IEC 60947-4-1:2009
(Main)Low-voltage switchgear and controlgear - Part 4-1: Contactors and motor-starters - Electromechanical contactors and motor-starters
Low-voltage switchgear and controlgear - Part 4-1: Contactors and motor-starters - Electromechanical contactors and motor-starters
IEC 60947-4-1:2009 applies to the types of equipment whose main contacts are intended to be connected to circuits the rated voltage of which does not exceed 1 000 V a.c. or 1 500 V d.c. Starters and/or contactors dealt with in this standard are not normally designed to interrupt short-circuit currents. Therefore, suitable short-circuit protection forms part of the installation but not necessarily of the contactor or the starter. This third edition replaces the second edition published in 2000 and its Amendments 1 (2002) and 2 (2005). It is a technical revision. This edition includes the following significant technical changes with respect to the previous edition (2000) and its Amendments 1 (2002) and 2 (2005):
- deletion of the test at -5 °C and +20 °C for thermal overload relays that are not compensated for ambient air temperature;
- addition of conditions of the tests according to Annex Q of IEC 60947-1;
- EMC tests: clarification of acceptance criteria and alignment with IEC 60947-1 for fast transient severity level;
- Annex B, test for Icd: modification of the duration of the dielectric test voltage from 5 s to 60 s;
- Annex B, electrical durability: improvement of the statistical aspects;
- Annex H: clarification and introduction of new extended functions within electronic overload relays;
- Annex K, procedure to determine data for electromechanical contactors used in functional safety applications: creation of this new annex. This standard shall be read in conjunction with IEC 60947-1, Low voltage switchgear and controlgear - Part 1: General rules. The provisions of the general rules are applicable to this standard, where specifically called for.
This publication shall be read in conjunction with IEC 60947-1 :2007.
Appareillage à basse tension - Partie 4-1: Contacteurs et démarreurs de moteurs - Contacteurs et démarreurs électromécaniques
La CEI 60947-4-1:2009 est applicable aux types de matériels dont les contacts principaux sont destinés à être reliés à des circuits dont la tension assignée ne dépasse pas 1 000 V en courant alternatif ou 1 500 V en courant continu. Les démarreurs et/ou contacteurs traités dans la présente norme ne sont pas normalement conçus pour interrompre les courants de court-circuit. En conséquence, une protection appropriée contre les courts-circuits fait partie de l'installation, mais pas nécessairement du contacteur ou du démarreur. Cette troisième édition annule et remplace la deuxième édition parue en 2000 et ses Amendements 1 (2002) et 2 (2005). Elle constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente (2000) et ses Amendements 1 (2002) et 2 (2005):
- suppression de l'essai à -5 °C et +20 °C pour les relais de surcharge thermiques qui ne sont pas compensés pour la température de l'air ambiant;
- ajout de conditions d'essai conformes à l'Annexe Q de la CEI 60947-1;
- essais CEM: clarification des critères d'acceptation et alignement sur la CEI 60947-1 pour le niveau de sécurité pour les transitoires rapides;
- Annexe B, essai pour Icd: modification de la durée de la tension de l'essai diélectrique de 5 s à 60 s;
- Annexe B: amélioration des aspects statistiques de la durabilité électrique;
- Annexe H: clarification et introduction de nouvelles fonctions étendues dans les relais électroniques de surcharge;
- Annexe K, procédure pour déterminer les données des contacteurs électromécaniques utilisés pour les applications de sécurité fonctionnelle: création de cette nouvelle annexe. La présente norme doit être lue conjointement avec la CEI 60947-1, Appareillage à basse tension - Partie 1: Règles générales. Les dispositions des règles générales sont applicables à la présente norme, lorsque cela est spécifiquement mentionné.
Cette publication doit être lue conjointement avec la CEI 60947-1 :2007.
General Information
Relations
Standards Content (Sample)
IEC 60947-4-1 ®
Edition 3.0 2009-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Low-voltage switchgear and controlgear –
Part 4-1: Contactors and motor-starters – Electromechanical contactors and
motor-starters
Appareillage à basse tension –
Partie 4-1: Contacteurs et démarreurs de moteurs – Contacteurs et démarreurs
électromécaniques
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 60947-4-1 ®
Edition 3.0 2009-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Low-voltage switchgear and controlgear –
Part 4-1: Contactors and motor-starters – Electromechanical contactors and
motor-starters
Appareillage à basse tension –
Partie 4-1: Contacteurs et démarreurs de moteurs – Contacteurs et démarreurs
électromécaniques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
XF
CODE PRIX
ICS 29.120.99; 29.130.20 ISBN 978-2-88910-338-6
– 2 – 60947-4-1 © IEC:2009
CONTENTS
FOREWORD.6
1 Scope and object.8
1.1 Scope.8
1.1.1 AC and DC contactors .8
1.1.2 AC motor-starters .8
1.2 Exclusions.10
1.3 Object .10
2 Normative references .11
3 Terms, definitions, symbols and abbreviations.12
3.1 General .12
3.2 Alphabetical index of terms .12
3.3 Terms and definitions concerning contactors .13
3.4 Terms and definitions concerning starters .15
3.5 Terms and definitions concerning characteristic quantities .19
3.6 Symbols and abbreviations.19
4 Classification.20
5 Characteristics of contactors and starters.20
5.1 Summary of characteristics .20
5.2 Type of equipment.20
5.2.1 Kind of equipment.20
5.2.2 Number of poles .20
5.2.3 Kind of current (a.c. or d.c.).20
5.2.4 Interrupting medium (air, oil, gas, vacuum, etc.) .20
5.2.5 Operating conditions of the equipment.20
5.3 Rated and limiting values for main circuits.21
5.3.1 Rated voltages .21
5.3.2 Currents or powers .22
5.3.3 Rated frequency .24
5.3.4 Rated duties .24
5.3.5 Normal load and overload characteristics .25
5.3.6 Rated conditional short-circuit current .27
5.4 Utilization category.27
5.4.1 General .27
5.4.2 Assignment of utilization categories based on the results of tests.27
5.5 Control circuits .29
5.6 Auxiliary circuits .30
5.7 Characteristics of relays and releases (overload relays) .30
5.7.1 Summary of characteristics.30
5.7.2 Types of relay or release .30
5.7.3 Characteristic values .30
5.7.4 Designation and current settings of overload relays.32
5.7.5 Time-current characteristics of overload relays.32
5.7.6 Influence of ambient air temperature .33
5.8 Co-ordination with short-circuit protective devices .33
5.9 Void .33
60947-4-1 © IEC:2009 – 3 –
5.10 Types and characteristics of automatic change-over devices and automatic
acceleration control devices .33
5.10.1 Types .33
5.10.2 Characteristics .33
5.11 Types and characteristics of auto-transformers for two-step auto-transformer
starters.34
5.12 Types and characteristics of starting resistors for rheostatic rotor starters.34
6 Product information .34
6.1 Nature of information.34
6.1.1 Identification.34
6.1.2 Characteristics, basic rated values and utilization.35
6.2 Marking .36
6.3 Instructions for installation, operation and maintenance .36
7 Normal service, mounting and transport conditions.37
8 Constructional and performance requirements.37
8.1 Constructional requirements.37
8.1.1 General .37
8.1.2 Materials .37
8.1.3 Current-carrying parts and their connections .37
8.1.4 Clearances and creepage distances .37
8.1.5 Actuator.37
8.1.6 Indication of the contact position .38
8.1.7 Additional requirements for equipment suitable for isolation .38
8.1.8 Terminals .38
8.1.9 Additional requirements for equipment provided with a neutral pole.38
8.1.10 Provisions for protective earthing .38
8.1.11 Enclosures for equipment .38
8.1.12 Degrees of protection of enclosed equipment .38
8.1.13 Conduit pull-out, torque and bending with metallic conduits .39
8.2 Performance requirements .39
8.2.1 Operating conditions.39
8.2.2 Temperature rise .44
8.2.3 Dielectric properties.46
8.2.4 Normal load and overload performance requirements .46
8.2.5 Co-ordination with short-circuit protective devices .51
8.2.6 Void.52
8.2.7 Additional requirements for combination starters and combination
switching devices suitable for isolation .52
8.3 Electromagnetic compatibility (EMC) .52
8.3.1 General .52
8.3.2 Immunity .52
8.3.3 Emission .53
9 Tests .53
9.1 Kinds of test .53
9.1.1 General .53
9.1.2 Type tests .54
9.1.3 Routine tests .54
9.1.4 Sampling tests.54
9.1.5 Special tests.55
– 4 – 60947-4-1 © IEC:2009
9.2 Compliance with constructional requirements .55
9.3 Compliance with performance requirements .55
9.3.1 Test sequences .55
9.3.2 General test conditions.56
9.3.3 Performance under no load, normal load and overload conditions .56
9.3.4 Performance under short-circuit conditions .64
9.3.5 Overload current withstand capability of contactors .69
9.3.6 Routine tests and sampling tests .69
9.4 EMC tests .70
9.4.1 General .70
9.4.2 Immunity .70
9.4.3 Emission .71
Annex A (normative) Marking and identification of terminals of contactors and
associated overload relays.81
Annex B (normative) Special tests .85
Annex C Void.93
Annex D (informative) Items subject to agreement between manufacturer and user .94
Annex E (informative) Examples of control circuit configurations.95
Annex F (normative) Requirements for auxiliary contact linked with power contact
(mirror contact) .98
Annex G (informative) Rated operational currents and rated operational powers of
switching devices for electrical motors .101
Annex H (normative) Extended functions within electronic overload relays. 105
Annex I (informative) AC1 contactors for use with semiconductor controlled motor
loads .111
Annex J Void .112
Annex K (normative) Procedure to determine data for electromechanical contactors
used in functional safety applications.113
Bibliography.122
Figure 1 – Typical curves of currents and torques during a star-delta start (see
1.1.2.2.1) .73
Figure 2 – Typical curves of currents and torques during an auto-transformer start
(see 1.1.2.2.2) .74
Figure 3 – Typical variants of protected starters, combination starters, protected
switching devices and combination switching devices .75
Figure 4 – Example of three-phase diagram of a rheostatic rotor starter with three
starting steps and one direction of rotation (in the case when all the mechanical
switching devices are contactors) .76
Figure 5 – Typical methods and diagrams of starting alternating-current induction
motors by means of auto-transformers.77
Figure 6 – Examples of speed/time curves corresponding to cases a), b), c), d), e) and
f) of 5.3.5.5 (the dotted parts of the curves correspond to the periods when no current
flows through the motor) .78
Figure 7 – Multiple of current setting limits for ambient air temperature compensated
time-delay overload relays (see 8.2.1.5.1) .79
Figure 8 – Thermal memory test .80
Figure B.1 – Examples of time-current withstand characteristic.92
60947-4-1 © IEC:2009 – 5 –
Figure F.1 − Mirror contact.99
Figure H.1 – Test circuit for the verification of the operating characteristic of a
ground/earth fault relay.
Figure K.1 – Plot of Weibull median rank regression . 121
Table 1 – Utilization categories .29
Table 2 – Trip classes of overload relays .32
Table 3 – Limits of operation of time-delay overload relays when energized on all poles.42
Table 4 – Limits of operation of three-pole time-delay overload relays when energized
on two poles only.43
Table 5 – Temperature rise limits for insulated coils in air and in oil.44
Table 6 – Intermittent duty test cycle data.45
Table 7 – Making and breaking capacities – Making and breaking conditions according
to utilization category.47
Table 8 – Relationship between current broken I and off-time for the verification of
c
rated making and breaking capacities .48
Table 9 – Operational current determination for utilization categories AC-6a and AC-6b
when derived from AC-3 ratings .49
Table 10 – Conventional operational performance – Making and breaking conditions
according to utilization category.50
Table 11 – Overload current withstand requirements .51
Table 12 – Specific acceptance criteria for immunity tests .53
Table 13 – Value of the prospective test current according to the rated operational
current .66
Table 14 – EMC immunity tests.70
Table 15 – Conducted radio-frequency emission test limits .72
Table 16 – Radiated emission test limits .72
Table B.1 – Verification of the number of on-load operating cycles – Conditions for
making and breaking corresponding to the several utilization categories.88
Table B.2 – Test conditions .91
Table F.1 – Test voltage according to altitude.99
Table G.1 – Rated operational powers and rated operational currents of motors . 102
Table H.1 – Operating time of ground/earth fault relays .107
Table K.1 – Failure mode of contactors.115
Table K.2 – Typical failure ratios for normally open contactors.119
Table K.3 – Example of 15 sorted ascending times to failure of contactors .120
– 6 – 60947-4-1 © IEC:2009
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
Part 4-1: Contactors and motor-starters –
Electromechanical contactors and motor-starters
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 60947-4-1 has been prepared by subcommittee 17B: Low-voltage
switchgear and controlgear, of IEC technical committee 17: Switchgear and controlgear.
This third edition replaces the second edition published in 2000 and its Amendments 1 (2002)
and 2 (2005). It is a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition (2000) and its Amendments 1 (2002) and 2 (2005):
• deletion of the test at –5 °C and +20 °C for thermal overload relays that are not
compensated for ambient air temperature;
• addition of conditions of the tests according to Annex Q of IEC 60947-1;
• EMC tests: clarification of acceptance criteria and alignment with IEC 60947-1 for fast
transient severity level;
• Annex B, test for Icd: modification of the duration of the dielectric test voltage from 5 s to
60 s;
60947-4-1 © IEC:2009 – 7 –
• Annex B, electrical durability: improvement of the statistical aspects;
• Annex H: clarification and introduction of new extended functions within electronic
overload relays;
• Annex K, procedure to determine data for electromechanical contactors used in functional
safety applications: creation of this new annex.
The text of this standard is based on the following documents:
FDIS Report on voting
17B/1674/FDIS 17B/1677/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 the IEC 60947 series can be found, under the general title Low-voltage
switchgear and controlgear, on the IEC website.
This standard shall be read in conjunction with IEC 60947-1, Low voltage switchgear and
controlgear – Part 1: General rules. The provisions of the general rules are applicable to this
standard, where specifically called for.
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.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.
– 8 – 60947-4-1 © IEC:2009
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
Part 4-1: Contactors and motor-starters –
Electromechanical contactors and motor-starters
1 Scope and object
1.1 Scope
This part of IEC 60947 applies to the types of equipment listed in 1.1.1 and 1.1.2 whose main
contacts are intended to be connected to circuits the rated voltage of which does not exceed
1 000 V a.c. or 1 500 V d.c.
Starters and/or contactors dealt with in this standard are not normally designed to interrupt
short-circuit currents. Therefore, suitable short-circuit protection (see 9.3.4) forms part of the
installation but not necessarily of the contactor or the starter.
In this context, this standard gives requirements for:
– contactors associated with overload and/or short-circuit protective devices;
– starters associated with separate short-circuit protective devices and/or with separate
short-circuit and integrated overload protective devices;
– contactors or starters combined, under specified conditions, with their own short-circuit
protective devices. Such combinations, e.g. combination starters or protected starters are
rated as units.
For circuit-breakers and fuse-combination units used as short-circuit protective devices in
combination starters and in protected starters, the requirements of IEC 60947-2 and
IEC 60947-3 respectively apply.
Equipment covered by this standard is as follows.
1.1.1 AC and DC contactors
AC and DC contactors intended for closing and opening electric circuits and, if combined with
suitable relays (see 1.1.2), for protecting these circuits against operating overloads which
may occur therein.
NOTE For contactors combined with suitable relays and which are intended to provide short-circuit protection, the
relevant conditions specified for circuit-breakers (IEC 60947-2) additionally apply.
This standard applies also to the actuators of contactor relays and to the contacts dedicated
exclusively to the coil circuit of a contactor.
Contactors or starters with an electronically controlled electromagnet are also covered by this
standard.
1.1.2 AC motor-starters
AC motor-starters intended to start and accelerate motors to normal speed, to ensure
continuous operation of motors, to switch off the supply from the motor and to provide means
for the protection of motors and associated circuits against operating overloads.
60947-4-1 © IEC:2009 – 9 –
For overload relays for starters, including those based on electronic technology with or without
extended functions according to Annex H, the requirements of this standard apply.
1.1.2.1 Direct-on-line (full voltage) a.c. starters
Direct-on-line starters intended to start and accelerate a motor to normal speed, to provide
means for the protection of the motor and its associated circuits against operating overloads,
and to switch off the supply from the motor.
This standard applies also to reversing starters.
1.1.2.2 Reduced voltage a.c. starters
Reduced voltage a.c. starters intended to start and accelerate a motor to normal speed by
connecting the line voltage across the motor terminals in more than one step or by gradually
increasing the voltage applied to the terminals, to provide means for the protection of the
motor and its associated circuits against operating overloads, and to switch off the supply
from the motor.
Automatic change-over devices may be used to control the successive switching operations
from one step to the others. Such automatic change-over devices are, for example, time-delay
contactor relays or specified time all-or-nothing relays, under-current devices and automatic
acceleration control devices (see 5.10).
1.1.2.2.1 Star-delta starters
Star-delta starters intended to start a three-phase motor in the star connection, to ensure
continuous operation in the delta connection, to provide means for the protection of the motor
and its associated circuits against operating overloads, and to switch off the supply from the
motor.
The star-delta starters dealt with in this standard are not intended for reversing motors rapidly
and, therefore, utilization category AC-4 does not apply.
NOTE In the star connection, the current in the line and the torque of the motor are about one-third of the
corresponding values for delta connection. Therefore, star-delta starters are used when the inrush current due to
the starting is to be limited, or when the driven machine requires a limited torque for starting. Figure 1 indicates
typical curves of starting current, of starting torque of the motor and of torque of the driven machine.
1.1.2.2.2 Two-step auto-transformer starters
Two-step auto-transformer starters, intended to start and accelerate an a.c. induction motor
from rest with reduced torque to normal speed and to provide means for the protection of the
motor and its associated circuits against operating overloads, and to switch off the supply
from the motor.
This standard applies to auto-transformers which are part of the starter or which constitute a
unit specially designed to be associated with the starter.
Auto-transformer starters with more than two steps are not covered by this standard.
The auto-transformer starters dealt with in this standard are not intended for inching duty or
reversing motors rapidly and, therefore, utilization category AC-4 does not apply.
NOTE In the starting position, the current in the line and the torque of the motor related to the motor starting with
rated voltage are reduced approximately as the square of the ratio (starting voltage):(rated voltage). Therefore,
auto-transformer starters are used when the inrush current due to the starting is to be limited or when the driven
machine requires a limited torque for starting. Figure 2 indicates typical curves of starting current, of starting
torque of the motor and of torque of the driven machine.
– 10 – 60947-4-1 © IEC:2009
1.1.2.3 Rheostatic rotor starters
Starters intended to start an a.c. induction motor having a wound rotor by cutting out resistors
previously inserted in the rotor circuit, to provide means for the protection of the motor against
operating overloads and to switch off the supply from the motor.
In the case of asynchronous slip-ring motors (wound-rotors), the highest voltage between
open slip-rings is not greater than twice the rated insulation voltage of the switching devices
inserted in the rotor circuit (see 5.3.1.1.2).
NOTE This requirement is based on the fact that the electric stresses are less severe in the rotor than in the
stator and are of short duration.
This standard applies also to starters for two directions of rotation when reversal of
connections is made with the motor stopped (see 5.3.5.5). Operations including inching and
plugging necessitate additional requirements and are subject to agreement between
manufacturer and user.
This standard applies to resistors which are part of the starter or constitute a unit specially
designed to be associated with the starter.
1.2 Exclusions
This standard does not apply to:
– d.c. starters;
– star-delta starters, rheostatic rotor starters, two-step auto-transformer starters intended for
special applications and designed for continuous operation in the starting position;
– unbalanced rheostatic rotor starters, i.e. where the resistances do not have the same
value in all phases;
– equipment designed not only for starting, but also for adjustment of speed;
– liquid starters and those of the "liquid-vapour" type;
– semiconductor contactors and starters making use of semiconductor contactors in the
main circuit;
– rheostatic stator starters;
– contactors or starters designed for special applications;
– auxiliary contacts of contactors and contacts of contactor relays. These are dealt with in
IEC 60947-5-1.
1.3 Object
The object of this standard is to state:
a) the characteristics of contactors and starters and associated equipment;
b) the conditions applicable to contactors and starters with reference to:
1) their operation and behaviour,
2) their dielectric properties,
3) the degrees of protection provided by their enclosures, where applicable,
4) their construction;
c) the tests intended for confirming that these conditions have been met, and the methods to
be adopted for these tests;
d) the information to be given with the equipment or in the manufacturer's literature.
60947-4-1 © IEC:2009 – 11 –
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 60034-1:2004, Rotating electrical machines – Part 1: Rating and performance
IEC 60085:2007, Electrical insulation – Thermal evaluation and designation
IEC 60300-3-5:2001, Dependability management – Part 3-5: Application guide – Reliability
test conditions and statistical test principles
IEC 60410:1973, Sampling plans and procedures for inspection by attributes
IEC 60947-1:2007, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-2:2006, Low-voltage switchgear and controlgear – Part 2: Circuit-breakers
IEC 60947-3:2008, Low-voltage switchgear and controlgear – Part 3: Switches, disconnectors,
switch-disconnectors and fuse-combination units
IEC 60947-5-1:2003, Low-voltage switchgear and controlgear – Part 5-1: Control circuit
devices and switching elements – Electromechanical control circuit devices
IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and measure-
ment techniques – Radiated, radio-frequency, electromagnetic field immunity test
Amendment 1 (2007)
IEC 61000-4-4:2004, Electromagnetic compatibility (EMC) – Part 4-4: Testing and measurement
techniques – Electrical fast transient/burst immunity test
IEC 61000-4-5:2005, Electromagnetic compatibility (EMC) – Part 4-5: Testing and
measurement techniques – Surge immunity test
IEC 61000-4-6:2008, Electromagnetic compatibility (EMC) – Part 4-6:Testing and
measurement techniques – Immunity to conducted disturbances, induced by radio-frequency
fields
IEC 61439-1:2009, Low-voltage switchgear and controlgear assemblies – Part 1: General
rules
IEC 61508 (all parts), Functional safety of electrical/electronic/programmable electronic
safety-related systems
IEC 61511 (all parts), Functional safety – Safety instrumented systems for the process
industry sector
IEC 61513:2001, Nuclear power plants –Instrumentation and control for systems important to
safety – General requirements for systems
IEC 61649:2008, Weibull analysis
IEC 61810-1:2008, Electromechanical elementary relays – Part 1: General requirements
(available in English only)
– 12 – 60947-4-1 © IEC:2009
IEC 62061:2005, Safety of machinery – Functional safety of safety-related electrical,
electronic and programmable electronic control systems
CISPR 11:2003, Industrial, scientific and medical (ISM) radio-frequency equipment –
Electromagnetic disturbance characteristics – Limits and methods of measurement
Amendment 1 (2004)
Amendment 2 (2006)
ISO 13849-1:2006, Safety of machinery – Safety-related parts of control systems – Part 1:
General principles for design
3 Terms, definitions, symbols and abbreviations
3.1 General
For the purposes of this document, the terms and definitions of Clause 2 of IEC 60947-1, as
well as the following terms, definitions, symbol and abbreviations apply.
3.2 Alphabetical index of terms
Reference
A
auto-transformer starter . 3.4.5.2
C
closed transition (with an auto-transformer starter or star-delta starter) . 3.4.23
combination starter . 3.4.8
combination switching device. 3.4.27
CO operation . 3.5.2
contactor (mechanical). 3.3.1
D
direct-on-line starter .
...
IEC 60947-4-1 ®
Edition 3.1 2012-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Low-voltage switchgear and controlgear –
Part 4-1: Contactors and motor-starters – Electromechanical contactors and
motor-starters
Appareillage à basse tension –
Partie 4-1: Contacteurs et démarreurs de moteurs – Contacteurs et démarreurs
électromécaniques
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 Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland 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.
Useful links:
IEC publications search - www.iec.ch/searchpub Electropedia - www.electropedia.org
The advanced search enables you to find IEC publications The world's leading online dictionary of electronic and
by a variety of criteria (reference number, text, technical electrical terms containing more than 30 000 terms and
committee,…). definitions in English and French, with equivalent terms in
It also gives information on projects, replaced and additional languages. Also known as the International
withdrawn publications. Electrotechnical Vocabulary (IEV) on-line.
IEC Just Published - webstore.iec.ch/justpublished Customer Service Centre - webstore.iec.ch/csc
Stay up to date on all new IEC publications. Just Published If you wish to give us your feedback on this publication
details all new publications released. Available on-line and or need further assistance, please contact the
also once a month by email. Customer Service Centre: csc@iec.ch.
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.
Liens utiles:
Recherche de publications CEI - www.iec.ch/searchpub Electropedia - www.electropedia.org
La recherche avancée vous permet de trouver des Le premier dictionnaire en ligne au monde de termes
publications CEI en utilisant différents critères (numéro de électroniques et électriques. Il contient plus de 30 000
référence, texte, comité d’études,…). termes et définitions en anglais et en français, ainsi que
Elle donne aussi des informations sur les projets et les les termes équivalents dans les langues additionnelles.
publications remplacées ou retirées. Egalement appelé Vocabulaire Electrotechnique
International (VEI) en ligne.
Just Published CEI - webstore.iec.ch/justpublished
Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications de la CEI.
Just Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur
Disponible en ligne et aussi une fois par mois par email. cette publication ou si vous avez des questions
contactez-nous: csc@iec.ch.
IEC 60947-4-1 ®
Edition 3.1 2012-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Low-voltage switchgear and controlgear –
Part 4-1: Contactors and motor-starters – Electromechanical contactors and
motor-starters
Appareillage à basse tension –
Partie 4-1: Contacteurs et démarreurs de moteurs – Contacteurs et démarreurs
électromécaniques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX CT
ICS 29.120.99; 29.130.20 ISBN 978-2-8322-0222-7
– 2 – 60947-4-1 IEC:2009+A1:2012
CONTENTS
FOREWORD . 6
INTRODUCTION (to amendment 1) . 8
1 Scope and object . 9
1.1 Scope . 9
1.1.1 AC and DC contactors . 9
1.1.2 AC motor-starters . 9
1.2 Exclusions . 11
1.3 Object . 11
2 Normative references . 12
3 Terms, definitions, symbols and abbreviations . 13
3.1 General . 13
3.2 Alphabetical index of terms . 13
3.3 Terms and definitions concerning contactors . 15
3.4 Terms and definitions concerning starters . 16
3.5 Terms and definitions concerning characteristic quantities . 20
3.6 Symbols and abbreviations . 20
4 Classification . 21
5 Characteristics of contactors and starters . 21
5.1 Summary of characteristics . 21
5.2 Type of equipment . 22
5.2.1 Kind of equipment. 22
5.2.2 Number of poles . 22
5.2.3 Kind of current (a.c. or d.c.) . 22
5.2.4 Interrupting medium (air, oil, gas, vacuum, etc.) . 22
5.2.5 Operating conditions of the equipment . 22
5.3 Rated and limiting values for main circuits . 22
5.3.1 Rated voltages . 22
5.3.2 Currents or powers . 24
5.3.3 Rated frequency . 25
5.3.4 Rated duties . 25
5.3.5 Normal load and overload characteristics . 26
5.3.6 Rated conditional short-circuit current . 28
5.3.7 Pole impedance of a contactor (Z) . 29
5.4 Utilization category . 29
5.4.1 General . 29
5.4.2 Assignment of utilization categories based on the results of tests . 29
5.5 Control circuits . 31
5.6 Auxiliary circuits . 31
5.7 Characteristics of relays and releases (overload relays) . 31
5.7.1 Summary of characteristics. 31
5.7.2 Types of relay or release . 31
5.7.3 Characteristic values . 32
5.7.4 Designation and current settings of overload relays . 33
5.7.5 Time-current characteristics of overload relays . 33
5.7.6 Influence of ambient air temperature . 34
60947-4-1 IEC:2009+A1:2012 – 3 –
5.8 Co-ordination with short-circuit protective devices . 34
5.9 Void . 34
5.10 Types and characteristics of automatic change-over devices and automatic
acceleration control devices . 34
5.10.1 Types . 34
5.10.2 Characteristics . 34
5.11 Types and characteristics of auto-transformers for two-step auto-transformer
starters . 35
5.12 Types and characteristics of starting resistors for rheostatic rotor starters . 35
6 Product information . 35
6.1 Nature of information . 35
6.1.1 Identification . 36
6.1.2 Characteristics, basic rated values and utilization . 36
6.2 Marking . 37
6.3 Instructions for installation, operation and maintenance . 37
7 Normal service, mounting and transport conditions . 38
8 Constructional and performance requirements . 38
8.1 Constructional requirements . 38
8.1.1 General . 38
8.1.2 Materials . 38
8.1.3 Current-carrying parts and their connections . 38
8.1.4 Clearances and creepage distances . 38
8.1.5 Actuator . 38
8.1.6 Indication of the contact position . 39
8.1.7 Additional requirements for equipment suitable for isolation . 39
8.1.8 Terminals . 39
8.1.9 Additional requirements for equipment provided with a neutral pole . 39
8.1.10 Provisions for protective earthing . 39
8.1.11 Enclosures for equipment . 39
8.1.12 Degrees of protection of enclosed equipment . 40
8.1.13 Conduit pull-out, torque and bending with metallic conduits . 40
8.2 Performance requirements . 40
8.2.1 Operating conditions . 40
8.2.2 Temperature rise . 45
8.2.3 Dielectric properties. 47
8.2.4 Normal load and overload performance requirements . 48
8.2.5 Co-ordination with short-circuit protective devices . 56
8.2.6 Void . 57
8.2.7 Additional requirements for combination starters and combination
switching devices suitable for isolation . 57
8.3 Electromagnetic compatibility (EMC) . 57
8.3.1 General . 57
8.3.2 Immunity . 57
8.3.3 Emission . 58
9 Tests . 58
9.1 Kinds of test . 58
9.1.1 General . 58
9.1.2 Type tests . 59
9.1.3 Routine tests . 59
– 4 – 60947-4-1 IEC:2009+A1:2012
9.1.4 Sampling tests . 59
9.1.5 Special tests . 60
9.2 Compliance with constructional requirements . 60
9.2.1 General . 60
9.2.2 Electrical performance of screwless-type clamping units . 60
9.2.3 Ageing test for screwless-type clamping units . 61
9.3 Compliance with performance requirements . 61
9.3.1 Test sequences . 61
9.3.2 General test conditions . 62
9.3.3 Performance under no load, normal load and overload conditions . 62
9.3.4 Performance under short-circuit conditions . 73
9.3.5 Overload current withstand capability of contactors . 78
9.3.6 Routine tests and sampling tests . 78
9.4 EMC tests . 79
9.4.1 General . 79
9.4.2 Immunity . 80
9.4.3 Emission . 81
Annex A (normative) Marking and identification of terminals of contactors and
associated overload relays. 91
Annex B (normative) Special tests . 95
Annex C Void . 103
Annex D (informative) Items subject to agreement between manufacturer and user . 104
Annex E (informative) Examples of control circuit configurations (Void) . 105
Annex F (normative) Requirements for auxiliary contact linked with power contact
(mirror contact) . 108
Annex G (informative) Rated operational currents and rated operational powers of
switching devices for electrical motors . 111
Annex H (normative) Extended functions within to electronic overload relays . 115
Annex I (informative) AC1 contactors for use with semiconductor controlled motor
loads . 123
Annex J Void . 124
Annex K (normative) Procedure to determine data for electromechanical contactors
used in functional safety applications . 125
Bibliography . 134
Figure 1 – Typical curves of currents and torques during a star-delta start (see
1.1.2.2.1) . 83
Figure 2 – Typical curves of currents and torques during an auto-transformer start (see
1.1.2.2.2) . 84
Figure 3 – Typical variants of protected starters, combination starters, protected
switching devices and combination switching devices . 85
Figure 4 – Example of three-phase diagram of a rheostatic rotor starter with three
starting steps and one direction of rotation (in the case when all the mechanical
switching devices are contactors) . 86
Figure 5 – Typical methods and diagrams of starting alternating-current induction
motors by means of auto-transformers . 87
60947-4-1 IEC:2009+A1:2012 – 5 –
Figure 6 – Examples of speed/time curves corresponding to cases a), b), c), d), e) and
f) of 5.3.5.5 (the dotted parts of the curves correspond to the periods when no current
flows through the motor) . 88
Figure 7 – Multiple of current setting limits for ambient air temperature compensated
time-delay overload relays (see 8.2.1.5.1) . 89
Figure 8 – Thermal memory test . 89
Figure 9 – Example of a pole impedance measurement for a 3 pole contactor . 90
Figure 10 – Voltage drop measurement at contact point of the clamping terminal . 90
Figure B.1 – Examples of time-current withstand characteristic . 102
Figure F.1 − Mirror contact . 109
Figure H.1 – Test circuit for the verification of the operating characteristic of a
ground/earth fault relay . 120
Figure K.1 – Plot of Weibull median rank regression . 133
Table 1 – Utilization categories . 30
Table 2 – Trip classes of overload relays . 33
Table 3 – Limits of operation of time-delay overload relays when energized on all poles . 43
Table 4 – Limits of operation of three-pole time-delay overload relays when energized
on two poles only . 44
Table 5 – Temperature rise limits for insulated coils in air and in oil . 45
Table 6 – Intermittent duty test cycle data . 47
Table 7 – Making and breaking capacities – Making and breaking conditions according
to utilization category . 49
Table 8 – Relationship between current broken I and off-time for the verification of
c
rated making and breaking capacities . 52
Table 9 – Operational current determination for utilization categories AC-6a and AC-6b
when derived from AC-3 ratings . 53
Table 10 – Conventional operational performance – Making and breaking conditions
according to utilization category . 54
Table 11 – Overload current withstand requirements . 56
Table 12 – Specific acceptance criteria for immunity tests . 58
Table 13 – Value of the prospective test current according to the rated operational
current . 75
Table 14 – EMC immunity tests . 80
Table 15 – Conducted radio-frequency emission test limits . 82
Table 16 – Radiated emission test limits . 82
Table 17 – Value of the prospective test current according to the rated operational
current (harmonized table) . 75
Table B.1 – Verification of the number of on-load operating cycles – Conditions for
making and breaking corresponding to the several utilization categories . 98
Table B.2 – Test conditions . 101
Table F.1 – Test voltage according to altitude . 110
Table G.1 – Rated operational powers and rated operational currents of motors . 112
Table H.1 – Operating time of ground/earth fault relays . 117
Table K.1 – Failure mode of contactors . 127
Table K.2 – Typical failure ratios for normally open contactors . 131
Table K.3 – Example of 15 sorted ascending times to failure of contactors . 132
– 6 – 60947-4-1 IEC:2009+A1:2012
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
Part 4-1: Contactors and motor-starters –
Electromechanical contactors and motor-starters
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.
This consolidated version of IEC 60947-4-1 consists of the third edition (2009)
[documents 17B/1674/FDIS and 17B/1677/RVD] and its amendment 1 (2012) [documents
17B/1769/FDIS and 17B/1780/RVD]. It bears the edition number 3.1.
The technical content is therefore identical to the base edition and its amendment and
has been prepared for user convenience. A vertical line in the margin shows where the
base publication has been modified by amendment 1. Additions and deletions are
displayed in red, with deletions being struck through.
60947-4-1 IEC:2009+A1:2012 – 7 –
International Standard IEC 60947-4-1 has been prepared by subcommittee 17B: Low-voltage
switchgear and controlgear, of IEC technical committee 17: Switchgear and controlgear.
This edition includes the following significant technical changes with respect to the previous
edition (2000) and its Amendments 1 (2002) and 2 (2005):
• deletion of the test at –5 °C and +20 °C for thermal overload relays that are not
compensated for ambient air temperature;
• addition of conditions of the tests according to Annex Q of IEC 60947-1;
• EMC tests: clarification of acceptance criteria and alignment with IEC 60947-1 for fast
transient severity level;
• Annex B, test for Icd: modification of the duration of the dielectric test voltage from 5 s to
60 s;
• Annex B, electrical durability: improvement of the statistical aspects;
• Annex H: clarification and introduction of new extended functions within electronic
overload relays;
• Annex K, procedure to determine data for electromechanical contactors used in functional
safety applications: creation of this new annex.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 60947 series can be found, under the general title Low-voltage
switchgear and controlgear, on the IEC website.
This standard shall be read in conjunction with IEC 60947-1, Low voltage switchgear and
controlgear – Part 1: General rules. The provisions of the general rules are applicable to this
standard, where specifically called for.
The committee has decided that the contents of the base publication and its amendments will
remain unchanged until the stability 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.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.
– 8 – 60947-4-1 IEC:2009+A1:2012
INTRODUCTION
(to amendment 1)
This amendment includes the following significant technical changes with respect to the
previous edition 3 (2009):
• introduction of the motor management starter;
• definitions and measurement method of the power consumption of the control circuit
during holding and pick-up operations;
• measurement method of the pole impedance;
• requirements for screwless terminals;
• performance requirements for latched contactors;
• alignments to Amendment 1 of IEC 60947-1:2007;
• harmonisation with IEC 60947-2 of the operation tests of under-voltage relays and shunt
releases;
• short-circuit tests harmonisation with North America;
• test requirements for utilisation AC-6b capacitor load;
• polarity for DC contactors;
• dielectric test method in presence of built-in varistor;
• addition of an extended function for electronic overload relay: control functions.
60947-4-1 IEC:2009+A1:2012 – 9 –
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
Part 4-1: Contactors and motor-starters –
Electromechanical contactors and motor-starters
1 Scope and object
1.1 Scope
This part of IEC 60947 applies to the types of equipment listed in 1.1.1 and 1.1.2 whose main
contacts are intended to be connected to circuits the rated voltage of which does not exceed
1 000 V a.c. or 1 500 V d.c.
Starters and/or contactors dealt with in this standard are not normally designed to interrupt
short-circuit currents. Therefore, suitable short-circuit protection (see 9.3.4) forms part of the
installation but not necessarily of the contactor or the starter.
In this context, this standard gives requirements for:
– contactors associated with overload and/or short-circuit protective devices;
– starters associated with separate short-circuit protective devices and/or with separate
short-circuit and integrated overload protective devices;
– contactors or starters combined, under specified conditions, with their own short-circuit
protective devices. Such combinations, e.g. combination starters or protected starters are
rated as units.
For circuit-breakers and fuse-combination units used as short-circuit protective devices in
combination starters and in protected starters, the requirements of IEC 60947-2 and
IEC 60947-3 respectively apply.
Equipment covered by this standard is as follows.
1.1.1 AC and DC contactors
AC and DC contactors intended for closing and opening electric circuits and, if combined with
suitable relays (see 1.1.2), for protecting these circuits against operating overloads which
may occur therein.
NOTE For contactors combined with suitable relays and which are intended to provide short-circuit protection, the
relevant conditions specified for circuit-breakers (IEC 60947-2) additionally apply.
This standard applies also to the actuators of contactor relays and to the contacts dedicated
exclusively to the coil circuit of a contactor.
Contactors or starters with an electronically controlled electromagnet are also covered by this
standard.
1.1.2 AC motor-starters
AC motor-starters (including motor management starter) intended to start and accelerate
motors to normal speed, to ensure continuous operation of motors, to switch off the supply
from the motor and to provide means for the protection of motors and associated circuits
against operating overloads.
– 10 – 60947-4-1 IEC:2009+A1:2012
For overload relays for starters, including those based on electronic technology with or without
extended functions according to Annex H, the requirements of this standard apply.
1.1.2.1 Direct-on-line (full voltage) a.c. starters
Direct-on-line starters intended to start and accelerate a motor to normal speed, to provide
means for the protection of the motor and its associated circuits against operating overloads,
and to switch off the supply from the motor.
This standard applies also to reversing starters.
1.1.2.2 Reduced voltage a.c. starters
Reduced voltage a.c. starters intended to start and accelerate a motor to normal speed by
connecting the line voltage across the motor terminals in more than one step or by gradually
increasing the voltage applied to the terminals, to provide means for the protection of the
motor and its associated circuits against operating overloads, and to switch off the supply
from the motor.
Automatic change-over devices may be used to control the successive switching operations
from one step to the others. Such automatic change-over devices are, for example, time-delay
contactor relays or specified time all-or-nothing relays, under-current devices and automatic
acceleration control devices (see 5.10).
1.1.2.2.1 Star-delta starters
Star-delta starters intended to start a three-phase motor in the star connection, to ensure
continuous operation in the delta connection, to provide means for the protection of the motor
and its associated circuits against operating overloads, and to switch off the supply from the
motor.
The star-delta starters dealt with in this standard are not intended for reversing motors rapidly
and, therefore, utilization category AC-4 does not apply.
NOTE In the star connection, the starting current in the line and the torque of the motor are about one-third of the
corresponding values for delta connection. Therefore, star-delta starters are used when the inrush current due to
the starting is to be limited, or when the driven machine requires a limited torque for starting. Figure 1 indicates
typical curves of starting current, of starting torque of the motor and of torque of the driven machine.
1.1.2.2.2 Two-step auto-transformer starters
Two-step auto-transformer starters, intended to start and accelerate an a.c. induction motor
from rest with reduced torque to normal speed and to provide means for the protection of the
motor and its associated circuits against operating overloads, and to switch off the supply
from the motor.
This standard applies to auto-transformers which are part of the starter or which constitute a
unit specially designed to be associated with the starter.
Auto-transformer starters with more than two steps are not covered by this standard.
The auto-transformer starters dealt with in this standard are not intended for inching duty or
reversing motors rapidly and, therefore, utilization category AC-4 does not apply.
NOTE In the starting position, the current in the line and the torque of the motor related to the motor starting with
rated voltage are reduced approximately as the square of the ratio (starting voltage):(rated voltage). Therefore,
auto-transformer starters are used when the inrush current due to the starting is to be limited or when the driven
machine requires a limited torque for starting. Figure 2 indicates typical curves of starting current, of starting
torque of the motor and of torque of the driven machine.
60947-4-1 IEC:2009+A1:2012 – 11 –
1.1.2.3 Rheostatic rotor starters
Starters intended to start an a.c. induction motor having a wound rotor by cutting out resistors
previously inserted in the rotor circuit, to provide means for the protection of the motor against
operating overloads and to switch off the supply from the motor.
In the case of asynchronous slip-ring motors (wound-rotors), the highest voltage between
open slip-rings is not greater than twice the rated insulation voltage of the switching devices
inserted in the rotor circuit (see 5.3.1.1.2).
NOTE This requirement is based on the fact that the electric stresses are less severe in the rotor than in the
stator and are of short duration.
This standard applies also to starters for two directions of rotation when reversal of
connections is made with the motor stopped (see 5.3.5.5). Operations including inching and
plugging necessitate additional requirements and are subject to agreement between
manufacturer and user.
This standard applies to resistors which are part of the starter or constitute a unit specially
designed to be associated with the starter.
1.2 Exclusions
This standard does not apply to:
– d.c. starters;
– star-delta starters, rheostatic rotor starters, two-step auto-transformer starters intended for
special applications and designed for continuous operation in the starting position;
– unbalanced rheostatic rotor starters, i.e. where the resistances do not have the same
value in all phases;
– equipment designed not only for starting, but also for adjustment of speed;
– liquid starters and those of the "liquid-vapour" type;
– semiconductor contactors and starters making use of semiconductor contactors in the
main circuit;
– rheostatic stator starters;
– contactors or starters designed for special applications;
– auxiliary contacts of contactors and contacts of contactor relays. These are dealt with in
IEC 60947-5-1.
1.3 Object
The object of this standard is to state:
a) the characteristics of contactors and starters and associated equipment;
b) the conditions applicable to contactors and starters with reference to:
1) their operation and behaviour,
2) their dielectric properties,
3) the degrees of protection provided by their enclosures, where applicable,
4) their construction;
c) the tests intended for confirming that these conditions have been met, and the methods to
be adopted for these tests;
d) the information to be given with the equipment or in the manufacturer's literature.
– 12 – 60947-4-1 IEC:2009+A1:2012
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 60034-1:2004, Rotating electrical machines – Part 1: Rating and performance
IEC 60085:2007, Electrical insulation – Thermal evaluation and designation
IEC 60300-3-5:2001, Dependability management – Part 3-5: Application guide – Reliability
test conditions and statistical test principles
IEC 60410:1973, Sampling plans and procedures for inspection by attributes
IEC 60947-1:2007, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-2:2006, Low-voltage switchgear and controlgear – Part 2: Circuit-breakers
IEC 60947-3:2008, Low-voltage switchgear and controlgear – Part 3: Switches, disconnectors,
switch-disconnectors and fuse-combination units
IEC 60947-5-1:2003, Low-voltage switchgear and controlgear – Part 5-1: Control circuit
devices and switching elements – Electromechanical control circuit devices
IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and measure-
ment techniques – Radiated, radio-frequency, electromagnetic field immunity test
Amendment 1 (2007)
IEC 61000-4
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...