SIST EN IEC 60034-26:2026

SLOVENSKI STANDARD
01-oktober-2026
Električni rotacijski stroji - 26. del: Vpliv nesimetričnih napetosti na lastnosti
trifaznih motorjev s kratkostično kletko (IEC 60034-26:2026)
Rotating electrical machines - Part 26: Effects of unbalanced voltages on the
performance of three-phase cage induction motors (IEC 60034-26:2026)
Drehende elektrische Maschinen - Teil 26: Auswirkungen von Spannungsunsymmetrien
auf das Betriebsverhalten von Drehstrom-Induktionsmotoren (IEC 60034-26:2026)
Machines électriques tournantes - Partie 26: Effets d'un système de tensions
déséquilibrées sur les caractéristiques de fonctionnement des moteurs à induction à
cage triphasés (IEC 60034-26:2026)
Ta slovenski standard je istoveten z: EN IEC 60034-26:2026
ICS:
29.160.30 Motorji Motors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60034-26

NORME EUROPÉENNE
EUROPÄISCHE NORM February 2026
ICS 29.160.01 Supersedes EN 60034-26:2006; EN 60034-
26:2006/AC:2014
English Version
Rotating electrical machines - Part 26: Effects of unbalanced
voltages on the performance of three-phase cage induction
motors
(IEC 60034-26:2026)
Machines électriques tournantes - Partie 26: Effets d'un Drehende elektrische Maschinen - Teil 26: Auswirkungen
système de tensions déséquilibrées sur les caractéristiques von Spannungsunsymmetrien auf das Betriebsverhalten
de fonctionnement des moteurs à induction à cage von Drehstrom-Induktionsmotoren
triphasés (IEC 60034-26:2026)
(IEC 60034-26:2026)
This European Standard was approved by CENELEC on 2026-02-20. 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.
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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 60034-26:2026 E

European foreword
The text of document 2/2224/CDV, future edition 2 of IEC 60034-26, prepared by 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) 2027-02-28
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-02-28
document have to be withdrawn
This document supersedes EN 60034-26:2006 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 60034-26:2026 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 60034-12:2024 NOTE Approved as EN IEC 60034-12:2024 (not modified)

IEC 60034-26 ®
Edition 2.0 2026-01
INTERNATIONAL
STANDARD
Rotating electrical machines -
Part 26: Effects of unbalanced voltages on the performance of three-phase cage
induction motors
ICS 29.160.01  ISBN 978-2-8327-0985-6

IEC 60034-26:2026-01(en)
IEC 60034-26:2026 © IEC 2026
CONTENTS
FOREWORD . 2
INTRODUCTION . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Effects of unbalanced voltages on performance . 5
4.1 General . 5
4.2 Currents . 5
4.3 Heating . 5
4.4 Torque . 5
4.5 Full-load speed . 6
4.6 Efficiency . 6
5 Derating of motor to prevent overheating . 6
Annex A (informative) Determination of the symmetrical components of the line-to-line
voltages U , U , U of a three-phase system . 7
1 2 3
A.1 Graphical determination . 7
A.2 Analytical determination . 8
Annex B (informative) Approximate determination of the unbalance factor . 9
Bibliography . 10

Figure 1 – Typical values of derating of design N or NE, three-phase cage induction
motors within the scope of IEC 60034-12 . 6
Figure A.1 – Phasor diagram . 7

IEC 60034-26:2026 © IEC 2026
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Rotating electrical machines -
Part 26: Effects of unbalanced voltages on the performance of three-
phase cage induction motors
FOREWORD
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