SIST EN IEC 63522-41:2026

• Abstract:

  IEC 63522-41:2026 provides guidelines for the insulation coordination of electromechanical elementary, solid state, time, forcibility guided and reed relays as well reed contacts and hybrid switching solutions. This document can also be used for similar devices when specified in a detail specification.

• Status: Published
• Public Enquiry End Date: 27-Sep-2023
• Publication Date: 20-Aug-2026
• ICS: 29.120.70 - Relays
• Technical Committee: ISS EIT.ERE - All-or-nothing electrical relays
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 14-Jul-2026
• Due Date: 18-Sep-2026
• Completion Date: 21-Aug-2026
• Ref Project: EN IEC 63522-41:2026 - Electrical relays - Tests and measurements - Part 41: Tests and measurement procedures - Insulation coordination

• Refers: SIST EN 60664-3:2017 - Insulation coordination for equipment within low-voltage systems - Part 3: Use of coating, potting or moulding for protection against pollution (IEC 60664-3:2016)
• Effective Date: 19-May-2026
• Refers: SIST EN 60664-5:2008 - Insulation coordination for equipment within low-voltage systems -- Part 5: Comprehensive method for determining clearances and creepage distances equal to or less than 2 mm
• Effective Date: 19-May-2026
• Refers: SIST EN IEC 60060-1:2025 - High-voltage test techniques - Part 1: General definitions and test requirements
• Effective Date: 19-May-2026
• Refers: SIST EN IEC 60270:2025 - High-voltage test techniques - Charge-based measurement of partial discharges
• Effective Date: 19-May-2026
• Refers: SIST EN IEC 60079-15:2019 - Explosive atmospheres - Part 15: Equipment protection by type of protection "n"
• Effective Date: 19-May-2026
• Refers: SIST EN IEC 63522-4:2026 - Electrical relays - Tests and Measurements - Part 7-4: Dielectric strength test
• Effective Date: 19-May-2026
• Refers: SIST EN IEC 60664-1:2020 - Insulation coordination for equipment within low-voltage supply systems - Part 1: Principles, requirements and tests (IEC 60664-1:2020)
• Effective Date: 19-May-2026
• Refers: kSIST FprEN IEC 63522-0:2026 - Electrical relays - Tests and Measurements - Part 0: General and Guidance
• Effective Date: 19-May-2026
• Referred By: SIST EN IEC 63522-1:2026 - Electrical relays - Tests and Measurements - Part 1: Visual inspection and check of dimensions
• Effective Date: 03-Feb-2026

Overview

SIST EN IEC 63522-41:2026 defines standardized guidelines for insulation coordination in electrical relays. This European and international standard applies to electromechanical elementary relays, solid state relays, time relays, forcibly guided relays, reed relays, reed contacts, and hybrid switching solutions. The principles can also be used for similar devices if specified in precise detail specifications.

The primary focus of IEC 63522-41:2026 is establishing uniform test and measurement procedures to ensure electrical safety and performance. Coordinating insulation in relays is essential to prevent electrical breakdown, ensure functional reliability, extend product lifetime, and meet safety regulations in a wide range of electrical and electronic systems.

Key Topics

• Insulation Types
  The standard covers different types of insulation within relays, including:

  • Functional, basic, supplementary, double, and reinforced insulation.
  • Requirements for clearances (the shortest distance in air between conductive parts), creepage distances (along the surface of insulating material), and solid insulation.

• Testing and Measurement Procedures
  SIST EN IEC 63522-41:2026 details the procedures for:

  • Measuring insulation parameters such as clearances and creepage distances.
  • Evaluating insulation capabilities under various environmental and operating conditions, with reference to pollution degrees, overvoltage categories, and material groups.
  • Systematic assessment of accessible surfaces and relay assemblies.

• Coordination Rules and Test Reports
  The standard prescribes:

  • The use of appropriate test voltages based on rated impulse and operational voltages.
  • Guidelines for insulation coordination in designs such as gas-filled relays or systems with compound insulation.
  • Documentation requirements for test results and conformity evaluation via detailed test reports.

• Terms and Definitions
  Standardized terminology helps unify understanding across international markets. Definitions cover key concepts like insulation coordination, pollution degree, micro-environment, conductive parts, and levels of contact separation.

Applications

IEC 63522-41:2026 is widely applicable in the electrical and electronics industries. Its insulation coordination guidelines are essential for:

• Relay Manufacturers: Ensuring products meet harmonized international safety and performance standards.
• Product Designers: Selecting appropriate insulation strategies based on relay type, application, and environmental conditions.
• Testing Laboratories: Conducting standardized tests to verify relay insulation properties and compliance.
• System Integrators: Choosing compliant relays for critical systems in automation, industrial control panels, energy management, and household appliances.
• Compliance and Certification: Facilitating conformity assessment to European (EN) and international (IEC) requirements for market access.

Adhering to this standard helps minimize electrical hazards, prevent relay failures, and support reliability in applications ranging from industrial automation to residential usage.

Related Standards

When applying SIST EN IEC 63522-41:2026, consider these related standards for comprehensive compliance and design guidance:

• IEC 60664 series: Core insulation coordination principles for low-voltage equipment.
• IEC 63522-0: General guidelines and definitions for relay tests and measurements.
• IEC 63522-4: Dielectric strength test procedures for relays.
• IEC 60060-1: General requirements and terminology for high-voltage test techniques.
• IEC 60270: Measurement of partial discharges in high-voltage systems.
• IEC 60079-15: Protection methods for equipment in explosive atmospheres.
• IEC/TS 62993: Criteria for clearances, creepage, and solid insulation in equipment with higher rated voltages.

For full implementation, always consult the latest editions and your national standards body for harmonized adoption. Keeping up-to-date ensures safe, reliable, and globally accepted relay products.

SLOVENSKI STANDARD
01-september-2026
Električni releji - Preskusi in meritve - 41. del: Preskusni in merilni postopki -
Uskladitev izolacije
Electrical relays - Tests and measurements - Part 41: Tests and measurement
procedures - Insulation coordination
Elektrische Relais – Mess- und Prüfverfahren – Teil 41: Isolationskoordination
Relais électriques - Essais et mesurages - Partie 41: Coordination de l'isolement
Ta slovenski standard je istoveten z: EN IEC 63522-41:2026
ICS:
29.120.70 Releji Relays
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 63522-41

NORME EUROPÉENNE
EUROPÄISCHE NORM July 2026
ICS 29.120.70
English Version
Electrical relays - Tests and measurements - Part 41: Tests and
measurement procedures - Insulation coordination
(IEC 63522-41:2026)
Relais électriques - Essais et mesurages - Partie 41: Essais Elektrische Relais - Mess- und Prüfverfahren - Teil 41:
et procédures de mesure - Coordination de l'isolement Isolationskoordination
(IEC 63522-41:2026) (IEC 63522-41:2026)
This European Standard was approved by CENELEC on 2026-05-20. 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 CEN-CENELEC
Management Centre 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 CEN-CENELEC Management Centre 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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 63522-41:2026 E

European foreword
The text of document 94/1181/FDIS, future edition 1 of IEC 63522-41, prepared by TC 94 "Electrical
relays" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-07-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-07-31
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 63522-41:2026 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 standard indicated:
IEC 60038 NOTE Approved as EN 60038
IEC 60664-4 NOTE Approved as EN 60664-4
IEC 60730-1:2022 NOTE Approved as EN IEC 60730-1:2024 (not modified) +A11:2024
IEC 63522 (series) NOTE Approved as EN IEC 63522 (series)
IEC 63522-10 NOTE Approved as EN IEC 63522-10
IEC 63522-43 NOTE Approved as EN IEC 63522-43
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60060-1 2025 High-voltage test techniques - Part 1: EN IEC 60060-1 2025
General terminology and test requirements
IEC 60079-15 2017 Explosive atmospheres - Part 15: EN IEC 60079-15 2019
Equipment protection by type of protection
"n"
IEC 60270 - High-voltage test techniques - Charge- EN IEC 60270 -
based measurement of partial discharges
IEC 60664-1 2020 Insulation coordination for equipment EN IEC 60664-1 2020
within low-voltage supply systems - Part 1:
Principles, requirements and tests
IEC 60664-3 2016 Insulation coordination for equipment EN 60664-3 2017
within low-voltage systems - Part 3: Use of
coating, potting or moulding for protection
against pollution
IEC 60664-5 2007 Insulation coordination for equipment - -
within low-voltage systems - Part 5:
Comprehensive method for determining
clearances and creepage distances equal
to or less than 2 mm
IEC/TS 62993 2017 Guidance for determination of clearances, - -
creepage distances and requirements for
solid insulation for equipment with a rated
voltage above 1 000 V AC and 1 500 V
DC, and up to 2 000 V AC and 3 000 V DC
IEC 63522-0 - Electrical relays - Tests and Measurements - -
- Part 0: General and Guidance
IEC 63522-4 2025 Electrical relays - Tests and measurements EN IEC 63522-4 2026
- Part 4: Dielectric strength test

Under preparation. Stage at the time of publication: IEC CDV 63522-0:2025.
IEC 63522-41 ®
Edition 1.0 2026-04
INTERNATIONAL
STANDARD
Electrical relays - Tests and measurements -
Part 41: Tests and measurement procedures - Insulation coordination
ICS 29.120.70  ISBN 978-2-8327-1162-0

IEC 63522-41:2026-04(en)
IEC 63522-41:2026 © IEC 2026
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
3.1 Terms and definitions related to insulation . 6
3.2 Terms and definitions related to contacts . 8
4 Test procedure . 9
4.1 Purpose . 9
4.1.1 Insulation coordination based on creepage, clearance, solid insulation
and accessible surfaces evaluation . 9
4.1.2 Insulation coordination evaluation as a system . 10
4.2 Procedure . 10
4.2.1 Clearances and creepage distances. 10
4.2.2 Solid insulation . 15
4.2.3 Accessible surfaces . 16
4.2.4 Solid insulation in the coil assembly as part of the insulation
coordination . 16
4.2.5 Insulation coordination evaluation as a system . 16
4.2.6 Requirements for solid insulating materials used in solid state relays . 17
4.2.7 Requirements for hybrid switching solutions . 18
4.3 Condition . 18
4.3.1 Conditions for 4.2.1 and. 18
4.3.2 Conditions for 4.2.2 . 18
4.3.3 Conditions for 4.2.3 . 18
4.3.4 Conditions for 4.2.4 . 18
4.3.5 Conditions for 4.2.5 . 18
4.3.6 Conditions for 4.2.6 . 19
4.3.7 Conditions for 4.2.7 . 19
5 Evaluation . 19
5.1 General . 19
5.1.1 Evaluation according 4.2.1 . 19
5.1.2 Evaluation according 4.2.2 . 19
5.1.3 Evaluation according 4.2.3 . 19
5.1.4 Evaluation according 4.2.4 . 19
5.1.5 Evaluation according 4.2.5 . 19
5.1.6 Evaluation according 4.2.6 . 20
5.2 Test report . 21
Annex A (normative) Measurement of clearances and creepage distances . 22
Annex B (normative) Relation between rated impulse voltage, nominal voltage and
overvoltage category . 28
Annex C (normative) Pollution degrees . 30
Bibliography . 31

Figure 1 – Test procedure of system evaluation . 20
Figure A.1 – Example 1 . 22
Figure A.2 – Example 2 . 23
IEC 63522-41:2026 © IEC 2026
Figure A.3 – Example 3 . 23
Figure A.4 – Example 4 . 23
Figure A.5 – Example 5 . 24
Figure A.6 – Example 6 . 24
Figure A.7 – Example 7 . 25
Figure A.8 – Example 8 . 25
Figure A.9 – Example 9 . 26
Figure A.10 – Example 10 . 26
Figure A.11 – Example 11 . 27

Table 1 – Provisions for the dimensioning of clearances and creepage distances . 11
Table 2 – Minimum clearances in air for insulation coordination . 12
Table 3 – Minimum clearances in controlled overvoltage conditions for internal circuits . 13
Table 4 – Material groups . 13
Table 5 – Minimum creepage distances for equipment subject to long-term stresses . 14
Table 6 – Rated insulation voltage according to supply system voltage . 15
Table A.1 – Pollution degrees – distance X dependency . 22
Table B.1 – Correspondence between the nominal voltage of the supply system and
the equipment rated impulse withstand voltage . 28

IEC 63522-41:2026 © IEC 2026
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Electrical relays - Tests and measurements -
Part 41: Tests and measurement procedures - Insulation coordination

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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 63522-41 has been prepared by IEC technical committee 94: Electrical relays. It is an
International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
94/1181/FDIS 94/1199/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.
IEC 63522-41:2026 © IEC 2026
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 parts of IEC 61810 series, published under the general title Electrical relays - Tests
and measurements, can be found on the IEC website.
This International Standard is to be used in conjunction with IEC 63522-0.
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, or
– revised.
IEC 63522-41:2026 © IEC 2026
1 Scope
This part of IEC 63522 provides guidelines for the insulation coordination of electromechanical
elementary, solid state, time, forcibility guided and reed relays as well reed contacts and hybrid
switching solutions. This document can also be used for similar devices when specified in a
detail specification.
Either the test, measurement of creepages, clearances, solid insulation and insulation systems
or combinations or all of them are carried out in conjunction with other parts of the IEC 63522
series.
The basis of the insulation coordination is given in the IEC 60664 series.
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.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60060-1:2025, High-voltage test techniques - Part 1: General terminology and test
requirements
IEC 60079-15:2017, Explosive atmospheres - Part 15: Equipment protection by type of
protection "n"
IEC 60270, High-voltage test techniques - Charge-based measurement of partial discharges
IEC 60664-1:2020, Insulation coordination for equipment within low-voltage supply systems -
Part 1: Principles, requirements and tests
IEC 60664-3:2016, Insulation coordination for equipment within low-voltage systems - Part 3:
Use of coating, potting or moulding for protection against pollution
IEC 60664-5:2007, Insulation coordination for equipment within low-voltage systems - Part 5:
Comprehensive method for determining clearances and creepage distances equal to or less
than 2 mm
IEC TS 62993:2017, Guidance for determination of clearances, creepage distances and
requirements for solid insulation for equipment with a rated voltage above 1 000 V AC and
1 500 V DC, and up to 2 000 V AC and 3 000 V DC
IEC 63522-0, Electrical relays - Tests and measurements - Part 0: General and guidance
IEC 63522-4:2025, Electrical relays - Tests and measurements - Part 4: Dielectric strength test
___________
This publication was withdrawn.
Under preparation. Stage at the time of publication: IEC CDV 63522-0:2025.
IEC 63522-41:2026 © IEC 2026
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 63522-0 and the
following 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 Terms and definitions related to insulation
3.1.1
functional insulation
insulation between conductive parts, necessary for the proper functioning of the relay
Note 1 to entry: A typical functional insulation is the coil wire insulation.
[SOURCE: IEC 60050-195:2021,195-02-41, modified – Replacement of "equipment" with
"relay" and addition of a Note 1 to entry.]
3.1.2
basic insulation
insulation of hazardous-live-parts which provides basic protection against electric shock
Note 1 to entry: Basic insulation does not necessarily include insulation used exclusively for functional purposes.
[SOURCE: IEC 60664-1:2020, 3.1.30, modified – Addition of "against electric shock" and Note 1
to entry has been reworded.]
3.1.3
supplementary insulation
independent insulation applied in addition to basic insulation, in order to provide protection
against electric shock in the event of a failure of basic insulation
[SOURCE: IEC 60050-195:2021, 195-06-07, modified – Replacement of ", that provides fault
protection" with "in order to provide protection against electric shock in the event of a failure of
basic insulation".]
3.1.4
double insulation
insulation comprising both basic insulation and supplementary insulation
[SOURCE: IEC 60050-195:2021, 195-06-08]
3.1.5
reinforced insulation
insulation of hazardous-live-parts which provides a degree of protection against electric shock
equivalent to double insulation
[SOURCE: IEC 60050-195:2021, 195-06-09, modified – Addition of "of hazardous-live-parts" in
the definition, and deletion of Note 1 to entry.]
IEC 63522-41:2026 © IEC 2026
3.1.6
conductive part
part which is capable of conducting electric current, although it may not necessarily be used for
this purpose
[SOURCE: IEC 60050-195:2021, 195-01-06, modified – Addition of "although it may not
necessarily be used for this purpose".]
3.1.7
live part
conductor or conductive part intended to be energized in normal operation, including a neutral
conductor, but by convention not a PEN conductor
Note 1 to entry: A PEN conductor combines the functions of both a protective earthing conductor and a neutral
conductor.
[SOURCE: IEC 60050-195:2021, 195-02-19, modified – Addition of "conductor" and deletion of
"and mid-point conductor" and "PEM conductor and PEL conductor" in the definition. Addition
of a Note 1 to entry.]
3.1.8
clearance
shortest distance in air between two conductive parts, or between a conductive part and the
accessible surface of a relay
Note 1 to entry: An example for an accessible surface is the actuating member of a relay used for manual operation.
[SOURCE: IEC 60664-1:2020, 3.1.4, modified – Addition of "or between a conductive part and
the accessible surface of a relay", and addition of a Note 1 to entry.]
3.1.9
solid insulation
solid insulating material interposed between two conductive parts
[SOURCE: IEC 60664-1:2020, 3.1.6, modified ─ Replacement of "or a combination of solid
insulating materials, placed between two conductive parts or between a conductive part and a
body part" with " interposed between two conductive parts".]
3.1.10
thin layer
solid, homogenic insulating material with specified dielectric strength
Note 1 to entry: Typical examples for thin layers are insulation tapes and similar.
3.1.11
creepage distance
shortest distance along the surface of the insulating material between two conductive parts
[SOURCE: IEC 60664-1:2020, 3.1.5, modified – Deletion of "solid" in the definition.]
3.1.12
tracking
progressive degradation of a solid insulating material by local discharges to form conducting or
partially conducting paths
Note 1 to entry: Tracking usually occurs due to surface contamination.
[SOURCE: IEC 60050-212:2010, 212-11-56, modified – The definition has been reworded.]
IEC 63522-41:2026 © IEC 2026
3.1.13
proof tracking index
PTI
numerical value of the proof voltage expressed in volts which a material can withstand without
tracking under specified test conditions
[SOURCE: IEC 60050-212:2010, 212-11-60, modified – "without tracking failure and without a
persistent flame occurring" replaced with "without tracking under specified test conditions".]
3.1.14
pollution
any addition of foreign matter, solid, liquid, or gaseous that can result in a reduction of electric
strength or surface resistivity of the insulation
[SOURCE: IEC 60664-1:2020, 3.1.24, modified ─ Deletion of "(ionized gases)", and "that can
affect" replaced with "that can result in a reduction of".]
3.1.15
pollution degree
numeral characterizing the expected pollution of the micro-environment
Note 1 to entry: Pollution degrees 1, 2 and 3 are used, see Annex C.
[SOURCE: IEC 60664-1:2020, 3.1.25, modified ─ Addition of Note 1 to entry.]
3.1.16
micro-environment
immediate environment of the insulation which particularly influences the dimensioning of the
creepage distances
[SOURCE: IEC 60664-1:2020, 3.1.23, modified ─ Rewording of the entire definition.]
3.2 Terms and definitions related to contacts
3.2.1
micro-interruption
interruption of a circuit by contact separation which does not provide full-disconnection or micro-
disconnection
Note 1 to entry: There are no dielectric strength or dimensional requirements for the contact gap.
[SOURCE: IEC 60730-1:2022, 3.4.4, modified – Deletion of "by a cycling action or by a non-
cycling action".]
3.2.2
micro-disconnection
adequate contact separation in at least one contact so as to provide functional security
Note 1 to entry: There is a requirement for the dielectric strength of the contact gap but no dimensional requirement.
[SOURCE: IEC 60730-1:2022, 3.4.3, modified – Replacement of "one pole for functional
disconnection" with "one contact so as to provide functional security". Deletion of Note 2 to
entry and Note 3 to entry.]
IEC 63522-41:2026 © IEC 2026
3.2.3
full disconnection
contact separation for the disconnection of conductors so as to provide the equivalent of basic
insulation between those parts intended to be disconnected
Note 1 to entry: There are dielectric strength and dimensional requirements.
[SOURCE: IEC 60730-1:2022, 3.4.2, modified – Replacement of "in all supply poles other than
protective earth" with "for the disconnection of conductors", deletion of " the supply mains and",
and deletion of Note 2 to entry and Note 3 to entry.]
4 Test procedure
4.1 Purpose
4.1.1 Insulation coordination based on creepage, clearance, solid insulation and
accessible surfaces evaluation
The requirements and tests indicated in 4.2.1 to 4.2.3 are based on IEC 60664-1.
NOTE 1 In case insulating media (solid, liquid and gaseous) are used which are not covered by this document,
other clearance and creepage distances can apply when verified for the entire lifetime of the relay.
If the construction or dedicated use of the relay allows, one or more of the following options a)
to c) can apply for the determination of insulation capabilities of a relay.
a) When all the conditions of IEC 60664-5:2007 are fulfilled, the dimensioning of clearances
and creepage distances for spacings up to 2 mm as given in that standard can apply instead.
NOTE 2 IEC 60664-5 applies in the case of printed wiring boards and similar constructions where the
clearances and creepage distances are identical and along the surface of solid insulation (see Figure A.1 to
Figure A.8 shown in Annex A). Smaller dimensioning than that based on IEC 60664-1 can be achieved dependent
on the water absorption characteristics of the solid insulating material. According to IEC 60664-5, the dimensions
for reinforced or double insulation can exceed 2 mm.
b) For constructions in accordance with IEC 60664-3, where protection against pollution is
achieved by using adequate bonding, coating, potting or moulding, the reduced clearances
and creepage distances as specified in IEC 60664-3 can be used. All the requirements and
tests of IEC 60664-3 shall be fulfilled. The following items apply when specified in the basic
safety standards:
1) value for lower temperature under 5.7.1 of IEC 60664-3:2016 −10 °C;
2) temperature cycle under 5.7.3 of IEC 60664-3:2016, Severity 1;
3) the partial discharge test under 5.8.5 of IEC 60664-3:2016;
4) none of the additional tests under 5.9 of IEC 60664-3:2016.
The temperature for preconditioning 5.7.2 of IEC 60664-3:2016 and upper temperature,
5.7.3 of IEC 60664-3:2016 shall be determined during a heating test on a single sample
under nominal conditions and maximum ambient temperature. The thermocouple shall be
placed next to interested area under consideration. In accordance with IEC 60079-15:2017,
the measured temperature shall be increased by 10 °C. It is permitted to reduce the test
duration of the dry heat test by using the following formula:
−0,069 3×−(TT)
Duration h 2 685×10
[ ]
where
T is the chosen test temperature, under consideration of all material temperature
limits in the investigated area;
T is the measured temperature +10 °C.
NOTE 3 The functional, mechanical and electrical properties of the involved materials can be considered.
=
IEC 63522-41:2026 © IEC 2026
The provisions for solid insulation (see 4.2.2) remain unchanged.
NOTE 4 In Annex A, Figure A.5b), Figure A.6b) and Figure A.8b) show the determination of clearance and
creepage distances in this case.
c) In the case of relays to be used for frequencies of the working voltage above 30 kHz, it is
strongly recommended to apply the provisions for insulation coordination as given in
IEC 60664-4.
4.1.2 Insulation coordination evaluation as a system
Insulation systems, where the IEC 60664 series does not or only partly apply, shall be evaluated
according to 4.2.5; typical examples are gas-filled relays.
NOTE The evaluation is based on the statistic evaluation method of IEC 60060-1.
This procedure shall be applied for the evaluation of insulation between open contacts and can
be applied for systems where insulation distances are composed of a part in air and another
part where the IEC 60664 series does not apply.
Any breakdown shall be between metal parts (contacts) only – meaning that the insulation is
able to recover. Any breakdown of solid insulation or via creepages is considered as a failure
and does not allow the evaluation with this method.
In case of compound insulation distances, the rules of IEC 60664-1:2020, 5.3.3.5 shall apply.
However, at least one of the distances shall withstand the given insulation requirements.
In cases where double or reinforced insulation is required, either one distance shall comply with
the requirements of double or reinforced insulation, or each distance shall comply with basic
insulation requirements. In this case the insulation system shall be evaluated according to the
requirements of 4.2.1 and 4.2.5.
For designs where a potential breakdown could only be between the contacts, this method could
be used alternatively to 4.2.1.
4.2 Procedure
4.2.1 Clearances and creepage distances
Clearances and creepage distances shall be dimensioned according to the criteria given in
Table 1.
IEC 63522-41:2026 © IEC 2026
Table 1 – Provisions for the dimensioning of clearances and creepage distances
Characteristics to be Clearances Creepage distances
tested
Clearances shall be so dimensioned that Creepage distances shall be dimensioned
they comply with the requirements of as given in Table 5 for the highest voltage
Table 2 depending on the impulse that can occur in the circuit(s) in normal
withstand voltage stated by the use, whereby the pollution degree
manufacturer, eventually taking into according to Annex C and the material
account the overvoltage category as group taken from Table 4 shall be
given in Annex B and the pollution considered. A creepage distance shall not
degree according to Annex C. be less than the associated clearance.
Details regarding the measurement of Details regarding the measurement of
creepage distances are described in
clearances are described in Annex A.
Annex A.
f
There are no requirements for the There are no requirements for the creepage
Functional insulation
clearances. distances.
e
Rated values according to Table 2 apply Rated values according to Table 5 apply to
Basic insulation
to all relevant parts of the relay. all relevant parts of the relay.
Inside the relay case the rated values Inside the relay case, the rated values shall
shall be chosen considering the be chosen considering the pollution degree
pollution degree according to Annex C. according to Annex C.
Supplementary Equal to basic insulation. Equal to basic insulation.
insulation
Double insulation Comprises basic and supplementary Comprises basic and supplementary
insulation. insulation.
c
Equal to basic insulation, however one Twice the value for basic insulation.
Reinforced insulation
step higher in the preferred series of
rated values of the impulse voltage, or
160 % of the rated impulse voltage for
a b
basic insulation.
Across open contact for Inside the relay case, there are no Inside the relay case, there are no require-
d
micro-disconnection requirements concerning clearances. ments concerning creepage distances.
Distances between the contact members Distances between the contact members
and other conducting parts of the and other conducting parts of the contact
contact down to its fixation within the down to its fixation within the relay shall not
relay shall not be smaller than the be smaller than the contact gap.
contact gap.
Across open contact for Rated value as for basic insulation in Rated value as for basic insulation in
full-disconnection accordance with Table 2. accordance with Table 5.
Distances between the contact members Distances between the contact members
and other conducting parts of the and other conducting parts of the contact
contact down to its fixing within the relay down to its fixing within the relay shall not
shall not be smaller than the contact be smaller than the contact gap.
gap.
NOTE The properties of the functional insulation are evaluated with the type tests of this document. Requirements
for the functional insulation can be given by the application and the relevant application standards.
a
Clearances for reinforced insulation shall be dimensioned using one of the values for the rated impulse voltage
taken from Table 2 by the manufacturer, if applicable taking into account the overvoltage category as given in
Annex B and the pollution degree according to Annex C, but one step higher in the preferred series of values
given in Table 2 than that specified for basic insulation. If the impulse withstand voltage required for basic
insulation is other than a value from the preferred series, reinforced insulation shall be dimensioned to withstand
160 % of the impulse withstand voltage required for basic insulation.
b
In case of relays provided with double insulation, where basic and supplementary insulation cannot be
tested separately, the insulation system is considered as a reinforced insulation.
c
In case of a foreseeable single failure condition – e.g. broken wire or loosened coil windings- the
requirements for basic insulation shall remain fulfilled by design.
d
The requirements for micro-disconnection also include those for micro-interruption.
e
At least basic insulation shall be given between terminals of opposite polarity (all possibilities):
– between uninsulated live parts and the relay housing with the contacts open and closed;
– between terminals of opposite polarity with the contacts closed;
– between uninsulated live parts of different circuits.
f
Between terminals of relay coils or input circuit, functional insulation applies.

IEC 63522-41:2026 © IEC 2026
Alternate to the measurement methods mentioned in Annex A, an impulse voltage withstand
test (1,2/50 µs) could be used if specified in the basic safety standards to verify the clearance
if it is adequate to the one required in Table 2. The test procedure described in
IEC 60664-1:2020 applies too.
Table 2 – Minimum clearances in air for insulation coordination
c d
Minimum clearances up to 2 000 m above sea level
a
e
Impulse withstand voltage
Pollution degree
1 2 3
kV mm mm mm
b c
0,01 0,8
0,33 0,2
c
0,40 0,02 0,8
0,2
b c
0,04 0,8
0,50 0,2
0,60 0,06 0,2 0,8
b
0,10 0,2 0,8
0,80
1,0 0,15 0,2 0,8
1,2 0,25 0,8
b
0,5 0,8
1,5
2,0 1,0
b
1,5
2,5
3,0 2,0
b
3,0
4,0
5,0 4,0
b
5,5
6,0
b
8,0
8,0
10 11
b
b
b
b
NOTE Values formatted in bold are preferred values.
a
This voltage is
– for basic insulation directly exposed to or significantly influenced by transient overvoltages from the low-
voltage mains: the rated impulse voltage of the equipment;
– for other basic insulation: the highest impulse voltage that can occur in the circuit;
– for reinforced insulation, see footnotes a and b of Table 1.
In special cases intermediate values derived by interpolation can be used for the dimensioning of clearances.
b
Preferred values for relating to the overvoltage category (see Annex B).
c
For printed wiring material, the values for pollution degree 1 apply except that the value shall not be less than
0,04 mm, as specified in Table 4.
d
As the dimensions in Table 2 are valid for altitudes up to and including 2 000 m above sea level, clearances for
altitudes above 2 000 m shall be multiplied by the altitude correction factor specified in Table A.2 of
IEC 60664-1:2020.
e
Details regarding pollution degrees are specified in Annex C.

When an overvoltage control component is used (e.g. surge suppressor), clearances can be
defined in accordance with Table 3.
IEC 63522-41:2026 © IEC 2026
Table 3 – Minimum clearances in controlled overvoltage conditions for internal circuits
a
Minimum clearances in millimetres
Voltage
Pollution degree
V 1 2 3
330 0,01 0,20 0,80
400 0,02 0,20 0,80
500 0,04 0,20 0,80
600 0,06 0,20 0,80
800 0,10 0,20 0,80
1 000 0,15 0,20 0,80
a
This voltage is the clamping voltage of the overvoltage control device.

The relationship between the material group and the proof tracking index (PTI) is given in
Table 4.
Table 4 – Material groups
Material group I 600 ≤ PTI
Material group II 400 ≤ PTI < 600
Material group IIIa 175 ≤ PTI < 400
a
100 ≤ PTI < 175
Material group IIIb
a
Material group IIIb is not recommended for use in pollution degree 3 above 630 V.

The PTI values are derived from the tracking test indicated in IEC 63522-43.
IEC 63522-41:2026 © IEC 2026
Table 5 – Minimum creepage distances for equipment subject to long-term stresses
Creepage distances
d, e
Pollution degree
Printed wiring
Other materials
Voltage RMS
material (PCB)
a,f
1 2 1 2 3
V
Material group Material group
b c b d
I II III I II
III
mm mm mm mm mm mm mm mm mm
10 0,025 0,04 0,08 0,4 1
12,5 0,025 0,04 0,09 0,42 1,05
16 0,025 0,04 0,1 0,45 1,1
20 0,025 0,04 0,11 0,48 1,2
25 0,025 0,04 0,125 0,5 1,25
32 0,025 0,04 0,14 0,53 1,3
40 0,025 0,04 0,16 0,56 0,8 1,1 1,4 1,6 1,8
50 0,025 0,04 0,18 0,6 0,85 1,2 1,5 1,7 1,9
63 0,04 0,063 0,2 0,63 0,9 1,25 1,6 1,8 2
80 0,063 0,1 0,22 0,67 0,95 1,3 1,7 1,9 2,1
100 0,1 0,16 0,25 0,71 1 1,4 1,8 2 2,2
125 0,16 0,25 0,28 0,75 1,05 1,5 1,9 2,1 2,4
160 0,25 0,4 0,32 0,8 1,1 1,6 2 2,2 2,5
200 0,4 0,63 0,42 1 1,4 2 2,5 2,8 3,2
250 0,56 1 0,56 1,25 1,8 2,5 3,2 3,6 4
320 0,75 1,6 0,75 1,6 2,2 3,2 4 4,5 5
400 1 2 1 2 2,8 4 5 5,6 6,3
500 1,3 2,5 1,3 2,5 3,6 5 6,3 7,1 8
630 1,8 3,2 1,8 3,2 4,5 6,3 8 9 10
800 2,4 4 2,4 4 5,6 8 10 11 12,5
1 000 3,2 5 3,2 5 7,1 10 12,5 14 16
1 250  4,2 6,3 9 12,5 16 18 20
1 600  5,6 8 11 16 20 22 25
NOTE Values formatted in bold are preferred values.
a
This voltage is
– for functional insulation: the working voltage;
voltage mains: the
– for basic and supplementary insulation of a circuit energized directly from the low-
rated voltage, or the rated insulation voltage;
– for basic and supplementary insulation of a circuit not energized directly from the low-voltage mains: the
highest RMS voltage which can occur in the equipment or internal circuit when supplied at rated voltage
and under the most onerous combination of conditions of operation within equipment rating.
600 V, minimum creepage distance for basic insulation shall comply with
For higher voltage exceeding 1
Table 5 of IEC TS 62993:2017.
b
Material groups I, II, IIIa, and IIIb (see Table 4).
c
Material groups I, II, and IIIa (see Table 4).
d
Material group IIIb is not recommended for application in pollution degree 3 above 630 V.
e
Details regarding pollution degrees are specified in Annex C.
f
Intermediate values derived by interpolation can be used for the dimensioning of creepage distances, if
specified within the product standard.

IEC 63522-41:2026 © IEC 2026
The relationship between rated insulation voltage and supply system voltage is given in Table 6.
Table 6 – Rated insulation voltage according to supply system voltage
a
Voltages
Rated voltage of the supply system
V (AC RMS or DC)
12,5 24 30 42 60 100 150 208 220 277 380 440 575 1 000 1 500
b
25 48 110 230 300 400 480 600
50 120 240 500
125 250
Rated 12,5 25 32 50 63 125 160 200 250 320 400 500 630
...