IEC 61000-4-9:2016

Electromagnetic compatibility (EMC) - Part 4-9: Testing and measurement techniques - Impulse magnetic field immunity test

IEC 61000-4-9:2016 specifies the immunity requirements, test methods, and range of recommended test levels for equipment subjected to impulse magnetic disturbances mainly encountered in industrial installations, power plants, railway installations, and medium voltage and high voltage sub-stations. This second edition cancels and replaces the first edition published in 1993 and Amendment 1:2000. This edition constitutes a technical revision.

Compatibilité électromagnétique (CEM) - Partie 4-9: Techniques d'essai et de mesure - Essai d'immunité au champ magnétique impulsionnel

L'IEC 61000-4-9:2016 spécifie les exigences en matière d'immunité, les méthodes d'essai et la plage des niveaux d'essai recommandés des équipements soumis aux perturbations magnétiques impulsionnelles, principalement dans les installations industrielles, centrales électriques, installations ferroviaires, et postes moyenne et haute tension. Cette deuxième édition annule et remplace la première édition parue en 1993 et l'Amendement 1:2000. Cette édition constitue une révision technique.

General Information

• Status: Published
• Publication Date: 12-Jul-2016
• ICS: 29.080.10 - Insulators
• ICS: 29.240.20 - Power transmission and distribution lines
• ICS: 33.100.20 - Immunity
• Technical Committee: SC 77B - High frequency phenomena
• Drafting Committee: MT 12 - TC 77/SC 77B/MT 12
• Current Stage: PPUB - Publication issued
• Start Date: 13-Jul-2016
• Completion Date: 15-Sep-2016

Relations

• Revises: IEC 61000-4-9:1993 - Electromagnetic compatibility (EMC) - Part 4: Testing and measurement techniques - Section 9: Pulse magnetic field immunity test. Basic EMC Publication
• Effective Date: 05-Sep-2023
• Revises: IEC 61000-4-9:1993/AMD1:2000 - Amendment 1 - Electromagnetic compatibility (EMC) - Part 4: Testing and measurement techniques - Section 9: Pulse magnetic field immunity test. Basic EMC Publication
• Effective Date: 05-Sep-2023

Overview

IEC 61000-4-9:2016 is the International Electrotechnical Commission (IEC) standard that specifies immunity requirements, test methods, and recommended test levels for equipment exposed to impulse (pulse) magnetic field disturbances. Focused on environments such as industrial installations, power plants, railway systems, and medium/high-voltage substations, this 2016 edition is a technical revision of the original standard and its amendment. It defines how to generate, apply and measure pulse magnetic fields for electromagnetic compatibility (EMC) immunity testing.

Key topics and technical requirements

• Scope and objective: Defines immunity criteria and the test environment for impulse magnetic disturbances typically found in heavy-industry and utility settings.
• Test waveforms and generators: Use of a combination wave generator and defined pulse current waveforms (document covers typical surge shapes such as 6.4/16 µs and references 8/20 µs waveforms in test instrumentation).
• Induction coils: Characteristics and field-distribution guidance for standard induction coils (notably 1 m × 1 m and 1 m × 2.6 m coils), including calibration and verification requirements.
• Test setups: Procedures for table‑top, floor‑standing and in‑situ tests; immersion and proximity methods; single and double coil arrangements and orientation considerations.
• Calibration and measurement: Calibration of generators and coils, measurement uncertainty analysis, and performance characteristics of test instrumentation (including annexes on calibration methods and uncertainty contributors).
• Test execution and reporting: Laboratory reference conditions (climatic and electromagnetic), step-by-step test procedures, evaluation of results, and required test report content.

Practical applications and users

IEC 61000-4-9 is applied where equipment must be demonstrated immune to short, high‑amplitude magnetic pulses that occur in industrial power systems and transportation infrastructure. Typical users include:

• EMC test laboratories performing compliance and type‑approval testing
• Manufacturers of electrical and electronic equipment destined for industrial, railway or utility environments
• Design and compliance engineers assessing product robustness against magnetic impulse events
• Utility and infrastructure safety/standards teams specifying acceptance criteria for installed equipment

Related standards and context

• Part of the broader IEC 61000 series addressing EMC testing and measurement techniques. IEC 61000-4-9 complements other immunity test methods in the series and should be used alongside site- and product-specific EMC requirements.

Keywords: IEC 61000-4-9, impulse magnetic field immunity, EMC testing, induction coil, combination wave generator, calibration, industrial installations, power plants, railway, substations.

Standards Content (Sample)

IEC 61000-4-9 ®
Edition 2.0 2016-07
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
BASIC EMC PUBLICATION
Electromagnetic compatibility (EMC) –
Part 4-9: Testing and measurement techniques – Pulse Impulse magnetic field
immunity test
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IEC 61000-4-9 ®
Edition 2.0 2016-07
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
BASIC EMC PUBLICATION
Electromagnetic compatibility (EMC) –

Part 4-9: Testing and measurement techniques – Pulse Impulse magnetic field

immunity test
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.100.20 ISBN 978-2-8322-3533-1

– 2 – IEC 61000-4-9:2016 RLV  IEC 2016
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope and object . 9
2 Normative references. 9
3 Terms, definitions and abbreviated terms . 10
3.1 Terms and definitions . 10
3.2 Abbreviated terms . 12
4 General . 12
5 Test levels . 13
6 Test equipment .
6 Test instrumentation . 17
6.1 General . 17
6.2 Combination wave generator . 17
6.2.1 General . 17
6.2.2 Performance characteristics of the generator . 18
6.2.3 Calibration of the generator . 19
6.3 Induction coil. 19
6.3.1 Field distribution . 19
6.3.2 Characteristics of the standard induction coils of 1 m × 1 m and
1 m × 2,6 m . 20
6.4 Calibration of the test system . 20
7 Test setup . 21
7.2 Verification of the test instrumentation . 23
7.3 Test setup for impulse magnetic field applied to a table-top EUT . 23
7.4 Test setup for impulse magnetic field applied to a floor standing EUT . 24
7.5 Test setup for impulse magnetic field applied in-situ . 25
7.1 Test equipment . 21
8 Test procedure . 26
8.1 General . 26
8.2 Laboratory reference conditions . 26
8.2.1 Climatic conditions . 26
8.2.2 Electromagnetic conditions . 26
8.3 Carrying out Execution of the test . 27
9 Evaluation of test results and test report . 28
10 Test report. 29
Annex A (normative informative) Characteristics of non standard induction coils
calibration method . 33
A.1 General . 33
A.2 Determination of the coil factor . 33
A.2.1 General . 33
A.2.2 Coil factor measurement . 33
A.2.3 Coil factor calculation . 34
A.3 Magnetic field measurement . 34
A.4 Verification of non standard induction coils . 35
Annex B (normative) Characteristics of the induction coils .

Annex B (informative) Information on the field distribution of standard induction coils . 42
B.1 General . 42
B.2 1 m × 1 m induction coil . 42
B.3 1 m × 2,6 m induction coil with reference ground plane . 43
B.4 1 m × 2,6 m induction coil without reference ground plane . 45
Annex C (informative) Selection of the test levels . 46
Annex D (informative) Information on magnetic field strength .
Annex D (informative) Measurement uncertainty (MU) considerations . 49
D.1 General . 49
D.2 Legend . 49
D.3 Uncertainty contributors to the surge current and to the surge magnetic field
measurement uncertainty . 50
D.4 Uncertainty of surge current and surge magnetic field calibration . 50
D.4.1 General . 50
D.4.2 Front time of the surge current . 50
D.4.3 Peak of the surge current and magnetic field . 52
D.4.4 Duration of the current impulse . 53
D.4.5 Further MU contributions to time measurements . 54
D.4.6 Rise time distortion due to the limited bandwidth of the measuring
system . 54
D.4.7 Impulse peak and width distortion due to the limited bandwidth of the
measuring system . 55
D.5 Application of uncertainties in the surge generator compliance criterion . 56
Annex E (informative) Mathematical modelling of surge current waveforms . 57
E.1 General . 57
E.2 Normalized time domain current surge (8/20 µs) . 57
Annex F (informative) Characteristics using two standard induction coils . 60
F.1 General . 60
F.2 Particular requirements for calibration . 60
F.3 Field distribution of the double induction coil arrangement . 61
Annex G (informative) 3D numerical simulations . 63
G.1 General . 63
G.2 Simulations . 63
G.3 Comments . 63
Bibliography . 71

Figure 1 – Example of application of the test field by the immersion method .
Figure 1 – Simplified circuit diagram of the combination wave generator . 18
Figure 2 – Current waveform of the test generator for pulse magnetic field (6,4/16 µs) .
Figure 2 – Waveform of short-circuit current (8/20 µs) at the output of the generator
with the 18 µF capacitor in series . 19
Figure 3 – Schematic circuit of the test generator for pulse magnetic field (6,4/16 µs) .
Figure 3 – Example of a current measurement of standard induction coils . 20
Figure 4 – Example of test set-up for table-top equipment .
Figure 4 – Example of test setup for table-top equipment showing the vertical
orthogonal plane . 24

– 4 – IEC 61000-4-9:2016 RLV © IEC 2016
Figure 5 – Example of test set-up for floor-standing equipment .
Figure 5 – Example of test setup for floor standing equipment showing the horizontal
orthogonal plane . 24
Figure 6 – Example of investigation of susceptibility to magnetic field by
the proximity method .
Figure 6 – Example of test setup for floor standing equipment showing the vertical
orthogonal plane . 25
Figure 7 – Illustration of Helmholtz coils .
Figure 7 – Example of test setup using the proximity method . 25
Figure A.1 – Rectangular induction coil with sides a + b and c . 34
Figure A.2 – Example of verification setup for non standard induction coils . 35
Figure B.1 – Characteristics of the field generated by a square induction coil (1 m side)
in its plane .
Figure B.2 – 3 dB area of the field generated by a square induction coil (1 m side)
in its plane .
Figure B.3 – 3 dB area of the field generated by a square induction coil (1 m side)
in the mean orthogonal plane (component orthogonal to the plane of the coil) .
Figure B.4 – 3 dB area of the field generated by two square induction coils (1 m side)
0,6 m spaced, in the mean orthogonal plane (component orthogonal to the plane
of the coils) .
Figure B.5 – 3 dB area of the field generated by two square induction coils (1 m side)
0,8 m spaced, in the mean orthogonal plane (component orthogonal to the plane
of the coils) .
Figure B.6 – 3 dB area of the field generated by a rectangular induction coil (1 m × 2,6 m)
in its plane .
Figure B.7 – 3 dB area of the field generated by a rectangular induction coil (1 m × 2,6 m)
in its plane (ground plane as a side of the induction coil) .
Figure B.8 – 3 dB area of the field generated by a rectangular induction coil (1 m × 2,6 m)
with ground plane, in the mean orthogonal plane (component orthogonal to the plane of
the coil) .
Figure B.1 – +3 dB isoline for the magnetic field strength (magnitude) in the x-y plane
for the 1 m × 1 m induction coil . 42
Figure B.2 – +3 dB and –3 dB isolines for the magnetic field strength (magnitude) in
the x-z plane for the 1 m × 1 m induction coil . 43
Figure B.3 – +3 dB isoline for the magnetic field strength (magnitude) in the x-z plane
for the 1 m × 2,6 m induction coil with reference ground plane . 44
Figure B.4 – +3 dB and -3 dB isolines for the magnetic field strength (magnitude) in the
x-y plane for the 1 m × 2,6 m induction coil with reference ground plane . 44
Figure B.5 – +3 dB isoline for the magnetic field strength (magnitude) in the x-y plane
for the 1 m × 2,6 m induction coil without reference ground plane . 45
Figure B.6 – +3 dB and –3 dB isolines for the magnetic field strength (magnitude) in
the x-z plane for the 1 m × 2,6 m induction coil without reference ground plane . 45
Figure E.1 – Normalized current surge (8/20 μs): Width time response T . 58
w
Figure E.2 – Normalized current surge (8/20 μs): Rise time response T . 58
r
Figure E.3 – Current surge (8/20 μs): Spectral response with Δf = 10 kHz . 59
Figure F.1 – Example of a test system using double standard induction coils . 60
Figure F.2 – +3dB isoline for the magnetic field strength (magnitude) in the x-y plane
for the double induction coil arrangement (0,8 m spaced) . 62

Figure F.3 – +3 dB and –3 dB isolines for the magnetic field strength (magnitude) in
the x-z plane for the double induction coil arrangement (0,8 m spaced) . 62
Figure G.1 – Current and H-field in the centre of the 1 m × 1 m induction coil . 64
Figure G.2 – Hx-field along the side of 1 m × 1 m induction coil in A/m . 64
Figure G.3 – Hx-field in direction x perpendicular to the plane of the 1 m × 1 m
induction coil . 65
Figure G.4 – Hx-field along the side in dB for the 1 m × 1 m induction coil . 65
Figure G.5 – Hx-field along the diagonal in dB for the 1 m × 1 m induction coil . 66
Figure G.6 – Hx-field plot on y-z plane for the 1 m × 1 m induction coil . 66
Figure G.7 – Hx-field plot on x-y plane for the 1 m × 1 m induction coil . 67
Figure G.8 – Hx-field along the vertical middle line in dB for the 1 m × 2,6 m induction
coil . 67
Figure G.9 – Hx-field 2D plot on y-z plane for the 1 m × 2,6 m induction coil . 68
Figure G.10 – Hx-field 2D plot on x-y plane at z = 0,5 m for the 1 m × 2,6 m induction
coil . 68
Figure G.11 – Helmholtz setup: Hx-field and 2D plot for two 1 m × 1 m induction coils,
0,6 m spaced . 69
Figure G.12 – Helmholtz setup: Hx-field and 2D plot for two 1 m × 1 m induction coils,
0,8 m spaced . 70

Table 1 – Test levels . 13
Table 2 – Definitions of the waveform parameters 8/20 µs . 18
Table 3 – Specifications of the waveform time parameters of the test system . 20
Table 4 – Specifications of the waveform peak current of the test system . 21
Table D.1 – Example of uncertainty budget for surge current front time (T ) . 51
f
Table D.2 – Example of uncertainty budget for the peak of surge current (I ) . 52
P
Table D.3 – Example of uncertainty budget for current impulse width (T ) . 53
d
Table D.4 – α factor (see equation (D.10)) of different unidirectional impulse
responses corresponding to the same bandwidth of system B . 55
Table D.5 – β factor (equation (D.14)) of the standard current surge waveform . 56
Table F.1 – Specifications of the waveform peak current of this test system . 61

– 6 – IEC 61000-4-9:2016 RLV  IEC 2016
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 4-9: Testing and measurement techniques –
Impulse magnetic field immunity test

FOREWORD
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This redline version of the official IEC Standard allows the user to identify the changes
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International Standard IEC 61000-4-9 has been prepared by subcommittee 77B: High
frequency phenomena, of IEC technical committee 77: Electromagnetic compatibility.
It forms Part 4-9 of the IEC 61000 series. It has the status of a basic EMC publication in
accordance with IEC Guide 107.
This second edition cancels and replaces the first edition published in 1993 and Amendment
1:2000. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) new Annex B on induction coil field distribution;
b) new Annex D on measurement uncertainty;
c) new Annex E on mathematical modeling of surge waveform;
d) new Annex F on characteristics using two standard induction coils;
e) new Annex G on 3D numerical simulations;
f) coil factor calculation and calibration using current measurement have been addressed in
this edition.
The text of this standard is based on the following documents:
CDV Report on voting
77B/728/CDV 77B/745A/RVC
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.
A list of all parts in the IEC 61000 series, published under the general title Electromagnetic
compatibility (EMC), 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 website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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.
– 8 – IEC 61000-4-9:2016 RLV  IEC 2016
INTRODUCTION
IEC 61000 is published in separate parts according to the following structure:
Part 1: General
General considerations (introduction, fundamental principles)
Definitions, terminology
Part 2: Environment
Description of the environment
Classification of the environment
Compatibility levels
Part 3: Limits
Emission limits
Immunity limits (insofar as they do not fall under the responsibility of the product
committees)
Part 4: Testing and measurement techniques
Measurement techniques
Testing techniques
Part 5: Installation and mitigation guidelines
Installation guidelines
Mitigation methods and devices
Part 6: Generic standards
Part 9: Miscellaneous
Each part is further subdivided into several parts, published either as international standards
or as technical specifications or technical reports, some of which have already been published
as sections. Others will be published with the part number followed by a dash and a second
number identifying the subdivision (example: IEC 61000-6-1).
These standards and reports will be published in chronological order and numbered
accordingly.
This part is an international standard which gives immunity requirements and test procedures
related to "pulse magnetic field".

ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 4-9: Testing and measurement techniques – Pulse
Impulse magnetic field immunity test

1 Scope and object
This part of IEC 61000 relates to specifies the immunity requirements, test methods, and
range of recommended test levels for equipment, only under operational conditions, subjected
to pulse impulse magnetic disturbances mainly related to encountered in:
– industrial installations,
– power plants,
– railway installations,
– medium voltage and high voltage sub-stations.
The applicability of this standard to equipment installed in different locations is determined by
the presence of the phenomenon, as specified in Clause 4.
This standard does not consider disturbances due to capacitive or inductive coupling in cables
or other parts of the field installation. Other IEC standards dealing with conducted
disturbances cover these aspects.
The object of this standard is to establish a common and reproducible basis reference for
evaluating the performance immunity of electrical and electronic equipment for household,
commercial and industrial applications when subjected to pulse impulse magnetic fields. The
test method documented in this part of IEC 61000 describes a consistent method to assess
the immunity of an equipment or system against a defined phenomenon.
NOTE As described in IEC Guide 107, this is a basic EMC publication for use by product committees of the IEC.
As also stated in Guide 107, the IEC product committees are responsible for determining whether this immunity
test standard is applied or not, and if applied, they are responsible for determining the appropriate test levels and
performance criteria. TC 77 and its sub-committees are prepared to co-operate with product committees in the
evaluation of the value of particular immunity test levels for their products.
This standard defines:
– recommended a range of test levels;
– test equipment;
– test setups;
– test procedures.
The task of the described laboratory test is to find the reaction of the equipment under test
(EUT) under specified operational conditions to impulse magnetic fields caused by switching
and lightning effects.
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.
– 10 – IEC 61000-4-9:2016 RLV  IEC 2016
IEC 60050 (all parts), International Electrotechnical Vocabulary (IEV) (available at
www.electropedia.org)
IEC 60060-2:1973, High-voltage test techniques – Part 2: Test procedures
IEC 60068-1:1988, Environmental testing – Part 1: General and guidance
IEC 60469-1:1987, Pulse techniques and apparatus – Part 1: Pulse terms and definitions
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
The following definitions and terms are used in this standard and apply to the restricted field
of magnetic disturbances; not all of them are included in IEC 60050(161) [IEV].
For the purposes of this document, the terms and definitions given in IEC 60050 as well as
the following apply.
3.1.1
calibration
set of operations which establishes, by reference to standards, the relationship which exists,
under specified conditions, between an indication and a result of a measurement
Note 1 to entry: This term is based on the "uncertainty" approach.
Note 2 to entry: The relationship between the indications and the results of measurement can be expressed, in
principle, by a calibration diagram.
[SOURCE: IEC 60050-311:2001, 311-01-09]
3.1.2
combination wave generator
CWG
generator with 1,2/50 µs open-circuit voltage waveform and 8/20 µs short-circuit current
waveform
Note 1 to entry: This definition is abbreviated from the equivalent definition in IEC 61000-4-5.
Note 2 to entry: This note applies to the French language only.
3.1.3
duration
T
d
virtual parameter defined as the time interval between the instant
at which the surge current rises to 0,5 of its peak value, and then falls to 0,5 of its peak value
(T ), multiplied by 1,18
w
T = 1,18 × T
d w
SEE: Figure 2.
3.1.4
front time
T
f
virtual parameter defined as 1,25 times the interval T between the instants
r
when the impulse is 10 % and 90 % of the peak value
SEE: Figure 2.
3.1.5
immunity
ability of a device, equipment or system to perform without degradation in the presence of an
electromagnetic disturbance
[SOURCE: IEC 60050-161:1990, 161-01-20]
3.1.6
induction coil
conductor loop of defined shape and dimensions, in which a current flows, generating a
magnetic field of defined constancy in its plane and in the enclosed volume uniformity in a
defined volume
3.1.7
induction coil factor
ratio between the magnetic field strength generated by an induction coil of given dimensions
and the corresponding current value
Note 1 to entry: The field is that measured at the centre of the coil plane, without the EUT.
3.1.8
proximity method
method of application of the magnetic field to the EUT, where a small induction coil is moved
along the side of the EUT in order to detect particularly sensitive areas
3.1.9
reference ground plane (GRP)
flat conductive surface whose potential is used as a common reference for the magnetic field
generator and the auxiliary equipment (the ground plane can be used to close the loop of the
induction coil, as in figure 5)
[IEV 161-04-36, modified]
3.1.10
rise time
T
r
interval of time between the instants at which the instantaneous value of an impulse first
reaches 10 % value and then 90 % value
SEE: Figure 2.
3.1.11
surge
transient wave of electrical current, voltage or power propagating along a line or a circuit and
characterized by a rapid increase followed by a slower decrease
3.1.12
system
set of interdependent elements constituted to achieve a given objective by performing a
specified function
Note 1 to entry: The system is considered to be separated from the environment and other external systems by an
imaginary surface which cuts the links between them and the considered system. Through these links, the system
is affected by the environment, is acted upon by the external systems, or acts itself on the environment or the
external systems.
3.1.13
transient, adjective and noun
pertaining to or designating a phenomenon or a quantity which varies between two
consecutive steady states during a time interval short compared to the time scale of interest

– 12 – IEC 61000-4-9:2016 RLV  IEC 2016
[SOURCE: IEC 60050-161:1990, 161-02-01]
3.1.14
verification
set of operations which is used to check the test equipment system (e.g. the test generator
and its interconnecting cables) to demonstrate that the test system is functioning
Note 1 to entry: The methods used for verification may be different from those used for calibration.
Note 2 to entry: For the purposes of this basic EMC standard this definition is different from the definition given in
IEC 60050-311:2001, 311-01-13.
4.4
immersion method
method of application of the magnetic field to the EUT, which is placed in the centre of an
induction coil (figure 1)
4.7
decoupling network, back filter
electrical circuit intended to avoid reciprocal influence with other equipment not submitted to
the magnetic field test
3.2 Abbreviated terms
AE Auxiliary equipment
CDN Coupling/decoupling network
CWG Combination wave generator
EFT/B Electrical fast transient/burst
EMC Electromagnetic compatibility
ESD Electrostatic discharge
EUT Equipment under test
MU Measurement uncertainty
RGP Reference ground plane
4 General
The magnetic fields to which equipment is subjected may influence the reliable operation of
equipment and systems.
The following tests are intended to demonstrate the immunity of equipment when subjected to
impulse magnetic fields related to the specific location and installation condition of the
equipment (e.g. proximity of equipment to the disturbance source).
Pulse magnetic fields are generated by lightning strokes strikes on buildings and other metal
structures including aerial masts, earth conductors and earth networks and by initial faults
transients in low, medium and high voltage electrical systems.
In high voltage sub-stations, a pulse an impulse magnetic field may also be generated by the
switching of high voltage bus-bars and lines by circuit breakers.
The test is mainly applicable to electronic equipment to be installed in electrical generation
and distribution plants as well as in telecontrol their control centres. It is not relevant for
distribution network equipment (e.g. transformers, power lines).
Product committees may consider other possible applications.

The test field waveform is that of the standard current pulse, waveform 6,4/16 µs.
NOTE  The waveform 6,4/16 µs according to IEC 60469-1 corresponds to the 8/20 µs of IEC 60060-2.
5 Test levels
The preferred range of test levels is given in Table 1.
Table 1 – Test levels
Pulse magnetic field strength
Level
A/m (peak)
1 not applicable
2 not applicable
3 100
4 300
5 1000
a
X special
NOTE  The magnetic field strength is expressed in A/m; 1 A/m corresponds to
a free space induction magnetic flux density of 1,26 µT.
a
"n.a." = not applicable.
"x" is an open can be any level, above, below or in between the others.
The level can be given in the product shall be specified in the dedicated
equipment specification.
Information on the selection of the test levels is given in Annex C.
Information on actual levels is given in annex D.
The test levels shall be selected according to the installation conditions. Classes of
installation are given in Annex C.
6 Test equipment
The test magnetic field is obtained by a current flowing in an induction coil; the application of
the test field to the EUT is by the immersion method.
An example of application of the immersion method is given in figure 1.
The test equipment includes the current source (test generator), the induction coil and
auxiliary test instrumentation.
6.1 Test generator
The generator, with the output waveform corresponding to the test magnetic field, shall be
able to deliver the required current in the induction coils specified in 6.2.
The generator power capability shall therefore be dimensioned by taking into account the coil
impedance; the inductance may range from 2,5 µH for the 1 m standard coil, to several µH
(e.g. 6 µH) for a rectangular induction coil (1 m × 2,6 m, see 6.2).
The specifications of the generator are:
– current capability, determined by the maximum selected test level and induction coil factor
–1
(see 6.2.2 and annex A), ranging from 0,87 m (1 m standard coil for testing table-top or

– 14 – IEC 61000-4-9:2016 RLV  IEC 2016
–1
small equipment) to 0,66 m (rectangular induction coil, 1 m × 2,6 m, for testing floor-
standing or large equipment);
– operability in short-circuit condition;
– low output terminal connected to the earth terminal (for connection to the safety earth of
the laboratory);
– precautions to prevent the emission of large disturbances that may be injected in the
power supply network or may influence the test results.
The characteristics and performances of the current source or test generator for the field
considered in this standard are given in 6.1.1.
6.1.1 Characteristics and performances of the test generator
The test generator is a non-repetitive (single shot) pulse current generator with characteristics
as follows:
Specifications
Rise time: 6,4 µs ± 30 %
Duration: 16 µs ± 30 %
Output current range: 100 A to 1 000 A, divided by the coil factor
Polarity: positive and negative
Phase relationship with
the power frequency: synchronizable from 0° to 360° with 10° steps
Synchronization: triggerable by external signal
A standard current pulse generator, e.g. the surge hybrid generator (waveform 1,2/50 –
6,4/16 µs), may be used.
NOTE  The output current range for the standard coil is from 120 A to 1 200 A peak.
The waveform of the output current is given in figure 2.
The schematic circuit of the generator is given in figure 3.
6.1.2 Verification of the characteristics of the test generator
In order to compare the results for different test generators, the essential characteristics of
the output current parameters shall be verified.
The output current shall be verified with the generator connected to the standard induction
coil specified in 6.2.1 a); the connection shall be realized by twisted conductors or coaxial
cable of up to 3 m length and suitable cross-section.
The emission of disturbances by the generator shall be verified (see 6.1).
The characteristics to be verified are:
– output current peak value;
– rise time;
– duration.
A 1,8 mm wire diameter (2,5 mm ) should be used for the loop for short-circuit current
operation; however, the mechanical rigidity should be taken into account.

The verifications shall be carried out with a current probe and oscilloscope or other equivalent
measurement instrumentation with 10 MHz minimum bandwidth.
The accuracy of the measurements shall be ±10 %.
6.2 Induction coil
6.2.1 Characteristics of the induction coil
The induction coil, connected to the test generator previously defined (see 6.1.1), shall
generate a field strength corresponding to the selected test level and the defined homo-
geneity.
The induction coil shall be made of copper, aluminium or any conductive non-magnetic
material, of such cross-section and mechanical arrangement as to facilitate its stable
positioning during the tests.
A same coil is suitable for the generation of the magnetic fields considered in this standard; it
may be a "single turn" coil and shall have a suitable current capability, as may be necessary
for the selected test level.
Multi-turn coils may be used in order to have a lower testing current.
The in
...

IEC 61000-4-9 ®
Edition 2.0 2016-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
BASIC EMC PUBLICATION
PUBLICATION FONDAMENTALE EN CEM
Electromagnetic compatibility (EMC) –
Part 4-9: Testing and measurement techniques – Impulse magnetic field
immunity test
Compatibilité électromagnétique (CEM) –
Partie 4-9: Techniques d'essai et de mesure – Essai d'immunité au champ
magnétique impulsionnel
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IEC 61000-4-9 ®
Edition 2.0 2016-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
BASIC EMC PUBLICATION
PUBLICATION FONDAMENTALE EN CEM

Electromagnetic compatibility (EMC) –

Part 4-9: Testing and measurement techniques – Impulse magnetic field

immunity test
Compatibilité électromagnétique (CEM) –

Partie 4-9: Techniques d'essai et de mesure – Essai d'immunité au champ

magnétique impulsionnel
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.100.20 ISBN 978-2-8322-3502-7

– 2 – IEC 61000-4-9:2016  IEC 2016
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope and object . 8
2 Normative references. 8
3 Terms, definitions and abbreviated terms . 9
3.1 Terms and definitions . 9
3.2 Abbreviated terms . 10
4 General . 11
5 Test levels . 11
6 Test instrumentation . 12
6.1 General . 12
6.2 Combination wave generator . 12
6.2.1 General . 12
6.2.2 Performance characteristics of the generator . 13
6.2.3 Calibration of the generator . 13
6.3 Induction coil. 14
6.3.1 Field distribution . 14
6.3.2 Characteristics of the standard induction coils of 1 m × 1 m and 1
m × 2,6 m . 14
6.4 Calibration of the test system . 14
7 Test setup . 15
7.1 Test equipment . 15
7.2 Verification of the test instrumentation . 16
7.3 Test setup for impulse magnetic field applied to a table-top EUT . 16
7.4 Test setup for impulse magnetic field applied to a floor standing EUT . 17
7.5 Test setup for impulse magnetic field applied in-situ . 18
8 Test procedure . 19
8.1 General . 19
8.2 Laboratory reference conditions . 19
8.2.1 Climatic conditions . 19
8.2.2 Electromagnetic conditions . 19
8.3 Execution of the test . 19
9 Evaluation of test results . 20
10 Test report. 20
Annex A (informative) Characteristics of non standard induction coils . 22
A.1 General . 22
A.2 Determination of the coil factor . 22
A.2.1 General . 22
A.2.2 Coil factor measurement . 22
A.2.3 Coil factor calculation . 23
A.3 Magnetic field measurement . 23
A.4 Verification of non standard induction coils . 24
Annex B (informative) Information on the field distribution of standard induction coils . 25
B.1 General . 25
B.2 1 m × 1 m induction coil . 25

B.3 1 m × 2,6 m induction coil with reference ground plane . 26
B.4 1 m × 2,6 m induction coil without reference ground plane . 28
Annex C (informative) Selection of the test levels . 29
Annex D (informative) Measurement uncertainty (MU) considerations . 31
D.1 General . 31
D.2 Legend . 31
D.3 Uncertainty contributors to the surge current and to the surge magnetic field
measurement uncertainty . 32
D.4 Uncertainty of surge current and surge magnetic field calibration . 32
D.4.1 General . 32
D.4.2 Front time of the surge current . 32
D.4.3 Peak of the surge current and magnetic field . 34
D.4.4 Duration of the current impulse . 35
D.4.5 Further MU contributions to time measurements . 36
D.4.6 Rise time distortion due to the limited bandwidth of the measuring
system . 36
D.4.7 Impulse peak and width distortion due to the limited bandwidth of the
measuring system . 37
D.5 Application of uncertainties in the surge generator compliance criterion . 38
Annex E (informative) Mathematical modelling of surge current waveforms . 39
E.1 General . 39
E.2 Normalized time domain current surge (8/20 µs) . 39
Annex F (informative) Characteristics using two standard induction coils . 42
F.1 General . 42
F.2 Particular requirements for calibration . 42
F.3 Field distribution of the double induction coil arrangement . 43
Annex G (informative) 3D numerical simulations . 45
G.1 General . 45
G.2 Simulations . 45
G.3 Comments . 45
Bibliography . 53

Figure 1 – Simplified circuit diagram of the combination wave generator . 12
Figure 2 – Waveform of short-circuit current (8/20 µs) at the output of the generator
with the 18 µF capacitor in series . 13
Figure 3 – Example of a current measurement of standard induction coils . 14
Figure 4 – Example of test setup for table-top equipment showing the vertical
orthogonal plane . 17
Figure 5 – Example of test setup for floor standing equipment showing the horizontal
orthogonal plane . 17
Figure 6 – Example of test setup for floor standing equipment showing the vertical
orthogonal plane . 18
Figure 7 – Example of test setup using the proximity method . 18
Figure A.1 – Rectangular induction coil with sides a + b and c . 23
Figure A.2 – Example of verification setup for non standard induction coils . 24
Figure B.1 – +3 dB isoline for the magnetic field strength (magnitude) in the x-y plane
for the 1 m × 1 m induction coil . 25

– 4 – IEC 61000-4-9:2016  IEC 2016
Figure B.2 – +3 dB and –3 dB isolines for the magnetic field strength (magnitude) in
the x-z plane for the 1 m × 1 m induction coil . 26
Figure B.3 – +3 dB isoline for the magnetic field strength (magnitude) in the x-z plane
for the 1 m × 2,6 m induction coil with reference ground plane . 27
Figure B.4 – +3 dB and -3 dB isolines for the magnetic field strength (magnitude) in the
x-y plane for the 1 m × 2,6 m induction coil with reference ground plane . 27
Figure B.5 – +3 dB isoline for the magnetic field strength (magnitude) in the x-y plane
for the 1 m × 2,6 m induction coil without reference ground plane . 28
Figure B.6 – +3 dB and –3 dB isolines for the magnetic field strength (magnitude) in
the x-z plane for the 1 m × 2,6 m induction coil without reference ground plane . 28
Figure E.1 – Normalized current surge (8/20 µs): Width time response T . 40
w
Figure E.2 – Normalized current surge (8/20 µs): Rise time response T . 40
r
Figure E.3 – Current surge (8/20 µs): Spectral response with ∆f = 10 kHz . 41
Figure F.1 – Example of a test system using double standard induction coils . 42
Figure F.2 – +3dB isoline for the magnetic field strength (magnitude) in the x-y plane
for the double induction coil arrangement (0,8 m spaced) . 44
Figure F.3 – +3 dB and –3 dB isolines for the magnetic field strength (magnitude) in
the x-z plane for the double induction coil arrangement (0,8 m spaced) . 44
Figure G.1 – Current and H-field in the centre of the 1 m × 1 m induction coil . 46
Figure G.2 – Hx-field along the side of 1 m × 1 m induction coil in A/m . 46
Figure G.3 – Hx-field in direction x perpendicular to the plane of the 1 m × 1 m
induction coil . 47
Figure G.4 – Hx-field along the side in dB for the 1 m × 1 m induction coil . 47
Figure G.5 – Hx-field along the diagonal in dB for the 1 m × 1 m induction coil . 48
Figure G.6 – Hx-field plot on y-z plane for the 1 m × 1 m induction coil . 48
Figure G.7 – Hx-field plot on x-y plane for the 1 m × 1 m induction coil . 49
Figure G.8 – Hx-field along the vertical middle line in dB for the 1 m × 2,6 m induction coil . 49
Figure G.9 – Hx-field 2D plot on y-z plane for the 1 m × 2,6 m induction coil . 50
Figure G.10 – Hx-field 2D plot on x-y plane at z = 0,5 m for the 1 m × 2,6 m induction coil . 50
Figure G.11 – Helmholtz setup: Hx-field and 2D plot for two 1 m × 1 m induction coils,
0,6 m spaced . 51
Figure G.12 – Helmholtz setup: Hx-field and 2D plot for two 1 m × 1 m induction coils,
0,8 m spaced . 52

Table 1 – Test levels . 11
Table 2 – Definitions of the waveform parameters 8/20 µs . 13
Table 3 – Specifications of the waveform time parameters of the test system . 15
Table 4 – Specifications of the waveform peak current of the test system . 15
Table D.1 – Example of uncertainty budget for surge current front time (T ) . 33
f
Table D.2 – Example of uncertainty budget for the peak of surge current (I ) . 34
P
Table D.3 – Example of uncertainty budget for current impulse width (T ) . 35
d
Table D.4 – α factor (see equation (D.10)) of different unidirectional impulse
responses corresponding to the same bandwidth of system B . 37
Table D.5 – β factor (equation (D.14)) of the standard current surge waveform . 38
Table F.1 – Specifications of the waveform peak current of this test system . 43

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 4-9: Testing and measurement techniques –
Impulse magnetic field immunity test

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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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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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 61000-4-9 has been prepared by subcommittee 77B: High
frequency phenomena, of IEC technical committee 77: Electromagnetic compatibility.
It forms Part 4-9 of the IEC 61000 series. It has the status of a basic EMC publication in
accordance with IEC Guide 107.
This second edition cancels and replaces the first edition published in 1993 and Amendment
1:2000. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) new Annex B on induction coil field distribution;
b) new Annex D on measurement uncertainty;
c) new Annex E on mathematical modeling of surge waveform;

– 6 – IEC 61000-4-9:2016  IEC 2016
d) new Annex F on characteristics using two standard induction coils;
e) new Annex G on 3D numerical simulations;
f) coil factor calculation and calibration using current measurement have been addressed in
this edition.
The text of this standard is based on the following documents:
CDV Report on voting
77B/728/CDV 77B/745A/RVC
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.
A list of all parts in the IEC 61000 series, published under the general title Electromagnetic
compatibility (EMC), 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 website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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.
INTRODUCTION
IEC 61000 is published in separate parts according to the following structure:
Part 1: General
General considerations (introduction, fundamental principles)
Definitions, terminology
Part 2: Environment
Description of the environment
Classification of the environment
Compatibility levels
Part 3: Limits
Emission limits
Immunity limits (insofar as they do not fall under the responsibility of the product
committees)
Part 4: Testing and measurement techniques
Measurement techniques
Testing techniques
Part 5: Installation and mitigation guidelines
Installation guidelines
Mitigation methods and devices
Part 6: Generic standards
Part 9: Miscellaneous
Each part is further subdivided into several parts, published either as international standards
or as technical specifications or technical reports, some of which have already been published
as sections. Others will be published with the part number followed by a dash and a second
number identifying the subdivision (example: IEC 61000-6-1).
This part is an international standard which gives immunity requirements and test procedures
related to "pulse magnetic field".

– 8 – IEC 61000-4-9:2016  IEC 2016
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 4-9: Testing and measurement techniques –
Impulse magnetic field immunity test

1 Scope and object
This part of IEC 61000 specifies the immunity requirements, test methods, and range of
recommended test levels for equipment subjected to impulse magnetic disturbances mainly
encountered in:
– industrial installations,
– power plants,
– railway installations,
– medium voltage and high voltage sub-stations.
The applicability of this standard to equipment installed in different locations is determined by
the presence of the phenomenon, as specified in Clause 4.
This standard does not consider disturbances due to capacitive or inductive coupling in cables
or other parts of the field installation. Other IEC standards dealing with conducted
disturbances cover these aspects.
The object of this standard is to establish a common reference for evaluating the immunity of
electrical and electronic equipment when subjected to impulse magnetic fields. The test
method documented in this part of IEC 61000 describes a consistent method to assess the
immunity of an equipment or system against a defined phenomenon.
NOTE As described in IEC Guide 107, this is a basic EMC publication for use by product committees of the IEC.
As also stated in Guide 107, the IEC product committees are responsible for determining whether this immunity
test standard is applied or not, and if applied, they are responsible for determining the appropriate test levels and
performance criteria. TC 77 and its sub-committees are prepared to co-operate with product committees in the
evaluation of the value of particular immunity test levels for their products.
This standard defines:
– a range of test levels;
– test equipment;
– test setups;
– test procedures.
The task of the described laboratory test is to find the reaction of the equipment under test
(EUT) under specified operational conditions to impulse magnetic fields caused by switching
and lightning effects.
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 60050 (all parts), International Electrotechnical Vocabulary (IEV) (available at
www.electropedia.org)
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050 as well as
the following apply.
3.1.1
calibration
set of operations which establishes, by reference to standards, the relationship which exists,
under specified conditions, between an indication and a result of a measurement
Note 1 to entry: This term is based on the "uncertainty" approach.
Note 2 to entry: The relationship between the indications and the results of measurement can be expressed, in
principle, by a calibration diagram.
[SOURCE: IEC 60050-311:2001, 311-01-09]
3.1.2
combination wave generator
CWG
generator with 1,2/50 µs open-circuit voltage waveform and 8/20 µs short-circuit current
waveform
Note 1 to entry: This definition is abbreviated from the equivalent definition in IEC 61000-4-5.
Note 2 to entry: This note applies to the French language only.
3.1.3
duration
T
d
virtual parameter defined as the time interval between the instant
at which the surge current rises to 0,5 of its peak value, and then falls to 0,5 of its peak value
(T ), multiplied by 1,18
w
T = 1,18 × T
d w
SEE: Figure 2.
3.1.4
front time
T
f
virtual parameter defined as 1,25 times the interval T between the instants
r
when the impulse is 10 % and 90 % of the peak value
SEE: Figure 2.
3.1.5
immunity
ability of a device, equipment or system to perform without degradation in the presence of an
electromagnetic disturbance
[SOURCE: IEC 60050-161:1990, 161-01-20]
3.1.6
induction coil
conductor loop of defined shape and dimensions, in which a current flows, generating a
magnetic field of defined uniformity in a defined volume

– 10 – IEC 61000-4-9:2016  IEC 2016
3.1.7
induction coil factor
ratio between the magnetic field strength generated by an induction coil of given dimensions
and the corresponding current value
Note 1 to entry: The field is that measured at the centre of the coil plane, without the EUT.
3.1.8
proximity method
method of application of the magnetic field to the EUT, where a small induction coil is moved
along the side of the EUT in order to detect particularly sensitive areas
3.1.9
reference ground plane
flat conductive surface whose potential is used as a common reference
3.1.10
rise time
T
r
interval of time between the instants at which the instantaneous value of an impulse first
reaches 10 % value and then 90 % value
SEE: Figure 2.
3.1.11
surge
transient wave of electrical current, voltage or power propagating along a line or a circuit and
characterized by a rapid increase followed by a slower decrease
3.1.12
system
set of interdependent elements constituted to achieve a given objective by performing a
specified function
Note 1 to entry: The system is considered to be separated from the environment and other external systems by an
imaginary surface which cuts the links between them and the considered system. Through these links, the system
is affected by the environment, is acted upon by the external systems, or acts itself on the environment or the
external systems.
3.1.13
transient, adjective and noun
pertaining to or designating a phenomenon or a quantity which varies between two
consecutive steady states during a time interval short compared to the time scale of interest
[SOURCE: IEC 60050-161:1990, 161-02-01]
3.1.14
verification
set of operations which is used to check the test equipment system (e.g. the test generator
and its interconnecting cables) to demonstrate that the test system is functioning
Note 1 to entry: The methods used for verification may be different from those used for calibration.
Note 2 to entry: For the purposes of this basic EMC standard this definition is different from the definition given in
IEC 60050-311:2001, 311-01-13.
3.2 Abbreviated terms
AE Auxiliary equipment
CDN Coupling/decoupling network

CWG Combination wave generator
EFT/B Electrical fast transient/burst
EMC Electromagnetic compatibility
ESD Electrostatic discharge
EUT Equipment under test
MU Measurement uncertainty
RGP Reference ground plane
4 General
The magnetic fields to which equipment is subjected may influence the reliable operation of
equipment and systems.
The following tests are intended to demonstrate the immunity of equipment when subjected to
impulse magnetic fields related to the specific location and installation condition of the
equipment (e.g. proximity of equipment to the disturbance source).
Pulse magnetic fields are generated by lightning strikes on buildings and other metal
structures including aerial masts, earth conductors and earth networks and by initial fault
transients in low, medium and high voltage electrical systems.
In high voltage sub-stations, an impulse magnetic field may also be generated by the
switching of high voltage bus-bars and lines by circuit breakers.
The test is mainly applicable to electronic equipment to be installed in electrical generation
and distribution plants as well as in their control centres. It is not relevant for distribution
network equipment (e.g. transformers, power lines).
Product committees may consider other applications.
5 Test levels
The preferred range of test levels is given in Table 1.
Table 1 – Test levels
Level Pulse magnetic field strength
A/m (peak)
1 not applicable
2 not applicable
3 100
4 300
5 1 000
a
X special
NOTE The magnetic field strength is expressed in A/m; 1 A/m corresponds to
a free space magnetic flux density of 1,26 µT.
a
"X" can be any level, above, below or in between the others. The level
shall be specified in the dedicated equipment specification.

The test levels shall be selected according to the installation conditions. Classes of
installation are given in Annex C.

– 12 – IEC 61000-4-9:2016  IEC 2016
6 Test instrumentation
6.1 General
The test system comprises the combination wave generator and the induction coil for a table-
top test setup and, in addition, an RGP for a floor-standing test setup.
6.2 Combination wave generator
6.2.1 General
For this application, the combination wave generator is used as a current source.
NOTE The combination wave generator specified in this standard has identical wave shape definitions to the ones
given in IEC 61000-4-5.
Therefore only the 8/20 µs waveform is relevant. The combination wave generator shall be
able to deliver the required impulse current to the induction coils specified in 6.3.
The waveform is specified as a short-circuit current and therefore shall be measured without
the induction coil connected.
This generator is intended to generate a surge having:
• a short-circuit current front time of 8 µs;
• a short-circuit current duration of 20 µs.
A simplified circuit diagram of the generator is given in Figure 1. The values for the different
components R , R , R , L , and C are selected so that the generator delivers an 8/20 µs
S1 S2 m r c
current surge into a short-circuit.
Switch
R R L C
c m r 0
Internal or
external
C R R
U c s1 s2
18 µF
capacitor
IEC
Key
U High-voltage source
R Charging resistor
c
C Energy storage capacitor
c
R Impulse duration shaping resistors
s
R Impedance matching resistor
m
L Rise time shaping inductor
r
C Internal or external 18 µF capacitor
o
Figure 1 – Simplified circuit diagram of the combination wave generator

6.2.2 Performance characteristics of the generator
Polarity positive and negative
Phase shifting in a range between 0° to 360° relative to the
phase angle of the a.c. line voltage to the EUT
with a tolerance of ± 10°
Repetition rate 1 per minute or faster
Short-circuit peak output current 100 A to 1 000 A or the required test level
divided by the coil factor
Waveform of the surge current see Table 2 and Figure 2
Short-circuit peak output current tolerance ± 10 %
Table 2 – Definitions of the waveform parameters 8/20 µs
Front time T Duration T
f d
µs µs
Short-circuit current T = 1,25 × T = 8 ± 20 % T = 1,18 × T = 20 ± 20 %
f r d w
A generator with floating output shall be used.
I
1,0
0,9
0,5
T
w
0,1
T t
r
0 to –0,3
IEC
Front time: T = 1,25 × T = 8 µs ± 20 %
f r
Duration: T = 1,18 × T = 20 µs ± 20 %
d w
NOTE 1 The value 1,25 is the reciprocal of the difference between the 0,9 and 0,1 thresholds.
NOTE 2 The value 1,18 is derived from empirical data.
Figure 2 – Waveform of short-circuit current (8/20 µs)
at the output of the generator with the 18 µF capacitor in series
6.2.3 Calibration of the generator
If a current transformer (probe) is used to measure short-circuit current, it should be selected
so that saturation of the magnetic core does not take place. The lower (-3 dB) corner
frequency of the probe should be less than 100 Hz. The calibration shall be carried out with a
current probe and oscilloscope or other equivalent measurement instrumentation with a
bandwidth of not less than 1 MHz. The calibration shall be performed for all test levels, which
are applied for testing.
– 14 – IEC 61000-4-9:2016  IEC 2016
The characteristics of the generator shall be measured through an external capacitor of 18 µF
in series with the output, under short-circuit conditions. If the 18 µF capacitor is implemented
in the generator, no external 18 µF capacitor is required for calibration.
All performance characteristics stated in 6.2.2, with the exception of phase shifting, shall be
met at the output of the generator.
6.3 Induction coil
6.3.1 Field distribution
For the two single-turn standard coils of 1 m × 1 m and 1 m × 2,6 m, the field distribution is
known and shown in Annex B. Therefore, no field verification or field calibration is necessary;
the current measurement as shown in Figure 3 is sufficient.
Oscilloscope
Attenuator
Current probe
Surge generator
IEC
Figure 3 – Example of a current measurement of standard induction coils
Other coils of different dimensions may be used for an EUT which does not fit inside either of
the two standard coils. In these cases, the field distribution shall be determined by
measurement or calculation (see Annex A).
6.3.2 Characteristics of the standard induction coils of 1 m × 1 m and 1 m × 2,6 m
The standard induction coil shall be made of copper, aluminium or any conductive non-
magnetic material, of such cross-section and mechanical arrangement as to facilitate its
stable positioning during the tests.
The tolerance of the standard coils is ±1 cm, measured between the centre lines (centre of
the cross-section). The characteristics of induction coils with respect to the magnetic field
distribution are given in Annex B.
6.4 Calibration of the test system
The essential characteristics of the test system shall be calibrated by a current measurement
(see Figure 3).
The output current shall be verified with the generator connected to the standard induction
coil specified in 6.2.1 for all applicable test levels. In order to comply with the specifications
given in Table 3 and Table 4, an external capacitor (e.g. 18 µF) in series may be required.

The capacitor may be incorporated in the generator. The connection shall be realized by
twisted conductors or a coaxial cable of up to 3 m length and of suitable cross-section.
The following specifications given in Table 3 and Table 4 shall be verified.
Table 3 – Specifications of the waveform time parameters of the test system
Front time T Duration T
f d
System using 1 m × 1 m +2,4 +6
T = 1,25 × T = 8 µs µs
T = 1,18 × T = 20 µs µs
f r −0,8 −2
standard induction coil d w
System using 1 m × 2,6 m +3,2
+8
T = 1,25 × T = 8 µs µs
T = 1,18 × T = 20 µs µs
f r −0,8
d w −2
standard induction coil
Table 4 – Specifications of the waveform peak current of the test system
Test
Peak current I ± 10 %
A
level
System using 1 m × 1 m System using 1 m × 2,6 m
standard induction coil standard induction coil
1 not applicable not applicable
2 not applicable not applicable
3 111 152
4 333 453
5 1 111 1 515
a
X special/0,9 special/0,66
NOTE The values 0,9 and 0,66 are the calculated coil factors of standard
induction coils as described in A.2.3 (see Annex A).
a
"X" can be any level, above, below or in between the others. The level shall
be specified in the dedicated equipment specification.

If a current transformer (probe) is used to measure short-circuit current it should be selected
so that saturation of the magnetic core does not take place. The lower (-3 dB) corner
frequency of the probe should be less than 100 Hz. The calibration shall be carried
...