EN IEC 60034-12:2024

SLOVENSKI STANDARD
01-marec-2025
Električni rotacijski stroji - 12. del: Zagonska zmogljivost eno- hitrostnih trifaznih
asinhronskih motrojev s kletko (IEC 60034-12:2024)
Rotating electrical machines - Part 12: Starting performance of single-speed three-phase
cage induction motors (IEC 60034-12:2024)
Drehende elektrische Maschinen - Teil 12: Anlaufverhalten von Drehstrommotoren mit
Käfigläufer ausgenommen polumschaltbare Motoren (IEC 60034-12:2024)
Machines électriques tournantes - Partie 12: Caractéristiques de démarrage des moteurs
triphasés à induction à cage à une seule vitesse (IEC 60034-12:2024)
Ta slovenski standard je istoveten z: EN IEC 60034-12:2024
ICS:
29.160.30 Motorji Motors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60034-12

NORME EUROPÉENNE
EUROPÄISCHE NORM November 2024
ICS 29.160.01 Supersedes EN 60034-12:2017
English Version
Rotating electrical machines - Part 12: Starting performance of
single-speed three-phase cage induction motors
(IEC 60034-12:2024)
Machines électriques tournantes - Partie 12: Drehende elektrische Maschinen - Teil 12: Anlaufverhalten
Caractéristiques de démarrage des moteurs triphasés à von Drehstrommotoren mit Käfigläufer ausgenommen
induction à cage à une seule vitesse polumschaltbare Motoren
(IEC 60034-12:2024) (IEC 60034-12:2024)
This European Standard was approved by CENELEC on 2024-09-25. 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye 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
© 2024 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60034-12:2024 E

European foreword
The text of document 2/2132/CDV, future edition 4 of IEC 60034-12, 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) 2025-11-30
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2027-11-30
document have to be withdrawn
This document supersedes EN 60034-12:2017 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 60034-12:2024 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 60034-2-1:2014 NOTE Approved as EN 60034-2-1:2014 (not modified)
Annex A
(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.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60034-1 2022 Rotating electrical machines - Part 1: - -
Rating and performance
IEC 60034-5 2020 Rotating electrical machines - Part 5: EN IEC 60034-5 2020
Degrees of protection provided by the
integral design of rotating electrical
machines (IP code) - Classification
IEC 60034-30-1 2014 Rotating electrical machines - Part 30-1: EN 60034-30-1 2014
Efficiency classes of line operated AC
motors (IE code)
IEC 60079-7 2015 Explosive atmospheres - Part 7: EN 60079-7 2015
Equipment protection by increased safety
"e"
+ A1 2017 + A1 2018
- - + A11 2024
ISO 80000-4 2019 Quantities and units - Part 4: Mechanics EN ISO 80000-4 2019

IEC 60034-12 ®
Edition 4.0 2024-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Rotating electrical machines –

Part 12: Starting performance of single-speed three-phase cage induction

motors
Machines électriques tournantes –

Partie 12: Caractéristiques de démarrage des moteurs triphasés à induction à

cage à une seule vitesse
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.160.01  ISBN 978-2-8322-8544-2

– 2 – IEC 60034-12:2024 © IEC 2024
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Symbols . 8
5 Designation . 9
5.1 General . 9
5.2 Design N . 9
5.3 Design NE . 9
5.4 Designs NY and NEY . 9
5.5 Design H . 9
5.6 Design HE . 9
5.7 Designs HY and HEY . 10
6 Design N requirements . 10
6.1 Torque characteristics . 10
6.2 Locked rotor current and apparent power . 10
6.3 Starting requirements . 10
7 Design NE starting requirements . 11
8 Designs NY and NEY starting requirements . 11
9 Design H requirements . 11
9.1 Starting torque . 11
9.2 Locked rotor current and apparent power . 11
9.3 Starting requirements . 11
10 Design HE starting requirements . 12
11 Designs HY and HEY starting requirements . 12
12 Determination of current and torque from measurement. 12
12.1 Locked-rotor current and locked-rotor torque . 12
12.2 Breakdown torque . 12
12.3 Torque-speed curve and current-speed curve . 13
12.3.1 General . 13
12.3.2 Torque-speed and current-speed curves from direct measurement
(method a) . 13
12.3.3 Torque-speed and current-speed curves from acceleration (method b) . 13
12.3.4 Torque-speed and current-speed curves from measured input power
(method c) . 14
12.4 Correction of data for tests performed at reduced voltage and/or other than
rated frequency . 14
Annex A (informative) Current and torque characteristics with locked rotor . 20
Annex B (informative) Correction method for test done on reduced voltage . 24
Bibliography . 25

Figure A.1 – Locked-rotor current in multiples of rated current versus time . 20
Figure A.2 – Locked-rotor torque in multiples of rated torque versus time . 21
Figure A.3 – Locked-rotor torque in cNm versus rotor position in °; left: preferable
number of rotor slots, right: less preferable number of rotor slots . 21

IEC 60034-12:2024 © IEC 2024 – 3 –
Figure A.4 – Locked-rotor torque in cNm versus rotor position in ° . 22
Figure A.5 – Time -courses (in s) of rotational speed (upper left), torque (lower left),
phase voltage (upper right) and phase current (lower right) during a star-delta start-up . 23

Table 1 – Minimum values of torques for design N . 15
Table 2 – Maximum values of locked rotor apparent power for designs N and H . 16
Table 3 – Maximum values of locked rotor apparent power for designs NE and HE . 16
Table 4 – External moment of inertia (J) . 17
Table 5 – Minimum values of torques for design H . 18
Table 6 – Minimum values of torques for design N motors with type of protection 'Ex
eb – increased safety' . 18
Table 7 – External moment of inertia (J) for motors with type of protection 'Ex eb –
increased safety' . 19

– 4 – IEC 60034-12:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ROTATING ELECTRICAL MACHINES –

Part 12: Starting performance of single-speed
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,
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60034-12 has been prepared by IEC technical committee 2: Rotating machinery. It is an
International Standard.
This fourth edition cancels and replaces the third edition published in 2016. This edition
constitutes a technical revision.

IEC 60034-12:2024 © IEC 2024 – 5 –
This edition includes the following significant technical changes with respect to the previous
edition:
Clause or
Change
subclause
Table 6 Aligned with the requirements for explosion protected motors from TC31 WG27
12 New clause on methods for measuring locked-rotor current and torque
Annex A New informative annex on the general current and torque characteristics with locked
rotor
Annex B New informative annex on correction of voltage and frequency

The text of this International Standard is based on the following documents:
Draft Report on voting
2/2132/CDV 2/2150A/RVC
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts of 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 webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

– 6 – IEC 60034-12:2024 © IEC 2024
ROTATING ELECTRICAL MACHINES –

Part 12: Starting performance of single-speed
three-phase cage induction motors

1 Scope
This part of IEC 60034 specifies the parameters for eight designs of starting performance of
single-speed three-phase 50 Hz or 60 Hz cage induction motors in accordance with
IEC 60034-1 that:
– have a rated voltage up to 1 000 V;
– are intended for direct-on-line or star-delta starting;
– are rated on the basis of duty type S1;
– are constructed to any degree of protection as defined in IEC 60034-5 and explosion
protection.
This document also applies to dual voltage motors provided that the flux saturation level is the
same for both voltages.
The values of torque, apparent power and current given in this document are limiting values
(that is, minimum or maximum without tolerance).
NOTE 1 It is not expected that all manufacturers will produce machines for all eight designs. The selection of any
specific design in accordance with this document will be a matter of agreement between the manufacturer and the
purchaser.
NOTE 2 Designs other than the eight specified can be necessary for particular applications.
NOTE 3 Values given in manufacturers' catalogues can include tolerances in accordance with IEC 60034-1.
NOTE 4 The values tabled for locked rotor apparent power are based on RMS symmetrical steady state locked rotor
currents. The start of the motor leads to transient asymmetrical currents in the whole supply, so called inrush
currents, the peak value of which can range from 1,8 to 2,8 times the steady state locked rotor value. The current
peak and decay time are a function of the motor design and switching angle. Similar effects can occur during the
switchover from star to delta operation. A more detailed description is provided in Annex A.
The application of the test methods described in Clause 12 can be applied to cage induction
motors outside the scope of this document. However, special care shall be taken in such cases
to prevent overheating of the stator or the rotor winding depending on the concrete method and
parameters chosen.
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 60034-1:2022, Rotating electrical machines – Part 1: Rating and performance
IEC 60034-5:2020, Rotating electrical machines – Part 5: Degrees of protection provided by the
integral design of rotating electrical machines (IP code) – Classification
IEC 60034-30-1:2014, Rotating electrical machines – Part 30-1: Efficiency classes of line-
operated AC motors (IE-code)
IEC 60034-12:2024 © IEC 2024 – 7 –
IEC 60079-7:2015, Explosive atmospheres – Part 7: Equipment protection by increased
safety "e"
IEC 60079-7:2015/AMD1:2017
ISO 80000-4:2019, Quantities and units – Part 4: Mechanics
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
rated torque
T
N
torque the motor develops at its shaft end at rated output and speed
[SOURCE: IEC 60050-411:1996, 411-48-05]
3.2
locked-rotor torque
T
l
smallest measured torque the motor develops at its shaft end with the rotor locked, over all its
angular positions, at rated voltage and frequency
[SOURCE: IEC 60050-411:1996, 411-48-06]
3.3
pull-up torque
T
u
smallest steady-state asynchronous torque which the motor develops between zero speed and
the speed which corresponds to the breakdown torque, when the motor is supplied at the rated
voltage and frequency
[SOURCE: IEC 60050-411:1996, 411-48-42, modified – The notes 1 and 2 to entry have been
modified.]
Note 1 to entry: This definition does not apply to those motors whose torque continually decreases with increase in
speed.
Note 2 to entry: In addition to the steady-state asynchronous torques, harmonic synchronous torques, which are a
function of rotor load angle, will be present at specific speeds. At such speeds, the accelerating torque can be
negative for some rotor load angles. Experience and calculation show this to be an unstable operating condition and
therefore harmonic synchronous torques do not prevent motor acceleration and are excluded from this definition.

– 8 – IEC 60034-12:2024 © IEC 2024
3.4
breakdown torque
T
b
maximum steady-state asynchronous torque which the motor develops without an abrupt drop
in speed, when the motor is supplied at the rated voltage and frequency
[SOURCE: IEC 60050-411:1996, 411-48-43, modified – The notes 1 and 2 to entry have been
modified.]
Note 1 to entry: This definition does not apply to those motors whose torque continually decreases with increase in
speed.
3.5
rated output
P
N
value of the output power included in the rating
Note 1 to entry: The terms rated value and rating are defined in IEC 60034-1:2022, 3.1 and 3.2 (see also IEC 60050-
411:1996, 411-51-23 and 411-51-24).
3.6
rated voltage
U
N
value of the voltage included in the rating
Note 1 to entry: The terms rated value and rating are defined in IEC 60034-1:2022, 3.1 and 3.2 (see also IEC 60050-
411:1996, 411-51-23 and 411-51-24).
3.7
locked rotor apparent power
S
l
apparent power input with the motor held at rest at rated voltage and frequency after the inrush
currents have decayed to a symmetrical system of current
[SOURCE: IEC 60050-411:1996, 411-48-49, modified – "after the inrush currents have decayed
to a symmetrical system of current" has been added.]
3.8
locked rotor current
I
l
current with the motor held at rest at rated voltage and frequency after the inrush currents have
decayed to a symmetrical system of current
4 Symbols
I Locked rotor current
l
J External moment of inertia
J Moment of inertia of motor under test
M
n Rotational speed
p Number of pole pairs
P Power at the motor terminals during test method c) in 12.3.4
P Power at the generator terminals during test method a) in 12.3.2
1,g
P Motor iron losses during test method c) in 12.3.4
fe
P Motor I R losses during test method c) in 12.3.4
L
IEC 60034-12:2024 © IEC 2024 – 9 –
P Total losses of the generator during test method a) in 12.3.2
T,g
P Rated output
N
S Locked rotor apparent power
l
T Rated torque
N
T Locked rotor torque
l
T Pull-up torque
u
Breakdown torque
T
b
T Motor friction and windage torque during test method c) in 12.3.4
fw
U Rated voltage
N
5 Designation
5.1 General
Motors designed according to this document are classified according to 5.2 to 5.7. The letters
used to specify the different designs stand for:
N: normal starting torque.
H: high starting torque.
Y: star-delta starting.
E: motors utilizing extended / higher locked rotor apparent power and current to achieve
efficiency classes of IE3 or higher according to IEC 60034-30-1.
5.2 Design N
Normal starting torque three-phase cage induction motors, intended for direct-on-line starting,
having 2, 4, 6 or 8 poles, rated from 0,12 kW to 1 600 kW.
5.3 Design NE
Normal starting torque three-phase cage induction motors having higher locked rotor apparent
power than design N, intended for direct-on-line starting, having 2, 4, 6 or 8 poles, rated from
0,12 kW to 1 600 kW.
5.4 Designs NY and NEY
Motors similar to designs N or NE, respectively, but intended for star-delta starting. For these
motors in star-connection, minimum values for T and T are 25 % of the values of design N or
l u
NE, respectively, see Table 1.
5.5 Design H
High starting torque three-phase cage induction motors with 4, 6 or 8 poles, intended for direct-
online starting, rated from 0,12 kW to 160 kW at a frequency of 60 Hz.
5.6 Design HE
High starting torque three-phase cage induction motors having higher locked rotor apparent
power than design H, with 4, 6 or 8 poles, intended for direct-online starting, rated from 0,12 kW
to 160 kW at a frequency of 60 Hz.

– 10 – IEC 60034-12:2024 © IEC 2024
5.7 Designs HY and HEY
Motors similar to designs H or HE, respectively, but intended for star-delta starting. For these
motors in star-connection, minimum values for T and T are 25 % of the values of design H or
l u
HE, respectively, see Table 5.
6 Design N requirements
6.1 Torque characteristics
The starting torque is represented by three characteristic features. These features shall be in
accordance with the appropriate values given in Table 1 or Table 6. The values in Table 1 and
Table 6 are minimum values at rated voltage. Higher values are allowed.
The motor torque at any speed between zero and that at which breakdown torque occurs shall
be not less than 1,3 times the torque obtained from a curve varying as the square of the speed
and being equal to rated torque at rated speed. However, for 2-pole motors with type of
protection 'Ex eb – increased safety' having a rated output greater than 100 kW, the motor
torque at any speed between zero and that at which breakdown torque occurs shall not be less
than 1,3 times the torque obtained from a curve varying as the square of the speed and being
equal to 70 % rated torque at rated speed. For motors with type of protection 'Ex eb', the three
characteristic torques shall be in accordance with the appropriate values g
...