EN 60034-18-1:1994

SLOVENSKI STANDARD
01-april-1999
Rotating electrical machines - Part 18: Functional evaluation of insulation systems
- Section 1: General guidelines (IEC 60034-18-1:1992 + corrigendum Aug. 1992)
Rotating electrical machines -- Part 18: Functional evaluation of insulation systems --
Section 1: General guidelines
Drehende elektrische Maschinen -- Teil 18: Funktionelle Bewertung von Isoliersystemen
-- Hauptabschnitt 1: Allgemeine Richtlinien
Machines électriques tournantes -- Partie 18: Evaluation fonctionnelle des systèmes
d'isolation -- Section 1: Principes directeurs généraux
Ta slovenski standard je istoveten z: EN 60034-18-1:1994
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.

34-18-1 © IEC - 3 -
CONTENTS
Page
FOREWORD .   5
INTRODUCTION .   7
Clause
1  Scope . 9
2  Normative references . 9
3  Definitions . 11
3.1  General terms . 11
3.2  Terms relating to the objects being tested . 13
3.3  Terms relating to factors of influence . 13
3.4  Terms relating to testing and evaluation . 15
4  General aspects of functional evaluation . 15
4.1  Effects of ageing factors . 15
4.2  Reference insulation system . 17
4.3  Functional tests . 17
5  Thermal functional tests . 19
5.1  General aspects of thermal functional tests . 19
5.2  Test objects and test specimens . 19
5.3  Thermal functional test procedures . 21
5.4  Thermal ageing sub-cycle . 27
5.5  Diagnostic sub-cycle . 27
5.6  Analyzing, reporting, and classification . 31
6  Electrical functional tests . 35
6.1  General aspects of electrical functional tests . 35
6.2  Test objects . 35
6.3  Electrical functional test procedures . 35
6.4  Analyzing and reporting . 37
7  Mechanical functional tests . 37
8  Environmental functional tests . 39
9  Multifactor functional tests . 39
Figure . 42
Annex A - Bibliographic references . 45

34-18-1 © IEC - 5 -
INTERNATIONAL ELECTROTECHNICAL COMMISSION
FUNCTIONAL EVALUATION OF INSULATION SYSTEMS FOR
ROTATING ELECTRICAL MACHINES
Part 1: General guidelines
FOREWORD
1) The formal decisions or agreements of the IEC on technical matters, prepared by Technical Committees on which all
the National Committees having a special interest therein are represented, express, as nearly as possible, an
international consensus of opinion on the subjects dealt with.
2) They have the form of recommendations for international use and they are accepted by the National Committees in that
sense.
3) In order to promote international unification, the IEC expresses the wish that all National Committees should adopt the
text of the IEC recommendation for their national rules in so far as national conditions will permit. Any divergence
between the IEC recommendation and the corresponding national rules should, as far as possible, be clearly indicated
in the latter.
This part of International Standard IEC 34-18 has been prepared by Sub-Committee 2J:
Classification of insulation systems for rotating machinery, of IEC Technical Committee No. 2:
Rotating machinery.
The text of this part is based on the following documents:
Six Months’ Rule Report on Voting
2J(CO)4 2J(CO)8
Full information on the voting for the approval of this part can be found in the Voting Report
indicated in the above table.
Annex A is for information only.
____________
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INTRODUCTION
IEC 34-18 comprises several parts:
Part 1: General guidelines
Part 2: Test procedures for wire-wound windings
Part 3: Test procedures for form-wound windings
Parts 2 and 3 are further divided into sub-parts, dealing with different types of functional
evaluation.
IEC 505 recognizes and defines all of the factors which might influence the time to end of life of
electrical equipment insulation. Those factors of influence causing ageing of the insulation are
considered to be thermal, electrical, environmental (ambient), and mechanical.
IEC 85 deals with thermal evaluation of insulating materials and insulation systems used
in electrical equipment. In particular, the thermal classes of insulation systems used in
rotating machines such as A, E, B, F and H, as well as the temperatures usually associated with
these thermal classes, are established in IEC 85. In the past, materials for insulation systems were
often selected solely on the basis of thermal endurance of individual materials.
However, the second edition of IEC 85 recognizes that such selection can be used only for
screening materials prior to further functional evaluation of a new insulation system which is not
service-proven. This evaluation is linked with earlier service experience through the use of a
service-proven reference insulation system as the basis for comparative evaluation. Service
experience is the preferred basis for assessing the thermal endurance of an insulation system.
IEC 611 describes the methodology based on the linear Arrhenius relationship (log life versus
reciprocal absolute temperature), to be used as a guide in the preparation of test procedures for
specific types of electromechanical products where the thermal ageing factor is considered to be
dominant.
IEC 727 deals with evaluation of electrical endurance of insulation systems.
IEC 791 gives instructions for evaluation of data from service experience and from functional tests.
IEC 792 describes general principles for multi-factor functional testing of insulation systems.
In the winding of an electrical machine, different factors of influence may be dominant in different
parts (e.g. turn insulation and end winding insulation). Therefore, different criteria may be
necessary to assess those parts of the insulation. It may also be appropriate to apply different
procedures of functional evaluation to these parts.
The large differences found in the rotating electrical machine windings, in terms of size, voltage
and operating conditions, necessitate the use of different procedures of functional evaluation to
evaluate various types of windings. These procedures may also be of different complexity, the
simplest being based on a single ageing mechanism (e.g. thermal or electrical). In the present
state of the art only thermal and electrical endurance testing procedures can be specified in some
detail. Principles of mechanical, environmental and multifactor functional testing are briefly
described to provide a basis for procedures to be developed later where appropriate.

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FUNCTIONAL EVALUATION OF INSULATION SYSTEMS FOR
ROTATING ELECTRICAL MACHINES
Part 1: General guidelines
1  Scope
This part of IEC 34-18 describes procedures for functional evaluation of electrical insulation
systems used or proposed to be used in rotating electrical machines within the scope of IEC 34-1,
and the classification of those insulation systems. This part (Part 1) provides general guidelines for
such procedures and classification principles, whereas the subsequent parts give detailed
procedures for the various types of windings.
2  Normative references
The following standards contain provisions which, through reference in this text, constitute
provisions of this part of IEC 34-18. At the time of publication, the editions indicated were valid. All
standards are subject to revision, and parties to agreements based on this part of IEC 34-18 are
encouraged to investigate the possibility of applying the most recent editions of the standards
indicated below. Members of IEC and ISO maintain registers of currently valid International
Standards.
IEC 34-1: 1983, Rotating electrical machines - Part 1: Rating and performance.
IEC 60-2: 1973, High-voltage test techniques - Part 2: Test procedures.
IEC 85: 1984, Thermal evaluation and classification of electrical insulation.
IEC 216-1: 1987, Guide for the determination of thermal endurance properties of electrical
insulating materials - Part 1: General guidelines for ageing and evaluation of test results.
IEC 216-2: 1974, Guide for the determination of thermal endurance properties of electrical
insulating materials - Part 2: List of materials and available tests.
IEC 216-3: 1980, Guide for the determination of thermal endurance properties of electrical
insulating materials - Part 3: Statistical methods.
IEC 216-4: 1980, Guide for the determination of thermal endurance properties of electrical
insulating materials - Part 4: Instructions for calculating the thermal endurance profile.
IEC 493-1: 1974, Guide for the statistical analysis of ageing test data - Part 1: Methods based on
mean values of normally distributed test results.

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IEC 505: 1975, Guide for the evaluation and identification of insulation systems of electrical
equipment.
IEC 544-1: 1977, Guide for determining the effects of ionizing radiation on insulating materials -
Part 1: Radiation interaction.
IEC 544-2: 1979, Guide for determining the effects of ionizing radiation on insulating materials -
Part 2: Procedures for irradiation.
IEC 544-3: 1979, Guide for determining the effects of ionizing radiation on insulating materials -
Part 3: Test procedures for permanent effects.
IEC 544-4: 1985, Guide for determining the effects of ionizing radiation on insulating materials -
Part 4: Classification system for service in radiation environments.
IEC 610: 1978, Principal aspects of functional evaluation of electrical insulation systems: Ageing
mechanisms and diagnostic procedures.
IEC 611: 1978, Guide for the preparation of test procedures for evaluating the thermal endurance
of electrical insulation systems.
IEC 727-1: 1982, Evaluation of electrical endurance of electrical insulation systems - Part 1:
General considerations and evaluation procedures based on normal distributions.
IEC 792-1: 1985, The multi-factor functional testing of electrical insulation systems - Part 1: Test
procedures.
3  Definitions
For the purposes of this International Standard, the following definitions apply.
3.1  General terms
3.1.1 class temperature: The temperature for which the insulation system is suitable, as defined
by the thermal class in IEC 85.
3.1.2 insulation system: An insulating material, or an assembly of insulating materials, to be
considered in relation with associated conducting parts, as applied to a particular type or size or
part of electrical equipment (according to IEC 505).
NOTES
1 There may be several insulation components within the windings, each being designed for different stresses in
service, viz. turn insulation, slot insulation and end-winding insulation. Different criteria may be applied to the various
components within the overall system.
2 There may be more than one insulation system in a particular type of machine. These insulation systems may
have different thermal classes (e.g. stator and rotor windings).
3.1.3 candidate insulation system: The insulation system being tested to determine its capability
with respect to ageing factors (e.g
...