SIST EN 61000-4-8:2010

Electromagnetic compatibility (EMC) -- Part 4-8: Testing and measurement techniques - Power frequency magnetic field immunity test

This part of IEC 61000 relates to the immunity requirements of equipment, only under operational conditions, to magnetic disturbances at power frequencies 50 Hz and 60 Hz related to: - residential and commercial locations; - industrial installations and power plants; - 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 for evaluating the performance of electrical and electronic equipment for household, commercial and industrial applications when subjected to magnetic fields at power frequency (continuous and short duration field). The standard defines: - recommended test levels; - test equipment; - test set-up; - test procedure.

Elektromagnetische Verträglichkeit (EMV) -- Teil 4-8: Prüf- und Meßverfahren - Prüfung der Störfestigkeit gegen Magnetfelder mit energietechnischen Frequenzen

Compatibilité électromagnétique (CEM) -- Partie 4-8: Techniques d'essai et de mesure - Essai d'immunité au champ magnétique à la fréquence du réseau

La CEI 61000-4-8:2009 traite des exigences en matière d'immunité des matériels, uniquement dans les conditions d'utilisation, contre les perturbations magnétiques à des fréquences de 50 Hz et 60 Hz relatives aux:  - locaux résidentiels et commerciaux;  - installations industrielles et centrales électriques;  - postes moyenne et haute tension. Les conditions d'application de la CEI 61000-4-8:2009 aux matériels installés dans les différents secteurs sont déterminées par la présence du phénomène dans les conditions spécifiées dans l'article 4. La présente norme ne traite pas des perturbations engendrées par le couplage capacitif ou inductif sur les câbles ou autres parties de l'installation. D'autres normes CEI traitant des perturbations conduites couvrent ces aspects. La CEI 61000-4-8:2009 a pour objet d'établir une base commune et reproductible pour évaluer la performance des matériels électriques et électroniques à vocation domestique, commerciale ou industrielle lorsqu'ils sont soumis à des champs magnétiques à la fréquence du réseau (champs permanents et courte durée). La CEI 61000-4-8:2009 définit:   - les niveaux recommandés d'essai;  - le matériel d'essai;  - l'installation d'essai;  - la procédure d'essai. Cette deuxième édition annule et remplace la première édition publiée en 1993 et son amendement 1 (2000). Elle constitue une révision technique. La présente édition inclut les modification techniques majeures suivantes par rapport à la première édition: le domaine d'application est étendu de façon à couvrir le 60 Hz. Les caractéristiques, les performances et la vérification du générateur d'essai et de la bobine d'induction associée sont révisées. Des modifications sont aussi introduites dans l'installation d'essai (PS) et dans la procédure d'essai. La CEI 61000-4-8:2009 a le statut de publication fondamentale en CEM en accord avec le Guide 107 de la CEI.

Elektromagnetna združljivost (EMC) - 4-8. del: Preskusne in merilne tehnike - Preskus odpornosti proti magnetnemu polju omrežne frekvence

Ta del IEC 61000 se nanaša na zahteve glede odpornosti opreme samo pod pogoji delovanja in na magnetne motnje pri moči frekvenc 50 Hz in 60 Hz, ki se nanašajo na: - stanovanjske in gospodarske lokacije; - industrijske obrate in elektrarne; - elektronapajalne postaje srednje in visoke napetosti.  Uporaba tega standarda na opremi, ki je vgrajena na različnih lokacijah, je določena s prisotnostjo pojava, kot je določen v Klavzuli 4. Ta standard ne upošteva motenj, ki so posledica kapacitivne ali induktivne spojke v kablih ali drugih delih polja napeljave. Te vidike zajemajo drugi IEC standardi, ki obravnavajo opravljene motnje. Cilj tega standarda je vzpostavitev splošne in ponovljive osnove za ocenjevanje delovanja električne in elektronske opreme za gospodinjsko, gospodarsko in industrijsko uporabo, ko je izpostavljena magnetnim poljem  pri frekvenčni moči (neprekinjeno in kratkotrajno polje). Standard opredeljuje: - priporočene preskusne stopnje; - preskusno opremo; - preskus postavitve; - preskusni postopek.

General Information

• Status: Published
• Publication Date: 14-Mar-2010
• ICS: 33.100.20 - Immunity
• Technical Committee: EMC - Electromagnetic compatibility
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 23-Feb-2010
• Due Date: 30-Apr-2010
• Completion Date: 15-Mar-2010
• Directive: 2004/108/EU - DIRECTIVE 2004/108/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 15 December 2004 on the approximation of the laws of the Member States relating to electromagnetic compatibility and repealing Directive 89/336/EEC
• Directive: 2014/32/EU - Directive 2014/32/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of measuring instruments
• Ref Project: EN 61000-4-8:2010 - Electromagnetic compatibility (EMC) - Part 4-8: Testing and measurement techniques - Power frequency magnetic field immunity test

Relations

• Replaces: SIST EN 61000-4-8:1997 - Electromagnetic compatibility (EMC) - Part 4-8: Testing and measurement techniques - Power frequency magnetic field immunity test
• Effective Date: 28-Jan-2023
• Replaces: SIST EN 61000-4-8:1997/A1:2002 - Electromagnetic compatibility (EMC) -- Part 4-8: Testing and measurement techniques - Power frequency magnetic field immunity test
• Effective Date: 28-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 61000-4-8:2010
01-maj-2010
1DGRPHãþD
SIST EN 61000-4-8:1997
SIST EN 61000-4-8:1997/A1:2002
Elektromagnetna združljivost (EMC) - 4-8. del: Preskusne in merilne tehnike -
Preskus odpornosti proti magnetnemu polju omrežne frekvence
Electromagnetic compatibility (EMC) -- Part 4-8: Testing and measurement techniques -
Power frequency magnetic field immunity test
Elektromagnetische Verträglichkeit (EMV) -- Teil 4-8: Prüf- und Meßverfahren - Prüfung
der Störfestigkeit gegen Magnetfelder mit energietechnischen Frequenzen
Compatibilité électromagnétique (CEM) -- Partie 4-8: Techniques d'essai et de mesure -
Essai d'immunité au champ magnétique à la fréquence du réseau
Ta slovenski standard je istoveten z: EN 61000-4-8:201
ICS:
33.100.20 Imunost Immunity
SIST EN 61000-4-8:2010 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 61000-4-8:2010

---------------------- Page: 2 ----------------------

SIST EN 61000-4-8:2010

EUROPEAN STANDARD
EN 61000-4-8

NORME EUROPÉENNE
February 2010
EUROPÄISCHE NORM

ICS 33.100.20 Supersedes EN 61000-4-8:1993 + A1:2001


English version


Electromagnetic compatibility (EMC) -
Part 4-8: Testing and measurement techniques -
Power frequency magnetic field immunity test
(IEC 61000-4-8:2009)


Compatibilité électromagnétique (CEM) - Elektromagnetische Verträglichkeit (EMV) -
Partie 4-8: Techniques d'essai Teil 4-8: Prüf- und Meßverfahren -
et de mesure - Prüfung der Störfestigkeit gegen
Essai d'immunité au champ magnétique Magnetfelder mit energietechnischen
à la fréquence du réseau Frequenzen
(CEI 61000-4-8:2009) (IEC 61000-4-8:2009)




This European Standard was approved by CENELEC on 2010-02-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: Avenue Marnix 17, B - 1000 Brussels


© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61000-4-8:2010 E

---------------------- Page: 3 ----------------------

SIST EN 61000-4-8:2010
EN 61000-4-8:2010 - 2 -
Foreword
The text of document 77A/694/FDIS, future edition 2 of IEC 61000-4-8, prepared by SC 77A, Low
frequency phenomena, of IEC TC 77, Electromagnetic compatibility, was submitted to the IEC-CENELEC
parallel vote and was approved by CENELEC as EN 61000-4-8 on 2010-02-01.
This European Standard supersedes EN 61000-4-8:1993 + A1:2001.
EN 61000-4-8:2010 includes the following significant technical changes with respect to
EN 61000-4-8:1993: the scope is extended in order to cover 60 Hz. Characteristics, performance and
verification of the test generator and related inductive coils are revised. Modifications are also introduced
in the test set-up (GRP) and test procedure.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2010-11-01
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2013-02-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61000-4-8:2009 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60068-1 NOTE  Harmonized as EN 60068-1.
IEC 61000-2-4 NOTE  Harmonized as EN 61000-2-4.
__________

---------------------- Page: 4 ----------------------

SIST EN 61000-4-8:2010
- 3 - EN 61000-4-8:2010

Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

IEC 60050-161 - International Electrotechnical Vocabulary - -
(IEV) -
Chapter 161: Electromagnetic compatibility

---------------------- Page: 5 ----------------------

SIST EN 61000-4-8:2010

---------------------- Page: 6 ----------------------

SIST EN 61000-4-8:2010
IEC 61000-4-8
®
Edition 2.0 2009-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC EMC PUBLICATION
PUBLICATION FONDAMENTALE EN CEM
Electromagnetic compatibility (EMC) –
Part 4-8: Testing and measurement techniques – Power frequency magnetic
field immunity test

Compatibilité électromagnétique (CEM) –
Partie 4-8: Techniques d'essai et de mesure – Essai d'immunité au champ
magnétique à la fréquence du réseau

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
V
CODE PRIX
ICS 33.100.20 ISBN 2-8318-1059-7
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 7 ----------------------

SIST EN 61000-4-8:2010
– 2 – 61000-4-8 © IEC:2009
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope.7
2 Normative references .7
3 Terms and definitions .7
4 General .8
5 Test levels.9
6 Test equipment.10
6.1 General .10
6.2 Test generator.10
6.2.1 Current source.10
6.2.2 Characteristics and performances of the test generator for different
inductive coils.10
6.2.3 Verification of the characteristics of the test generator .11
6.3 Inductive coil .12
6.3.1 Field distribution.12
6.3.2 Characteristics of the inductive standard coils 1 m × 1 m and
1 m × 2,6 m .12
6.3.3 Characteristics of the inductive coils for table top and floor standing
equipment .12
6.3.4 Measurement of the inductive coil factor.13
6.4 Test and auxiliary instrumentation .13
6.4.1 Test instrumentation .13
6.4.2 Auxiliary instrumentation .14
7 Test set-up .14
7.1 Test set-up components .14
7.2 Ground (reference) plane for floor standing equipment .14
7.3 Equipment under test .14
7.4 Test generator.15
7.5 Inductive coil .15
8 Test procedure .15
8.1 General .15
8.2 Laboratory reference conditions .15
8.2.1 General .15
8.2.2 Climatic conditions .15
8.2.3 Electromagnetic conditions .16
8.3 Carrying out the test.16
9 Evaluation of the test results .17
10 Test report.17
Annex A (normative) Inductive coil calibration method .22
Annex B (normative) Characteristics of the inductive coils .23
Annex C (informative) Selection of the test levels .29
Annex D (informative) Information on power frequency magnetic field strength .31
Bibliography.33

---------------------- Page: 8 ----------------------

SIST EN 61000-4-8:2010
61000-4-8 © IEC:2009 – 3 –
Figure 1 – Example of application of the test field by the immersion method .18
Figure 2 – Example of schematic circuit of the test generator for power frequency
magnetic field .18
Figure 3 – Example of test set-up for table-top equipment .19
Figure 4 – Calibration of the standard coils .19
Figure 5 – Example of test set-up for floor-standing equipment.20
Figure 6 – Example of investigation of susceptibility to magnetic field by the proximity
method with the 1 m × 1 m inductive coil.20
Figure 7 – Illustration of Helmholtz coils .21
Figure B.1 – Characteristics of the field generated by a square inductive coil (1 m
side) in its plane .25
Figure B.2 – 3 dB area of the field generated by a square inductive coil (1 m side) in its
plane .25
Figure B.3 – 3 dB area of the field generated by a square inductive coil (1 m side) in
the mean orthogonal plane (component orthogonal to the plane of the coil) .26
Figure B.4 – 3 dB area of the field generated by two square inductive coils (1 m side)
0,6 m spaced, in the mean orthogonal plane (component orthogonal to the plane of
the coils).26
Figure B.5 – 3 dB area of the field generated by two square inductive coils (1 m side)
0,8 m spaced, in the mean orthogonal plane (component orthogonal to the plane of
the coils).27
Figure B.6 – 3 dB area of the field generated by a rectangular inductive coil (1 m × 2,6 m)
in its plane .27
Figure B.7 – 3 dB area of the field generated by a rectangular inductive coil (1 m × 2,6 m)
in its plane (ground plane as a side of the inductive coil) .28
Figure B.8 – 3 dB area of the field generated by a rectangular inductive coil (1 m × 2,6 m)
with ground plane, in the mean orthogonal plane (component orthogonal to the plane of
the coil) .28

Table 1 – Test levels for continuous field .9
Table 2 – Test levels for short duration: 1 s to 3 s.10
Table 3 – Specification of the generator for different inductive coils .11
Table 4 – Verification parameter for the different inductive coils .11
Table D.1 – Values of the maximum magnetic field produced by household appliances
(results of the measurements of 100 different devices of 25 basic types) .31
Table D.2 – Values of the magnetic field generated by a 400 kV line .31
Table D.3 – Values of the magnetic field in high voltage sub-station areas .32
Table D.4 – Values of the magnetic field in power plants .32

---------------------- Page: 9 ----------------------

SIST EN 61000-4-8:2010
– 4 – 61000-4-8 © IEC:2009
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 4-8: Testing and measurement techniques –
Power frequency 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
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
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 61000-4-8 has been prepared by subcommittee 77A: Low
frequency phenomena, of IEC technical committee 77: Electromagnetic compatibility.
This second edition cancels and replaces the first edition published in 1993 and its
Amendment 1 (2000). It forms a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition: the scope is extended in order to cover 60 Hz. Characteristics, performance and
verification of the test generator and related inductive coils are revised. Modifications are also
introduced in the test set-up (GRP) and test procedure.
It forms Part 4-8 of the IEC 61000 series of standards. It has the status of a basic EMC
publication in accordance with IEC Guide 107.

---------------------- Page: 10 ----------------------

SIST EN 61000-4-8:2010
61000-4-8 © IEC:2009 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
77A/694/FDIS 77A/706/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.
A list of all parts of the IEC 61000 series, under the general title Electromagnetic
compatibility, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.

---------------------- Page: 11 ----------------------

SIST EN 61000-4-8:2010
– 6 – 61000-4-8 © IEC:2009
INTRODUCTION
This standard is part of the IEC 61000 series of standards, 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 (in so far 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 9: Miscellaneous
Each part is further subdivided into several parts, published either as international standards,
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 "power frequency magnetic field".

---------------------- Page: 12 ----------------------

SIST EN 61000-4-8:2010
61000-4-8 © IEC:2009 – 7 –
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 4-8: Testing and measurement techniques –
Power frequency magnetic field immunity test



1 Scope
This part of IEC 61000 relates to the immunity requirements of equipment, only under
operational conditions, to magnetic disturbances at power frequencies 50 Hz and 60 Hz
related to:
– residential and commercial locations;
– industrial installations and power plants;
– 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 for evaluating the
performance of electrical and electronic equipment for household, commercial and industrial
applications when subjected to magnetic fields at power frequency (continuous and short
duration field).
The standard defines:
– recommended test levels;
– test equipment;
– test set-up;
– test procedure.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60050(161), International Electrotechnical Vocabulary (IEV) – Chapter 161: Electro-
magnetic compatibility
3 Terms and definitions
For the purposes of this document the following terms and definitions apply to the restricted
field of magnetic disturbances as well as the terms and definitions from IEC 60050(161) [IEV].
3.1
current distortion factor
ratio of the root-mean square value of the harmonics content of an alternating current to the
root-mean square value of the fundamental current

---------------------- Page: 13 ----------------------

SIST EN 61000-4-8:2010
– 8 – 61000-4-8 © IEC:2009
3.2
EUT
equipment under test
3.3
inductive coil
conductor loop of defined shape and dimensions, in which flows a current, generating a
magnetic field of defined constancy in its plane and in the enclosed volume
3.4
inductive coil factor
ratio between the magnetic field strength generated by an inductive coil of given dimensions
and the corresponding current value; the field is that measured at the centre of the coil plane,
without the EUT
3.5
immersion method
method of application of the magnetic field to the EUT, which is placed in the centre of an
inductive coil (see Figure 1)
3.6
proximity method
method of application of the magnetic field to the EUT, where a small inductive coil is moved
along the side of the EUT in order to detect particularly sensitive areas
3.7
ground (reference) 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
inductive coil, as in Figure 5)
[IEV 161-04-36, modified]
3.8
decoupling network, back filter
electrical circuit intended to avoid reciprocal influence with other equipment not submitted to
the magnetic field immunity test
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
power frequency magnetic fields related to the specific location and installation condition of
the equipment (e.g. proximity of equipment to the disturbance source).
The power frequency magnetic field is generated by power frequency current in conductors
or, more seldom, from other devices (e.g. Ieakage of transformers) in the proximity of
equipment.
As for the influence of nearby conductors, one should differentiate between:
– the current under normal operating conditions, which produces a steady magnetic field,
with a comparatively small magnitude;

---------------------- Page: 14 ----------------------

SIST EN 61000-4-8:2010
61000-4-8 © IEC:2009 – 9 –
– the current under fault conditions which can produce comparatively high magnetic fields
but of short duration, until the protection devices operate (a few milliseconds with fuses, a
few seconds for protection relays).
The test with a steady magnetic field may apply to all types of equipment intended for public
or industrial low voltage distribution networks or for electrical plants.
The test with a short duration magnetic field related to fault conditions, requires test levels
that differ from those for steady-state conditions; the highest values apply mainly to
equipment to be installed in exposed places of electrical plants.
The test field waveform is that of power frequency.
In many cases (household areas, sub-stations and power plant under normal conditions), the
magnetic field produced by harmonics is negligible.
5 Test levels
The preferential range of test levels, respectively for continuous and short duration application
of the magnetic field, applicable to distribution networks at 50 Hz and 60 Hz, is given in Table 1
and Table 2.
The magnetic field strength is expressed in A/m; 1 A/m corresponds to a free space magnetic
flux density of 1,26 μT.
Table 1 – Test levels for continuous field
Level Magnetic field strength
A/m
1 1
2 3
3 10
4 30
5 100
a
x special
a
"x" can be any level, above, below or in-between
the other levels. This level can be given in the product
specification.

---------------------- Page: 15 ----------------------

SIST EN 61000-4-8:2010
– 10 – 61000-4-8 © IEC:2009
Table 2 – Test levels for short duration: 1 s to 3 s
Level Magnetic field strength
A/m
b
1 n.a.
b
2 n.a.
b
3 n.a.
4 300
5 1 000
a
x special
a
"x" can be any level, above, below or in-between
the other levels. This level, as well the duration of the
test, can be given in the product specification.
b
"n.a." = not applicable.
Information on the selection of the test levels is given in Annex C.
Information on actual levels is given in Annex D.
6 Test equipment
6.1 General
The test magnetic field is obtained by a current flowing in an inductive 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 inductive coil and
auxiliary test instrumentation, that are also given in Figure 3.
6.2 Test generator
6.2.1 Current source
The current source typically consists of a voltage regulator (connected to the mains
distribution network, or other sources), a current transformer and a circuit for the control of
short duration application. The generator shall be able to operate in continuous mode or short
duration mode.
The connection between the current transformer and the inductive coil input should be as
short as possible to avoid that the currents which flow in the connection produce magnetic
fields that affect the magnetic field in the test volume. Preferably the cables should be twisted
together.
The characteristics and performances of the current source or test generator for the different
fields and for different inductive coils considered in this s
...