SIST EN IEC 60112:2025

SLOVENSKI STANDARD
01-oktober-2025
Nadomešča:
SIST EN IEC 60112:2021
Metoda za ugotavljanje preskusnih in primerjalnih indeksov ustvarjanja prevodnih
poti trdnih izolacijskih materialov (IEC 60112:2025)
Method for the determination of the proof and the comparative tracking indices of solid
insulating materials (IEC 60112:2025)
Verfahren zur Bestimmung der Prüfzahl und der Vergleichszahl der Kriechwegbildung
von festen, isolierenden Werkstoffen (IEC 60112:2025)
Méthode de détermination des indices de résistance et de tenue au cheminement des
matériaux isolants solides (IEC 60112:2025)
Ta slovenski standard je istoveten z: EN IEC 60112:2025
ICS:
19.080 Električno in elektronsko Electrical and electronic
preskušanje testing
29.035.01 Izolacijski materiali na Insulating materials in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60112

NORME EUROPÉENNE
EUROPÄISCHE NORM August 2025
ICS 29.035.01; 19.080 Supersedes EN IEC 60112:2020
English Version
Method for the determination of the proof and the comparative
tracking indices of solid insulating materials
(IEC 60112:2025)
Méthode de détermination des indices de résistance et de Verfahren zur Bestimmung der Prüfzahl und der
tenue au cheminement des matériaux isolants solides Vergleichszahl der Kriechwegbildung von festen,
(IEC 60112:2025) isolierenden Werkstoffen
(IEC 60112:2025)
This European Standard was approved by CENELEC on 2025-07-28. 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
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60112:2025 E
European foreword
The text of document 112/679/FDIS, future edition 6 of IEC 60112, prepared by TC 112 "Evaluation
and qualification of electrical insulating materials and systems" was submitted to the IEC-CENELEC
parallel vote and approved by CENELEC as EN IEC 60112:2025.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-08-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-08-31
document have to be withdrawn
This document supersedes EN IEC 60112:2020 and all of its amendments and corrigenda (if any).
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 60112:2025 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 60212 NOTE Approved as EN 60212
IEC 60587 NOTE Approved as EN IEC 60587
IEC 60664-1 NOTE Approved as EN IEC 60664-1
ISO 293 NOTE Approved as EN ISO 293
ISO 294-1 NOTE Approved as EN ISO 294-1
ISO 294-3 NOTE Approved as EN ISO 294-3
ISO 295 NOTE Approved as EN ISO 295
ISO 3167 NOTE Approved as EN ISO 3167
ISO 3696 NOTE Approved as EN ISO 3696
ISO 7888 NOTE Approved as EN 27888
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
ISO 4287 - Geometrical Product Specifications (GPS) - -
- Surface texture: Profile method - Terms,
definitions and surface texture parameters

IEC 60112 ®
Edition 6.0 2025-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Method for the determination of the proof and the comparative tracking indices
of solid insulating materials
Méthode de détermination des indices de résistance et de tenue au
cheminement des matériaux isolants solides

ICS 19.080, 29.035.01 ISBN 978-2-8327-0492-9

IEC 60112:2025-06(en-fr)
IEC 60112:2025 © IEC 2025
CONTENTS
FOREWORD . 2
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 6
5 Test specimen . 6
6 Test specimen conditioning . 7
6.1 Environmental conditioning . 7
6.2 Test specimen surface state . 7
7 Test apparatus . 7
7.1 Electrodes . 7
7.2 Test circuit . 9
7.3 Test solutions . 10
7.4 Dropping device . 11
7.5 Test specimen support platform . 11
7.6 Electrode assembly installation . 12
7.7 Conditioning chamber . 12
8 Basic test procedure . 12
8.1 General . 12
8.2 Preparation . 12
8.3 Test procedure. 13
9 Determination of erosion. 13
10 Proof tracking index test (PTI) . 13
10.1 Procedure . 13
10.2 Report . 14
11 Determination of comparative tracking index (CTI). 15
11.1 General . 15
11.2 Screening test . 15
11.3 Determination of the maximum 50 drop withstand voltage . 15
11.4 Determination of the 100 drop point . 16
11.5 Report . 17
Annex A (informative) List of factors that should be considered by product committees . 18
Annex B (informative) Solution B . 19
Annex C (informative) Electrode material selection . 20
C.1 Platinum electrodes . 20
C.2 Alternatives . 20
Bibliography . 21

Figure 1 – Electrode . 8
Figure 2 – Electrode and specimen arrangement . 8
Figure 3 – Example of typical electrode mounting and specimen support . 9
Figure 4 – Example of test circuit . 10

IEC 60112:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Method for the determination of the proof and the comparative tracking
indices of solid insulating materials
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 60112 has been prepared by IEC technical committee 112: Evaluation and qualification of
electrical insulating materials and systems. It is an International Standard.
This sixth edition cancels and replaces the fifth edition published in 2020. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) In 7.3, the term "resistivity" has been replaced by "conductivity".
It has the status of a basic safety publication in accordance with IEC Guide 104.
IEC 60112:2025 © IEC 2025
The text of this International Standard is based on the following documents:
Draft Report on voting
112/679/FDIS 112/686/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.
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 60112:2025 © IEC 2025
1 Scope
This document specifies the method of test for the determination of the proof and comparative
tracking indices of solid insulating materials on pieces taken from parts of equipment and on
plaques of material using alternating voltage.
This document provides a procedure for the determination of erosion when required.
The proof tracking index is used as an acceptance criterion as well as a means for the quality
control of materials and fabricated parts. The comparative tracking index is mainly used for the
basic characterization and comparison of the properties of materials.
This test method evaluates the composition of the material as well as the surface of the material
being evaluated. Both the composition and surface condition directly influence the results of
the evaluation and are considered when using the results in material selection process.
The described test method is designed for a test voltage up to 600 V AC, because higher test
voltages and DC voltage will lead to a reduced test severity.
Test results are not directly suitable for the evaluation of safe creepage distances when
designing electrical apparatus.
The results of this method have been used for insulation coordination of equipment. It is
important that use of these results also considers the overvoltage levels, creepage distances,
and establishes the pollution degree to which the product insulation system will be expected to
be subjected. This is in compliance with IEC 60664-1.
This basic safety publication focusing on a safety test method is primarily intended for use by
technical committees in the preparation of safety publications in accordance with the principles
laid down in IEC Guide 104 and lSO/lEC Guide 51.
One of the responsibilities of a technical committee is, wherever applicable, to make use of
basic safety publications in the preparation of its publications.
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.
ISO 4287, Geometrical Product Specification (GPS) – Surface texture: Profile method – Terms,
definitions and surface texture parameters
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org
• ISO Online browsing platform: available at http://www.iso.org/obp
IEC 60112:2025 © IEC 2025
3.1
tracking
progressive formation of conducting paths, which are produced on the surface or within a solid
insulating material or both, due to the combined effects of electric stress and electrolytic
contamination
3.2
tracking failure
failure of insulation due to tracking between conductive parts
Note 1 to entry: In the present test, tracking is indicated by operation of an over-current device due to the passage
of a current across the test surface or within the specimen or both.
3.3
electrical erosion
wearing away of insulating material by the action of electrical discharges
3.4
air arc
arc between the electrodes above the surface of the specimen
3.5
comparative tracking index
CTI
numerical value of the maximum voltage (in V) at which five test specimens withstand the test
period for 50 drops without tracking failure and without a persistent flame occurring and
including also a statement relating to the behaviour of the material when tested using 100 drops
(see 11.3)
Note 1 to entry: No tracking failure and no persistant flame are allowed at any lower test voltage.
Note 2 to entry: The criteria for CTI can also require a statement concerning the degree of erosion.
Note 3 to entry: Although a non-persistent flame is allowed in the test without constituting failure, materials which
generate no flame at all are preferred unless other factors are considered to be more important. See also Annex A.
Note 4 to entry: Some materials can withstand high test voltages, but fail at lower test voltages. See also 11.2.
3.6
persistent flame
flame which burns for more than 2 s
Note 1 to entry: In the present test, persistent flame is indicated by a visual check.
3.7
proof tracking index
PTI
numerical value of the proof voltage (in V) at which five test specimens withstand the test period
for 50 drops without tracking failure and without a persistent flame occurring
Note 1 to entry: Although a non-persistent flame is allowed in the test without constituting failure, materials which
generate no flame at all are preferred unless other factors are considered to be more important. See also Annex A.
3.8
de-ionized water
water for analytical laboratory use in accordance with ISO 3696, grade 3, or equivalent quality
IEC 60112:2025 © IEC 2025
4 Principle
The upper surface of the test specimen is supported in a horizontal plane and subjected to an
electrical stress via two electrodes. The surface between the electrodes is subjected to a
succession of drops of electrolyte either until the over-current device operates, or until a
persistent flame occurs, or until the test period has elapsed.
The individual tests are of short duration (less than 1 h) with up to 50 or 100 drops of about
20 mg of electrolyte falling at 30 s intervals between platinum electrodes, 4 mm apart on the
test specimen surface.
An AC voltage between 100 V and 600 V is applied to the electrodes during the test.
During the test, specimens may also erode or soften, thereby allowing the electrodes to
penetrate them. The formation of a hole through the test specimen during a test is to be reported
together with the hole depth (test specimen thickness). Retests may be made using thicker test
specimens, up to a maximum of 10 mm.
NOTE The number of drops needed to cause failure by tracking usually increases with decreasing applied voltage
and, below a critical value, tracking ceases to occur. For some materials, tracking also ceases to occur above an
upper critical value.
5 Test specimen
Any approximately flat surface may be used, provided that the area is sufficient to ensure that
during the test no liquid flows away from the test electrodes.
NOTE 1 In general, flat surfaces of not less than 20 mm × 20 mm are used to reduce the probability of electrolyte
flows away from the test electrodes although smaller sizes can be used, subject to no electrolyte loss, e.g. ISO 3167,
15 mm × 15 mm multi-purpose test specimens.
NOTE 2 In general separate test specimens for each test are used. If several tests are to be made on the same
test piece, testing points can be sufficiently far from each other so that splashes, fumes, or erosion, from the testing
point will not contaminate or influence the other areas to be tested.
The thickness of the test specimen shall be 3 mm or more. Individual pieces of material may be
stacked to obtain the required thickness of at least 3 mm.
NOTE 3 The values of the CTI obtained on specimens with a thickness below 3 mm cannot be comparable with
those obtained on thicker specimens because of greater heat transmission to the glass support through thinner test
specimens. For this reason, stacked specimens are possible.
Test specimens shall have uniformly smooth and untextured surfaces which are free from
surface imperfections such as scratches, blemishes, impurities, etc, unless otherwise stated in
the product standard. If this is impossible, the results shall be reported together with a statement
describing the surface of the specimen because certain characteristics on the surface of the
specimen can add to the dispersion of the results.
For tests on parts of products, where it is impossible to cut a suitable test specimen from a part
of a product, specimens cut from moulded plaques of the same insulating material may be used.
In these cases, care should be taken to ensure that both the part and the plaque are produced
by the same fabrication process, resulting in the same surface texture, wherever possible.
Where the details of the final fabrication process are unknown, methods given in ISO 293,
ISO 294-1 and ISO 294-3 and ISO 295 can be appropriate.
NOTE 4 The use of different fabrication conditions or processes can lead to different levels of performance in the
PTI and CTI test.
NOTE 5 Parts moulded using different flow directions can also exhibit different levels of performance in the PTI and
CTI test.
IEC 60112:2025 © IEC 2025
In special cases, the test specimen may be ground to obtain a flat surface. In this case, the
surface texture according ISO 4287 (e.g. R values) shall be reported (see 10.2 and 11.5).
z
NOTE 6 Any grinding can damage the specimen. In this case, material surface made by grinding has higher or
lower tracking value than the original surface.
Where the direction of the electrodes relative to any feature of the material is significant,
measurements shall be made in the direction of the feature and orthogonal to it. The direction
giving the lower CTI shall be reported, unless otherwise specified in a contract.
NOTE 7 Use of an aggressive electrolyte, such as solution C, is common, when the material has a hydrophobic
surface.
6 Test specimen conditioning
6.1 Environmental conditioning
Unless otherwise specified in a contract, the test specimens shall be conditioned for a minimum
of 24 h at (23 ± 2) °C, with (50 ± 10) % RH. Once the test specimen has been removed from
the conditioning chamber (see 7.7), the test shall be started within 30 minutes.
6.2 Test specimen surface state
Unless otherwise specified in a contract,
a) tests shall be made on clean surfaces;
b) any cleaning procedure used shall be reported. Wherever possible, the details shall be
agreed between supplier and customer.
Dust, dirt, fingerprints, grease, oil, mould release or other contaminants can influence the
results. When cleaning the test specimen, swelling, softening, abrasion or other damage to the
material shall be avoided.
7 Test apparatus
7.1 Electrodes
Two electrodes of platinum with a minimum purity of 99 % shall be used (see Annex C). The
two electrodes shall have a rectangular cross-section of (5 ± 0,1) mm × (2 ± 0,1) mm, with one
end chisel-edged with an angle of 30° ± 2° (see Figure 1). The sharp edge shall be removed to
produce an approximately flat surface, 0,01 mm to 0,1 mm wide.
NOTE 1 A microscope with a calibrated eyepiece has been found suitable for checking the size of the end surface.
NOTE 2 In general, mechanical means are used to re-furbish the electrode shape after a test to ensure that the
electrodes maintain the required tolerances, especially with respect to the edges and corners.
IEC 60112:2025 © IEC 2025
Dimensions in millimetres
Key
1 platinum electrode
Figure 1 – Electrode
At the start of the test, the electrodes shall be symmetrically arranged in a vertical plane, the
total angle between them being 60° ± 5° and with opposing electrode faces approximately
vertical on a flat horizontal surface of the test specimen (see Figure 2). Their separation along
the surface of the test specimen at the start of the test shall be (4,0 ± 0,1) mm.
Dimensions in millimetres
Key
1 platinum electrode
2 brass extension (optional)
3 table
4 tip of dropping device
5 specimen
6 glass specimen support
Figure 2 – Electrode and specimen arrangement
IEC 60112:2025 © IEC 2025
A thin metal rectangular slip gauge shall be used to check the electrode separation. The
electrodes shall move freely and the force exerted by each electrode on the surface of the test
specimen at the start of the test shall be (1,00 ± 0,05) N. The design shall be such that the
force can be expected to remain at the initial level during the test.
One typical type of arrangement for applying the electrodes to the test specimen is shown in
...