IEC 60255-26:2023

Measuring relays and protection equipment - Part 26: Electromagnetic compatibility requirements

IEC 60255-26:2023 specifies the requirements for electromagnetic compatibility for measuring relays and protection equipment. It is applicable to measuring relays and protection equipment and combinations of devices to form schemes for power system protection including the control, monitoring, communication and process interface equipment used with those systems. This document specifies limits and test methods, for measuring relays and protection equipment in relation to electromagnetic emissions which might cause interference in other equipment. This document specifies the immunity test requirements for measuring relays and protection equipment in relation to continuous and transient, conducted and radiated disturbances, including electrostatic discharges.

Relais de mesure et dispositifs de protection - Partie 26: Exigences de compatibilité électromagnétique

l'IEC 60255-26:2023 spécifie les exigences de compatibilité électromagnétique pour les relais de mesure et les dispositifs de protection. Elle s'applique aux relais de mesure et aux dispositifs de protection ainsi qu'aux combinaisons de dispositifs pour former des systèmes pour la protection des réseaux d'alimentation, y compris les dispositifs de commande, de surveillance de communication et d'interface de processus utilisés avec ces systèmes. Le présent document spécifie, pour les relais de mesure et les dispositifs de protection, les limites et les méthodes d'essai pour les émissions électromagnétiques susceptibles de perturber le fonctionnement d'autres matériels. Le présent document spécifie, pour les relais de mesure et les dispositifs de protection, les exigences d'essai d'immunité pour les perturbations continues et transitoires, conduites et rayonnées, décharges électrostatiques incluses.

General Information

• Status: Published
• Publication Date: 23-Jan-2023
• ICS: 29.120.70 - Relays
• Technical Committee: TC 95 - Measuring relays and protection equipment
• Drafting Committee: MT 2 - TC 95/MT 2
• Current Stage: PPUB - Publication issued
• Start Date: 27-Jan-2023
• Completion Date: 24-Jan-2023

Relations

• Revises: IEC 60255-26:2013 - Measuring relays and protection equipment - Part 26: Electromagnetic compatibility requirements
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60255-26
®

Edition 4.0 2023-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Measuring relays and protection equipment –
Part 26: Electromagnetic compatibility requirements

Relais de mesure et dispositifs de protection –
Partie 26: Exigences de compatibilité électromagnétique

IEC 60255-26:2023-01(en-fr)

---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2023 IEC, Geneva, Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.


Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland

About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.

Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: [e-mail].


A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC - Découvrez notre puissant moteur de recherche et consultez
webstore.iec.ch/advsearchform gratuitement tous les aperçus des publications. Avec un
La recherche avancée permet de trouver des publications IEC abonnement, vous aurez toujours accès à un contenu à jour
en utilisant différents critères (numéro de référence, texte, adapté à vos besoins.
comité d’études, …). Elle donne aussi des informations sur les
projets et les publications remplacées ou retirées. Electropedia - www.electropedia.org

Le premier dictionnaire d'électrotechnologie en ligne au monde,
IEC Just Published - webstore.iec.ch/justpublished
avec plus de 22 300 articles terminologiques en anglais et en
Restez informé sur les nouvelles publications IEC. Just
français, ainsi que les termes équivalents dans 19 langues
Published détaille les nouvelles publications parues.
additionnelles. Egalement appelé Vocabulaire
Disponible en ligne et une fois par mois par email.
Electrotechnique International (IEV) en ligne.


Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
[e-mail].
IEC Products & Services Portal - products.iec.ch

---------------------- Page: 2 ----------------------
IEC 60255-26

®


Edition 4.0 2023-01




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE











Measuring relays and protection equipment –

Part 26: Electromagnetic compatibility requirements



Relais de mesure et dispositifs de protection –

Partie 26: Exigences de compatibilité électromagnétique
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 29.120.70 ISBN 978-2-8322-6317-4



Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 3 ----------------------
– 2 – IEC 60255-26:2023 © IEC 2023
CONTENTS
FOREWORD . 5
1 Scope . 7
1.1 General . 7
1.2 Emission . 7
1.3 Immunity . 7
2 Normative references . 7
3 Terms, definitions, and abbreviated terms . 9
3.1 Terms and definitions . 9
3.2 Abbreviated terms . 12
4 Electromagnetic environmental levels . 13
4.1 General . 13
4.2 Zone A, severe electromagnetic environment . 13
4.3 Zone B, typical electromagnetic environment . 14
5 Emission. 14
5.1 Radiated emission . 14
5.2 Conducted emission . 15
6 Immunity. 16
6.1 Immunity of enclosure . 16
6.2 Immunity of auxiliary power supply port . 17
6.3 Immunity of signal/control port and wired network port . 20
6.4 Immunity of input and output ports . 21
6.5 Immunity of earth port . 24
7 Test set-up and procedures . 24
7.1 General . 24
7.2 Emission . 25
7.2.1 General . 25
7.2.2 Radiated emission . 26
7.2.3 Conducted emission . 26
7.3 Immunity . 26
7.3.1 General . 26
7.3.2 Electrostatic discharge immunity test . 28
7.3.3 Radiated electromagnetic field immunity test . 29
7.3.4 Electrical fast transient/burst immunity test . 31
7.3.5 Damped oscillatory wave immunity test . 32
7.3.6 Surge immunity test . 33
7.3.7 Conducted RF immunity test . 35
7.3.8 Conducted power frequency immunity test on binary inputs . 37
7.3.9 Power frequency magnetic field immunity test . 38
7.3.10 Voltage dips and short interruptions test (AC or DC) . 38
7.3.11 Ripple on DC input power port immunity test . 39
7.3.12 Gradual shutdown / start-up tests . 40
8 Criteria for acceptance . 40
8.1 Emission . 40
8.2 Immunity . 41
9 Test report . 42
(normative) Power frequency immunity tests on binary inputs . 43

---------------------- Page: 4 ----------------------
IEC 60255-26:2023 © IEC 2023 – 3 –
A.1 General . 43
A.2 Test classes . 43
A.3 Test equipment . 43
A.3.1 General . 43
A.3.2 Test generator . 43
A.3.3 Verification of the test generator . 44
A.3.4 Coupling networks . 44
A.4 Test set-up . 44
A.4.1 General . 44
A.4.2 Earthing connections . 44
A.4.3 Auxiliary equipment . 44
(informative) Background information for power frequency tests . 47
(informative) Background information about spot frequency tests . 48
(informative) EMC risk assessment . 50
D.1 EMC design risk assessment . 50
D.2 Product platform risk assessment . 52
(informative) Considerations regarding radio interfaces . 54
(informative) Immunity test to be considered in future . 55
Bibliography . 56

Figure 1 – Gradual shutdown / start-up test . 40
Figure A.1 – Example of Zone A differential mode tests . 45
Figure A.2 – Example of Zone B differential mode tests . 45
Figure A.3 – Example of Zone A and Zone B common mode tests . 46

Table 1 – Radiated emission tests – Enclosure port . 14
Table 2 – Required highest frequency for radiated measurement . 15
Table 3 – Conducted emission tests – AC and DC auxiliary power supply port . 15
Table 4 – Conducted emission tests – Wired network port . 15
Table 5 – Immunity tests – Enclosure port . 16
Table 6 – Immunity tests – Auxiliary power supply port . 17
Table 7 – Immunity tests – signal/control port and wired network port . 20
Table 8 – Immunity tests – Input and output port . 21
Table 9 – Immunity tests – Earth port . 24
Table 10 – Radiated emission test . 26
Table 11 – Conducted emission test . 26
Table 12 – Electrostatic discharge immunity test . 28
Table 13 – Radiated electromagnetic field immunity test (frequency sweep) . 29
Table 14 – Radiated electromagnetic field immunity test (spot frequencies) . 30
Table 15 – Electrical fast transient/burst immunity test . 31
Table 16 –Damped oscillatory wave immunity test . 32
Table 17 – Surge immunity test . 33
Table 18 – Conducted RF immunity test (frequency sweep) . 35
Table 19 – Conducted RF immunity test (spot frequencies) . 36
Table 20 – Conducted power frequency immunity test on binary inputs . 37

---------------------- Page: 5 ----------------------
– 4 – IEC 60255-26:2023 © IEC 2023
Table 21 – Power frequency magnetic field immunity test . 38
Table 22 – Voltage dips and short interruptions test (AC or DC) . 38
Table 23 – Ripple on DC input power port immunity test . 39
Table 24 – Gradual shutdown and start-up test . 40
Table 25 – Acceptance criteria for immunity tests . 41
Table C.1 – Selection of spot frequencies . 48
Table D.1 – Risk assessment based on a hardware design modification . 51
Table D.2 – Risk assessment, selecting representative EUT configuration(s) . 52
Table E.1 – Listed standard with relevance . 54
Table F.1 – Immunity test to be considered in future . 55

---------------------- Page: 6 ----------------------
IEC 60255-26:2023 © IEC 2023 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

MEASURING RELAYS AND PROTECTION EQUIPMENT –

Part 26: Electromagnetic compatibility requirements

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or 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.
IEC 60255-26 has been prepared by IEC technical committee 95: Measuring relays and
protection equipment. It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2013. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) update of normative references
b) introduction of a wired network port and signal/control port in accordance with CISPR 32;
c) introduction of low-power instrument transformer (LPIT) and battery monitor port;
d) expansion of the frequency range on radiated radio-frequency immunity test up to 6 GHz;
e) updated requirements on electrostatic discharge tests;
f) introduction of fast damped oscillatory wave test for Zone A applications;
g) specification of higher immunity requirements on power frequency magnetic field tests;

---------------------- Page: 7 ----------------------
– 6 – IEC 60255-26:2023 © IEC 2023
h) update of the spot frequency test and addition of a new annex with background
information;
i) addition of details and further guidance on the relay settings;
j) additional test condition for AC voltage dips and interruptions;
k) addition of an annex about EMC risk assessments;
l) addition of an annex on radio interfaces.
The text of this International Standard is based on the following documents:
Draft Report on voting
95/515/FDIS 95/525/RVD

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all the parts in the IEC 60255 series, published under the general title Measuring relays
and protection equipment, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

---------------------- Page: 8 ----------------------
IEC 60255-26:2023 © IEC 2023 – 7 –
MEASURING RELAYS AND PROTECTION EQUIPMENT –

Part 26: Electromagnetic compatibility requirements



1 Scope
1.1 General
This part of IEC 60255 specifies the requirements for electromagnetic compatibility for
measuring relays and protection equipment. It is applicable to measuring relays and protection
equipment and combinations of devices to form schemes for power system protection including
the control, monitoring, communication and process interface equipment used with those
systems.
Tests specified in this document are not required for equipment not incorporating electronic
circuits, for example electromechanical relays.
The requirements specified in this document are applicable to measuring relays and protection
equipment in a condition representative of how new equipment is provided by the manufacturer.
All tests specified are type tests only.
1.2 Emission
This document specifies limits and test methods, for measuring relays and protection equipment
in relation to electromagnetic emissions which might cause interference in other equipment.
These emission limits represent electromagnetic compatibility requirements and have been
selected to ensure that the disturbances generated by measuring relays and protection
equipment, operated normally in substations and power plants, do not exceed a specified level
which could prevent other equipment from operating as intended.
Test requirements are specified for the enclosure, auxiliary power supply ports, input/output
ports, signal/control ports and wired network ports.
1.3 Immunity
This document specifies the immunity test requirements for measuring relays and protection
equipment in relation to continuous and transient, conducted and radiated disturbances,
including electrostatic discharges.
These test requirements represent the electromagnetic compatibility immunity requirements
and have been selected so as to ensure an adequate level of immunity for measuring relays
and protection equipment, operated normally in substations and power plants.
NOTE 1 Product safety considerations are not covered in this document.
NOTE 2 In special cases, situations will arise where the levels of disturbance could exceed the levels specified in
this document, for example where a hand-held transmitter or a mobile telephone is used close to measuring relays
and protection equipment. In these instances, special precautions and procedures could be needed.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.

---------------------- Page: 9 ----------------------
– 8 – IEC 60255-26:2023 © IEC 2023
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60255-1:2022, Measuring relays and protection equipment – Part 1: Common requirements
IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
IEC 61000-4-3:2020, Electromagnetic compatibility (EMC) – Part 4-3: Testing and
measurement techniques – Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-4:2012, Electromagnetic compatibility (EMC) – Part 4-4: Testing and
measurement techniques – Electrical fast transient/burst immunity test
IEC 61000-4-5:2014, Electromagnetic compatibility (EMC) – Part 4-5: Testing and
measurement techniques – Surge immunity test
IEC 61000-4-5:2014/AMD1:2017
IEC 61000-4-6:2013, Electromagnetic compatibility (EMC) – Part 4-6: Testing and
measurement techniques – Immunity to conducted disturbances, induced by radio-frequency
fields
IEC 61000-4-8:2009, Electromagnetic compatibility (EMC) – Part 4-8: Testing and
measurement techniques – Power frequency magnetic field immunity test
IEC 61000-4-11:2020, Electromagnetic compatibility (EMC) – Part 4-11: Testing and
measurement techniques – Voltage dips, short interruptions and voltage variations immunity
tests for equipment with input current up to 16 A per phase
IEC 61000-4-16:2015, Electromagnetic compatibility (EMC) – Part 4-16: Testing and
measurement techniques – Test for immunity to conducted, common mode disturbances in the
frequency range 0 Hz to 150 kHz
IEC 61000-4-17:1999, Electromagnetic compatibility (EMC) – Part 4-17: Testing and
measurement techniques – Ripple on d.c. input power port immunity test
IEC 61000-4-17:1999/AMD1:2001
IEC 61000-4-17:1999/AMD2:2008
IEC 61000-4-18:2019, Electromagnetic compatibility (EMC) – Part 4-18: Testing and
measurement techniques – Damped oscillatory wave immunity test
IEC 61000-4-29:2000, Electromagnetic compatibility (EMC) – Part 4-29: Testing and
measurement techniques – Voltage dips, short interruptions and voltage variations on d.c. input
power port immunity tests
CISPR 11:2015, Industrial, scientific and medical equipment – Radio-frequency disturbance
characteristics – Limits and methods of measurement
CISPR 11:2015/AMD1:2016
CISPR 11:2015/AMD2:2019
CISPR 32:2015, Electromagnetic compatibility of multimedia equipment – Emission
requirements
CISPR 32:2015/AMD1:2019

---------------------- Page: 10 ----------------------
IEC 60255-26:2023 © IEC 2023 – 9 –
3 Terms, definitions, and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1.1
analogue output port
port that generates an analogue output signal to drive actuators, analogue panel meters, etc.
Note 1 to entry: Typically a current or voltage less than or equal to 20 mA or 10 V DC respecti
...