EN 60034-26:2006

Rotating electrical machines - Part 26: Effects of unbalanced voltages on the performance of three-phase cage induction motors

Describes the effects of unbalanced voltages on the performance of three-phase cage induction motors.

Drehende elektrische Maschinen - Teil 26: Auswirkungen von Spannungsunsymmetrien auf das Betriebsverhalten von Drehstrom-Induktionsmotoren

Machines électriques tournantes - Partie 26: Effets d'un système de tensions déséquilibrées sur les caractéristiques de fonctionnement des moteurs à cage asynchrones triphasés

Décrit les effets des tensions déséquilibrées sur les caractéristiques de fonctionnement des moteurs asynchrones triphasés à cage.

Električni rotacijski stroji - 26. del: Učinkovanje nesimetričnih napetosti na lastnosti trifaznih motrojev s kratkostično kletko (IEC 60034-26:2006)

Opisuje vpliv nesimetričnih napetosti na lastnosti trifaznih motorjev s kratkostično kletko.

General Information

• Status: Published
• Publication Date: 29-Nov-2006
• Withdrawal Date: 31-Oct-2009
• ICS: 29.160 - Rotating machinery
• Technical Committee: CLC/TC 2 - Rotating machinery
• Drafting Committee: IEC/TC 2 - IEC_TC_2
• Parallel Committee: IEC/TC 2 - IEC_TC_2
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 30-Nov-2006
• Completion Date: 30-Nov-2006
• Directive: 73/23/EEC - Electrical equipment designed for use within certain voltage limits
• Ref Project: SIST EN 60034-26:2007 - Rotating electrical machines - Part 26: Effects of unbalanced voltages on the performance of three-phase cage induction motors (IEC 60034-26:2006)

Relations

• Replaces: CLC/TS 60034-26:2004 - Rotating electrical machines - Part 26: Effects of unbalanced voltages on the performance of three-phase induction motors
• Effective Date: 29-Jan-2023
• Corrected By: EN 60034-26:2006/AC:2014 - Rotating electrical machines - Part 26: Effects of unbalanced voltages on the performance of three-phase cage induction motors
• Effective Date: 17-Sep-2014

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2007
1DGRPHãþD
SIST-TS CLC/TS 60034-26:2005
(OHNWULþQLURWDFLMVNLVWURMLGHO8þLQNRYDQMHQHVLPHWULþQLKQDSHWRVWLQD
ODVWQRVWLWULID]QLKPRWURMHYVNUDWNRVWLþQRNOHWNR,(&
Rotating electrical machines - Part 26: Effects of unbalanced voltages on the
performance of three-phase cage induction motors (IEC 60034-26:2006)
Drehende elektrische Maschinen - Teil 26: Auswirkungen von Spannungsunsymmetrien
auf das Betriebsverhalten von Drehstrom-Induktionsmotoren (IEC 60034-26:2006)
Machines électriques tournantes - Partie 26: Effets d'un système de tensions
déséquilibrées sur les caractéristiques de fonctionnement des moteurs à cage
asynchrones triphasés (CEI 60034-26:2006)
Ta slovenski standard je istoveten z: EN 60034-26:2006
ICS:
29.160.30 Motorji Motors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 60034-26
NORME EUROPÉENNE
November 2006
EUROPÄISCHE NORM
ICS 29.160 Supersedes CLC/TS 60034-26:2004

English version
Rotating electrical machines
Part 26: Effects of unbalanced voltages on the performance
of three-phase cage induction motors
(IEC 60034-26:2006)
Machines électriques tournantes Drehende elektrische Maschinen
Partie 26: Effets d'un système de tensions Teil 26: Auswirkungen
déséquilibrées sur les caractéristiques von Spannungsunsymmetrien
de fonctionnement des moteurs auf das Betriebsverhalten
à cage asynchrones triphasés von Drehstrom-Induktionsmotoren
(CEI 60034-26:2006) (IEC 60034-26:2006)

This European Standard was approved by CENELEC on 2006-11-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60034-26:2006 E
Foreword
The text of document 2/1391/FDIS, future edition 1 of IEC 60034-26, prepared by IEC TC 2, Rotating
machinery, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as
EN 60034-26 on 2006-11-01.
This European Standard supersedes CLC/TS 60034-26:2004.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2007-08-01
– latest date by which the national standards conflicting
(dow) 2009-11-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60034-26:2006 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 60034-26:2006
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application 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  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

1) 2)
IEC 60034-12 - Rotating electrical machines EN 60034-12 2002
Part 12: Starting performance of single-speed
three-phase cage induction motors

1)
Undated reference.
2)
Valid edition at date of issue.

NORME CEI
INTERNATIONALE
IEC
60034-26
INTERNATIONAL
Première édition
STANDARD
First edition
2006-07
Machines électriques tournantes –
Partie 26:
Effets d’un système de tensions déséquilibrées
sur les caractéristiques de fonctionnement des
moteurs à cage asynchrones triphasés

Rotating electrical machines –
Part 26:
Effects of unbalanced voltages on the performance
of three-phase cage induction motors
 IEC 2006 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
CODE PRIX
L
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

60034-26  IEC:2006 – 3 –
CONTENTS
FOREWORD.5
INTRODUCTION.9

1 Scope.11
2 Normative references .11
3 Effects of unbalanced voltages on performance.11
3.1 Currents .11
3.2 Heating .11
3.3 Torques.13
3.4 Full-load speed .13
4 Derating of motor to prevent overheating.13

Annex A (informative) Determination of the symmetrical components of the line-to-line
voltages U , U , U of a three-phase system .17
1 2 3
Annex B (informative) Approximate determination.21

Figure 1 – Typical values of derating of design N, three-phase cage induction motors
within the scope of IEC 60034-12 .15
Figure A.1 – Phasor diagram .17

60034-26  IEC:2006 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ROTATING ELECTRICAL MACHINES –

Part 26: Effects of unbalanced voltages on the performance
of three-phase cage induction motors

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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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 60034-26 has been prepared by IEC technical committee 2:
Rotating machinery.
This standard cancels and replaces IEC TS 60034-26 published in 2002.
The text of this standard is based on the following documents:
FDIS Report on voting
2/1391/FDIS 2/1398/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.

60034-26  IEC:2006 – 7 –
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of IEC 60034 series, under the general title Rotating electrical machines can be found
on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
60034-26  IEC:2006 – 9 –
INTRODUCTION
When the line voltages applied to a three-phase cage induction motor are not equal, the
currents in the stator windings will also be unequal. A small percentage voltage unbalance will
result in a much larger percentage current unbalance.
The application of unbalanced voltages to a three-phase induction motor introduces a
negative sequence voltage, and this produces in the air gap, a flux rotating against the
rotation of the rotor, thus tending to produce high currents. A small negative sequence voltage
may produce currents in the windings considerably in excess of those present under balanced
voltage conditions. Consequently, the temperature rise of the motor operating at a particular
load and percentage of voltage unbalance will be greater than for the motor operating under
the same conditions with balanced voltages.
The analytical and graphical methods used to calculate the symmetrical components from the
voltage readings of the three phases are well-known and can be taken from textbooks. Thus,
the calculation schemes are not incorporated in this standard, but shown in the informative
Annex A. Besides, the evaluation of the symmetrical components can be done automatically
by modern instrumentation.
An approximate evaluation of imbalance is given in the informative Annex B.

60034-26  IEC:2006 – 11 –
ROTATING ELECTRICAL MACHINES –

Part 26: Effects of unbalanced voltages on the performance
of three-phase cage induction motors

1 Scope
This part of IEC 60034 describes the effects of u
...