IEC 61557-16:2014

IEC 61557-16 ®
Edition 1.0 2014-12
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 16: Equipment for testing the effectiveness of the protective measures of
electrical equipment and/or medical electrical equipment

Sécurité électrique dans les réseaux de distribution basse tension de
1 000 V c.a. et 1 500 V c.c. – Dispositifs de contrôle, de mesure ou de
surveillance de mesures de protection –
Partie 16: Équipement pour les essais de bon fonctionnement des mesures de
protection de l'équipement électrique et/ou de l'équipement médical électrique

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IEC 61557-16 ®
Edition 1.0 2014-12
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 16: Equipment for testing the effectiveness of the protective measures of

electrical equipment and/or medical electrical equipment

Sécurité électrique dans les réseaux de distribution basse tension de

1 000 V c.a. et 1 500 V c.c. – Dispositifs de contrôle, de mesure ou de

surveillance de mesures de protection –

Partie 16: Équipement pour les essais de bon fonctionnement des mesures de

protection de l'équipement électrique et/ou de l'équipement médical électrique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX R
ICS 17.220.20; 29.080.01 ISBN 978-2-8322-1979-9

– 2 – IEC 61557-16:2014 © IEC 2014
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Requirements . 9
4.1 Measurement requirements for measuring equipment . 9
4.1.1 General . 9
4.1.2 Measurement of the resistance of the protective bonding or the
protective earth resistance . 9
4.1.3 Measurement of insulation resistance . 10
4.1.4 Measurement of protective conductor current and/or equipment leakage
current with the alternative method . 10
4.1.5 Measurement of touch current, patient leakage current and applied part
leakage current with the alternative method . 10
4.1.6 Measurement of protective conductor current and or equipment leakage
current with the direct method or differential method (residual method) . 11
4.1.7 Measurement of touch current, patient leakage current and applied part
leakage current with the direct method or differential method (residual
method) . 11
4.2 Construction requirements for testing equipment . 12
4.2.1 Overload capability . 12
4.2.2 Terminals . 12
4.2.3 Sockets for service purposes . 12
4.2.4 Degree of protection . 12
4.2.5 Class of protection . 12
4.2.6 Resistance of protective bonding . 12
4.2.7 Battery control . 12
4.2.8 Mechanical requirements . 13
4.2.9 Pollution degree . 13
4.2.10 Safety . 13
4.2.11 Electromagnetic compatibility (EMC) . 13
4.2.12 Accessories . 13
5 Markings and operating instructions . 13
5.1 Markings . 13
5.2 Operating instructions . 14
6 Tests . 14
6.1 General . 14
6.2 Operating uncertainty . 14
6.3 Variations . 16
6.3.1 Variation due to position . 16
6.3.2 Variation due to supply voltage . 16
6.3.3 Variation due to temperature . 16
6.3.4 Variation due to harmonics . 16
6.3.5 Variations due to external low frequency magnetic field . 16
6.3.6 Variations due to load current . 16

6.3.7 Variations due to touch current caused by common mode voltage (if
applicable) . 16
6.3.8 Variations due to frequency of measured leakage current with direct
method or differential method . 17
6.3.9 Variations due to repeated clamping (if applicable) . 17
6.4 Tests of measuring circuits according to measuring functions . 17
6.5 Test of construction requirements of test and measurement equipment . 17
Annex A (normative) Measuring circuit MD . 18
A.1 Current measuring circuit MD . 18
A.2 Frequency characteristic of current measuring circuit MD . 18

Figure A.1 – Example of a current measuring circuit MD . 18
Figure A.2 – Example of a frequency characteristic of current measuring circuit MD . 19

Table 1 – Determination of operating uncertainty . 15
Table 2 – Compliance tests of measuring circuits according to measuring function . 17
Table 3 – Compliance test of construction requirements of test and measuring
equipment . 17

– 4 – IEC 61557-16:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
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 16: Equipment for testing the effectiveness of the protective
measures of electrical equipment and/or medical electrical equipment

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
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agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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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
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Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61557-16 has been prepared by IEC technical committee 85:
Measuring equipment for electrical and electromagnetic quantities.
The text of this standard is based on the following documents:
FDIS Report on voting
85/487/FDIS 85/504/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

This part of IEC 61557 shall be used in conjunction with Part 1.
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 a.c. and 1 500 V d.c. – 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 publication will remain unchanged until
the stability date indicated on the IEC web site 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.
– 6 – IEC 61557-16:2014 © IEC 2014
INTRODUCTION
This part of IEC 61557 defines performance requirements for measuring equipment using
measuring methods described in IEC 62353, especially for evaluation of leakage currents
within electrical equipment. It is the intention of this standard to achieve comparable
measuring results, additional safety for the testing person and negligible electrical stress for
the unit under test.
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 16: Equipment for testing the effectiveness of the protective
measures of electrical equipment and/or medical electrical equipment

1 Scope
This part of IEC 61557 defines performance requirements for test and measurement
equipment to determine the effectiveness of the protective measures of electrical measures
for electrical equipment and/or medical electrical equipment described in IEC 62353.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 61000-4-8, Electromagnetic compatibility (EMC) – Part 4-8: Testing and measurement
techniques – Power frequency magnetic field immunity test
IEC 61010-1, Safety requirements for electrical equipment for measurement, control, and
laboratory use – Part 1: General requirements
IEC 61010-031, Safety requirements for electrical equipment for measurement, control and
laboratory use – Part 031: Safety requirements for hand-held probe assemblies for electrical
measurement and test
IEC 61010-2-030, Safety requirements for electrical equipment for measurement, control, and
laboratory use – Part 2-030: Particular requirements for testing and measuring circuits
IEC 61010-2-032, Safety requirements for electrical equipment for measurement, control and
laboratory use – Part 2-032: Particular requirements for hand-held and hand-manipulated
current sensors for electrical test and measurement
IEC 61326-1, Electrical equipment for measurement, control and laboratory use – EMC
requirements – Part 1: General requirements
IEC 61326-2-2, Electrical equipment for measurement, control and laboratory use – EMC
requirements – Part 2-2: Particular requirements – Test configurations, operational conditions
and performance criteria for portable test, measuring and monitoring equipment used in low-
voltage distribution systems
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
– 8 – IEC 61557-16:2014 © IEC 2014
IEC 61557-2, 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
IEC 61557-4:2007, 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 4:
Resistance of earth connection and equipotential bonding
IEC 61557-10, 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
10: Combined measuring equipment for testing, measuring or monitoring of protective
measures
IEC 61557-13:2011, 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
IEC 62353, Medical electrical equipment – Recurrent test and test after repair of medical
electrical equipment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61557-1,
IEC 61557-2, IEC 61557-4, IEC 61557-10 and, IEC 61557-13 (if applicable) and the following
apply.
3.1
test socket outlet
socket outlet on the test equipment for the unit under test, separated from the active parts of
the mains circuit by double insulation
3.2
mains socket outlet
socket outlet on the test equipment used to supply mains to the equipment under test
3.3
combined test-mains socket outlet
socket outlet on the test equipment that can be switched to either test-condition and/or supply
condition
3.4
service socket
socket outlet on the test equipment to supply mains to further test equipment or additional
equipment
3.5
test terminal
terminal used independently, in parallel or in combination, with the test socket
3.6
measuring circuit MD
electric circuit with defined components and defined frequency characteristic
3.7
peak factor
ratio of the maximum absolute value of an alternating quantity to its root-mean-square value

[SOURCE: IEC 60050-103:2009, 103-06-15]
4 Requirements
4.1 Measurement requirements for measuring equipment
4.1.1 General
The measuring equipment shall be capable of measuring at least the following quantities:
– resistance of protective bonding and/or protective earth resistance,
– insulation resistance,
– protective conductor current and/or equipment leakage current,
– touch current and/or applied part leakage current.
The operating uncertainty for all measured parameters within the required ranges at the
applicable limits according to IEC 62353 shall be ± 15 % at the maximum. This requirement
shall be fulfilled for the measurement of leakage currents within a frequency range given by
the frequency characteristic of the measuring circuit MD.
If external current clamps are connected to the test and measurement equipment, they shall
comply with the requirements of IEC 61557-13 and their operating uncertainty shall be
included in the operating uncertainty of the measurement. In case of current clamps of class 2
and class 1 and external magnetic fields of 30 A/m and 100 A/m, the overall operating
uncertainty may be extended to ± 20 % (class 2 and 30 A/m) or ± 30 % (class 1 and 100 A/m).
The operating uncertainty shall be determined according to IEC 61557-1 with the influence
quantities E , E , E , E modified, E , E , and, if applicable, E , E , E according to
1 2 3 9 11 12 13 14 15
IEC 61557-13.
4.1.2 Measurement of the resistance of the protective bonding or the protective earth
resistance
The measuring equipment shall be in accordance with IEC 61557-4. The withstand capability
against extraneous voltages is not required if the test and measurement equipment is not
intended to be used on fixed installed or permanently connected equipment.
The measuring circuit MD shall be separated from the active parts of mains by double or
reinforced insulation according to IEC 61010-1. The protective conductor may be connected
but parallel earth connections shall be indicated and/or taken into account by the test and
measurement equipment.
In case of calibrated detachable test leads, the calibration shall be indicated and the
indication shall continue as long as the calibration is valid.
The measuring range shall include the values between 0,05 Ω and 1,99 Ω and the display
shall have a minimum resolution of 0,01 Ω. Within the range of 0,1 Ω and 1,99 Ω, the
measuring current shall not be below 0,2 A. The operating uncertainty shall be within the
limits of 4.1.
Continuous measurements shall be possible for measuring currents below 5 A. For higher
currents a limitation is allowed after a specified time or by temperature control.

– 10 – IEC 61557-16:2014 © IEC 2014
4.1.3 Measurement of insulation resistance
The measuring equipment shall be in accordance with IEC 61557-2. The withstand capability
against extraneous voltages is not required if the test and measurement equipment is not
intended to test fixed installed or permanently connected equipment.
The measuring range shall include the values between 100 kΩ and 100 MΩ and the operating
uncertainty shall be within the limits of 4.1. If the test and measurement equipment is not
intended to test applied parts type F according to IEC 62353, the measuring range is limited
to 10 MΩ.
The measuring circuit shall be separated from the active parts of mains by double or
reinforced insulation according to IEC 61010-1. The protective conductor may be connected.
4.1.4 Measurement of protective conductor current and/or equipment leakage current
with the alternative method
If the test and measurement equipment includes the alternative method, the following
requirements for the measuring circuit apply:
– sinusoidal test voltage at mains frequency, THD shall not exceed 5 %;
– open circuit test voltage between 25 V and 250 V. If test and measurement equipment is
specified according to IEC 62353 the test voltage shall be on the same level as the
nominal mains supply voltage;
– current measuring range between 0,02 mA and 19,99 mA at the minimum;
– minimum resolution 0,01 mA;
– current measuring circuit MD;
– output current limitation to 3,5 mA for test voltages above 50 V;
– recalculation of the measuring result up to the nominal supply voltage.
If the test and measurement equipment is intended only for tests on non-medical equipment
the lower limit of the measuring range may be increased to 0,2 mA and the resolution to
0,1 mA.
The measuring circuit shall be separated from the active parts of mains by double or
reinforced insulation according to IEC 61010-1. The protective conductor may be connected.
4.1.5 Measurement of touch current, patient leakage current and applied part leakage
current with the alternative method
If the test and measurement equipment includes the alternative method, the following
requirements for the measuring circuit apply:
– sinusoidal test voltage at mains frequency,
– open circuit test voltage between 25 V and 250 V. If test and measurement equipment is
specified according to IEC 62353 the test voltage shall be equal to the nominal mains
supply voltage,
– current measuring range between 0,02 mA and 19,99 mA at the minimum,
– minimum resolution 0,001 mA,
– current measuring circuit MD,
– output current limitation to 3,5 mA for test voltages above 50 V,
– recalculation of the measuring result up to the nominal supply voltage.
If the test and measurement equipment is intended only for tests on non-medical equipment,
the lower limit of the measuring range may be increased to 0,1 mA and the resolution to
0,01 mA.
The measuring circuit shall be separated from the active parts of mains by double or
reinforced insulation according to IEC 61010-1.The protective conductor may be connected.
4.1.6 Measurement of protective conductor current and or equipment leakage current
with the direct method or differential method (residual method)
If the test and measurement equipment includes the direct method or differential method the
following requirements apply:
– measurement in both polarities of mains supply voltage in case of single phase equipment,
– current measuring range (frequency weighted) between 0,01 mA and 19,99 mA at the
minimum,
– current measuring range (non-frequency weighted according to Figure A.2) shall be
specified,
– minimum resolution 0,01 mA,
– current measuring circuit MD for the direct method,
– measurement of r.m.s values up to a peak factor 2 at the minimum taking into account the
required frequency characteristic see Annex A. In case of differential method the lower
limit of frequency range is 40 Hz and the upper limit shall include 100 kHz at the minimum.
If the test and measurement equipment is intended only for tests on non-medical equipment,
the lower limit of the measuring range is increased to 0,1 mA and the resolution to 0,1 mA.
The test and measurement equipment shall provide additional protective means against
electric shock or fire when the units under test are in single fault condition.
In case of automatic test sequences, the unit under test shall not be connected to the supply
voltage as long as the applicable limits for resistance of protective bonding and insulation
resistance according to IEC 62353 are exceeded.
In case of non-automatic test sequences, the test and measurement equipment shall indicate
or display a warning to be aware of connection to the mains supply
If external current clamps are used for measurements, they shall comply with the
requirements of IEC 61557-13 and their operating uncertainty shall be included. The lower
limit of measuring range may be increased to 1 mA. In case of current clamps of class 2 and
class 1 and external magnetic fields of 30 A/m and 100 A/m, the overall operating uncertainty
may be extended to 20 % (class 2 and 30A/m) and 30 % (class 1 and 100 A/m). Leakage
currents shall be evaluated according to the frequency characteristic beginning at 40 Hz and
up to 10 kHz at the minimum and a warning shall be added to the operating instructions in 5.2.
4.1.7 Measurement of touch current, patient leakage current and applied part leakage
current with the direct method or differential method (residual method)
If the test and measurement equipment includes the direct method or differential method, the
following requirements apply:
– measurement in both polarities of mains supply voltage in case of single phase equipment;
– current measuring range (frequency weighted according to Figure A.2) between 0,01 mA
and 1,999 mA at the minimum;
– current measuring range (non-frequency weighted) shall be specified;
– minimum resolution 0,001 mA;
– current measuring circuit MD for the direct method,
– measurement of r.m.s values up to a peak factor of 2 at the minimum taking in account the
required frequency characteristic see Annex A. In case of the differential method, the

– 12 – IEC 61557-16:2014 © IEC 2014
lower limit of the frequency range shall be 40 Hz and the upper limit shall include 100 kHz
at the minimum.
If the test and measurement equipment is intended only for tests on non-medical equipment,
the lower limit of the measuring range may be increased to 0,1 mA and the resolution to
0,01 mA.
The test and measurement equipment shall provide additional protective means against
electric shock and fire in case of faulty units under test.
In case of automatic test sequences, the unit under test shall not be connected to the supply
voltage as long as the applicable limits for resistance of protective bonding and insulation
resistance according to IEC 62353 are exceeded.
In case of non-automatic test sequences, the test and measurement equipment shall indicate
or display a warning to make aware of connection to the mains supply.
4.2 Construction requirements for testing equipment
4.2.1 Overload capability
The overload capability of test and measurement equipment shall be in accordance with the
requirements of IEC 61557-10, if the test and measurement equipment is intended to test
fixed installed or permanently connected equipment.
4.2.2 Terminals
All terminals shall be designed in such a way that, during connection, it will not be possible for
an operator to unintentionally touch a hazardous live part.
4.2.3 Sockets for service purposes
Sockets for the connection of further external equipment shall be clearly marked. Protection
against overcurrent and short-circuits shall be provided. Protection against electric shock
shall be achieved by using an RCD with a tripping current of 30 mA at the maximum. The
inner wiring of the service socket shall be designed according to the maximum nominal
current, but at least for 16 A.
4.2.4 Degree of protection
The degree of protection for the enclosure, except service-sockets and terminals, shall be at
least IP40 in accordance with IEC 60529.
4.2.5 Class of protection
Measuring equipment intended to be hand-held during measurement shall be double insulated
according to IEC 61010-1 and IEC 61010-2-030. Other equipment may be protected by
protective bonding.
4.2.6 Resistance of protective bonding
The resistance between protective conductor terminal and connected conductive parts
including the protective conductor terminal of service-sockets shall not exceed 0,1 Ω.
4.2.7 Battery control
Battery control circuits shall be in accordance with IEC 61557-1:2007, 4.3.

4.2.8 Mechanical requirements
The vibrational test requirements according to IEC 61557-1:2007, 4.10 apply.
4.2.9 Pollution degree
The measurement equipment shall be designed for at least pollution class 2 in accordance
with IEC 61557-1:2007, 4.6.
4.2.10 Safety
4.2.10.1 General
Test and measurement equipment shall be in accordance with IEC 61010-1, with
IEC 61010-2-030 and, if applicable, with IEC 61010-2-032.
4.2.10.2 Overvoltage category
The supply circuit should be designed to overvoltage category II in accordance with
IEC 61010-1.
4.2.10.3 Measurement category
Measuring circuits of the test and measurement equipment shall be rated at least for CAT II
according to IEC 61010-2-030. If the test and measurement equipment is not intended to test
fixed installed or permanently connected equipment, measuring circuits to measure resistance
of protective bonding, insulation resistance or leakage currents with the alternative method
may be classified as secondary circuits according to IEC 61010-2-030. External current
clamps shall be rated for CAT II at the minimum.
For safety reasons, it is advisable to give a warning that there might be a possible connection
to the unit under power supply.
4.2.11 Electromagnetic compatibility (EMC)
The measuring equipment shall be in accordance with the requirements of IEC 61326-2-2 and
in addition with the requirements of IEC 61326-1 for industrial locations.
4.2.12 Accessories
Specified accessories shall be in accordance with the requirements of IEC 61010-031.
Current clamps shall be type A in accordance with the requirements of IEC 61010-2-032.
5 Markings and operating instructions
5.1 Markings
In addition to the requirements of IEC 61010-1, IEC 61010-2-030, IEC 61557-1 and other
applicable parts of IEC 61557, the measuring equipment shall have the following markings
clearly visible:
– service-socket, if applicable, with maximum rated current,
– test and measurement terminals,
– measuring function,
– instructions for connection.
Markings may be visible on a display.

– 14 – IEC 61557-16:2014 © IEC 2014
5.2 Operating instructions
In addition to the requirements of IEC 61010-1, IEC 61010-2-030 and IEC 61557-1 the
operating instructions shall include the following information:
– warnings about possible hazards during connection of unit under test to the mains power
supply,
– operating uncertainty, intrinsic uncertainty, influencing quantities and their effect,
– recommendations about intervals for recalibration,
– a warning, not to use external clamps with a reduced frequency range according to 4.1.6
for measuring leakage currents of EUTs who are able to generate leakage currents with
frequencies above 10 kHz or above the specified frequency range of the clamp,
– if applicable, a warning not to use the test and measuring equipment on fixed installed or
permanently connected equipment.
6 Tests
6.1 General
Safety of measuring equipment shall be tested according to IEC 61010-1, IEC 61010-2-030,
IEC 61010-2-032 and IEC 61010-031, if not otherwise stated. All tests shall be carried out
under reference conditions, if not otherwise stated.
6.2 Operating uncertainty
The percentage operating uncertainty shall be determined according to IEC 61557-1:2007, 4.1
taking into account applicable influencing quantities according to Table 1.
The intrinsic uncertainty A shall be determined for each measured parameter under the
following reference conditions (routine test):
– nominal system voltage,
– nominal system frequency,
– reference temperature (23 °C ± 2 °C),
– reference position according to manufacturer’s specification,
– nominal supply voltage or battery voltage,
– no low-frequency external magnetic field,
– specified load current for the differential method (50 % of the maximum load current or
higher).
The intrinsic uncertainty A shall be determined at least at the upper and lower limit of the
measuring range. Digitizing error, non-linearity and traceability shall be taken into account.
The highest value shall be used for the calculation of the operating uncertainty.

Table 1 – Determination of operating uncertainty
Intrinsic Reference conditions or specified operating range Designation Requirements Type
uncertainty or code or test of
influencing according to test
quantity
Intrinsic Reference conditions A 6.2, R
uncertainty
IEC 61557-
13:2011, 4.4
and 6.2
Position Reference position ± 90° E 6.3.1, T
For clamps: IEC 61557-13
Reference position ±30°, for any position within the
clamp jaws, if no fixing device is specified
Mains supply 85 % and 110 % E 6.3.2 T
voltage
Battery As specified
voltage
Temperature 0 °C to +35 °C or extended range specified by the E 6.3.3 T
manufacturer
rd
Distorted 5 % of 3 harmonic at 0° E 6.3.4, T
waveform
th
6 % of 5 harmonic at 180° IEC 61557-
13:2011, 4.1,
th
5 % of 7 harmonic at 0°
6.1
External low For test equipment: 30 A/m E 6.3.5, T
frequency IEC 61557-
For current clamps:
magnetic field 13:2011, 4.2
15 Hz to
Operating class 1 at 100 A/m
400 Hz
30 A/m
according to
10 A/m
IEC 61000-4-8
Operating class 2 at 30 A/m
10 A/m
Operating class 3 at 10 A/m
Load current Nominal range of load current according to E 6.3.6, T
manufacturer’s specification
IEC 61557-
13:2011, 4.1
Touch current Touch current through circuit A1 according to E 6.3.7, T
caused by IEC 61010-1 between hand-held parts (covered with
IEC 61557-
common mode metal foil) and earth. Conductor held at maximum
13:2011, 4.5
voltage common mode voltage and highest rated mains
frequency.
Repeatability Difference between the highest and lowest value of E 6.3.9, R
the intrinsic uncertainty
IEC 61557-
13:2011, 4.5
Percentage T
operating
uncertainty
B
B%= ⋅100%
Fiducial
R routine test
T type test
A intrinsic uncertainty
B operating uncertainty
E further variations, if applicable
n
– 16 – IEC 61557-16:2014 © IEC 2014
6.3 Variations
6.3.1 Variation due to position
If applicable, the variation E due to position shall be determined in positions +90° and –90°
from the reference position for all measuring functions (routine test).
6.3.2 Variation due to supply voltage
The variation E due to supply voltage shall be determined for all measuring functions under
the following conditions (routine test):
– for measuring equipment with mains supply at -15 % and +10 % of the nominal voltage;
– for measuring equipment with battery supply at the limits defined in IEC 61557-1:2007, 4.3.
6.3.3 Variation due to temperature
The variation E due to temperature shall be determined for all measuring functions under the
following conditions:
– at 0 °C and +35 °C after the equipment will have reached steady state conditions (type
test).
6.3.4 Variation due to harmonics
The variation E due to harmonics shall be determined for the measurement of leakage
currents with the direct or differential method at:
rd
– 5 % of 3 harmonic / 0° phase shift
th
– 6 % of 5 harmonic / 180° phase shift
th
– 5 % of 7 harmonic / 0° phase shift
In addition the variation due to the peak factor shall be determined at:
rd
– 30 % of 3 harmonic/ 180° phase shift
th
– 3,4 % of 7 harmonic / 180° phase shift
The variation shall be determined at the values of all applicable limits of leakage currents
according to IEC 62353. The highest variation shall be used for calculation.
The percentage of harmonics shall be determined from the nominal wave (type test).
6.3.5 Variations due to external low frequency magnetic field
The variation E due to external low frequency magnetic field shall be determined at a field
strength of 30 A/m, and for external current clamps according to IEC 61
...