IEC 60034-30:2008

IEC 60034-30
Edition 1.0 2008-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Rotating electrical machines –
Part 30: Efficiency classes of single-speed, three-phase, cage-induction motors
(IE-code)
Machines électriques tournantes –
Partie 30: Classes de rendement pour les moteurs à induction triphasés à cage,
mono vitesse (Code IE)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by
any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or
IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,
please contact the address below or your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
publication, utilisez les coordonnées ci-après ou contactez le Comité national de la CEI de votre pays de résidence.

IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: inmail@iec.ch
Web: www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
ƒ IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
ƒ Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
ƒ Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: csc@iec.ch
Tel.: +41 22 919 02 11
Fax: +41 22 919 03 00
A propos de la CEI
La Commission Electrotechnique Internationale (CEI) est la première organisation mondiale qui élabore et publie des
normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications CEI
Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possédez
l’édition la plus récente, un corrigendum ou amendement peut avoir été publié.
ƒ Catalogue des publications de la CEI: www.iec.ch/searchpub/cur_fut-f.htm
Le Catalogue en-ligne de la CEI vous permet d’effectuer des recherches en utilisant différents critères (numéro de référence,
texte, comité d’études,…). Il donne aussi des informations sur les projets et les publications retirées ou remplacées.
ƒ Just Published CEI: www.iec.ch/online_news/justpub
Restez informé sur les nouvelles publications de la CEI. Just Published détaille deux fois par mois les nouvelles
publications parues. Disponible en-ligne et aussi par email.
ƒ Electropedia: www.electropedia.org
Le premier dictionnaire en ligne au monde de termes électroniques et électriques. Il contient plus de 20 000 termes et
définitions en anglais et en français, ainsi que les termes équivalents dans les langues additionnelles. Egalement appelé
Vocabulaire Electrotechnique International en ligne.
ƒ Service Clients: www.iec.ch/webstore/custserv/custserv_entry-f.htm
Si vous désirez nous donner des commentaires sur cette publication ou si vous avez des questions, visitez le FAQ du
Service clients ou contactez-nous:
Email: csc@iec.ch
Tél.: +41 22 919 02 11
Fax: +41 22 919 03 00
IEC 60034-30
Edition 1.0 2008-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Rotating electrical machines –
Part 30: Efficiency classes of single-speed, three-phase, cage-induction motors
(IE-code)
Machines électriques tournantes –
Partie 30: Classes de rendement pour les moteurs à induction triphasés à cage,
mono vitesse (Code IE)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
Q
CODE PRIX
ICS 29.160 ISBN 978-2-88910-022-4
– 2 – 60034-30 © IEC:2008
CONTENTS
FOREWORD.3
INTRODUCTION.5
1 Scope.7
2 Normative references .7
3 Terms, definitions and symbols .8
3.1 Terms and definitions .8
3.2 Symbols .8
4 Fields of application (informative) .8
5 Efficiency .9
5.1 Determination.9
5.1.1 General .9
5.1.2 Rated voltages, rated frequencies and rated output .9
5.1.3 Auxiliary devices .10
5.2 Rating .10
5.3 Classification and marking.10
5.3.1 General .10
5.3.2 Efficiency classification.11
5.3.3 Motors below standard efficiency.11
5.3.4 Marking .11
5.4 Nominal efficiency limits .11
5.4.1 Interpolation .11
5.4.2 Nominal limits for Standard Efficiency (IE1) .12
5.4.3 Nominal limits for High Efficiency (IE2) .14
5.4.4 Nominal limits for Premium Efficiency (IE3) .15
Bibliography.17

Figure 1 – Allocation of the saving potential by installed motors in the industrial sector .5

Table 1 – IE-Efficiency classification.11
Table 2 – Interpolation coefficients (informative) .12
Table 3 – Nominal limits (%) for Standard Efficiency (IE1) 50 Hz .12
Table 4 – Nominal limits (%) for Standard Efficiency (IE1) 60 Hz .13
Table 5 – Nominal limits (%) for High Efficiency (IE2) 50 Hz .14
Table 6 – Nominal limits (%) for High Efficiency (IE2) 60 Hz .14
Table 7 – Nominal limits (%) for Premium Efficiency (IE3) 50 Hz.15
Table 8 – Nominal limits (%) for Premium Efficiency (IE3) 60 Hz.16

60034-30 © IEC:2008 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ROTATING ELECTRICAL MACHINES –

Part 30: Efficiency classes of single-speed,
three-phase, cage-induction motors (IE-code)

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 60034-30 has been prepared by IEC technical committee 2:
Rotating machinery.
The text of this standard is based on the following documents:
FDIS Report on voting
2/1518/FDIS 2/1521/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.
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.

– 4 – 60034-30 © IEC:2008
A table of cross-references of all IEC technical committee 2 publications can be found in the
IEC technical committee 2 dashboard 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.
60034-30 © IEC:2008 – 5 –
INTRODUCTION
This International Standard provides for the global harmonization of energy-efficiency classes
for electric motors.
Electric motor applications in industry consume between 30 % and 40 % of the generated
electrical energy worldwide. Improving efficiency of the complete drive system (i.e. motor and
adjustable-speed drives) including the application (or process) is therefore a major concern in
energy-efficiency efforts. The total energy saving potential of an optimized system is assumed
to be around 30 % to 60 %.
According to the findings of the IEA 7 July 2006 Motor Workshop, electric motors with
improved efficiency in combination with frequency converters can save about 7 % of the total
worldwide electrical energy. Roughly one quarter to one third of these savings come from the
improved efficiency of the motor. The remaining part results from system improvements.
Many different energy efficiency standards for cage induction motors are already in use
(NEMA, EPACT, CSA, CEMEP, COPANT, AS/NZS, JIS, GB and others) with new classes
currently being developed. It becomes increasingly difficult for manufacturers to design
motors for a global market and for customers to understand differences and similarities of
standards in different countries.
Motors from 0,75 kW up to 375 kW make up the vast majority of installed motor population
and are covered by this standard as shown in Figure 1.

Allocation of the saving potential by installed motors in the industrial sector
(installed capacity multiplied by the average efficiency improvement)
35 %
30 %
25 %
20 %
15 %
10 %
5 %
0 %
0,75 kW 4 kW 10 kW 30 kW 70 kW 130 kW
< 500 kW
< 0,75 kW to to to to to to
< 4 kW < 10 kW < 30 kW < 70 kW < 130 kW < 500 kW
Sources: 1. SAVE-Report "Improving the Penetration of Energy Efficient Motors and Drives" (1996)
2. CEMEP calculations
IEC  1823/08
Figure 1 – Allocation of the saving potential by installed motors in the industrial sector
In some countries smaller motors are included in energy efficiency regulations. Most of these
motors are not three-phase, cage-induction machines. Also they typically do not run
continuously so their energy saving potential is rather limited.
In some countries 8-pole motors are included in energy efficiency regulations. However, their
market share is already very low (1 % or less). Due to increasing acceptance of variable-
speed drives and the low cost associated with 4- and 6-pole standard motors it is expected
that 8-pole motors will even further disappear from the general market in the future.
Therefore, this standard does not include provisions for 8-pole motors.

– 6 – 60034-30 © IEC:2008
For a given output power and frame size it is generally easier to reach a high motor efficiency
when the motor is designed for and operated at 60 Hz mains supply frequency rather than at
50 Hz.
NOTE 1 As the utilization and size of motors are related to torque rather than power the theoretical output power
increases linearly with speed, i.e. by 20 % from 50 Hz to 60 Hz.
I²R winding-losses are dominant especially in small and medium sized induction motors. They basically remain
constant for 50 Hz and 60 Hz as long as the torque is kept constant. Although windage, friction and iron losses
increase with frequency, they play a minor role in these motors. Therefore, at 60 Hz, the losses increase less than
the 20 % output-power increase compared to 50 Hz and the efficiency improves.
In practice, both 60 Hz and 50 Hz output power designations should conform to standard power levels in
accordance with IEC 60072-1 and local standards like EN 50347. Therefore, an increased rating of motor power by
20 % is not always possible. However, the general advantage of 60 Hz still applies if the motor design is optimized
for the respective supply frequency rather than just re-rated.
The difference in efficiency between 50 Hz and 60 Hz varies with the number of poles and the size of the motor. In
general, the 60 Hz efficiency of three-phase, cage-induction motors in the output power range from 0,75 kW up to
375 kW is between 2,5 % to less than 0,5 % points greater when compared to the 50 Hz efficiency. Only large 2-
pole motors may experience a reduced efficiency at 60 Hz due to their high share of iron, windage and friction
losses.
In this standard, the nominal 50 Hz limits of Standard (IE1) and High Efficiency (IE2) are
based on the CEMEP-EU EFF2 and EFF1 limits respectively. However, they have been
adjusted to take the different test procedures into account (CEMEP: Additional load losses
P flat 0,5 % of input power; in this standard P is determined from test).
LL LL
The nominal 50 Hz limits for Premium Efficiency (IE3) are set with the losses about 15 % to
20 % lower compared to the limits for High Efficiency (IE2).
The nominal 60 Hz limits for Standard Efficiency (IE1) are identical to Brazilian regulations.
The nominal 60 Hz limits for High Efficiency (IE2) and for Premium Efficiency (IE3) are
identical to US American EPAct regulations.
A new Super-Premium class (IE4) is envisaged for future editions of this standard.
It is not expected that all manufacturers will produce motors for all efficiency classes or all
ratings for a given class.
Users should select the efficiency class in accordance with the application depending on the
actual operating hours. It may not be energy efficient to select High- or Premium-Efficiency
motors for intermittent or short-time duty.
NOTE 2 An application guide with more details is planned to be released as an IEC publication soon.
In order to achieve a significant market share it is essential for high-efficiency motors to meet
national/regional standards for assigned output powers in relation to mechanical dimensions
(frame-size, flanges, etc.). There are a number of national/regional frame assignment
standards (EN 50347, JISC 4212, NBR 7094, NEMA MG1, SANS 1804 and others) but there
is no IEC standard. As this standard (IEC 60034-30) defines energy-efficiency classes
independent of dimensional constraints it may not be possible in all markets to produce
motors with higher efficiency classes and maintain the mechanical dimensions of the
national/regional standards.
Regulators should consider the above constraints as well as the field of applications as
detailed in Clause 4 when assigning minimum energy-efficiency performance standards
(MEPS).
60034-30 © IEC:2008 – 7 –
ROTATING ELECTRICAL MACHINES –

Part 30: Efficiency classes of single-speed,
three-phase, cage-induction motors (IE-code)

1 Scope
This part of IEC 60034 specifies efficiency classes for single-speed, three-phase, 50 Hz and
60 Hz, cage-induction motors that:
• have a rated voltage U up to 1 000 V;
N
NOTE The standard also applies to motors rated for two or more voltages and/or frequencies.
• have a rated output P between 0,75 kW and 375 kW;
N
• have either 2, 4 or 6 poles;
• are rated on the basis of either duty type S1 (continuous duty) or S3 (intermittent periodic
duty) with a rated cyclic duration factor of 80 % or higher;
• are capable of operating direct on-line;
• are rated for operating conditions in accordance with IEC 60034-1, Clause 6.
Motors with flanges, feet and/or shafts with mechanical dimensions different from
IEC 60072-1 are covered by this standard.
Geared motors and brake motors are covered by this standard although special shafts and
flanges may be used in such motors.
Excluded are:
• Motors made solely for converter operation in accordance with IEC 60034-25.
• Motors completely integrated into a machine (for example pump, fan and compressor) that
cannot be tested separately from the machine.
2 Normative references
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.
IEC 60034-1, Rotating electrical machines – Part 1: Rating and performance
IEC 60034-2-1, Rotating electrical machines – Part 2-1: Standard methods for determining
losses and efficiency from tests (excluding machines for traction vehicles)
IEC 60034-6, Rotating electrical machines – Part 6: Methods of cooling (IC Code)
IEC 60072-1, Dimensions and output series for rotating electrical machines – Part 1: Frame
numbers 56 to 400 and flange numbers 55 to 1080

– 8 – 60034-30 © IEC:2008
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60034-1 and the
following apply.
3.1.1
brake motor
a motor equipped with an electro-mechanical brake unit operating directly on the motor shaft
without couplings
3.1.2
geared motor
a motor directly attached to a gearbox without couplings (i.e. the first gear wheel is fixed to
the motor shaft)
3.1.3
pump motor
a motor directly attached to a pump without couplings (i.e. the impeller is fixed to the motor
shaft)
3.1.4
average efficiency
the average efficiency value for a motor population of the same design and rating
3.1.5
nominal efficiency
the efficiency value required to meet a certain efficiency class according to the efficiency
tables in this standard
3.1.6
rated efficiency
the efficiency value assigned by the manufacturer, equal to the nominal efficiency value or
higher
3.2 Symbols
η is the nominal efficiency, %
n
η is the rated efficiency, %
N
f is the rated frequency, Hz
N
–1
n is the rated speed, min
N
P is the rated output power, kW
N
T is the rated output torque, Nm
N
U is the rated voltage, V
N
4 Fields of application (informative)
Motors covered by this standard may be used in variable-speed drive applications (see
IEC 60034-17). In such applications the rated efficiency of the motor should not be assumed
to apply due to increased losses from the harmonic-voltage content of the power supply.
Motors with cooling methods other than IC0Ax, IC1Ax, IC2Ax, IC3Ax or IC4Ax (see
IEC 60034-6) may not be able to achieve the higher efficiency classes specification.

60034-30 © IEC:2008 – 9 –
In some countries, motors are built for a restricted space (high-output design, i.e. smaller
frame sizes than usual in national standards). These motors are covered by this standard.
However, as a result of the small frame-size they may not be able to achieve the higher
efficiency classes specification.
Motors specifically built for operation in explosive environments according to IEC 60079-0 are
covered by this standard. However, as a result of safety requirements and certain design
constraints of explosion proof motors (like increased air-gap, reduced starting current,
enhanced sealing and others) some may not be able to achieve higher efficiency
classifications.
NOTE 1 Due to the required certification processes additional time and cost may be necessary to achieve the
higher efficiency ratings for some of these motors.
Motors specifically designed
• for special requirements of the driven machine (e.g. heavy starting duty, special
torque stiffness and/or breakdown torque characteristics, large number of
start/stop cycles, very low rotor inertia);
• for special characteristics of the grid supply (e.g. limited starting current, high
tolerances of voltage and/or frequency);
• for special ambient conditions (e.g. very high or low ambient temperature; smoke
extraction motors, high altitudes of installation),
may not be able to achieve higher efficiency classifications.
NOTE 2 Regulators should consider the above constraints when assigning national minimum energy efficiency
performance standards (MEPS).
5 Efficiency
5.1 Determination
5.1.1 General
The efficiency shall be determined at rated output power P , rated voltage U and rated
N N
frequency f .
N
Efficiency and losses shall be determined in accordance with IEC 60034-2-1.
For IE1 (standard efficiency) and motors below standard efficiency, test methods associated
with low and medium uncertainty are acceptable. The selected test method shall be stated in
the documentation of the motor.
For all higher energy efficiency levels only methods associated with low uncertainty shall be
acceptable.
5.1.2 Rated voltages, rated frequencies and rated output
Motors rated for an extended voltage tolerance (for example 400 V ±10 %) shall be assigned
a single rated efficiency and rated efficiency-class (IE-code), i.e. the extended tolerance shall
be disregarded.
Motors with more than one rated voltage/frequency/output-power combination may be
assigned a rated efficiency and a rated efficiency-class (IE-code) for each rated
voltage/frequency/output combination.
However, as a minimum the lowest efficiency value and the associated IE-code (of all rated
voltage/frequency/output combinations) shall always be printed on the rating plate.

– 10 – 60034-30 © IEC:2008
All efficiency values and associated IE-codes shall be available in the product documentation
(catalogue or operating instructions).
NOTE For example in Japan the rating combination “200 V/50 Hz – 200 V/60 Hz – 220 V/60 Hz” is commonly
used and in Europe the rating combination “380 V/50 Hz – 400 V/50 Hz – 415 V/50 Hz – 460 V/60 Hz” is
sometimes used. For these examples there will be three or four efficiency ratings and there may be several
different IE-codes.
Rated voltage/frequency combinations of the same magnetic flux and output-power, for
example 230/400 V (delta/star) or 230/460 V (double-star/star), shall have only one rated
efficiency and efficiency-class (IE-code).
5.1.3 Auxiliary devices
Some electric motors covered by this standard may be equipped with auxiliary devices like
shaft seals, external fans, mechanical brakes, back-stops, speed sensors, tacho-generators,
etc. in various combinations.
However, as long as these auxiliary devices are not an integral part of the motor construction,
the determination of efficiency in all possible combinations is not practical. Tests for efficiency
of such modified standard motors shall be performed on basic motors without auxiliary
devices installed.
Geared motors and pump motors are often standard motors equipped with shaft seals to
prevent ingress of oil or water into the motor. The seals are therefore considered a feature of
the gearbox or pump and consequently the efficiency of these motors shall be determined
without the seals installed.
5.2 Rating
Variations in materials, manufacturing processes, and testing result in motor-to-motor
efficiency variations for a given motor design; the full-load (rated output) efficiency for a large
population of motors of a single design is not a unique value but rather a band of efficiency.
Therefore, the rated output energy-efficiency limits given in this standard are nominal.
The efficiency declared by the manufacturer on the rating plate (rated efficiency) shall be
greater or equal to the nominal efficiency as defined in this standard (according to the
efficiency class (IE-code) on the rating plate).
The full-load efficiency of any individual motor, when tested at rated voltage and frequency,
shall not be less than the rated efficiency minus the tolerance on efficiency in accordance with
IEC 60034-1.
NOTE It is recommended to report efficiencies at 50 %, 75 % and rated output in the product documentation. For
the purpose of this standard the efficiency at rated output applies.
5.3 Classification and marking
5.3.1 General
The designation of the energy efficiency class consists of the letters “IE” (short for
“International Energy-efficiency Class”), directly followed by a numeral representing the
classification according to Table 1.

60034-30 © IEC:2008 – 11 –
5.3.2 Efficiency classification
Table 1 – IE-Efficiency classification
Characteristic Brief description Definition
numeral
1 Standard Motors with a rated efficiency at full-load (rated output) equal to or exceeding
the limits listed in 5.4.2.
2 High Motors with a rated efficiency at full-load (rated output) equal to or exceeding
the limits listed in 5.4.3.
3 Premium Motors with a rated efficiency at full-load (rated output) equal to or exceeding
the limits listed in 5.4.4.
4 Super-Premium Under consideration*.
* The levels of the IE4 efficiency class are envisaged to be incorporated into the next edition of this standard. It is
the goal to reduce the losses of IE4 by some 15 % relative to IE3. It is expected that technologies other than cage-
induction motors will be required to meet IE4 levels. The scope of this standard will be amended accordingly.

5.3.3 Motors below standard efficiency
Some motors have rated efficiencies below the limits given in Tables 3 and 4. No marking of
an IE-code for these motors is required.
5.3.4 Marking
The rated efficiency and the IE-code shall be durably marked on the rating plate, for example
“IE2 – 84,0 %”.
5.4 Nominal efficiency limits
5.4.1 Interpolation
5.4.1.1 50 Hz mains supply frequency
For general use the following formula may be applied:
3 2
⎡ ⎤ ⎡ ⎤
⎛ P ⎞ ⎛ P ⎞ ⎛ P ⎞
N N N
η =A⋅ log + B ⋅ log +C ⋅log + D
⎜ ⎟ ⎜ ⎟ ⎜ ⎟
N 10 10 10
⎢ ⎥ ⎢ ⎥
1 kW 1 kW 1 kW
⎣ ⎝ ⎠ ⎝ ⎠ ⎝ ⎠
⎦ ⎣ ⎦
where A, B, C, D are interpolation coefficients (see Table 2); P is given in kW.
N
NOTE 1 The formula and interpolation coefficients were mathematically derived to create a best fitting curve for
the desired nominal efficiency limits. They do not have a physical meaning.
The resulting efficiency (%) shall be rounded to the nearest tenth, i.e. xx,x %.
Normative, 50 Hz, nominal limits are given in Tables 3, 5 and 7. Normative, 50 Hz, nominal
limits for rated output power values not defined in the tables within the output power range of
0,75 kW up to 200 kW shall be computed by applying the preceding formula.
NOTE 2 When efficiency classification of motors below 0,75 kW is requested by customers the interpolation
function and coefficients may be used to compute informative values.

– 12 – 60034-30 © IEC:2008
Table 2 – Interpolation coefficients (informative)
50 Hz up to 200 kW
IE-Code Coefficients
2-pole 4-pole 6-pole
A 0,5234 0,5234 0,0786
B –5,0499 –5,0499 –3,5838
IE1
C 17,4180 17,4180 17,2918
D 74,3171 74,3171 72,2383
A
0,2972 0,0278 0,0148
B –3,3454 –1,9247 –2,4978
IE2
C 13,0651 10,4395 13,2470
D 79,077 80,9761 77,5603
A 0,3569 0,0773 0,1252
B –3,3076 –1,8951 –2,613
IE3
C 11,6108 9,2984 11,9963
D 82,2503 83,7025 80,4769
5.4.1.2 60 Hz mains supply frequency
Normative, 60 Hz, nominal limits are given in Tables 4, 6, and 8. Normative, 60 Hz, nominal
limits for rated output power values not defined in the tables shall be determined as follows:
• The efficiency of a rated power at or above the midpoint between two consecutive power
ratings shall be the higher of the two efficiencies.
• The efficiency of a rated power below the midpoint between two consecutive power ratings
shall be the lower of the two efficiencies.
5.4.2 Nominal limits for Standard Efficiency (IE1)
Table 3 – Nominal limits (%) for Standard Efficiency (IE1) 50 Hz
P Number of poles
N
kW
2 4 6
0,75 72,1 72,1 70,0
1,1 75,0 75,0 72,9
1,5 77,2 77,2 75,2
2,2 79,7 79,7 77,7
3 81,5 81,5 79,7
4 83,1 83,1 81,4
5,5 84,7 84,7 83,1
7,5 86,0 86,0 84,7
11 87,6 87,6 86,4
15 88,7 88,7 87,7
18,5 89,3 89,3 88,6
22 89,9 89,9 89,2
30 90,7 90,7 90,2
37 91,2 91,2 90,8
45 91,7 91,7 91,4
55 92,1 92,1 91,9
60034-30 © IEC:2008 – 13 –
P Number of poles
N
kW
2 4 6
75 92,7 92,7 92,6
90 93,0 93,0 92,9
110 93,3 93,3 93,3
132 93,5 93,5 93,5
160 93,8 93,8 93,8
200 up to 375 94,0 94,0 94,0
Table 4 – Nominal limits (%) for Standard Efficiency (IE1) 60 Hz
P Number of poles
N
kW 2 4 6
0,75 77,0 78,0 73,0
1,1 78,5 79,0 75,0
1,5 81,0 81,5 77,0
2,2 81,5 83,0 78,5
3,7 84,5 85,0 83,5
5,5 86,0 87,0 85,0
7,5 87,5 87,5 86,0
11 87,5 88,5 89,0
15 88,5 89,5 89,5
18,5 89,5 90,5 90,2
22 89,5 91,0 91,0
30 90,2 91,7 91,7
37 91,5 92,4 91,7
45 91,7 93,0 91,7
55 92,4 93,0 92,1
75 93,0 93,2 93,0
90 93,0 93,2 93,0
110 93,0 93,5 94,1
150 94,1 94,5 94,1
185 up to 375 94,1 94,5 94,1
– 14 – 60034-30 © IEC:2008
5.4.3 Nominal limits for High Efficiency (IE2)
Table 5 – Nominal limits (%) for High Efficiency (IE2) 50 Hz
P Number of poles
N
kW
2 4 6
0,75 77,4 79,6 75,9
1,1 79,6 81,4 78,1
1,5 81,3 82,8 79,8
2,2 83,2 84,3 81,8
3 84,6 85,5 83,3
4 85,8 86,6 84,6
5,5 87,0 87,7 86,0
7,5 88,1 88,7 87,2
11 89,4 89,8 88,7
15 90,3 90,6 89,7
18,5 90,9 91,2 90,4
22 91,3 91,6 90,9
30 92,0 92,3 91,7
37 92,5 92,7 92,2
45 92,9 93,1 92,7
55 93,2 93,5 93,1
75 93,8 94,0 93,7
90 94,1 94,2 94,0
110 94,3 94,5 94,3
132 94,6 94,7 94,6
160 94,8 94,9 94,8
200 up to 375 95,0 95,1 95,0
Table 6 – Nominal limits (%) for High Efficiency (IE2) 60 Hz
Number of poles
P
N
kW 2 4 6
0,75 75,5 * 82,5 80,0
1,1 82,5 84,0 85,5
1,5 84,0 84,0 86,5
2,2 85,5 87,5 87,5
3,7 87,5 87,5 87,5
5,5 88,5 89,5 89,5
7,5 89,5 89,5 89,5
11 90,2 91,0 90,2
15 90,2 91,0 90,2
18,5 91,0 92,4 91,7
22 91,0 92,4 91,7
30 91,7 93,0 93,0
37 92,4 93,0 93,0
60034-30 © IEC:2008 – 15 –
P Number of poles
N
kW
2 4 6
45 93,0 93,6 93,6
55 93,0 94,1 93,6
75 93,6 94,5 94,1
90 94,5 94,5 94,1
110 94,5 95,0 95,0
150 95,0 95,0 95,0
185 up to 375 95,4 95,4 ** 95,0
* This value has been copied from NEMA MG1 and not a typing error.
** In NEMA Energy Efficiency the nominal limit is 95,0 % for 185 kW and 95,8 % for 375 kW.
5.4.4 Nominal limits for Premium Efficiency (IE3)
Table 7 – Nominal limits (%) for Premium Efficiency (IE3) 50 Hz
P Number of poles
N
kW
2 4 6
0,75 80,7 82,5 78,9
1,1 82,7 84,1 81,0
1,5 84,2 85,3 82,5
2,2 85,9 86,7 84,3
3 87,1 87,7 85,6
4 88,1 88,6 86,8
5,5 89,2 89,6 88,0
7,5 90,1 90,4 89,1
11 91,2 91,4 90,3
15 91,9 92,1 91,2
18,5 92,4 92,6 91,7
22 92,7 93,0 92,2
30 93,3 93,6 92,9
37 93,7 93,9 93,3
45 94,0 94,2 93,7
55 94,3 94,6 94,1
75 94,7 95,0 94,6
90 95,0 95,2 94,9
110 95,2 95,4 95,1
132 95,4 95,6 95,4
160 95,6 95,8 95,6
200 up to 375 95,8 96,0 95,8
– 16 – 60034-30 © IEC:2008
Table 8 – Nominal limits (%) for Premium Efficiency (IE3) 60 Hz
P Number of poles
N
kW 2 4 6
0,75 77,0 * 85,5 82,5
1,1 84,0 86,5 87,5
1,5 85,5 86,5 88,5
2,2 86,5 89,5 89,5
3,7 88,5 89,5 89,5
5,5 89,5 91,7 91,0
7,5 90,2 91,7 91,0
11 91,0 92,4 91,7
15 91,0 93,0 91,7
18,5 91,7 93,6 93,0
22 91,7 93,6 93,0
30 92,4 94,1 94,1
37 93,0 94,5 94,1
45 93,6 95,0 94,5
55 93,6 95,4 94,5
75 94,1 95,4 95,0
90 95,0 95,4 95,0
110 95,0 95,8 95,8
150 95,4 96,2 95,8
185 up to 375 95,8 96,2 95,8
* This value has been copied from NEMA MG1 and is not a typing error.

60034-30 © IEC:2008 – 17 –
Bibliography
IEC 60034-5, Rotating electrical machines – Part 5: Degrees of protection provided by the
integral design of rotating electrical machines (IP code) – Classification
IEC 60034-12, Rotating electrical machines – Part 12: Starting performance of single-speed
three-phase cage induction motors
IEC 60034-17, Rotating electrical machines – Part 17: Cage induction motors when fed from
converters - Application guide
IEC/TS 60034-25, Rotating electrical machines – Part 25: Guidance for the design and
performance of a.c. motors specifically designed for converter supply
IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements
ISO 3, Preferred numbers – Series of preferred numbers
EN 50347, General purpose three-phase induction motors having standard dimensions and
outputs – Frame numbers 56 to 315 and flange numbers 65 to 740
EN 12101-3, Smoke and heat control systems – Part 3: Specification for powered smoke and
heat exhaust ventilators
JISC 4212 (Japanese Industrial Standard), Low-voltage three-phase squirrel-cage high-
efficiency induction motors
NBR 7094, Rotating electrical machines – Induction motors – Specification
NEMA MG1, Motors and Generators
SANS 1804-1 (South African Standard), Induction motors – Part 1: IEC requirements

___________
– 18 – 60034-30 © CEI:2008
SOMMAIRE
AVANT-PROPOS.19
INTRODUCTION.21
1 Domaine d’application .24
2 Références normatives.24
3 Termes, définitions et symboles .25
3.1 Termes et définition.25
3.2 Symboles .25
4 Champ d’application (informatif) .25
5 Rendement.26
5.1 Détermination.26
5.1.1 General .26
5.1.2 Tensions assignées, fréquences assignées et puissances de sortie
assignées .27
5.1.3 Equipements auxiliaires.27
5.2 Assignations.27
5.3 Classification et marquage .28
5.3.1 Genéral .28
5.3.2 Classification du rendement .28
5.3.3 Moteurs inférieur au rendement « Standard » .28
5.3.4 Marquage .28
5.4 Limites de rendement nominal.28
5.4.1 Interpolation .28
5.4.2 Limites nominales pour le rendement « Standard » (IE1) .30
5.4.3 Limites nominales pour le « Haut » rendement (IE2).31
5.4.4 Limites nominales pour le rendement « Premium » (IE3) .33
Bibliographie.35

Figure 1 – Affectation des économies potentielles par gamme de moteurs installés
dans le secteur industriel .21

Tableau 1 – Classification IE du rendement .28
Tableau 2 – Coefficients d’interpolation (informatif) .29
Tableau 3 – Limites nominales (%) pour le rendement « Standard » (IE1) 50 Hz .30
Tableau 4 – Limites nominales (%) pour le rendement « Standard » (IE1) 60 Hz .30
Tableau 5 – Limites nominales (%) pour le « Haut » rendement (IE2) 50 Hz .31
Tableau 6 – Limites nominales (%) pour le « Haut » rendement (IE2) 60 Hz .32
Tableau 7 – Limites nominales (%) pour le rendement « Premium » (IE3) 50 Hz.33
Tableau 8 – Limites nominales (%) pour le rendement « Premium » (IE3) 60 Hz.33

60034-30 © CEI:2008 – 19 –
COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
____________
MACHINES ÉLECTRIQUES TOURNANTES –

Partie 30: Classes de rendement pour les moteurs
à induction triphasés à cage, mono vitesse (Code IE)

AVANT-PROPOS
1) La Commission Electrotechnique Internationale (CEI) est une organisation mondiale de normalisation
composée de l'ensemble des comités électrotechniques nationaux (Comités nationaux de la CEI). La CEI a
pour objet de favoriser la coopération internationale pour toutes les questions de normalisation dans les
domaines de l'électricité et de l'électronique. A cet effet, la CEI – entre autres activités – publie des Normes
internationales, des Spécifications techniques, des Rapports techniques, des Spécifications accessibles au
public (PAS) et des Guides (ci-après dénommés "Publication(s) de la CEI"). Leur élaboration est confiée à des
comités d'études, aux travaux desquels tout Comité national intéressé par le sujet traité peut participer. Les
organisations internationales, gouvernementales et non gouvernementales, en liaison avec la CEI, participent
également aux travaux. La CEI collabore étroitement avec l'Organisation Internationale de Normalisation (ISO),
selon des conditions fixées par accord entre les deux organisations.
2) Les décisions ou accords officiels de la CEI concernant les questions techniques représentent, dans la mesure
du possible, un accord international sur les sujets étudiés, étant donné que les Comités nationaux de la CEI
intéressés sont représentés dans chaque comité d’études.
3) Les Publication
...