IEC 61326-2-4:2012

IEC 61326-2-4 ®
Edition 2.0 2012-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical equipment for measurement, control and laboratory use –
EMC requirements –
Part 2-4: Particular requirements – Test configurations, operational conditions and
performance criteria for insulation monitoring devices according to IEC 61557-8 and
for equipment for insulation fault location according to IEC 61557-9

Matériel électrique de mesure, de commande et de laboratoire – Exigences relatives
à la CEM –
Partie 2-4: Exigences particulières – Configurations d'essai, conditions de
fonctionnement et critères de performance pour les contrôleurs d'isolement conformes
à la CEI 61557-8 et pour les dispositifs de localisation de défaut d’isolement conformes
à la CEI 61557-9
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IEC 61326-2-4 ®
Edition 2.0 2012-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical equipment for measurement, control and laboratory use –

EMC requirements –
Part 2-4: Particular requirements – Test configurations, operational conditions and

performance criteria for insulation monitoring devices according to IEC 61557-8 and

for equipment for insulation fault location according to IEC 61557-9

Matériel électrique de mesure, de commande et de laboratoire – Exigences relatives

à la CEM –
Partie 2-4: Exigences particulières – Configurations d'essai, conditions de

fonctionnement et critères de performance pour les contrôleurs d'isolement conformes

à la CEI 61557-8 et pour les dispositifs de localisation de défaut d’isolement conformes

à la CEI 61557-9
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX N
ICS 17.220; 19.080; 25.040.40; 33.100 ISBN 978-2-83220-209-8

– 2 – 61326-2-4 © IEC:2012
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 General . 6
5 EMC test plan . 6
5.1 General . 6
5.2 Configuration of EUT during testing . 7
5.2.1 General . 7
5.2.2 Composition of EUT . 7
5.2.3 Assembly of EUT . 7
5.2.4 I/O ports . 7
5.2.5 Auxiliary equipment . 7
5.2.6 Cabling and earthing (grounding) . 7
5.3 Operation conditions of EUT during testing . 7
5.3.101 Operational conditions . 7
5.4 Specification of functional performance . 8
5.5 Test description . 8
6 Immunity requirements . 8
6.1 Conditions during the tests . 8
6.1.101 Electrostatic discharge immunity tests . 8
6.1.102 Electromagnetic field tests . 9
6.1.103 Burst tests . 9
6.1.104 Surge immunity tests. 9
6.1.105 Conducted RF tests . 9
6.1.106 Power frequency magnetic field tests . 9
6.2 Immunity test requirements . 9
6.3 Random aspects. 10
6.4 Performance criteria . 10
7 Emission requirements . 12
7.1 Conditions during measurements. . 12
7.2 Emission limits . 12
8 Test results and test report . 12
9 Instructions for use . 13
Annex A (normative) Immunity test requirements for portable test and measurement
equipment powered by battery or from the circuit being measured . 14
Bibliography . 15

Table 101 – Immunity tests . 10
Table 102 – Performance criteria definition . 11
Table 103 – Test conditions for quiescent and operate modes . 12

61326-2-4 © IEC:2012 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL EQUIPMENT FOR MEASUREMENT,
CONTROL AND LABORATORY USE –
EMC REQUIREMENTS –
Part 2-4: Particular requirements –
Test configurations, operational conditions and performance
criteria for insulation monitoring devices according to IEC 61557-8
and for equipment for insulation fault location according to IEC 61557-9

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
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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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 61326-2-4 has been prepared by subcommittee 65A: System
aspects, of IEC technical committee 65: Industrial-process measurement, control and
automation.
This second edition cancels and replaces the first edition published in 2006. This edition
constitutes a technical revision.

– 4 – 61326-2-4 © IEC:2012
This edition includes the following significant technical change with respect to the previous
edition:
– update of the document with respect to IEC 61326-1:2012.
The text of this standard is based on the following documents:
FDIS Report on voting
65A/630/FDIS 65A/639/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 the IEC 61326 series is to be used in conjunction with IEC 61326-1:2012 and
follows the same numbering of clauses, subclauses, tables and figures.
When a particular subclause of IEC 61326-1 is not mentioned in this part, that subclause
applies as far as is reasonable. When this standard states “addition”, “modification” or
“replacement”, the relevant text in IEC 61326-1 is to be adapted accordingly.
NOTE The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in IEC 61326-
1;
– unless notes are in a new subclause or involve notes in IEC 61326-1, they are numbered starting from
101 including those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
A list of all parts of the IEC 61326 series, under the general title Electrical equipment for
measurement, control and laboratory use, control and laboratory use – EMC requirements 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.
61326-2-4 © IEC:2012 – 5 –
ELECTRICAL EQUIPMENT FOR MEASUREMENT,
CONTROL AND LABORATORY USE –
EMC REQUIREMENTS –
Part 2-4: Particular requirements –
Test configurations, operational conditions and performance
criteria for insulation monitoring devices according to IEC 61557-8
and for equipment for insulation fault location according to IEC 61557-9

1 Scope
In addition to IEC 61236-1, this part of IEC 61326 specifies more detailed test configurations,
operational conditions and performance criteria than IEC 61326-1 for equipment for
– insulation monitoring according to IEC 61557-8;
– insulation fault location according to IEC 61557-9.
This applies to insulation monitoring devices and insulation fault location systems
permanently or semi-permanently connected to the distribution system.
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.
Clause 2 of IEC 61326-1:2012 applies, except as follows:
Addition:
IEC 61326-1:2012, Electrical equipment for measurement, control and laboratory use – EMC
requirements – Part 1: General requirements
IEC 61557-8:2007, 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 8: Insulation monitoring devices for IT systems
IEC 61557-9:2009, 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
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61326-1 apply,
except as follows.
Addition:
– 6 – 61326-2-4 © IEC:2012
3.101
insulation resistance
R
F
resistance in the system being monitored, including the resistance of all the connected
appliances to earth
[SOURCE: IEC 61557-8:2007, 3.2]
3.102
specified response value
R
an
value of the insulation resistance, permanently set or adjustable, on the device and monitored
if the insulation resistance falls below this limit
[SOURCE: IEC 61557-8:2007, 3.3]
3.103
response sensitivity
value of the evaluating current or insulation resistance at which the evaluator responds under
specified conditions
[SOURCE: IEC 61557-9:2009, 3.4]
3.104
nominal voltage of the distribution system
U
n
voltage by which a distribution system or equipment is designated and to which certain
operating characteristics are referred
[SOURCE: IEC 61557-1:2007, 3.1]
3.105
supply voltage
U
S
voltage at a point where the measuring equipment does or can accept electric energy as a
supply
[SOURCE: IEC 61557-1:2007, 3.8, modified]
3.106
system leakage capacitance
C
e
maximum permissible value of the total capacitance to earth of the system to be monitored,
including any connected appliances, up to which value the insulation monitoring device can
work as specified
[SOURCE: IEC 61557-8:2007, 3.6]
4 General
Clause 4 of IEC 61326-1:2012 applies.
5 EMC test plan
5.1 General
Subclause 5.1 of IEC 61326-1:2012 applies.

61326-2-4 © IEC:2012 – 7 –
5.2 Configuration of EUT during testing
5.2.1 General
Subclause 5.2.1 of IEC 61326-1:2012 applies, except as follows.
Addition:
During the tests, the EUT is supplied as specified by the manufacturer.
For EUT having several ratings, the EUT shall be connected
– to the lowest nominal supply voltage U ;
S
– to the highest nominal voltage of the distribution system U , but not more than 400 V.
n
If the EUT has only a combined terminal for the supply voltage and the voltage of the
distribution system, it shall be connected to the highest nominal voltage, but not more than
400V.
If the EUT has interfaces for remote functions, they shall be connected during the tests as
specified by the manufacturer for normal installation.
Insulation monitoring devices and equipment for insulation fault location shall be tested
separately.
5.2.2 Composition of EUT
Subclause 5.2.2 of IEC 61326-1:2012 applies.
5.2.3 Assembly of EUT
Subclause 5.2.3 of IEC 61326-1:2012 applies.
5.2.4 I/O ports
Subclause 5.2.4 of IEC 61326-1:2012 applies.
5.2.5 Auxiliary equipment
Subclause 5.2.5 of IEC 61326-1:2012 applies.
5.2.6 Cabling and earthing (grounding)
Subclause 5.2.6 of IEC 61326-1:2012 applies.
5.3 Operation conditions of EUT during testing
Subclause 5.3 of IEC 61326-1:2012 applies, except as follows.
Addition:
5.3.101 Operational conditions
The EUT shall be set as specified by the manufacturer for normal operation.
If the EUT has adjustable specified response values, tests shall be performed as follows:

– 8 – 61326-2-4 © IEC:2012
– for insulation monitoring devices, one value shall be selected by the manufacturer among
the following possibilities:
• at the value equal or closest to the internal d.c. resistance value;
• at the value equal or closest to the internal a.c. impedance value;
– for insulation fault location equipment at the value in the middle of the response sensitivity
range;
The insulation resistance shall be simulated by a single phase insulation resistance.
If the EUT has a selectable time delay, the time delay shall be set to the minimum value.
The system leakage capacitance shall be set to the maximum value as defined by the
manufacturer but not more than 1 µF. The system leakage capacitance is to be installed
symmetrically to all phases of U . For example:
n
– 2 × 0,5 µF for single-phase a.c. and d.c. systems,
– 3 × 0,33 µF for 3-phase a.c. systems.
5.4 Specification of functional performance
Subclause 5.4 of IEC 61326-1:2012 applies.
5.5 Test description
Subclause 5.5 of IEC 61326-1:2012 applies.
6 Immunity requirements
6.1 Conditions during the tests
Subclause 6.1 of IEC 61326-1:2012 applies, except as follows.
Addition:
The configuration and modes of operation during the tests shall be precisely noted in the test
report.
Tests shall be applied to the relevant ports in accordance with Table 101.
The tests shall be conducted in accordance with the basic standards. The tests shall be
carried out one at a time. If additional methods are required, the method and rationale shall
be documented.
6.1.101 Electrostatic discharge immunity tests
The test shall only be applied to parts of the EUT which are accessible to the user in normal
operations, for example, push-buttons, displays; this test does not apply to connection
terminals.
Electrostatic discharges of positive and negative polarity shall be applied 10 times to each of
the selected test points.
The points of application shall be stated in the report.

61326-2-4 © IEC:2012 – 9 –
6.1.102 Electromagnetic field tests
The dwell time for each frequency shall be 1,5 times the longest response time of the EUT
specified by the manufacturer, plus the time delay, see 5.3. The actual dwell time shall be
stated in the test report
6.1.103 Burst tests
Ports for remote control functions shall be tested separately. Cables for functions not tested
shall be disconnected.
The bursts shall be applied for a minimum time of 1 min, however, the time of application shall
be greater than the response time of the EUT specified by the manufacturer.
6.1.104 Surge immunity tests
In deviation from the general test conditions of 5.2.1 this test is applied at the maximum
supply voltage U .
S
Pulses both with positive and negative polarity shall be injected with a phase angle being 90°
and 270°.
A series of five pulses is applied for each polarity and each phase angle with a time between
the pulses of 1 min or less.
6.1.105 Conducted RF tests
The dwell time for each frequency shall be 1,5 times the longest response time of the EUT
specified by the manufacturer, plus the time delay (see 5.3). The actual dwell time shall be
stated in the test report.
6.1.106 Power frequency magnetic field tests
The test is performed only on EUT with integrated magnetic sensitive components.
6.2 Immunity test requirements
Subclause 6.2 of IEC 61326-1:2012 does not apply.
Replacement:
The immunity requirements are given in Table 101.
NOTE The required tests correspond to the required tests applicable for equipment of industrial electromagnetic
environments.
– 10 – 61326-2-4 © IEC:2012
Table 101 – Immunity tests
Port Phenomenon Basic standard Test value Performance
criteria
(as defined
in 6.4)
Enclosure Electrostatic IEC 61000-4-2 4 kV contact discharge, A2
discharge (ESD) 8 kV air discharge A2
Enclosure Electromagnetic field IEC 61000-4-3 80 MHz to 1 000 MHz, 10 V/m A1
1,4 GHz to 2 GHz, 3 V/m A1
2,0 GHz to 2,7 GHz, 1 V/m A1
80 % AM modulation
AC and DC power Fast transients IEC 61000-4-4 2 kV (5/50 ns, 5 kHz) A2
supply, AC and DC (burst)
connections to
distribution system
(including
connection to earth)
and I/O signal /
control connected
directly to
distribution network
I/O signal / control 1 kV (5/50 ns, 5 kHz) A2
(including functional
earth lines and
remote connections)
AC power supply, Surge IEC 61000-4-5 2 kV line to earth B
AC connections to
1 kV line to line A2
distribution system
(including
connection to earth)
and I/O signal /
control connected
directly to
distribution network
I/O signal / control 1 kV line to earth B
(including functional
earth lines and
remote connections)
All ports except Conducted RF IEC 61000-4-6 150 kHz to 80 MHz, 10 V A1
enclosure port
Common mode
80 % AM modulation
Enclosure Power frequency IEC 61000-4-8 30 A/m A1
magnetic field
Only for EUT with integrated
magnetic sensitive
components
AC power Voltage dip IEC 61000-4-11 0% during 1 cycle, A2
a
40 % during 10/12 cycles C
a
70 % during 25/30 cycles C
a
Short interruptions IEC 61000-4-11 0 % during 250/300 cycles C
a
For example “25/30 cycles” means “25 cycles for 50 Hz test” or “30 cycles for 60 Hz test”.

6.3 Random aspects
Subclause 6.3 of IEC 61326-1:2012 applies.
6.4 Performance criteria
Subclause 6.4 of IEC 61326-1:2012 does not apply.

61326-2-4 © IEC:2012 – 11 –
Replacement:
The performance criteria A1, A2 and B for the evaluation of the immunity test results are
given in Table 102. The performance criteria C defined in IEC 61326-1:2012, 6.4.4 applies.
Table 102 – Performance criteria definition
Function Criterion A1 Criterion A2 Criterion B
(for permanent phenomena) (for transient phenomena)
a a a
Alarm In Quiescent mode : The In Quiescent mode : The In Quiescent mode : The
functions alarm digital output and the alarm digital output and the alarm digital output and the
visual indicators shall not visual indicators shall not visual indicators may switch
switch to the alarm state switch to the alarm state to the alarm state but shall
during the test. during the test. not remain in the alarm state
after the test.
a a a
In Operate mode : The alarm In Operate mode : The alarm In Operate mode : The alarm
digital output and the visual digital output and the visual digital output and the visual
indicators shall switch to the indicators shall switch to the indicators need not remain in
alarm state and remain in the alarm state and remain in the the alarm state during this
alarm state during the test. alarm state during the test. test but shall switch to or
remain in the alarm state after
the test.
Measurement When insulation fault location During the test, the During the test, the
functions equipment include indicators measurement functions may measurement functions may
for the insulation resistance or be transiently influenced. be transiently influenced.
equivalent values, the After the test, the EUT shall After the test, the EUT shall
measurement uncertainty continue to operate as continue to operate as
during the immunity test shall intended for normal operation. intended for normal operation.
not be greater than the
specified measurement
uncertainty declared by the
manufacturer.
Man Machine Visual indicators (for example, Visual indicators (for example, Visual indicators (for example,
Interface displays, LEDs) and remote displays, LEDs) and remote displays, LEDs) and remote
functions control shall work as functions (for example, functions (for example,
intended. analogue or digital control analogue or digital control
interfaces) may be transiently interfaces) may be transiently
influenced. influenced.
a
Quiescent mode and Operate mode are defined in Table 103.

– 12 – 61326-2-4 © IEC:2012
Table 103 – Test conditions for quiescent and operate modes
Operation modes Definition
Quiescent mode (the device is For devices allowing the specified response value R to be configured within
an
operating under conditions where a range of values, the test shall be performed in accordance with 5.3.101.
– as a result of insulation
For devices with a fixed value for the specified response value R , the test
resistance measurement – no an
shall be made with this specified value.
alarm should be detected)
For insulation monitoring devices, an insulation resistance R of 1,3 × R is
F an
applied.
For equipment for insulation fault location, the following values shall be
applied:
– for equipment evaluating the insulation resistance: 1,3 × (the specified
response sensitivity plus uncertainty of response sensitivity declared by the
manufacturer).
– for equipment evaluating the current: 0,7 × (the specified response
sensitivity minus uncertainty of response sensitivity declared by the
manufacturer).
Operate mode (the device is in a For devices allowing R to be configured within a range of values, the test
an
mode where an alarm should be shall be performed in accordance with 5.3.101.
detected)
For devices with a fixed value for R , the test shall be made with this
an
specified value.
For insulation monitoring devices, an insulation resistance R of 0,7 × R is
F an
applied.
For equipment for insulation fault location, the following values shall be
applied:
– for equipment evaluating the insulation resistance: 0,7 × (the s
...