, the marking shall be clearly readable legible in the
position of normal use.
If a pictogram in accordance with 5.2 is used, the meaning of the relevant pictogram shall be
clearly explained in the user manual operating instructions.
5.2 Marking and Pictogram
When the combined measuring equipment bears one of the following marking or pictogram, the
applied extraneous overvoltage can be reduced to a voltage of 1,1 times the maximum expected
phase-to-phase line-to-line voltage:
a) Marking
Figure 1 – Maximum distribution system voltage marking
The marking shown in Figure 1 shall be written in the corresponding country a language that
can be easily understood by the user.
The value of the voltage shown on the marking shall be 1,1 times the maximum expected
phase-to-phase line-to-line voltage.
b) Figure 2 shows an example of a pictogram for a 500 V AC system

The value of the voltage shown on the marking shall be 1,1 times
the maximum expected phase-to-phase voltage
IEC  892/13
Figure 2 – Example of a pictogram for a 500V AC system

Combined measuring equipment bearing one of the markings of a) or pictograms of b) the
marking in Figure 1 or the pictogram in Figure 2 shall withstand the above specified overvoltage
for 1 min without any defect. The test configuration shall be in accordance with 4.2; protective
devices may be activated in accordance with 4.3.
If the combined measuring equipment includes an insulation resistance measuring or testing
function, this function shall also fulfil the overvoltage requirements in accordance with
IEC 61557-2.
6 Tests
In addition to the tests specified in Clause 6 of the respective parts of IEC 61557, the following
tests shall be performed:
• the overvoltage withstand capability for the combined measuring equipment shall be type
tested by using an extraneous overvoltage either in accordance with 4.1 or in accordance
with 4.2;
• the technical specifications of protective devices shall be verified;
• the voltage source for the overload test shall be capable of driving providing the highest
maximum expected overload current., taking in account the expected short circuit currents
for measurement categories according to IEC 61010-2-030:2023, Table AA.1 5. If certified
protective devices are used, the test can be limited in accordance with IEC 61010-2-
030:2023, 101.3.1;
• compliance with the requirements of Clause 5 shall be verified as a routine test.
• compliance with the tests in Clause 6 shall be documented.

– 10 – IEC 61557-10:2024 CMV © IEC 2024
Bibliography
IEC 61010-1:2010, Safety requirements for electrical equipment for measurement, control, and
laboratory use – Part 1: General requirements
IEC 61557-8, 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 8: Insulation
monitoring devices for IT systems
IEC 61557-9, 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 9:
Equipment for insulation fault location in IT systems
IEC 61557-11, 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 11:
Effectiveness of residual current monitors (RCMs) type A and type B in TT, TN and IT systems
IEC 61557-12, 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 12:
Performance measuring and monitoring devices (PMD)
IEC 61557-13, 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 13:
Hand-held and hand-manipulated current clamps and sensors for measurement of leakage
currents in electrical distribution systems

List of comments
1 The scope is not limited to the combination of measuring functions covered by the
respective parts of IEC 61557.
If any of the measuring functions in combined measuring equipment are covered by the
IEC 61557 series, the measuring equipment is within scope.
2 Measuring equipment that incorporates different measuring functions is more prone to
misuse. For example, the user may select the incorrect measurement function before
connecting test probes to an energy source.
3 Access to terminals may be restricted to reduce the risk of foreseeable misuse, for example
by use of a cover that requires a tool to gain access to a terminal or set of terminals.
If access is restricted such that a tool is required, then the terminals with restricted access
do not need to meet the requirements of Subclause 4.2.
4 Table 1 is updated to clarify when an AC test, a DC test or both AC and DC tests are
required.
The DC extraneous overvoltage test is only applicable to combined measuring equipment
that includes an insulation resistance measurement function.
5 The AC extraneous overvoltage test is intended to simulate connection of the test probes
to an electrical installation. The voltage source used for this test must be capable of
providing the maximum current expected for this condition. IEC 61010-2-030, Table AA.1
provides typical short-circuit currents for each measurement category.
The requirements for the DC extraneous overvoltage test source are given in IEC 61557-2.
_____________
IEC 61557-10 ®
Edition 3.0 2024-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
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 10: Combined measuring equipment for testing, measuring and monitoring
of protective measures
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 10: Appareils combinés de contrôle, de mesure et de surveillance de
mesures de protection
– 2 – IEC 61557-10:2024 © IEC 2024
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Requirements . 6
4.1 General . 6
4.2 Extraneous overvoltage withstand capability . 6
4.3 Performance after application of extraneous overvoltage . 7
5 Marking and operating instructions . 7
5.1 General . 7
5.2 Pictogram . 8
6 Tests . 8
Bibliography . 9

Figure 1 – Maximum distribution system voltage marking . 8
Figure 2 – Example of a pictogram for a 500V AC system . 8

Table 1 – Extraneous overvoltage . 7

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 10: Combined measuring equipment for testing, measuring and
monitoring of protective measures

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,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or ind
...