EN IEC 60034-23:2019

Rotating electrical machines - Part 23: Repair, overhaul and reclamation

This part of IEC 60034 covers the procedures necessary to ensure the satisfactory repair, overhaul, and reclamation of all types and sizes of rotating electrical machines covered by the IEC 60034 series. The standard creates a generic industry procedure covering common aspects of a complete repair. The scope of work depends on the machine type, rating, condition, and the importance of plant reliability and safety. It includes - determining cause of failure, where necessary; - determining the extent of repair, as applicable; - defining revised performance, operating and ambient conditions, if required; - reviewing the original design, and upgrading the specification of the design, if required; - proving the quality and performance of the repaired machine, maintaining or improving the rated energy efficiency; - ensuring environmental considerations are taken into account. This document does not supersede the requirements prescribed in IEC 60079-19 or elsewhere concerning the repair and overhaul for machines used in explosive atmospheres. Machines for special applications such as hermetic, submersible, nuclear, hydrogen cooled machines, military, aviation and traction motors might have additional requirements, which are the subject of agreement between the service facility and user. This document is not intended to take the place of the original machine manufacturer’s instructions and recommendations. Re-designs and performance changes requiring machine designer input are beyond the scope of this document.

Drehende elektrische Maschinen - Teil 23: Reparatur, Überholung und Sanierung

Machines électriques tournantes - Partie 23: Réparation, révision et remise en état

La présente partie de l'IEC 60034 couvre les procédures nécessaires pour assurer la réparation, la révision et la remise en état de tous types et tailles de machines électriques tournantes couvertes par la série IEC 60034. La norme crée une procédure industrielle générique qui couvre les aspects courants d'une réparation complète. L’étendue du travail dépend du type de machine, de ses caractéristiques assignées, de son état, ainsi que de l’importance de la fiabilité et de la sécurité de l’installation. Elle comprend - la détermination de la cause de défaillance, si nécessaire; - la détermination de l'étendue de la réparation, le cas échéant; - la définition des caractéristiques de fonctionnement révisées, les conditions de fonctionnement et les conditions ambiantes, si elles sont exigées; - l’examen de la conception originale et l’amélioration de la spécification de la conception, si cela est exigé; - la mise en évidence de la qualité et des caractéristiques de fonctionnement de la machine réparée; maintien ou amélioration du rendement énergétique assigné - l’assurance de la prise en compte des considérations liées à l’environnement Cette norme ne remplace pas les exigences spécifiées dans l’IEC 60079-19 ou dans tout autre document concernant la réparation et la révision des machines utilisées dans des atmosphères explosives. Les machines pour applications spéciales, telles que les applications hermétiques, submersibles, nucléaires, avec machines à refroidissement par hydrogène, militaires, aéronautiques et avec moteurs à traction peuvent avoir des exigences supplémentaires pour lesquelles un accord est conclu entre l’atelier de service et l'utilisateur. La norme technique n’est pas destinée à se substituer aux instructions et aux recommandations du constructeur de la machine d'origine. Les nouvelles conceptions et les modifications des caractéristiques de fonctionnement exigeant la communication de données du concepteur de la machine ne relèvent pas du domaine d’application de la présente spécification.

Električni rotacijski stroji - 23. del: Popravilo, obnova in remont opreme (IEC 60034-23:2019)

General Information

• Status: Published
• Publication Date: 21-Mar-2019
• Withdrawal Date: 27-Feb-2022
• ICS: 29.160.01 - Rotating machinery in general
• Technical Committee: CLC/TC 2 - Rotating machinery
• Drafting Committee: IEC/TC 2 - IEC_TC_2
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 22-Mar-2019
• Completion Date: 22-Mar-2019
• Ref Project: SIST EN IEC 60034-23:2019 - Rotating electrical machines - Part 23: Repair, overhaul and reclamation (IEC 60034-23:2019)

Overview

EN IEC 60034-23:2019 - "Rotating electrical machines - Part 23: Repair, overhaul and reclamation" is a harmonized CLC/IEC standard that defines generic procedures and good practices for the repair, overhaul and reclamation of rotating electrical machines covered by the IEC 60034 series. It sets out a structured industry approach to determine causes of failure, define the scope of repair, verify restored performance (including energy efficiency), and address environmental and end-of-life considerations.

Key topics and technical requirements

• Scope and principles: Applies to all types and sizes of rotating electrical machines in the IEC 60034 series; repair scope depends on machine type, rating, condition and plant safety/reliability needs.
• Pre-repair evaluation: Inspection and tests of the assembled machine (visual, safety checks, no‑load test, winding resistance, insulation resistance, polarization index, phase balance) to establish condition and failure root cause.
• Dismantling and component inspection: Cleaning, air-gap verification, stator and rotor inspection (including rotor-cage integrity), ventilation, slip rings, brushes, bearings, seals.
• Repair processes: Guidance for rewinding (random and form-wound coils), impregnation, insulation systems, thermal protection, conductor connections, rotor repairs, banding and component replacement.
• Testing after repair: Rewound stator tests (winding resistance, surge/phase-balance, withstand voltage), mechanical balancing and performance proving to maintain or improve rated efficiency.
• Quality and documentation: Requirements for service facility capability, quality programs, user-supplied information, records, labels and rating plates.
• Safety, environment and lifecycle: Addresses hazardous-area exclusions (does not replace IEC 60079-19), environmental considerations, recycling, circular economy and end-of-life handling.
• Limitations: Does not supersede specialized requirements for machines in explosive atmospheres or special applications (hermetic, submersible, nuclear, hydrogen-cooled, military, aviation, traction) and does not replace original manufacturer instructions. Major redesigns requiring machine-designer input are outside scope.

Applications and users

• Who uses it: Repair workshops, motor service facilities, plant maintenance teams, OEM service departments, reliability engineers, asset managers and third-party contractors.
• Practical use cases: Establishing standardized repair procedures, documenting repair scope, performing tests to prove restored performance and efficiency, ensuring compliant handling of bearings, windings and rotors, and integrating environmental/end-of-life practices into service contracts.

Related standards

• IEC 60034 series (general machine performance and tests)
• IEC 60079-19 (repair for explosive atmospheres) - not superseded by this document
• Relevant IEC/EN standards on cooling, thermal protection, vibration, and testing referenced in the norm

EN IEC 60034-23:2019 is essential for organizations that perform or oversee motor repairs and need a consistent, industry-recognized framework to ensure safe, reliable and efficient reclamation of rotating electrical machines.

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2019
Električni rotacijski stroji - 23. del: Popravilo, obnova in remont opreme (IEC 60034
-23:2019)
Rotating electrical machines - Part 23: Repair, overhaul and reclamation (IEC 60034-
23:2019)
Drehende elektrische Maschinen - Teil 23: Reparatur, Überholung und Sanierung (IEC
60034-23:2019)
Machines électriques tournantes - Partie 23: Réparation, révision et remise en état (IEC
60034-23:2019)
Ta slovenski standard je istoveten z: EN IEC 60034-23:2019
ICS:
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 60034-23

NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2019
ICS 29.160.01
English Version
Rotating electrical machines - Part 23: Repair, overhaul and
reclamation
(IEC 60034-23:2019)
Machines électriques tournantes - Partie 23: Réparation, Drehende elektrische Maschinen - Teil 23: Reparatur,
révision et remise en état Überholung und Sanierung
(IEC 60034-23:2019) (IEC 60034-23:2019)
This European Standard was approved by CENELEC on 2019-02-28. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey 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
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60034-23:2019 E

European foreword
The text of document 2/1923/FDIS, future edition 1 of IEC 60034-23, prepared by IEC/TC 2 "Rotating
machinery" 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) 2019-11-28
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2022-02-28
document have to be withdrawn
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.
Endorsement notice
The text of the International Standard IEC 60034-23:2019 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 standards
indicated:
IEC 60034-2-1 NOTE Harmonized as EN 60034-2-1
IEC 60034-2-2 NOTE Harmonized as EN 60034-2-2
IEC 60034-3 NOTE Harmonized as EN 60034-3
IEC 60034-4-1 NOTE Harmonized as EN IEC 60034-4-1
IEC 60034-5 NOTE Harmonized as EN 60034-5
IEC 60034-7 NOTE Harmonized as EN 60034-7
IEC 60034-8 NOTE Harmonized as EN 60034-8
IEC 60034-9 NOTE Harmonized as EN 60034-9
IEC 60034-12 NOTE Harmonized as EN 60034-12
IEC 60034-14 NOTE Harmonized as EN IEC 60034-14
IEC 60034-15 NOTE Harmonized as EN 60034-15
IEC 60034-16-1 NOTE Harmonized as EN 60034-16-1
IEC 60034-18-1 NOTE Harmonized as EN 60034-18-1
IEC 60034-18-21 NOTE Harmonized as EN 60034-18-21
IEC 60034-18-22 NOTE Harmonized as EN 60034-18-22
IEC 60034-18-31 NOTE Harmonized as EN 60034-18-31
IEC 60034-18-32 NOTE Harmonized as EN 60034-18-32
IEC 60034-18-34 NOTE Harmonized as EN 60034-18-34
IEC 60034-18-41 NOTE Harmonized as EN 60034-18-41
IEC 60034-18-42 NOTE Harmonized as EN 60034-18-42
IEC 60034-19 NOTE Harmonized as EN 60034-19
IEC 60034-27-1 NOTE Harmonized as EN IEC 60034-27-1
IEC 60034-27-3 NOTE Harmonized as EN 60034-27-3
IEC 60034-27-4 NOTE Harmonized as EN IEC 60034-27-4
IEC 60349-1 NOTE Harmonized as EN 60349-1
ISO 4287 NOTE Harmonized as EN ISO 4287
ISO 4526 NOTE Harmonized as EN ISO 4526
ISO 6158 NOTE Harmonized as EN ISO 6158
ISO 9001 NOTE Harmonized as EN ISO 9001

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.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60034 series R otating electrical machines EN IEC 60034 series
IEC 60034-1 -  Rotating electrical machines - Part 1: Rating - -
and performance
IEC 60034-6 -  Rotating electrical machines - Part 6: Methods EN 60034-6 -
of cooling (IC Code)
IEC 60034-11 -  Rotating electrical machines - Part 11: Thermal EN 60034-11 -
protection
IEC 60034-30-1 -  Rotating electrical machines - Part 30-1: EN 60034-30-1 -
Efficiency classes of line operated AC motors
(IE code)
IEC/TS 60034-30-2 -  Rotating electrical machines - Part 30-2: - -
Efficiency classes of variable speed AC motors
(IE-code)
IEC 60050-411 1996 International Electrotechnical Vocabulary - - -
Chapter 411: Rotating machinery
IEC 60060-1 -  High-voltage test techniques - Part 1: General EN 60060-1 -
definitions and test requirements
IEC 60072-2 -  Dimensions and output series for rotating - -
electrical machines - Part 2: Frame numbers
355 to 1000 and flange numbers 1180 to 2360
IEC 60079-19 -  Explosive atmospheres - Part 19: Equipment EN 60079-19 -
repair, overhaul and reclamation
IEC 60136 1986 Dimensions of brushes and brush-holders for - -
electrical machinery
ISO 21940-11 -  Mechanical vibration - Rotor balancing - Part - -
11: Procedures and tolerances for rotors with
rigid behaviour
IEC 60034-23 ®
Edition 1.0 2019-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Rotating electrical machines –

Part 23: Repair, overhaul and reclamation

Machines électriques tournantes –

Partie 23: Réparation, révision et remise en état

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.160.01 ISBN 978-2-8322-6264-1

– 2 – IEC 60034-23:2019 © IEC 2019
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 General principles . 10
4.1 Use of referenced documents . 10
4.2 Hazardous areas . 10
4.3 Special applications . 11
4.4 Efficiency . 11
4.5 System efficiencies . 11
4.6 Environment and End of life recycling . 11
4.7 Circular economy . 12
5 General requirements for repair . 12
5.1 General . 12
5.2 Service facility . 13
5.3 Scope of work . 13
5.4 Standards . 14
5.5 Quality program . 14
5.6 User supplied information . 15
5.6.1 User transfer document . 15
5.6.2 Operating environment . 15
5.6.3 Converter/inverter operation . 15
5.6.4 Health and safety. 15
5.7 Documentation . 15
5.7.1 Records . 15
5.7.2 Labels and rating plates. 16
6 Assembled machine: inspection, tests and evaluation . 16
6.1 Visual inspection . 16
6.2 Tests before dismantling . 17
6.2.1 Safety . 17
6.2.2 Application . 17
6.3 Stator winding or rotor winding tests . 17
6.3.1 Winding resistance test . 17
6.3.2 Phase balance test . 17
6.3.3 Insulation resistance test . 17
6.3.4 Polarization index test . 18
6.3.5 No load test . 19
6.4 Shaft and bearings . 19
6.4.1 Shaft checks . 19
6.4.2 Bearing checks . 19
6.4.3 Bearing insulation resistance . 19
6.5 Rotor cage integrity . 20
6.5.1 General . 20
6.5.2 Current signature analysis (harmonic analysis) . 20
6.5.3 Single-phase test method . 20
6.5.4 Pole drop test – Salient pole rotor (motor or generator) . 20

IEC 60034-23:2019 © IEC 2019 – 3 –
7 Dismantled machine: inspection, tests, and evaluation . 20
7.1 General . 20
7.2 Cleaning . 20
7.3 Visual inspection . 21
7.4 Air gap . 21
7.5 Ventilation. 21
7.6 Stator . 21
7.7 Rotor . 22
7.7.1 General . 22
7.7.2 Rotor removal: vertical machines . 22
7.7.3 Cage rotor . 22
7.7.4 Cylindrical wound rotor windings . 23
7.7.5 Permanent magnet (PM) machines: rotor removal . 23
7.7.6 Salient pole rotor . 23
7.7.7 Cylindrical solid rotors . 23
7.8 Slip rings . 24
7.9 Brushes and brush-holders . 24
7.10 Rolling element bearings . 24
7.11 Sleeve bearings . 25
7.12 Seals and labyrinth seals . 25
8 Repair work . 25
8.1 Winding inspection . 25
8.2 Core inspection . 26
8.3 Rewinding . 26
8.3.1 General . 26
8.3.2 Random wound coils . 27
8.3.3 Form-wound coils . 27
8.3.4 Rewound stator tests . 28
8.3.5 Winding resistance test . 28
8.3.6 Surge comparison (or phase balance) test . 28
8.3.7 Withstand voltage test . 28
8.3.8 Thermal protection . 30
8.3.9 Conductors and connections . 30
8.3.10 Insulation system . 30
8.3.11 Impregnation . 30
8.3.12 Wound rotor banding . 31
8.4 Components . 31
8.4.1 General . 31
8.4.2 Housing and end brackets . 31
8.4.3 Fans and fan cowls . 32
8.5 Rotor . 32
8.5.1 General . 32
8.5.2 Air gap . 32
8.5.3 Cage rotor . 32
8.5.4 Salient pole rotor . 33
8.5.5 Slip-rings . 33
8.5.6 Capacitors . 33
8.5.7 Switches and starting components . 33
8.5.8 Excitation components . 33

– 4 – IEC 60034-23:2019 © IEC 2019
8.6 Shafts . 33
8.7 Bearings . 34
8.8 Lubrication . 34
8.8.1 Grease . 34
8.8.2 Oil . 35
8.9 Space heaters . 35
8.10 Temperature sensors . 35
8.11 Ingress and corrosion protection . 35
8.12 Terminal boxes and connections . 35
9 Final tests . 35
9.1 Test equipment . 35
9.2 Insulation resistance . 36
9.3 Winding resistance. 36
9.4 No load test . 36
9.5 Magnetic centre marking (by agreement) . 37
9.6 Locked rotor test (where applicable) . 37
9.7 Full load run for motors . 37
9.8 Zero power factor full current heat run (by agreement) . 37
9.9 Electromagnetic compatibility (by agreement) . 37
9.10 Auxiliaries . 37
9.11 Salient pole DC or AC drop test . 37
10 Additional requirements for DC machines . 37
10.1 General . 37
10.2 Assembled DC machine: inspection, tests and evaluation . 37
10.2.1 General . 37
10.2.2 No load test, or light load run . 38
10.2.3 Bar to bar test . 38
10.2.4 Surge test . 38
10.3 Dismantled condition: inspection, tests and evaluation . 38
10.3.1 Field winding . 38
10.3.2 Inter-pole and compensation winding . 38
10.3.3 Armature winding . 38
10.3.4 Commutator . 39
10.4 Repair work . 39
10.4.1 Commutator dimensions . 39
10.4.2 Brush-holders . 39
10.4.3 Brushes . 40
10.4.4 Brush neutral . 40
10.4.5 Field, inter-pole, and compensation windings . 41
10.4.6 Air gap . 41
10.4.7 Rotor run-outs . 41
10.4.8 Rotor balance . 41
10.5 DC machines final tests . 42
10.5.1 Brush holders . 42
10.5.2 No load test or light load test . 42
11 Additional requirements for high voltage AC machines (by agreement) . 42
11.1 Assembled HV machine, inspection and tests . 42
11.1.1 General . 42
11.1.2 The tan-delta (tip-up test in North America) . 42

IEC 60034-23:2019 © IEC 2019 – 5 –
11.1.3 Partial discharge test . 42
11.2 Dismantled HV machine , inspection and tests . 42
11.2.1 Dielectric dissipation factor test . 42
11.2.2 Dielectric dissipation factor tests of stator winding coils and bars . 42
11.2.3 Stator slot wedge deterioration . 42
11.2.4 Stator winding slot and overhangs discharge suppression . 42
11.3 High voltage machines: final tests . 43
11.3.1 High voltage withstand test: for HV machines . 43
11.3.2 Withstand voltage tests, for overhauls and partial rewinds (by
agreement) . 43
11.3.3 Over-speed test (by agreement) . 43
11.3.4 Short circuit run (by agreement) . 43
11.3.5 Remnant voltage (by agreement) . 43
11.3.6 Cooling circuit leakage tests (by agreement) . 43
12 Additional tests for high voltage generators . 44
12.1 Stator winding crevice corrosion . 44
12.2 Solid cylindrical rotor . 44
12.3 Cooling circuits (hydrogen/water) . 44
13 Customer reports and handover . 44
13.1 Exterior finish . 44
13.2 Transport and packaging . 44
13.3 Report to the user . 44
Annex A (informative) Flow chart for repair, overhaul and reclamation . 45
Annex B (informative) Standard extracts and tolerance tables. 46
Bibliography . 49

Figure 1 – Electrical machine components . 13

Table 1 – Recommended minimum insulation resistance values at a base temperature
of 40 °C reference IEC 60034-27-4 . 18
Table 2 – Guide to application of DC voltages for the insulation resistance and PI test . 19
Table 3 – Withstand voltage tests as per IEC 60034-1 . 28
Table 4 – Minimum schedule of routine tests as per IEC 60034-1 . 36
Table 5 – Brush to brush holder clearance (Extract from Table 1 of IEC 60136:1986) . 40
Table B.1 – Shaft extensions and couplings reference IEC 60072-1 . 46
Table B.2 – Dimensions for the width of keyway to take keys to a tap fit (IEC 60072-
1:1991, C.1.5) . 46
Table B.3 – Table of tolerances for shaft extension run-out . 47
Table B.4 – Table for mounting spigot diameter tolerances (IEC 60072-1:1991, C.1.7) . 48
Table B.5 – Table for concentricity of spigot diameter and perpendicularity of mounting
face to shaft extension (IEC 60072-1:1991, C.7.1) . 48

– 6 – IEC 60034-23:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ROTATING ELECTRICAL MACHINES –

Part 23: Repair, overhaul and reclamation

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.
International Standard IEC 60034-23 has been prepared by IEC technical committee 2: Rotating
machinery.
This first edition cancels and replaces IEC TS 60034-23 published in 2003. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– the title of the standard has been changed to Rotating electrical machines – Part 23: Repair,
overhaul and reclamation;
– Clause 1 Scope
• Hydrogen cooled turbine generators added to special applications,
• maintaining or improving the rated energy efficiency added
• ensuring environmental considerations are taken into account added;

IEC 60034-23:2019 © IEC 2019 – 7 –
– Clause 4 General Principles added to cover: hazardous areas, traction motors, machine
efficiency, environment, end of life recycling. and circular economy considerations;
– Clause 5 General: Scope of work, health and safety, standards, quality, information required
and documentation now covered;
– Original Annexes B and C incorporated into the standard;
– Clause 9 Final tests updated;
– Clause 10 Additional requirements for the repair and testing of DC machines added;
– Clause 11 Additional requirements for the repair and testing of High Voltage AC machines
added;
– Clause 12 Customer reports and handover added;
– New Annex B standard tolerances added.
The text of this International Standard is based on the following documents:
FDIS Report on voting
2/1923/FDIS 2/1924/RVD
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
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 "http://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.
– 8 – IEC 60034-23:2019 © IEC 2019
ROTATING ELECTRICAL MACHINES –

Part 23: Repair, overhaul and reclamation

1 Scope
This part of IEC 60034 covers the procedures necessary to ensure the satisfactory repair,
overhaul, and reclamation of all types and sizes of rotating electrical machines covered by the
IEC 60034 series. The standard creates a generic industry procedure covering common aspects
of a complete repair. The scope of work depends on the machine type, rating, condition, and
the importance of plant reliability and safety. It includes
• determining cause of failure, where necessary;
• determining the extent of repair, as applicable;
• defining revised performance, operating and ambient conditions, if required;
• reviewing the original design, and upgrading the specification of the design, if required;
• proving the quality and performance of the repaired machine, maintaining or improving the
rated energy efficiency;
• ensuring environmental considerations are taken into account.
This document does not supersede the requirements prescribed in IEC 60079-19 or elsewhere
concerning the repair and overhaul for machines used in explosive atmospheres.
Machines for special applications such as hermetic, submersible, nuclear, hydrogen cooled
machines, military, aviation and traction motors might have additional requirements, which are
the subject of agreement between the service facility and user.
This document is not intended to take the place of the original machine manufacturer’s
instructions and recommendations.
Re-designs and performance changes requiring machine designer input are beyond the scope
of this document.
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 (all parts), Rotating electrical machines
IEC 60034-1, Rotating electrical machines – Part 1: Rating and performance
IEC 60034-6, Rotating electrical machines – Part 6: Methods of cooling (IC Code)
IEC 60034-11, Rotating electrical machines – Part 11: Thermal protection
IEC 60034-30-1, Rotating electrical machines – Part 30-1: Efficiency classes of line operated
AC motors (IE code)
IEC 60034-23:2019 © IEC 2019 – 9 –
IEC TS 60034-30-2, Rotating electrical machines – Part 30-2: Efficiency classes of variable
speed AC motors (IE-code)
IEC 60050-411:1996, International Electrotechnical Vocabulary – Chapter 411: Rotating
machines
IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements
IEC 60072-2, Dimensions and output series for rotating electrical machines – Part 2: Frame
numbers 355 to 1000 and flange numbers 1180 to 2360
IEC 60079-19, Explosive atmospheres – Part 19: Equipment repair, overhaul, and reclamation
IEC 60136:1986, Dimensions of brushes and brush-holders for electrical machinery
ISO 21940-11, Mechanical vibration – Rotor balancing – Part 11:Procedures and tolerances for
rotors with rigid behaviour
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60034 (all parts) and
the following 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
customer
person or company, who places the order for a repair with the service facility and may or may
not be the owner or user of the machine
3.2
dismantling
disassembly of a machine into component parts or sub-assemblies
3.3
maintenance
routine actions taken to preserve the installed equipment in a fully serviceable condition
3.4
manufacturer
party responsible for the manufacture of the machine as originally supplied
3.5
overhaul
action to restore to fully serviceable condition equipment which has been in use or in storage
for a period of time but which is not faulty
3.6
reclamation
means of repair involving the removal or addition of material to reclaim component parts which
have sustained damage, in order to restore such parts to a serviceable condition in accordance
with the original standards and specifications

– 10 – IEC 60034-23:2019 © IEC 2019
3.7
refurbisher
party responsible for the refurbishing work, its sub-contractors and suppliers
3.8
refurbishment
total process of preparing a machine, no longer adequate for duty with normal maintenance, to
make it suitable for further service
3.9
relevant standard
standard to which the equipment was originally designed
3.10
repair
action to restore faulty equipment to its fully serviceable condition complying with the relevant
standard
3.11
repairer
manufacturer, user, or a third party (repair agency) who carries out the repair of the equipment
3.12
rewinding
part of the refurbishment related to removing and replacing some or all of the machine winding
their insulation, connection and support systems
3.13
service facility
manufacturer, user, or a third party (repair agency) providing a service that consists of the
repair, overhaul, or reclamation of equipment
3.14
serviceable condition
condition which permits parts or equipment to be used without prejudice to performance
3.15
user
owner, or party arranging or requiring the repair
4 General principles
4.1 Use of referenced documents
Older machines being repaired were designed to conform to earlier versions of the relevant
standards applicable when they were manufactured. It is possible that they would not be able
to meet the requirements of the latest standards. If this is the case the earlier standard should
be referred to for the specifications that the machine was manufactured to.
4.2 Hazardous areas
This document can be used in conjunction with IEC 60079-19, but does not supersede the
requirements prescribed in the latest version of IEC 60079-19. Special restrictions apply
including
• the scope of repair allowed by machine certification,
• individual personnel 'Ex' competency,
• the specific design limitations of different protection concepts.

IEC 60034-23:2019 © IEC 2019 – 11 –
4.3 Special applications
For rail and road traction motors, IEC 60349-1 is used by the manufacturers of these machines.
The service centre should also use the information in IEC 60349-1 to ensure the quality of their
repair, in conjunction with the IEC 60034-23 repair standard.
4.4 Efficiency
Where machines have been designed to meet Minimum Energy Performance Standards
(MEPS), as in the IEC 60034-30-1 efficiency classes and IEC TS 60034-30-2, they might be
subject to legal requirements to maintain efficiency levels. The designs might have been verified
by third party testing with declared minimum efficiencies shown on the nameplate. It is important
to follow when repairing or rewinding all machines to ensure no degradation of performance.
Current energy efficient motors have to be within a set tolerance of their rated efficiency label.
Any repair workshop, manufacturer’s or independent service centre, with a good quality control
system, using modern materials and using this standard, can maintain or improve the efficiency
of a machine within the original efficiency tolerances that the machine was designed to meet.
4.5 System efficiencies
If a motor has already been updated to an energy efficient machine, then a repair is often the
most environmentally friendly solution to extend the life of the machine, and maintain its rated
efficiency. During the course of a machine evaluation the decision to repair or replace should
be considered.
This is often the best time to calculate whether replacemen
...