EN IEC 60947-5-8:2021

Low-voltage switchgear and controlgear - Part 5-8: Control circuit devices and switching elements - Three-position enabling switches

IEC 60947-5-8:2020 is available as IEC 60947-5-8:2020 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 60947-5-8:2020 specifies requirements for three-position enabling switches. These switches are used as components of enabling devices to provide signals that, - when activated, allow machine operation to be initiated by a separate start control, and - when de-activated, -- initiate a stop function, and -- prevent initiation of machine operation. This second edition cancels and replaces the first edition published in 2006. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - due to the increasing range of useful applications of three-position enabling switches, note of scope, operational characteristics and tests are reviewed; - figures for example of devices incorporating enabling switch are added in Annex A; - new Annex B for procedure to determine reliability data for the switch used in functional safety applications is added.

Niederspannungsschaltgeräte - Teil 5-8: Steuergeräte und Schaltelemente - Drei-Stellungs-Zustimmschalter

Appareillage à basse tension - Partie 5-8: Appareils et éléments de commutation pour circuits de commande - Interrupteurs de commande de validation à trois positions

IEC 60947-5-8:2020 est disponible sous forme de IEC 60947-5-8:2020 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.L'IEC 60947-5-8:2020 spécifie les exigences pour les interrupteurs de commande de validation à trois positions. Ces interrupteurs sont utilisés comme composants dans les appareils de commande de validation pour fournir des signaux qui: - lorsqu’ils sont activés, permettent la mise en marche de la machine par une commande séparée de démarrage; et - lorsqu’ils sont désactivés: -- initient une fonction d’arrêt; et -- évitent la mise en marche de la machine. Cette deuxième édition annule et remplace la première édition parue en 2006. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: - en raison du nombre croissant d’applications utiles possibles avec les interrupteurs de commande de validation à trois positions, le domaine d’application, les caractéristiques de fonctionnement et les essais sont revus; - des figures représentant des exemples d’appareils incorporant un interrupteur de commande de validation sont ajoutées dans l’Annexe A; - une nouvelle Annexe B est ajoutée, incluant une procédure visant à déterminer des données de fiabilité pour l’interrupteur utilisé dans des applications de sécurité fonctionnelle.

Nizkonapetostne stikalne naprave - 5-8. del: Krmilne naprave in stikalni elementi - Tripoložajna omogočilna stikala (IEC 60947-5-8:2020)

General Information

• Status: Published
• Publication Date: 01-Apr-2021
• ICS: 29.130.20 - Low voltage switchgear and controlgear
• Technical Committee: CLC/TC 121A - Low-voltage switchgear and controlgear
• Drafting Committee: IEC/SC 121A - Low-voltage switchgear and controlgear
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 02-Apr-2021
• Completion Date: 02-Apr-2021
• Directive: 2014/35/EU - Directive 2014/35/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of electrical equipment designed for use within certain voltage limits
• Directive: 2014/53/EU - Directive 2014/53/EU of The European Parliament and of the Council of 16 April 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of radio equipment and repealing Directive 1999/5/EC
• Mandate: M/511 - Mandate to CEN, CENELEC and ETSI relating to harmonised standards in the field of the Low Voltage Directive
• Ref Project: SIST EN IEC 60947-5-8:2021 - Low-voltage switchgear and controlgear - Part 5-8: Control circuit devices and switching elements - Three-position enabling switches (IEC 60947-5-8:2020)

Relations

• Replaces: EN 60947-5-8:2006 - Low-voltage switchgear and controlgear - Part 5-8: Control circuit devices and switching elements - Three-position enabling switches
• Effective Date: 13-Apr-2021

Overview

EN IEC 60947-5-8:2021 (CLC adoption of IEC 60947-5-8:2020) is the European/International standard for three-position enabling switches used in low-voltage control circuits. It defines constructional and performance requirements, classification, tests and product information for switches that form part of enabling devices which:

• allow machine operation to be initiated by a separate start control when the enabling switch is activated, and
• initiate a stop function and prevent initiation of machine operation when the enabling switch is de-activated.

This second edition (2020/2021) is a technical revision of the 2006 edition and adds practical guidance and reliability procedures for functional safety.

Key topics and requirements

• Scope & Purpose: Requirements specifically for three-position enabling switches used in enabling devices for machine control and safety.
• Construction & Performance: Mandatory constructional features and performance characteristics to ensure reliable enabling/stop behaviour under normal service, mounting and transport conditions.
• Classification & Characteristics: Definitions of operating positions, contact status, forces and travel behaviour (figures and force tables included).
• Testing: Environmental and mechanical tests (references include IEC 60068 series) plus electrical and functional tests to verify durability and correct operation.
• Product Information: Manufacturer marking, documentation and user information required for safe selection and installation.
• Annexes:
  • Annex A (informative) - examples of devices incorporating three-position enabling switches (grips, pendants, joysticks, foot actuators, etc.).
  • Annex B (normative) - procedure to determine reliability data for use in functional safety applications (useful for safety engineers assessing MTBF/MTTF data).
• Regulatory linkage: Includes Annex ZZ that maps the standard to the safety objectives of EU Directive 2014/35/EU (Low Voltage Directive).

Applications

• Machine safety systems where a human-operated enabling device is required (e.g., teaching pendants, hand grips, joysticks, hoist controls, hand-held machines).
• Integration in control circuits that must reliably permit starting only under a deliberate enabling action and stop/prevent start otherwise.
• Use in functional safety assessments where switch reliability data is required for Safety Integrity Level (SIL) or performance level calculations.

Who should use this standard

• Machine designers and OEMs specifying enabling devices and safety controls.
• Control and safety engineers performing risk assessments and functional safety validation.
• Manufacturers of low-voltage switchgear and three-position enabling switches.
• Test laboratories and certification bodies verifying compliance to IEC/EN requirements.
• Regulatory and compliance professionals applying the Low Voltage Directive.

Related standards

• IEC 60947-1:2020 - General rules for low-voltage switchgear and controlgear.
• IEC 60947-5-1:2016 - Electromechanical control circuit devices.
• Environmental test standards referenced (IEC 60068 series).

Keywords: EN IEC 60947-5-8:2021, three-position enabling switches, low-voltage switchgear, controlgear, enabling device, functional safety, reliability data, Annex B, machine safety.

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2021
Nadomešča:
SIST EN 60947-5-8:2007
Nizkonapetostne stikalne naprave - 5-8. del: Krmilne naprave in stikalni elementi -
Tripoložajna omogočilna stikala (IEC 60947-5-8:2020)
Low-voltage switchgear and controlgear - Part 5-8: Control circuit devices and switching
elements - Three-position enabling switches (IEC 60947-5-8:2020)
Niederspannungsschaltgeräte - Teil 5-8: Steuergeräte und Schaltelemente - Drei-
Stellungs-Zustimmschalter (IEC 60947-5-8:2020)
Appareillage à basse tension - Partie 5-8: Appareils et éléments de commutation pour
circuit de commande - Interrupteurs de commande de validation à trois positions (IEC
60947-5-8:2020)
Ta slovenski standard je istoveten z: EN IEC 60947-5-8:2021
ICS:
29.130.20 Nizkonapetostne stikalne in Low voltage switchgear and
krmilne naprave controlgear
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60947-5-8

NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2021
ICS 29.130.20 Supersedes EN 60947-5-8:2006 and all of its
amendments and corrigenda (if any)
English Version
Low-voltage switchgear and controlgear - Part 5-8: Control
circuit devices and switching elements - Three-position enabling
switches
(IEC 60947-5-8:2020)
Appareillage à basse tension - Partie 5-8: Appareils et Niederspannungsschaltgeräte - Teil 5-8: Steuergeräte und
éléments de commutation pour circuits de commande - Schaltelemente - Drei-Stellungs-Zustimmschalter
Interrupteurs de commande de validation à trois positions (IEC 60947-5-8:2020)
(IEC 60947-5-8:2020)
This European Standard was approved by CENELEC on 2020-09-16. 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,
Turkey 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
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60947-5-8:2021 E

European foreword
The text of document 121A/358/FDIS, future edition 2 of IEC 60947-5-8, prepared by SC 121A "Low-
voltage switchgear and controlgear" of IEC/TC 121 "Switchgear and controlgear and their assemblies
for low voltage" 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) 2021-10-02
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-04-02
document have to be withdrawn
This document supersedes EN 60947-5-8:2006 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CENELEC by the European Commission
and the European Free Trade Association, and supports essential requirements of EU Directive(s).
For the relationship with EU Directive(s) see informative Annex ZZ, which is an integral part of this
document.
Endorsement notice
The text of the International Standard IEC 60947-5-8:2020 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 60204-1:2016 NOTE Harmonized as EN 60204-1:2018 (modified)
IEC 60695-2-10:2013 NOTE Harmonized as EN 60695-2-10:2013 (not modified)
IEC 60695-2-11:2014 NOTE Harmonized as EN 60695-2-11:2014 (not modified)
IEC 60695-2-12:2010 NOTE Harmonized as EN 60695-2-12:2010 (not modified)
IEC 60695-2-12:2010/A1:2014 NOTE Harmonized as EN 60695-2-12:2010/A1:2014 (not modified)
IEC 60947-5-5:1997 NOTE Harmonized as EN 60947-5-5:1997 (not modified)
IEC 60947-5-5:1997/A1:2005 NOTE Harmonized as EN 60947-5-5:1997/A1:2005 (not modified)
IEC 60947-5-5:1997/A2:2016 NOTE Harmonized as EN 60947-5-5:1997/A2:2017 (not modified)
Annex ZA
(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.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60068-2-1 2007 Environmental testing - Part 2-1: Tests - EN 60068-2-1 2007
Test A: Cold
IEC 60068-2-2 2007 Environmental testing - Part 2-2: Tests - EN 60068-2-2 2007
Test B: Dry heat
IEC 60068-2-6 2007 Environmental testing - Part 2-6: Tests - EN 60068-2-6 2008
Test Fc: Vibration (sinusoidal)
IEC 60068-2-27 2008 Environmental testing - Part 2-27: Tests - EN 60068-2-27 2009
Test Ea and guidance: Shock
IEC 60947-1 2020 Low-voltage switchgear and controlgear - EN IEC 60947-1 2021
Part 1: General rules
IEC 60947-5-1 2016 Low-voltage switchgear and controlgear - EN 60947-5-1 2017
Part 5-1: Control circuit devices and
switching elements - Electromechanical
control circuit devices
Annex ZZ
(informative)
Relationship between this European standard and the safety
objectives of Directive 2014/35/EU [2014 OJ L96] aimed to be
covered
This European standard has been prepared under a Commission’s standardisation request relating to
harmonised standards in the field of the Low Voltage Directive, M/511, to provide one voluntary means
of conforming to safety objectives of Directive 2014/35/EU of the European Parliament and of the
Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the
making available on the market of electrical equipment designed for use within certain voltage limits
[2014 OJ L96].
Once this standard is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this standard given in Table ZZ.1 confers, within the limits of
the scope of this standard, a presumption of conformity with the corresponding safety objectives of
that Directive, and associated EFTA regulations.
Table ZZ.1 — Correspondence between this European standard and Annex I of Directive
2014/35/EU [2014 OJ L96]
Safety objectives of Clause(s) / sub-clause(s) of Remarks/note
Directive 2014/35/EU this EN
1 a) 6
1 b) 4, 5, 6
1 c) 4, 5, 6 Also refer to 2 a) to 2 d) and 3 a) to 3
c) in this table
2 a) 4, 5, 6.1, 6.3, 7.2, 8.1, 9.2, 9.3
2 b) 6.1, 6.3, 8.1, 8.2, 9.1, 9.2, 9.3 This standard does not deal with any
specific requirements on acoustic
noise and optical radiation.
2 c) 4, 5, 6.2, 6.3, 8.1, 8.2, 9.2, 9.3
2 d) 4, 5, 6.2, 6.3, 7, 8.1, 8.2, 9.2, Special environmental conditions
9.3 differing from those given in 7.1 are not
covered by this standard.
3 a) 4, 5, 6.2, 6.3, 7, 9.2, 9.3
3 b) 4, 5, 9.1 Special environmental conditions
differing from those given in 7.1 are not
covered by this standard.
3 c) 4, 5, 6.2, 7, 8.2, 9.3
WARNING 1: Presumption of conformity stays valid only as long as a reference to this European
standard is maintained in the list published in the Official Journal of the European Union. Users of this
standard should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2: Other Union legislation may be applicable to the product(s) falling within the scope of
this standard.
IEC 60947-5-8 ®
Edition 2.0 2020-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Low-voltage switchgear and controlgear –

Part 5-8: Control circuit devices and switching elements – Three-position

enabling switches
Appareillage à basse tension –

Partie 5-8: Appareils et éléments de commutation pour circuits de commande –

Interrupteurs de commande de validation à trois positions

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.130.20 ISBN 978-2-8322-8606-7

– 2 – IEC 60947-5-8:2020 © IEC 2020
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Classification . 7
5 Characteristics . 7
6 Product information . 8
7 Normal service, mounting and transport conditions . 9
8 Constructional and performance requirements . 10
9 Tests . 14
Annex A (informative) Example of enabling devices incorporating a three-position
enabling switch . 21
Annex B (normative) Procedure to determine reliability data for three-position enabling
switches used in functional safety applications . 24
Bibliography . 25

Figure 1 – Operation of three-position enabling switches . 12
Figure 2 – Operating force, travel and enabling contact status . 13
Figure A.1 – Grip type enabling device . 21
Figure A.2 – One hand teaching pendant type enabling device . 21
Figure A.3 – Two hand teaching pendant type enabling device . 22
Figure A.4 – Manual pulse generator . 22
Figure A.5 – Grip type enabling device for hand-held machine . 22
Figure A.6 – Foot actuated enabling device . 23
Figure A.7 – Hoist controller . 23
Figure A.8 – Joystick type enabling device . 23

Table 1 – Force values for F . 13
IEC 60947-5-8:2020 © IEC 2020 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 5-8: Control circuit devices and switching elements –
Three-position enabling switches

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
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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
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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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.
International Standard IEC 60947-5-8 has been prepared by subcommittee 121A: Low-voltage
switchgear and controlgear, of IEC technical committee 121: Switchgear and controlgear and
their assemblies for low voltage.
This second edition cancels and replaces the first edition published in 2006. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) due to the increasing range of useful applications of three-position enabling switches, note
of scope, operational characteristics and tests are reviewed;
b) figures for example of devices incorporating enabling switch are added in Annex A;
c) new Annex B for procedure to determine reliability data for the switch used in functional
safety applications is added.
– 4 – IEC 60947-5-8:2020 © IEC 2020
The text of this document is based on the following documents:
FDIS Report on voting
121A/358/FDIS 121A/369/RVD
Full information on the voting for the approval of this document can be found in the report on
voting indicated in the above table.
This document should be used in conjunction with IEC 60947-1:2020 and
IEC 60947-5-1:2016.
The provisions of the general rules, IEC 60947-1, are applicable to this standard, where
specifically called for. General rules clauses and subclauses thus applicable, as well as tables,
figures and annexes are identified by a reference to IEC 60947-1, for example 1.2.3 or
Annex A of IEC 60947-1:2020.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60947 series, under the general title Low-voltage switchgear and
controlgear, 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 "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document 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 document using a
colour printer.
IEC 60947-5-8:2020 © IEC 2020 – 5 –
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 5-8: Control circuit devices and switching elements –
Three-position enabling switches

1 Scope
This part of IEC 60947 series specifies requirements for three-position enabling switches.
These switches are used as components of enabling devices to provide signals that,
a) when activated, allow machine operation to be initiated by a separate start control, and
b) when de-activated,
– initiate a stop function, and
– prevent initiation of machine operation.
NOTE 1 The enabling control function is described in 9.2.3.9 of IEC 60204-1:2016 but the application of three-
position enabling switches is not limited to a component of the enabling device described in IEC 60204-1.
NOTE 2 This document does not deal with enabling devices.
These switches are intended to be connected to circuits which rated voltage does not exceed
250 V AC 50 Hz/60 Hz or 300 V DC.
EXAMPLE Devices incorporating three-position enabling switches are:
– push-button enabling devices;
– grip actuated enabling devices;
– foot actuated enabling devices.
See Annex A for more typical examples.
This document does not apply to:
– three-position enabling switches for non-electrical control circuits, for example hydraulic,
pneumatic;
– enabling switches without three-position mechanism;
– emergency stop devices (see IEC 60947-5-5).
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 60068-2-1:2007, Environmental testing – Part 2-1: Tests – Test A: Cold
IEC 60068-2-2:2007, Environmental testing – Part 2-2: Tests – Test B: Dry heat
IEC 60068-2-6:2007, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
IEC 60068-2-27:2008, Environmental testing – Part 2-27: Tests – Test Ea and guidance:
Shock
– 6 – IEC 60947-5-8:2020 © IEC 2020
IEC 60947-1:2020, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-5-1:2016, Low-voltage switchgear and controlgear – Part 5-1: Control circuit
devices and switching elements – Electromechanical control circuit devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in Clause 3 of IEC 60947-
1:2020 and Clause 2 of IEC 60947-5-1:2016, and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
Alphabetical index of definitions
Reference
A
Actuating system . 3.3
Actuator . 3.4
Auxiliary contact . 3.5

E
Enabling contact . 3.6
Enabling device . 3.1

T
Three-position enabling switch . 3.2
3.1
enabling device
manually operated control device used in conjunction with a start control and which, when
continuously actuated, allows a machine operation
3.2
three-position enabling switch
three-position switch having enabling contact(s)
3.3
actuating system
all the mechanical parts which transmit the actuating force to
the contact elements
[SOURCE: IEC 60050-441:2000, 441-15-21, modified – "all the operating means of a control
switch" replaced by "all the mechanical parts", note to entry deleted.]
3.4
actuator
part of the actuating system which is actuated by a part of
the human body
IEC 60947-5-8:2020 © IEC 2020 – 7 –
EXAMPLE A button.
3.5
auxiliary contact
contact of a three-position enabling switch that provides an auxiliary function
Note 1 to entry: Auxiliary contacts can be normally open and/or normally closed.
3.6
enabling contact
contact of a three-position enabling switch, which is closed when the actuator is in the mid
position (partly depressed, position 2 in Figure 1) and is open when the actuator is in the rest
position (not pressed, position 1 in Figure 1) and in the fully depressed position (position 3 in
Figure 1)
4 Classification
4.1 Contact elements
Subclause 3.1 of IEC 60947-5-1:2016 applies.
4.2 Three-position enabling switch
Three-position enabling switches may be classified according to the contact element and the
nature of the actuating system, e.g. three-position enabling switches, form B.
5 Characteristics
5.1 Summary of characteristics
5.1.1 General
Subclause 4.1.1 of IEC 60947-5-1:2016 applies except for following type of equipment (see
5.2).
5.1.2 Operation of an enabling switch
Subclause 4.1.2 of IEC 60947-5-1:2016 applies.
5.2 Type of three-position enabling switch
5.2.1 Number of poles
The number of poles shall be stated by the manufacturer.
5.2.2 Kind of current
Alternating current or direct current.
5.3 Rated and limiting values for switching elements
Subclause 4.3 of IEC 60947-5-1:2016 applies.
5.4 Utilization categories for switching elements
Subclause 4.4 of IEC 60947-5-1:2016 applies.

– 8 – IEC 60947-5-8:2020 © IEC 2020
5.5 Vacant
5.6 Vacant
5.7 Vacant
5.8 Vacant
5.9 Vacant
5.10 Electrically separated contact elements
Subclause 4.10 of IEC 60947-5-1:2016 applies.
6 Product information
6.1 Nature of information
The following information shall be given by the manufacturer:
Identification
a) The manufacturer's name or trade mark.
b) A type designation or serial number that makes it possible to get the relevant information
concerning the switching element (or the entire control switch) from the manufacturer.
c) “IEC 60947-5-8” if the manufacturer claims compliance with this document.
d) Three-position
...