SIST EN IEC 60034-18-1:2023

Rotating electrical machines - Part 18-1: Functional evaluation of insulation systems - General guidelines

This part of IEC 60034 deals with the general guidelines for functional evaluation of electrical insulation systems, used or proposed to be used in rotating electrical machines within the scope of IEC 60034-1, in order to qualify them.

Drehende elektrische Maschinen - Teil 18-1: Funktionelle Bewertung von Isoliersystemen - Allgemeine Richtlinien

Machines électriques tournantes - Partie 18-1: Evaluation fonctionnelle des systèmes d'isolation - Principes directeurs généraux

L’IEC 60034-18-1:2022 traite des lignes directrices générales pour l'évaluation fonctionnelle des systèmes d'isolation électrique, utilisés ou dont l'utilisation est proposée dans les machines électriques tournantes relevant du domaine d'application de l'IEC 60034-1, en vue de leur qualification. L’IEC 60034-18-1 définit les exigences générales pour la qualification des systèmes d’isolation, dans lesquels, pour le vieillissement thermique, les équations d’Arrhenius ne sont pas nécessairement adaptées, comme cela ressort de nombreux retours d’expérience.
Cette troisième édition annule et remplace la deuxième édition parue en 2010. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a. comme auparavant, fournit des lignes directrices générales pour l'évaluation fonctionnelle de différents types d'enroulements, mais inclut les modifications qui ont été introduites pour la qualification et l'évaluation électriques des enroulements qui subissent une contrainte électrique du fait d'une alimentation par convertisseur;

b. met désormais l'accent sur les lignes directrices générales, tous les détails techniques des procédures et des principes de qualification étant déplacés vers les parties subséquentes;

c. décrit des aspects généraux supplémentaires de l'évaluation et de la qualification fonctionnelles, en particulier la procédure de comparaison entre les systèmes d'isolation candidat et de référence, l'introduction du concept de qualification pour différentes durées de vie en service prévues, ainsi que l'évaluation des changements mineurs de composants ou de processus de fabrication.

Električni rotacijski stroji - 18-1. del: Funkcijsko ocenjevanje izolacijskih sistemov - Splošne smernice

Ta del IEC 60034 obravnava splošne smernice za funkcionalno vrednotenje električnih izolacijskih sistemov, ki se uporabljajo ali so predlagani za uporabo v električnih rotacijskih strojih s področja uporabe IEC 60034-1, da bi se jih označilo.

General Information

• Status: Published
• Public Enquiry End Date: 29-Nov-2020
• Publication Date: 12-Mar-2023
• ICS: 29.080.30 - Insulation systems
• ICS: 29.160 - Rotating machinery
• ICS: 29.160.01 - Rotating machinery in general
• Technical Committee: ERS - Rotating machinery
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 02-Feb-2023
• Due Date: 09-Apr-2023
• Completion Date: 13-Mar-2023
• Ref Project: EN IEC 60034-18-1:2023 - Rotating electrical machines - Part 18-1: Functional evaluation of insulation systems - General guidelines

Relations

• Revised: SIST EN 60034-18-1:2011 - Rotating electrical machines - Part 18-1: Functional evaluation of insulation systems - General guidelines (IEC 60034-18-1:2010)
• Effective Date: 22-Oct-2019

Overview

EN IEC 60034-18-1:2023 (CLC) - Rotating electrical machines - Part 18‑1: Functional evaluation of insulation systems - General guidelines - provides high‑level guidance for qualifying electrical insulation systems used or proposed for use in rotating electrical machines covered by IEC 60034‑1. This third edition (based on IEC 60034‑18‑1:2022) updates general principles for thermal, electrical, mechanical, environmental and multifactor evaluation, and defines procedures for comparing a reference insulation system with a candidate system and for assessing minor design or manufacturing changes.

Key topics and requirements

• Scope and purpose: General guidelines to support qualification and functional evaluation of insulation systems for motors and generators.
• Types of functional tests: Thermal, electrical, mechanical, environmental and multifactor (combined stress) tests are addressed at a guideline level.
• Reference vs candidate systems: Procedures for comparing performance of a candidate insulation system against an established reference to establish equivalence or improved performance.
• Qualification for expected life‑times: Guidance on defining qualification levels corresponding to different service life expectations.
• Minor change evaluation: Criteria and approaches to evaluate component, manufacturing or design changes without full requalification where justified.
• Converter‑supply considerations: Incorporates changes relevant to electrical stresses from inverter/converter supply and references specific parts for converter‑fed machines (e.g., partial discharge Type I/II treatments).
• Reporting and analysis: Emphasis on consistent analysis, statistical treatment of ageing data and clear reporting for classification.
• Normative references: Integrates background standards (e.g., IEC 60034‑1, IEC 60216, IEC 60505, IEC 60085 and related IEC 60034‑18 parts).

Applications and users

This standard is practical for:

• Motor and generator manufacturers qualifying new or modified insulation systems
• Insulation material and component suppliers demonstrating compatibility and lifetime performance
• Test laboratories and quality‑control teams performing functional and acceptance tests
• Design and R&D engineers assessing converter‑fed machine insulation solutions
• Certification bodies and OEMs seeking harmonized qualification principles

Typical applications include qualifying form‑wound and wire‑wound windings, assessing converter‑induced electrical stresses (partial discharge issues), and deciding when minor changes require requalification.

Related standards

• IEC/EN 60034‑1 (rating & performance)
• IEC 60034‑18‑21, ‑18‑31, ‑18‑32, ‑18‑33, ‑18‑34 (detailed test procedures)
• IEC 60034‑18‑41 / ‑18‑42 (partial discharge and converter‑supply tests)
• IEC 60216, IEC 60505, IEC 60085 (thermal/electrical ageing and evaluation)

Keywords: EN IEC 60034‑18‑1:2023, rotating electrical machines, insulation systems, functional evaluation, qualification, thermal evaluation, converter supply, partial discharge, multifactor tests.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2023
Električni rotacijski stroji - 18-1. del: Funkcijsko ocenjevanje izolacijskih sistemov
- Splošne smernice
Rotating electrical machines - Part 18-1: Functional evaluation of insulation systems -
General guidelines
Drehende elektrische Maschinen - Teil 18-1: Funktionelle Bewertung von
Isoliersystemen - Allgemeine Richtlinien
Machines électriques tournantes - Partie 18-1: Evaluation fonctionnelle des systèmes
d'isolation - Principes directeurs généraux
Ta slovenski standard je istoveten z: EN IEC 60034-18-1:2023
ICS:
29.080.30 Izolacijski sistemi Insulation systems
29.160.01 Rotacijski stroji na splošno Rotating machinery in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60034-18-1

NORME EUROPÉENNE
EUROPÄISCHE NORM January 2023
ICS 29.160.01 Supersedes EN 60034-18-1:2010
English Version
Rotating electrical machines - Part 18-1: Functional evaluation of
insulation systems - General guidelines
(IEC 60034-18-1:2022)
Machines électriques tournantes - Partie 18-1: Évaluation Drehende elektrische Maschinen - Teil 18-1: Funktionelle
fonctionnelle des systèmes d'isolation - Lignes directrices Bewertung von Isoliersystemen - Allgemeine Richtlinien
générales (IEC 60034-18-1:2022)
(IEC 60034-18-1:2022)
This European Standard was approved by CENELEC on 2023-01-26. 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
© 2023 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60034-18-1:2023 E

European foreword
The text of document 2/2113/FDIS, future edition 3 of IEC 60034-18-1, prepared by IEC/TC 2
"Rotating machinery" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC
as EN IEC 60034-18-1:2023.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2023-10-26
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2026-01-26
document have to be withdrawn
This document supersedes EN 60034-18-1:2010 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 60034-18-1:2022 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60216 (series) NOTE Approved as EN 60216 (series)
Annex A
(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.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60034-1 - Rotating electrical machines - Part 1: EN 60034-1 -
Rating and performance
IEC 60034-18-21 - Rotating electrical machines - Part 18-21: EN 60034-18-21 -
Functional evaluation of insulation systems
- Test procedures for wire-wound windings
- Thermal evaluation and classification
IEC 60034-18-31 - Rotating electrical machines - Part 18-31: EN 60034-18-31 -
Functional evaluation of insulation systems
- Test procedures for form-wound windings
- Thermal evaluation and classification of
insulation systems used in rotating
machines
IEC 60034-18-32 - Rotating electrical machines - Part 18-32: EN IEC 60034-18-32 -
Functional evaluation of insulation systems
(Type II) - Electrical endurance
qualification procedures for form-wound
windings
IEC/TS 60034-18-33 - Rotating electrical machines - Part 18-33: CLC/TS 60034-18-33 -
Functional evaluation of insulation systems
- Test procedures for form-wound windings
- Multifactor evaluation by endurance
under simultaneous thermal and electrical
stresses
IEC 60034-18-34 - Rotating electrical machines - Part 18-34: EN 60034-18-34 -
Functional evaluation of insulation systems
- Test procedures for form-wound windings
- Evaluation of thermomechanical
endurance of insulation systems

Under preparation. Stage at the time of publication: FprEN 60034-1 and FprEN 60034-1/prAA.
IEC 60034-18-41 2014 Rotating electrical machines - Part 18-41: EN 60034-18-41 2014
Partial discharge free electrical insulation
systems (Type I) used in rotating electrical
machines fed from voltage converters -
Qualification and quality control tests
+ A1 2019  + A1 2019
IEC 60034-18-42 - Rotating electrical machines - Part 18-42: EN 60034-18-42 -
Partial discharge resistant electrical
insulation systems (Type II) used in
rotating electrical machines fed from
voltage converters - Qualification tests
IEC 60034-27-3 - Rotating electrical machines - Part 27-3: EN 60034-27-3 -
Dielectric dissipation factor measurement
on stator winding insulation of rotating
electrical machines
IEC 60085 - Electrical insulation - Thermal evaluation EN 60085 -
and designation
IEC 60493-1 - Guide for the statistical analysis of ageing - -
test data - Part 1: Methods based on mean
values of normally distributed test results
IEC 60505 2011 Evaluation and qualification of electrical EN 60505 2011
insulation systems
IEC 61858-1 2014 Electrical insulation systems - Thermal EN 61858-1 2014
evaluation of modifications to an
established electrical insulation system
(EIS) - Part 1: Wire-wound winding EIS
IEC 61858-2 2014 Electrical insulation systems - Thermal EN 61858-2 2014
evaluation of modifications to an
established electrical insulation system
(EIS) - Part 2: Form-wound EIS
IEC 62539 - Guide for the statistical analysis of - -
electrical insulation breakdown data

IEC 60034-18-1 ®
Edition 3.0 2022-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Rotating electrical machines –

Part 18-1: Functional evaluation of insulation systems – General guidelines

Machines électriques tournantes –

Partie 18-1: Évaluation fonctionnelle des systèmes d'isolation – Lignes

directrices générales
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.160.01 ISBN 978-2-8322-6303-7

– 2 – IEC 60034-18-1:2022 © IEC 2022
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
3.1 General terms . 7
3.2 Terms relating to the objects being tested . 8
3.3 Terms relating to factors of influence and ageing factors . 9
3.4 Terms relating to testing and evaluation . 9
4 General aspects of functional evaluation . 10
4.1 Introductory remarks . 10
4.2 Effects of ageing factors . 11
4.3 Reference/candidate insulation system . 11
4.4 Evaluation of minor changes by components, manufacturing or design . 11
4.5 Functional tests . 12
4.6 Acceptance tests . 13
5 Thermal functional tests . 13
5.1 General aspects of thermal functional tests . 13
5.2 Analysis, reporting and classification . 14
6 Electrical functional tests . 15
6.1 General aspects of electrical functional tests . 15
6.2 Analysis and reporting . 15
7 Mechanical functional tests . 16
8 Environmental functional tests . 16
9 Multifactor functional tests . 16
Bibliography . 18

IEC 60034-18-1:2022 © IEC 2022 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ROTATING ELECTRICAL MACHINES –

Part 18-1: Functional evaluation of insulation systems –
General guidelines
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 60034-18-1 has been prepared by IEC technical committee 2: Rotating machinery. It is an
International Standard.
This third edition cancels and replaces the second edition published in 2010. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) provides general guidelines for functional evaluation of different types of windings as before
but incorporates those changes, which have been introduced for the electrical qualification
and evaluation of windings which are electrically stressed by converter-supply;
b) is now focused on general guidelines with all technical details of procedures and
qualification principles moved to the subsequent parts;

– 4 – IEC 60034-18-1:2022 © IEC 2022
c) details additional general aspects of functional evaluation and qualification, particularly the
procedure for comparison between reference and candidate insulation systems, the
introduction of the concept of qualification for different expected life-times in service and
the evaluation of minor component or manufacturing changes.
The text of this International Standard is based on the following documents:
Draft Report on voting
2/2113/FDIS 2/2118/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/standardsdev/publications.
A list of all parts in the IEC 60034 series, published under the general title Rotating electrical
machines, 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.
IEC 60034-18-1:2022 © IEC 2022 – 5 –
INTRODUCTION
IEC 60034-18 comprises several parts, dealing with different types of functional evaluation and
special kinds of test procedures for insulation systems of rotating electrical machines.
IEC 60034-18-1 provides general guidelines for such procedures and qualification principles,
whereas the subsequent parts IEC 60034-18-21, IEC 60034-18-31, IEC 60034-18-32,
IEC TS 60034-18-33, IEC 60034-18-34, IEC 60034-18-41 and IEC 60034-18-42 give detailed
procedures for the various types of windings. Beyond that, part IEC 60034-18-41 and
IEC 60034-18-42 contain special test procedures for electrical evaluation of windings
electrically stressed by converter-supply.
The following standards provide the basis and background for the development of the afore
mentioned standards.
IEC 60505 establishes the basis for estimating the ageing of electrical insulation systems under
conditions of either electrical, thermal, mechanical, environmental stresses or combinations of
these (multifactor stresses). It specifies the general principles and procedures that should be
followed defining functional test and evaluation procedures.
The IEC 60216 series deals with the determination of thermal endurance properties of single
insulating materials. On the assumption, that the Arrhenius formulas describe the rate of
thermal ageing of the materials, test procedures and analyzing instructions for getting
characteristic parameters like the “Temperature index” (TI), the “Halving interval” (HIC) and the
“Relative thermal endurance index” (RTE) are given. For all these parameters selected
properties and accepted end-point-criteria are specified. Consequently, a material may be
assigned with more than one temperature index, derived from the measurement of different
properties and the use of different end-point criteria.
IEC 60034-18-1 defines general requirements on the qualification of insulation systems, where
– for thermal ageing – the Arrhenius equations do not necessarily fit, according to many
experiences.
IEC 60085 deals with thermal evaluation of electrical insulation materials and in particular
insulation systems used in electrical equipment. In particular, thermal classes of insulation
systems are defined and designations are given, such as 130 (B), 155 (F) and 180 (H) for use
in rotating machines belonging to IEC 60034-1. In the past, materials for insulation systems
were often selected solely on the basis of thermal endurance of individual materials performed
according to the IEC 60216 series. However, IEC 60085 recognizes that such selection may
be used only for screening materials prior to further functional evaluation of a new insulation
system which is not service-proven. Evaluation is performed on the basis of a comparison with
a service-proven reference insulation system. Service experience is the preferred basis for
assessing the thermal endurance of an insulation system.
IEC 62539 defines statistical methods to analyse times to breakdown and breakdown voltage
data obtained from electrical testing of solid insulation materials, for the purposes of
characterization of the system and comparison with other insulation systems. The methods of
analysis are described for the Weibull-distribution, but other distributions are also presented.

– 6 – IEC 60034-18-1:2022 © IEC 2022
ROTATING ELECTRICAL MACHINES –

Part 18-1: Functional evaluation of insulation systems –
General guidelines
1 Scope
This part of IEC 60034 deals with the general guidelines for functional evaluation of electrical
insulation systems, used or proposed to be used in rotating electrical machines within the scope
of IEC 60034-1, in order to qualify them.
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 60034-1, Rotating electrical machines – Part 1: Rating and performance
IEC 60034-18-21, Rotating electrical machines – Part 18-21: Functional evaluation of insulation
systems – Test procedures for wire-wound windings – Thermal evaluation and classification
IEC 60034-18-31, Rotating electrical machines – Part 18-31: Functional evaluation of insulation
systems – Test procedures for form-wound windings – Thermal evaluation and classification of
insulation systems used in rotating machines
IEC 60034-18-32, Rotating electrical machines – Part 18-32: Functional evaluation of insulation
systems (Type II) – Electrical endurance qualification procedures for form-wound windings
IEC TS 60034-18-33, Rotating electrical machines – Part 18-33: Functional evaluation of
insulation systems – Test procedures for form-wound windings – Multifactor evaluation by
endurance under simultaneous thermal and electrical stresses
IEC 60034-18-34, Rotating electrical machines – Part 18-34: Functional evaluation of insulation
systems – Test procedures for form-wound windings – Evaluation of thermomechanical
endurance of insulation systems
IEC 60034-18-41:2014, Rotating electrical machines – Part 18-41: Partial discharge free
electrical insulation systems (Type I) used in rotating electrical machines fed from voltage
converters – Qualification and quality control tests
IEC 60034-18-41:2014/AMD1:2019
IEC 60034-18-42, Rotating electrical machines – Part 18-42: Partial discharge resistant
electrical insulation systems (Type II) used in rotating electrical machines fed from voltage
converters – Qualification tests
IEC 60034-27-3, Rotating electrical machines – Part 27-3: Dielectric dissipation factor
measurement on stator winding insulation of rotating electrical machines
IEC 60085, Electrical insulation – Thermal evaluation and designation

IEC 60034-18-1:2022 © IEC 2022 – 7 –
IEC 60493-1, Guide for the statistical analysis of ageing test data – Part 1: Methods based on
mean values of normally distributed test results
IEC 60505:2011, Evaluation and qualification of electrical insulation systems
IEC 61858-1:2014, Electrical insulation systems – Thermal evaluation of modifications to an
established electrical insulation system (EIS) – Part 1: Wire-wound winding EIS
IEC 61858-2:2014, Electrical insulation systems – Thermal evaluation of modifications to an
established electrical insulation system (EIS) – Part 2: Form-wound EIS
IEC 62539, Guide for the statistical analysis of electrical insulation breakdown data
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
3.1 General terms
3.1.1
class temperature
temperature for which the insulation system is suitable, as defined by the thermal class in
and as used in IEC 60505
IEC 60085
3.1.2
electrical insulation system
EIS
insulating structure containing one or more electrical insulating materials (EIM) together with
associated conducting parts employed in an electrotechnical device
[SOURCE: IEC 60505:2011, 3.1.1]
3.1.3
candidate insulation system
insulation system being tested to determine its capability with respect to ageing factors
[SOURCE: IEC 60050-411:1996, 411-39-26]
3.1.4
reference insulation system
insulation system whose performance has been established by satisfactory service experience
[SOURCE: IEC 60050-411:1996, 411-39-27]
3.1.5
coil
one or more turns of insulated conductors connected in series and surrounded by common
insulation, arranged to link or produce magnetic flux
[SOURCE: IEC 60050-411:1996, 411-38-03]

– 8 – IEC 60034-18-1:2022 © IEC 2022
3.1.6
bar
either of two parts which, after placed in their slots and when connected together, will form the
complete form-wound coil (see 3.1.8) and which comprise a coil side and an appropriate end
winding
Note 1 to entry: Large AC machines commonly use bars, and usually, though not always, they form single-turn coils
in a two-layer winding.
[SOURCE: IEC 60050-411:1996, 411-38-05]
3.1.7
wire-wound winding
winding which is wound with one or several insulated conductors and in which the individual
conductors occupy random positions in the coil side
Note 1 to entry: It is usually random-wound with round conductors.
[SOURCE: IEC 60050-411:1996, 411-38-13]
3.1.8
form-wound winding
winding consisting of coils or bars which are preformed to shape, insulated and substantially
completed before they are inserted into their final places
Note 1 to entry: Coils or bars are usually wound with rectangular conductors.
[SOURCE: IEC 60050-411:1996, 411-38-11]
3.2 Terms relating to the objects being tested
3.2.1
test object
unit being tested
Note 1 to entry: It may be an actual machine or part thereof or a special test model (see 3.2.3 and 3.2.4) which can
be subjected to functional tests.
Note 2 to entry: A test object may contain more than one test specimen (see 3.2.2).
3.2.2
test specimen
individual component within a test o
...