SIST EN IEC 60851-5:2026

SLOVENSKI STANDARD
01-december-2026
Nadomešča:
SIST EN 60851-5:2009
SIST EN 60851-5:2009/A1:2011
SIST EN 60851-5:2009/A2:2020
Navijalne žice - Preskusne metode - 5. del: Električne lastnosti (IEC 60851-5:2026)
Winding wires - Test methods - Part 5: Electrical properties (IEC 60851-5:2026)
Wickeldrähte - Prüfverfahren - Teil 5: Elektrische Eigenschaften (IEC 60851-5:2026)
Fils de bobinage - Méthodes d'essai - Partie 5: Propriétés électriques (IEC 60851-
5:2026)
Ta slovenski standard je istoveten z: EN IEC 60851-5:2026
ICS:
29.060.10 Žice Wires
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60851-5

NORME EUROPÉENNE
EUROPÄISCHE NORM October 2026
ICS 29.060.10 Supersedes EN 60851-5:2008; EN 60851-
5:2008/A1:2011; EN 60851-5:2008/A2:2019
English Version
Winding wires - Test methods - Part 5: Electrical properties
(IEC 60851-5:2026)
Fils de bobinage - Méthodes d'essai - Partie 5: Propriétés Wickeldrähte - Prüfverfahren - Teil 5: Elektrische
électriques Eigenschaften
(IEC 60851-5:2026) (IEC 60851-5:2026)
This European Standard was approved by CENELEC on 2026-09-17. 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 60851-5:2026 E

European foreword
The text of document 55/2089/FDIS, future edition 5 of IEC 60851-5, prepared by TC 55 "Winding
wires" 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) 2027-10-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-10-31
document have to be withdrawn
This document supersedes EN 60851-5:2008 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 60851-5:2026 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 60296 NOTE Approved as EN IEC 60296
IEC 60851-1:2021 NOTE Approved as EN IEC 60851-1:2021 (not modified)
IEC 60851-6:2012 NOTE Approved as EN 60851-6:2012 (not modified)

IEC 60851-5 ®
Edition 5.0 2026-08
INTERNATIONAL
STANDARD
Winding wires - Test methods -
Part 5: Electrical properties
ICS 29.060.10  ISBN 978-2-8327-1446-1

IEC 60851-5:2026-08(en)
IEC 60851-5:2026 © IEC 2026
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Test 5: Electrical resistance . 6
5 Test 13: Breakdown voltage . 7
5.1 Principle . 7
5.2 Equipment . 7
5.3 Enamelled round wire . 8
5.3.1 Grade 1 to grade 3 with a nominal diameter up to and including
0,500 mm . 8
5.3.2 Grade of FIW 3 to FIW 9 with a nominal conductor diameter up to and
including 1,600 mm . 9
5.4 Enamelled round wire with a nominal conductor diameter over 0,100 mm up
to and including 2,500 mm, grade 1 to grade 3. 10
5.4.1 Test at room temperature . 10
5.4.2 Test at elevated temperature . 11
5.5 Round wire with a nominal conductor diameter over 2,500 mm . 12
5.5.1 Test at room temperature . 12
5.5.2 Test at elevated temperature . 13
5.6 Fibre wound round wire . 14
5.6.1 Test at room temperature . 14
5.6.2 Test at elevated temperature . 15
5.7 Rectangular wire . 16
5.7.1 Test at room temperature . 16
5.7.2 Test at elevated temperature . 16
5.8 Overview of breakdown voltage specimen preparation . 16
6 Test 14: Continuity of insulation (applicable to enamelled round and tape wrapped
round wire) . 17
6.1 General . 17
6.2 Low-voltage continuity (nominal conductor diameter up to and including
0,050 mm, grade 1 to grade 3) . 17
6.3 High-voltage continuity (nominal conductor diameter over 0,050 mm up to
and including 1,600 mm, grade 1 to grade 3, and over 0,035 mm, up to and
including 1,600 mm, grade 3 of FIW 3 to FIW 9) . 18
6.3.1 Principle . 18
6.3.2 Equipment . 18
6.3.3 Procedure . 22
6.3.4 Result . 24
6.4 Inline high-voltage continuity (wires in accordance with grade of FIW 3 to
FIW 9 with nominal conductor diameter over 0,035 mm up to and including
1,600 mm) . 24
6.4.1 Principle . 24
6.4.2 Equipment . 24
6.4.3 Procedure . 24
6.4.4 Result . 25
6.5 Inline high-voltage continuity (enamelled rectangular wire) . 25
IEC 60851-5:2026 © IEC 2026
7 Test 19: Dielectric dissipation factor (applicable to enamelled wire and bunched
wire) . 25
7.1 Principle . 25
7.2 Equipment . 26
7.3 Specimen . 26
7.3.1 Specimen for a metal bath electrode . 26
7.3.2 Specimen for a conductive suspension electrode . 27
7.4 Procedure . 27
7.5 Result . 27
8 Test 23: Pin hole test . 27
Annex A (informative) Dissipation factor methods . 29
A.1 Tangent delta – Intersection point . 29
A.2 Test methods . 29
A.2.1 Method A . 29
A.2.2 Method B – Wire coated with a conductive film . 30
A.3 Interpretation of results . 30
A.3.1 General . 30
A.3.2 Linear method . 30
A.3.3 Logarithmic method . 31
Bibliography . 32

Figure 1 – Arrangement of cylinder and specimen for the breakdown voltage test . 9
Figure 2 – Device for twisting the specimen for breakdown voltage test . 11
Figure 3 – U-bend specimen for the breakdown voltage test (specimen placed in shot
bath) . 13
Figure 4 – Coil-wound specimen for the breakdown voltage test . 15
Figure 5 – Apparatus for testing the low-voltage continuity of covering . 18
Figure 6 – High-voltage DC continuity – Pulleys for wire size 0,050 mm to 0,250 mm . 19
Figure 7 – Pulley dimensions and spacing for wire size 0,250 mm to 1,600 mm . 20
Figure 8 – Graphite fibre single brush electrode assembly . 21
Figure 9 – Graphite fibre dual brush electrode assembly . 22
Figure 10 – Suitable electrode arrangement for testing the dielectric dissipation factor . 26
Figure A.1 – Example of linear method for sole coating . 31
Figure A.2 – Example of logarithmic method for sole coating . 31

Table 1 – Rates of test voltage increase . 7
Table 2 – Loads applied to enamelled wire . 8
Table 3 – Loads and diameters of test cylinders applied to wire . 10
Table 4 – Loads applied to the wire and number of twists . 11
Table 5 – Breakdown voltage specimen preparation methods . 17
Table 6 – Fault current . 19
Table 7 – Off-line HVC test voltages for grades 1 to 3. 23
Table 8 – Off-line HVC test voltages for grade of FIW 3 to FIW 9 . 23
Table 9 – In-line HVC test voltages . 25

IEC 60851-5:2026 © IEC 2026
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Winding wires - Test methods -
Part 5: Electrical properties
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 60851-5 has been prepared by IEC technical committee 55: Winding wires. It is an
International Standard.
This fifth edition cancels and replaces the fourth edition published in 2008, Amendment 1:2011
and Amendment 2:2019. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Subclauses 5.3.1 and 5.3.2 modified to expand the conductor size range for the loads
applied during cylinder method testing for dielectric breakdown voltage of enameled wires
and for fully insulated wires.
b) Addition of subclause 6.5 for inline continuity testing of rectangular wire (under
consideration).
IEC 60851-5:2026 © IEC 2026
The text of this International Standard is based on the following documents:
Draft Report on voting
55/2089/FDIS 55/2117/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 60851 series, under the general title Winding wires - Test
methods, can be found on the 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, or
– revised.
IEC 60851-5:2026 © IEC 2026
INTRODUCTION
This part of IEC 60851 forms an element of a series of standards which deals with insulated
wires used for windings in electrical equipment. The series has three groups describing:
a) winding wires – test methods (IEC 60851);
b) specifications for particular types of winding wires (IEC 60317);
c) packaging of winding wires (IEC 60264).

IEC 60851-5:2026 © IEC 2026
1 Scope
This part of IEC 60851 specifies the following tests:
– Test 5: Electrical resistance;
– Test 13: Breakdown voltage;
– Test 14: Continuity of insulation;
– Test 19: Dielectric dissipation factor;
– Test 23: Pin hole.
For definitions and general notes on methods of test, Clause 3 of IEC 60851-1:2021 applies.
This part of IEC 60851 also specifies methods for determining the dissipation factor of
enamelled winding wire, provided in Annex A.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
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
4 Test 5: Electrical resistance
Electrical resistance is the DC resistance at 20 °C of 1 m of wire.
The method used shall provide a precision of 0,5 %.
For bunched wires a length of up to 10 m shall be used and the ends shall be soldered before
the measurement. When measuring the resistance to check for an excessive number of broken
wires, a length of 10 m of bunched wire shall be used.
If the resistance R is measured at a temperature t other than 20 °C, the resistance R at 20 °C
t 20
shall be calculated by means of the following formula:
R
t
R =
1+∝ t−20
( )
where
t is the actual temperature in degrees Celsius during the measurement;
–1
α is the temperature coefficient in K .
IEC 60851-5:2026 © IEC 2026
In the temperature range from 15 °C to 25 °C, the temperature coefficient to be used shall be:
–3 –1
– for copper: α = 3,96 × 10 K ;
–3 –1
– for aluminium: α = 4,07 × 10 K .
One test shall be made. The electrical resistance measurement shall be reported.
5 Test 13: Breakdown voltage
5.1 Principle
The test voltage shall be an AC voltage of 50 Hz or 60 Hz nominal frequency. The test voltage
shall be applied at zero and increased at a uniform rate in accordance with Table 1.
Table 1 – Rates of test voltage increase
Breakdown voltage Rate of increase
V V/s
Over Up to and including
– 500 20
500 2 500 100
2 500 – 500
An overview of breakdown voltage specimen preparations specified in 5.3 to 5.7 is provided in
5.8.
5.2 Equipment
The following equipment shall be used:
– test transformer with a rated power of at least 500 VA providing an AC voltage of an
undistorted sine waveform under test conditions, with a peak factor being within the limits
of 2 ± 5 % (1,34 to 1,48) and with a capacity to supply a current of 5 mA with a maximum
voltage drop of 2 %;
– fault detection circuit, which operates at a current of 5 mA or more;
– arrangement to provide a uniform rise of the test voltage at the specified rate;
– oven with forced air circulation;
– polished metal cylinder, 25 mm ± 1 mm in diameter, mounted with its axis horizontal
(see Figure 1) and electrically connected to one terminal of the test voltage supply;
– twisting device in accordance with Figure 2, that allows to twist two pieces of wire for a
length of 125 mm;
– strips of metal foil, 6 mm in width and pressure sensitive tape, 12 mm in width;
– container with metal shot of stainless steel or nickel-plated iron. The diameter of the shot
shall not exceed 2 mm. The shot shall be cleaned periodically by suitable means;
– metal mandrel, 50 mm ± 2 mm in diameter;
– metal mandrel, 25 mm ± 1 mm in diameter;
– metal mandrel, 80 mm ± 3 mm in diameter.
IEC 60851-5:2026 © IEC 2026
5.3 Enamelled round wire
5.3.1 Grade 1 to grade 3 with a nominal diameter up to and including 0,500 mm
The test is carried out on a cylinder with a diameter of 25 mm ± 1 mm. A straight piece of wire
with the insulation removed at one end shall be connected to the upper terminal as shown in
Figure 1 and wound once around the cylinder. A load as specified in Table 2 shall be applied
to the lower end of the wire to keep the specimen in close contact with the cylinder.
The test voltage shall be applied in accordance with 5.1 between the conductor of the wire and
the cylinder. The test shall be carried out at room temperature.
Five specimens shall be tested. The five single values shall be reported.
Table 2 – Loads applied to enamelled wire
Nominal conductor diameter Load
mm N
Over Up to and including
–
0,018 0,013
0,018
0,020 0,015
0,020
0,022 0,020
0,022
0,025 0,025
0,025
0,028 0,030
0,028
0,032 0,040
0,032
0,036 0,050
0,036
0,040 0,060
0,040
0,045 0,080
0,045
0,050 0,100
0,050
0,056 0,120
0,056
0,063 0,150
0,063
0,071 0,200
0,071
0,080 0,250
0,080
0,090 0,300
0,090
0,100 0,400
0,100
0,160 0,600
0,160
0,250 0,850
0,250
0,355 1,700
0,355
0,500 3,400
IEC 60851-5:2026 © IEC 2026
Key
1 specimen
2 insulating material
3 upper terminal
4 cylinder
Figure 1 – Arrangement of cylinder and specimen for the breakdown voltage test
5.3.2 Grade of FIW 3 to FIW 9 with a nominal conductor diameter up to and including
1,600 mm
The test is carried out on a cylinder with a diameter as set out in Table 3.
A straight piece of wire with the insulation removed at one end shall be connected to the upper
terminal as shown in Figure 1 and wound once around the cylinder. A load as specified in
Table 3 shall be applied to the lower end of the wire to keep the specimen in close contact with
the cylinder.
The test voltage shall be applied in accordance with 5.1 between the conductor of the wire and
the cylinder. The test shall be carried out at room temperature. Five specimens shall be tested.
The five single values shall be reported.
IEC 60851-5:2026 © IEC 2026
Table 3 – Loads and diameters of test cylinders applied to wire
Nominal diameter Load Diameter of test cylinder
mm N mm
Over Up to and including
- 0,040 0,080 25 ± 1
0,040 0,045 0,100 25 ± 1
0,045 0,050 0,130 25 ± 1
0,050 0,056 0,160 25 ± 1
0,056 0,063 0,200 25 ± 1
0,063 0,071 0,260 25 ± 1
0,071 0,080 0,330 25 ± 1
0,080 0,090 0,400 25 ± 1
0,090 0,100 0,500 25 ± 1
0,100 0,160 0,600 25 ± 1
0,160 0,250 0,850 25 ± 1
0,250 0,355 1,700 25 ± 1
0,355 0,500 3,400 25 ± 1
0,500 0,710 7,000 50 ± 2
0,710 1,060 13,500 50 ± 2
1,060 1,400 27,000 80 ± 3
1,400 1,600 54,000 80 ± 3
5.4 Enamelled round wire with a nominal conductor diameter over 0,100 mm up to
and including 2,500 mm, grade 1 to grade 3
5.4.1 Test at room temperature
A straight piece of wire, approximately 400 mm in length, with the insulation removed at both
ends, shall be twisted back on itself for a distance of (125 ± 5) mm on the twisting device as
shown in Figure 2. The ends of the wire shall be joined, and the load applied with the number
of twists, as given in Table 4. The loop at the end of the twisted section shall be cut at two
places to provide a maximum spacing between the cut ends. Any bending to ensure adequate
separation between the two wire ends shall avoid sharp bends or damage to the coating.
The test voltage shall be applied in accordance with 5.1 between the conductors of the wires.
Five specimens shall be tested. The five single values shall be reported.
IEC 60851-5:2026 © IEC 2026
Table 4 – Loads applied to the wire and number of twists
Nominal conductor diameter Load Number of twists
N
mm
Over Up to and including
0,100 0,250 0,85 33
0,250 0,355 1,70 23
0,355 0,500 3,40 16
0,500 0,710 7,00 12
0,710 1,060 13,50 8
1,060 1,400 27,00 6
1,400 2,000 54,00 4
2,000 2,500 108,00 3
Key
1 spacer
2 rotary hook
3 specimen
Figure 2 – Device for twisting the specimen for breakdown voltage test
5.4.2 Test at elevated temperature
A specimen prepared in accordance with 5.4.1 shall be placed in the oven preheated to the
specified test temperature ±3 °C. The test voltage shall be applied in accordance with 5.1
between the conductors of the wires in not less than 15 min after placing the specimen in the
oven. The test shall be completed within 30 min.
Five specimens shall be tested. The five single values shall be reported.
IEC 60851-5:2026 © IEC 2026
5.5 Round wire with a nominal conductor diameter over 2,500 mm
5.5.1 Test at room temperature
A straight piece of wire of sufficient length, with the insulation removed at one end, shall be
bent around a mandrel as shown in Figure 3.
The diameter of the mandrel shall be 50 mm ± 2 mm.
The specimen shall be placed in the container and shall be surrounded by shot at least 5 mm
between the specimen and the inner walls of the container. The ends of the specimen shall be
sufficiently long to avoid flashover.
The shot shall be poured gently into a container until the specimen is covered by shot at a depth
of 90 mm. The metal shot shall be not more than 2 mm in diameter; balls of stainless steel,
nickel or nickel-plated iron have been found suitable. The shot shall be cleaned periodically
with a suitable solvent (for example, 1,1,1-trichloroethane).
The test voltage shall be applied in accordance with 5.1, between the conductor and the shot.
By agreement between the purchaser and the supplier, the test may be carried out with the
specimen under oil. Oil should be in accordance with IEC 60296 or as agreed upon between
customer and supplier.
Five specimens shall be tested. The five single values shall be reported.
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