EN 60034-18-21:1994
(Main)Rotating electrical machines - Part 18: Functional evaluation of insulation systems - Section 21: Test procedures for wire-wound windings - Thermal evaluation and classification
Rotating electrical machines - Part 18: Functional evaluation of insulation systems - Section 21: Test procedures for wire-wound windings - Thermal evaluation and classification
Provides procedures for the thermal evaluation and classification of insulation systems of wire-wound winding machines. Should be used in conjunction with section 1.
Drehende elektrische Maschinen - Teil 18: Funktionelle Bewertung von Isoliersystemen - Hauptabschnitt 21: Prüfverfahren für Runddraht-Wicklungen - Thermische Bewertung und Klassifizierung
Machines électriques tournantes - Partie 18: Evaluation fonctionnelle des systèmes d'isolation - Section 21: Procédures d'essai pour enroulements à fils - Evaluation thermique et classification
Donne les procédures particulières pour l'évaluation thermique et la classification des systèmes d'isolation des machines avec enroulements à fils. Doit être utilisée conjointement avec la section 1.
Rotating electrical machines - Part 18: Functional evaluation of insulation systems - Section 21: Test procedures for wire-wound windings - Thermal evaluation and classification (IEC 60034-18-21:1992)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-1999
Rotating electrical machines - Part 18: Functional evaluation of insulation systems
- Section 21: Test procedures for wire-wound windings - Thermal evaluation and
classification (IEC 60034-18-21:1992)
Rotating electrical machines -- Part 18: Functional evaluation of insulation systems --
Section 21: Test procedures for wire-wound windings - Thermal evaluation and
classification
Drehende elektrische Maschinen -- Teil 18: Funktionelle Bewertung von Isoliersystemen
-- Hauptabschnitt 21: Prüfverfahren für Runddraht-Wicklungen - Thermische Bewertung
und Klassifizierung
Machines électriques tournantes -- Partie 18: Evaluation fonctionnelle des systèmes
d'isolation -- Section 21: Procédures d'essai pour enroulements à fils - Evaluation
thermique et classification
Ta slovenski standard je istoveten z: EN 60034-18-21:1994
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.
CEI
NORME
I EC
INTERNATIONALE
34-18-21
INTERNATIONAL
Première
édition
STANDARD First edition
1992-07
Machines électriques tournantes
Dix-huitième partie:
systèmes d'isolation
Evaluation fonctionnelle des
enroulements
Section 21: Procédures d'essai pour
à fils – Evaluation thermique et classification
Rotating electrical machines
Part 18:
Functional evaluation of insulation systems
Section 21: Test procedures for wire-wound
windings – Thermal evaluation and classification
right — all rights reserved
© CEI 1992 Droits de reproduction réservés — Copy
No part of this publication may be reproduced or utilized in
Aucune partie de cette publication ne peut être reproduite ni
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cédé, électronique ou mécanique, y compris la photocopie et including photocopying and microfilm, without permission
les microfilms, sans l'accord écrit de l'éditeur. in writing from the publisher.
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34-18-21 ©IEC —3—
CONTENTS
Page
FOREWORD 7
INTRODUCTION
Clause
1 Scope
2 Normative references
3 General considerations
11 3.1 Relationship to Section 1
3.2 Standard procedures 13
13 3.3 Reference insulation system
3.4 Test objects 13
3.5 Verification of diagnostic tests
3.6 Thermal ageing test procedure
3.7 Ageing temperatures and sub-cycle lengths
17 4 Procedure 1: Motorette test procedure
4.1 General
4.2 Test objects
4.3 Thermal ageing sub-cycle 19
4.4 Diagnostic sub-cycle
4.5 Analyzing, reporting and class ification
5 Procedure 2: Motor test procedure
5.1 General 23
5.2 Test objects
5.3 Thermal ageing sub-cycle
27 5.4 Diagnostic sub-cycle
29 5.5 Analyzing, reporting and classification
6 Procedure 3: Test procedure for stator windings in slots
6.1 General
6.2 Test objects 31
6.3 Thermal ageing sub-cycle
6.4 Diagnostic sub-cycle
6.5 Analyzing, reporting and classification
34-18-21 © IEC – 5 —
Clause Page
7 Procedure 4: Test procedure for pole windings
7.1 General
7.2 Test objects
7.3 Thermal ageing sub-cycle
7.4 Diagnostic sub-cycle
7.5 Analyzing, reporting and classification
8 Procedure 5: Test procedure for rotor windings in slots
8.1 General
8.2 Test objects
8.3 Thermal ageing sub-cycle
8.4 Diagnostic sub-cycle
8.5 Analyzing, reporting and classification
Annexes
A - Motorette construction (example)
B - Models for windings on poles (examples) 57
C - Equipment for moisture tests
Figures 65
34-18-21 ©IEC – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
ROTATING ELECTRICAL MACHINES
Part 18: Functional evaluation of insulation systems
Section 21: Test procedures for wire-wound windings –
Thermal evaluation and classification
FOREWORD
The formal decisions or agreements of the IEC on technical matters, prepared by Technical Committees on
1)
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.
They have the form of recommendations for international use and they are accepted by the National
2)
Committees in that sense.
In order to promote international unification, the IEC expresses the wish that all National Committees
3)
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 section of International Standard IEC 34-18 has been prepared by Sub-Com-
mittee 2J: Classification of insulation systems for rotating machinery, of IEC Technical
Committee No. 2: Rotating machinery.
The text of this section is based on the following documents:
Six Months' Rule Report on Voting
2J(CO)9
2J(CO)5
Full information on the voting for the approval of this section can be found in the Voting
Report indicated in the above table.
Annexes A, B and C are for information only.
34-18-21 © IEC – 9 –
INTRODUCTION
Section 1 of IEC 34-18 presents general principles for the evaluation and classification of
insulation systems used in rotating electrical machines.
This section of IEC 34-18 deals with the thermal evaluation and classification of insulation
systems for wire-wound (usually random wound) windings.
Several standard test procedures are given for various types of wire-wound windings and
testing techniques.
18 of a series of publications dealing with the functional evalu-
This section belongs to Part
rts being:
ation of insulation systems for rotating electrical machines, the other pa
Section 1: General guidelines (IEC 34-18-1).
Section 31: Test procedures for form-wound windings (IEC 34-18-31).
34-18-21 © IEC -11 -
ROTATING ELECTRICAL MACHINES
Part 18: Functional evaluation of insulation systems
Section 21: Test procedures for wire-wound windings –
Thermal evaluation and classification
1 Scope
This section of IEC 34-18 gives test procedures for the thermal evaluation and classifi-
cation of insulation systems used or proposed for use in wire-wound alternating current
(a.c.) or direct current (d.c.) rotating electrical machines. The test procedures are compara-
tive in that the performance of a candidate insulation system is compared to that of a
reference insulation system with proven se rvice experience.
Section 21 shall be used in conjunction with Section 1.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute
provisions of this section of IEC 34-18. At the time of publication, the editions indicated
were valid. All standards are subject to revision, and pa rties to agreements based on this
section 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 455, Specification for solventless polymerisable resinous compounds used for
electrical insulation.
IEC 464, Specification for insulating varnishes containing solvent.
IEC 34-18-1: 1991, Rotating electrical machines - Pa rt 18: Functional evaluation of insula-
tion systems - Section 1: General guidelines.
3 General considerations
3.1 Relationship to Section 1
Section 1 describes general testing principles applicable to thermal endurance testing of
insulation systems in rotating machines. Unless the procedures of this pa rt indicate other-
wise, the principles of Section 1 shall be followed.
34-18-21 ©IEC –13 –
3.2 Standard procedures
4 through 8. The user of this standard
Five standard procedures are specified in clauses
shall select that test procedure which most closely corresponds to the type and size of the
windings to be tested and classified, also taking into account facilities and past
experience.
3.3 Reference insulation system
A reference insulation system shall be tested using the same test procedure as for the
candidate system. See 4.2 of Section 1.
The thermal class temperatures of the two systems shall not differ by more than 50 K.
3.4 Test objects
3.4.1 Construction of test objects
Tests for the selection of materials according to 5.2.1 of section 1 may be performed, as
appropriate.
Test objects may be actual machines, machine components or models. The components
and models should embody all the essential elements.
Insulation thickness, creepage distances and discharge protection where required shall be
appropriate for the intended maximum rated voltage and equipment standards or practice.
The systems compared shall have arrangements consistent with those to be used in
machines.
NOTE - It is recognized that markedly different values of test life may be obtained for the same insulating
materials, depending on insulation thicknesses and creepage distances.
s of a coil or winding may be used for evaluation, if
Test specimens simulating part
rts in se rvice can be reproduced reliably in the test.
stresses acting on these pa
Particular types of models have been used successfully in some countries and examples
of these are illustrated in annexes A and B.
rtain that the materials proposed for use in the new
The manufacturer should make ce
insulation system can be handled without deterioration of properties in the intended manu-
facturing processes.
3.4.2 Quality assurance tests
To eliminate defective test objects, they should be qualified first, as per 5.2.3 of Section 1,
by visual examination and then by over-voltage tests consistent with the machine or coil
tests in the manufacturing facility, or as described in the appropriate subclauses for
diagnostic tests, whichever voltage test is greater.
–15 –
34-18-21 © IEC
NOTE - When appropriate. additional screening (or qualifying) tests may be used, including the following:
insulation resistance measurement;
loss tangent and capacitance measurement;
partial discharge inception voltage measurement;
balance of phase currents while running;
repetitive surge;
leakage current;
high-voltage test.
Any widely deviating object should be discarded or inspected to determine the reason for
the deviation and appropriate allowances should be made for the deviations.
Verification of diagnostic tests
3.5
A preliminary ageing test according to 5.3.4 of Section 1, to check the feasibility of the
diagnostic sub-cycle, may be performed.
3.6 Thermal ageing test procedure
The test procedure consists of several ageing tests, performed at different ageing tempera-
tures. At each temperature, the test life of the insulation systems tested is determined.
Based on these test life values, the life at the class temperature is estimated relative to
that of the reference system at its class temperature.
Each ageing test is performed in cycles, each cycle consisting of a thermal ageing sub-
cycle and a diagnostic sub-cycle. The diagnostic sub-cycle may include a mechanical test,
a moisture test, a voltage test and other diagnostic tests.
Ageing temperatures and sub-cycle lengths
3.7
The considerations and procedures of 5.3.2 of Section 1 should be observed and followed.
For the normal procedure, the number of ageing temperatures shall be at least three.
Where the candidate insulation system represents a minor change from a classified
system, 5.3.2.2 of Section 1 may be followed.
Ageing temperatures and lengths of ageing sub-cycles may be selected from table 2 of
Section 1.
If the intended thermal class for the candidate insulation system differs from the known
class of the reference system, different ageing temperatures and sub-cycle lengths are to
be selected in an appropriate manner.
The lowest ageing temperature should be selected such as to produce the log mean test
life of about 5 000 h or more. This is generally accomplished by choosing the lowest
ageing temperature to correspond to an exposure period of 28 to 35 days or longer.
IEC - 17 -
34-18-21 ©
In addition, at least two higher ageing temperatures should be selected, separated by
intervals of 20 K or more. Intervals of 10 K may be suitable when tests are made at more
than three ageing temperatures.
To minimize the uncertainty introduced by extrapolation the lowest test temperature
should not exceed by more than 25 K the temperature to which the results will be extra-
polated.
4 Procedure 1: Motorette test procedure
4.1 General
4.1.1 Procedure 1
This procedure, using "motorette" type models as test objects, shall be referred to as
IEC 34-18-1, Procedure 1.
4.1.2 General features
This thermal endurance test procedure consists of several cycles. Each cycle consists of:
- a thermal ageing sub-cycle;
- a diagnostic sub-cycle which includes a mechanical test, a moisture test with test-
specimen cooling and a voltage test, performed in that order.
4.2 Test objects
4.2.1 Construction of test objects
The test object in this procedure, designated motorette, models the insulation system to
be tested.
The motorette shall be made to embody all of the essential elements and should be as
nearly as possible representative of a complete winding insulation system. The motorette
simulates a wire-wound
...
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