SIST EN ISO 14119:2025
(Main)Safety of machinery - Interlocking devices associated with guards - Principles for design and selection (ISO 14119:2025)
Safety of machinery - Interlocking devices associated with guards - Principles for design and selection (ISO 14119:2025)
This document specifies principles for the design and selection (independent of the nature of the energy source) of interlocking devices associated with guards and provides guidance on measures to minimize the possibility of defeat of interlocking devices in a reasonably foreseeable manner.
This document covers principles for the design, selection and application of the following:
— parts of the guards which actuate interlocking devices;
— trapped key interlocking devices and systems for machinery applications.
NOTE ISO 14120 specifies general requirements for the design and construction of guards provided primarily to protect persons from mechanical hazards. The processing of the signal from the interlocking device to stop the machine and prevent unexpected start up is covered in ISO 14118, ISO 13849-1 and IEC 62061.
Sicherheit von Maschinen - Verriegelungseinrichtungen in Verbindung mit trennenden Schutzeinrichtungen - Leitsätze für Gestaltung und Auswahl (ISO 14119:2025)
-Dieses Dokument legt die Grundsätze für die Gestaltung und Auswahl (unabhängig von der Art der Energiequelle) von Verriegelungseinrichtungen in Verbindung mit trennenden Schutzeinrichtungen fest und enthält eine Anleitung für Maßnahmen, mit denen die Möglichkeit Verriegelungseinrichtungen auf vernünftigerweise vorhersehbare Art und Weise zu umgehen, auf ein Minimum verringert wird.
Dieses Dokument behandelt die Grundsätze für die Gestaltung, Auswahl und Anwendung von Folgendem:
Teilen der trennenden Schutzeinrichtungen, welche die Verriegelungseinrichtungen betätigen;
Verriegelungseinrichtungen mit Schlüsseltransfer und Schlüsseltransfersystemen für Maschinenanwendungen.
ANMERKUNG ISO 14120 legt allgemeine Anforderungen an die Gestaltung und die Konstruktion von trennenden Schutzeinrichtungen fest, die hauptsächlich dafür vorgesehen sind, Personen vor mechanischen Gefährdungen zu schützen. Die Verarbeitung des von der Verriegelungseinrichtung ausgehenden Signals zum Anhalten der Maschine und um deren unerwarteten Anlauf zu verhindern wird von ISO 14118, ISO 13849 1 und IEC 62061 abgedeckt.
Sécurité des machines - Dispositifs de verrouillage associés à des protecteurs - Principes de conception et de choix (ISO 14119:2025)
Le présent document spécifie des principes de conception et de choix (indépendamment de la nature de la source d'énergie) des dispositifs de verrouillage associés à des protecteurs et fournit des recommandations concernant les mesures visant à minimiser la possibilité de neutralisation des dispositifs de verrouillage d'une manière raisonnablement prévisible.
Le présent document couvre les principes de conception, de choix et de fonction suivants:
— des composants constituant les protecteurs responsables de l'activation des dispositifs de verrouillage;
— des dispositifs et systèmes de verrouillage à clé captive pour l'application aux machines.
NOTE L'ISO 14120 spécifie les exigences générales relatives à la conception et à la construction des protecteurs principalement destinés à préserver les personnes des phénomènes dangereux mécaniques. Le traitement du signal issu du dispositif de verrouillage entraînant l'arrêt de la machine et empêchant toute mise en marche intempestive est couvert dans l'ISO 14118, l'ISO 13849-1 et l'IEC 62061.
Varnost strojev - Zaporne naprave, povezane z varovali - Načela za načrtovanje in izbiro (ISO 14119:2025)
Ta dokument določa načela za načrtovanje in izbiro (neodvisno od vrste vira energije) zapornih naprav, povezanih z varovali, ter podaja smernice o ukrepih za zmanjšanje možnosti okvare zapornih naprav na razumno predvidljiv način. Ta dokument zajema načela za načrtovanje, izbiro in uporabo: – delov varoval, ki aktivirajo zaporne naprave; – zapornih naprav in sistemov z varnostnim mehanizmom za uporabo pri strojih. OPOMBA: Standard ISO 14120 določa splošne zahteve za načrtovanje in izdelavo varoval, namenjenih predvsem zaščiti oseb pred mehanskimi tveganji. Obdelava signala iz zaporne naprave za zaustavitev stroja in preprečitev nepričakovanega zagona je zajeta v standardih ISO 14118, ISO 13849-1 in IEC 62061.
General Information
Relations
Overview
EN ISO 14119:2025 (identical to ISO 14119:2024) - titled Safety of machinery - Interlocking devices associated with guards - Principles for design and selection - provides principles for the design, selection and application of interlocking devices associated with guards. It is published by CEN (adopted March 2025) and supersedes EN ISO 14119:2013. The standard is energy-source independent and gives guidance to minimize the possibility of defeat of interlocking devices in reasonably foreseeable situations.
Key topics and technical requirements
- Scope and purpose
- Principles for design and selection of interlocking devices and guidance to reduce deliberate or accidental defeat.
- Covers parts of guards that actuate interlocking devices and trapped key interlocking systems.
- Operating principles
- Interlocking with and without guard locking, actuator modes, cams and mechanical stops.
- Design and arrangement
- Requirements for fastening/arrangement of position switches, bolt locks, access locks and actuators.
- Rules for guard-locking devices (electromechanical, electromagnetic), locking force considerations and whole-body access.
- Supplementary releases & safety features
- Escape, auxiliary and emergency releases; requirements for interlock blocking and supplementary release selection.
- Selection and application
- System response time vs. access time, environmental considerations (e.g., dust effects), and criteria for trapped key systems.
- Human factors and defeat prevention
- Measures and system design approaches to reduce motivation and opportunities to defeat interlocks.
- Normative references
- Integrates with risk and control-system standards (see Related Standards).
Practical applications and users
Who uses EN ISO 14119:2025:
- Machine designers and OEMs selecting interlock hardware and guard actuation methods.
- Safety engineers and integrators implementing machine safeguarding and control-system interfaces.
- Compliance officers, notified bodies and assessors demonstrating conformity with the EU Machinery Directive (2006/42/EC) where the standard is cited.
- Maintenance personnel and safety managers specifying trapped key systems, lock types and emergency/escape release arrangements.
Typical applications:
- Selecting and positioning interlocks for access panels, hinged guards, removable covers.
- Designing trapped key interlocking in sequence control or lock-out procedures.
- Defining guard-locking solutions where personnel access and machine motion must be controlled.
- Ensuring safeguarding solutions align with functional safety requirements and risk reduction strategies.
Related standards
Key referenced standards for implementation and compliance:
- ISO 12100 - Risk assessment and reduction
- ISO 13849-1 / ISO 13849-2 - Safety-related parts of control systems
- ISO 14118 - Prevention of unexpected start-up
- IEC 62061 - Functional safety of control systems
- IEC 60204-1, IEC 60947 series - Electrical/electromechanical components
Using EN ISO 14119:2025 helps organizations choose appropriate interlocking devices and document safe, defendable design choices for machine guarding and compliance.
Frequently Asked Questions
SIST EN ISO 14119:2025 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Safety of machinery - Interlocking devices associated with guards - Principles for design and selection (ISO 14119:2025)". This standard covers: This document specifies principles for the design and selection (independent of the nature of the energy source) of interlocking devices associated with guards and provides guidance on measures to minimize the possibility of defeat of interlocking devices in a reasonably foreseeable manner. This document covers principles for the design, selection and application of the following: — parts of the guards which actuate interlocking devices; — trapped key interlocking devices and systems for machinery applications. NOTE ISO 14120 specifies general requirements for the design and construction of guards provided primarily to protect persons from mechanical hazards. The processing of the signal from the interlocking device to stop the machine and prevent unexpected start up is covered in ISO 14118, ISO 13849-1 and IEC 62061.
This document specifies principles for the design and selection (independent of the nature of the energy source) of interlocking devices associated with guards and provides guidance on measures to minimize the possibility of defeat of interlocking devices in a reasonably foreseeable manner. This document covers principles for the design, selection and application of the following: — parts of the guards which actuate interlocking devices; — trapped key interlocking devices and systems for machinery applications. NOTE ISO 14120 specifies general requirements for the design and construction of guards provided primarily to protect persons from mechanical hazards. The processing of the signal from the interlocking device to stop the machine and prevent unexpected start up is covered in ISO 14118, ISO 13849-1 and IEC 62061.
SIST EN ISO 14119:2025 is classified under the following ICS (International Classification for Standards) categories: 13.110 - Safety of machinery. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN ISO 14119:2025 has the following relationships with other standards: It is inter standard links to SIST EN ISO 14119:2014. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN ISO 14119:2025 is associated with the following European legislation: EU Directives/Regulations: 2006/42/EC; Standardization Mandates: M/396. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
You can purchase SIST EN ISO 14119:2025 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of SIST standards.
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2025
Varnost strojev - Zaporne naprave, povezane z varovali - Načela za načrtovanje in
izbiro (ISO 14119:2025)
Safety of machinery - Interlocking devices associated with guards - Principles for design
and selection (ISO 14119:2025)
Sicherheit von Maschinen - Verriegelungseinrichtungen in Verbindung mit trennenden
Schutzeinrichtungen - Leitsätze für Gestaltung und Auswahl (ISO 14119:2025)
Sécurité des machines - Dispositifs de verrouillage associés à des protecteurs -
Principes de conception et de choix (ISO 14119:2025)
Ta slovenski standard je istoveten z: EN ISO 14119:2025
ICS:
13.110 Varnost strojev Safety of machinery
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 14119
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2025
EUROPÄISCHE NORM
ICS 13.110 Supersedes EN ISO 14119:2013
English Version
Safety of machinery - Interlocking devices associated with
guards - Principles for design and selection (ISO
14119:2024)
Sécurité des machines - Dispositifs de verrouillage Sicherheit von Maschinen -
associés à des protecteurs - Principes de conception et Verriegelungseinrichtungen in Verbindung mit
de choix (ISO 14119:2024) trennenden Schutzeinrichtungen - Leitsätze für
Gestaltung und Auswahl (ISO 14119:2024)
This European Standard was approved by CEN on 21 July 2024.
CEN 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 CEN
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 CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14119:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of 2006/42/EC aimed to be covered . 4
European foreword
This document (EN ISO 14119:2025) has been prepared by Technical Committee ISO/TC 199 "Safety of
machinery" in collaboration with Technical Committee CEN/TC 114 “Safety of machinery” the
secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2025, and conflicting national standards
shall be withdrawn at the latest by September 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 14119:2013.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
For the relationship with EU Legislation, see informative Annex ZA, which is an integral part of this
document.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 14119:2024 has been approved by CEN as EN ISO 14119:2025 without any modification.
Annex ZA
(informative)
Relationship between this European Standard and the essential
requirements of 2006/42/EC aimed to be covered
This European Standard has been prepared under a Commission’s standardization request “M/396
Mandate to CEN and CENELEC for Standardisation in the field of machinery" to provide one voluntary
means of conforming to essential requirements of Directive 2006/42/EC of the European Parliament
and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast).
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 ZA.1 confers, within the limits of
the scope of this standard, a presumption of conformity with the corresponding essential requirements
of that Directive, and associated EFTA regulations.
Table ZA.1 — Correspondence between this European Standard and Annex I of
Directive 2006/42/EC
The relevant Essential Clause(s)/subclause(s) of this EN Remarks/Notes
Requirements of Directive
2006/42/EC
1.1.2 6, 7, 8, Annex K
1.2.1 6, 9
1.2.2 6, 7, Annex K
1.2.3 9
1.2.4 9
1.4.2.2 5, 6, 7, 8
1.5.4. 6
1.5.14 6, 7, Annex K
1.6.1 6, 8, 10
1.7.3 10
1.7.4.2 10
Table ZA.2 — Applicable Standards to confer presumption of conformity as described in this
Annex ZA
Reference in Clause 2 International Title Corresponding
Standard Edition European Standard
Edition
ISO 12100:2010 ISO 12100:2010 Safety of machinery — EN ISO 12100:2010
General principles for design
— Risk assessment and risk
reduction
ISO 13849-1:2023 ISO 13849-1:2023 Safety of machinery — EN ISO 13849-1:2023
Safety-related parts of
control systems — Part 1:
General principles for design
ISO 13849-2:2012 ISO 13849-2:2012 Safety of machinery — EN ISO 13849-2: 2012
Safety-related parts of
control systems — Part 2:
Validation
ISO 13855:20— ISO 13855:2023 Safety of machinery — EN ISO 13855: 20—
Positioning of safeguards
with respect to the approach
speeds of parts of the human
body
ISO 14118:2017 ISO 14118:2017 Safety of machinery — EN ISO 14118:2017
Prevention of unexpected
start-up
IEC 60204-1:2016 +AM IEC 60204-1:2016 + Safety of machinery — EN 60204-1:2018
D1:2021 AMD1:2021 Electrical equipment of
machines — Part 1: General
requirements
IEC 60947-1:2020 IEC 60947-1:2020 Low-voltage switchgear and EN IEC 60947-1: 2021
controlgear — Part 1:
General rules
IEC 60947-3 IEC 60947-3 Low-voltage switchgear and EN IEC 60947-3: 2021
controlgear — Part 3:
Switches, disconnectors,
switch-disconnectors and
fuse-combination units
IEC 60947-5-1:2016 +C IEC 60947-5-1:2016 Low voltage switchgear and EN 60947-5-1:2017
OR:2016 +COR:2016 controlgear — Part 5-1:
Control circuit devices and
switching elements —
Electromechanical control
circuit devices
IEC 60947-5-3 IEC 60947-5-3 Low-voltage switchgear and EN 60947-5-3:2013
controlgear — Part 5-3:
Control circuit devices and
switching elements —
Requirements for proximity
devices with defined
behaviour under fault
conditions (PDDB)
IEC 62061:2021 IEC 62061:2021 Safety of machinery - EN IEC 62061:2021
Functional safety of safety-
related control systems
The documents listed in the Column 1 of Table ZA.2, in whole or in part, are normatively referenced in
this document, i.e. are indispensable for its application. The achievement of the presumption of
conformity is subject to the application of the edition of Standards as listed in Column 4 or, if no
European Standard Edition exists, the International Standard Edition given in Column 2 of Table ZA.2.
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.
International
Standard
ISO 14119
Third edition
Safety of machinery — Interlocking
2024-09
devices associated with guards —
Principles for design and selection
Sécurité des machines — Dispositifs de verrouillage associés à des
protecteurs — Principes de conception et de choix
Reference number
ISO 14119:2024(en) © ISO 2024
ISO 14119:2024(en)
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 14119:2024(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 9
5 Operating principles and types of interlocking devices associated with guards .10
5.1 General .10
5.2 Principles of guard interlocking without guard locking . 13
5.3 Principles of guard interlocking with guard locking . 13
5.3.1 General . 13
5.3.2 Interlocking device with guard locking .14
6 Requirements for the design and the arrangements of interlocking devices with and
without guard locking .16
6.1 General .16
6.2 Arrangement and fastening of position switches, bolt locks and access locks .16
6.3 Arrangement and fastening of actuators .17
6.3.1 General .17
6.3.2 Cams .17
6.4 Actuation modes of interlocking devices .17
6.5 Mechanical stop .18
6.6 Additional requirements on guard-locking devices .18
6.6.1 General .18
6.6.2 Locking force .19
6.6.3 Electromechanical guard-locking device .19
6.6.4 Electromagnetic guard-locking device . 20
6.7 Additional requirements on access locks .21
6.7.1 General .21
6.7.2 Locking force .21
6.8 Whole body access . 22
6.9 Supplementary releases . 22
6.9.1 Escape release of guard locking. 22
6.9.2 Auxiliary release of guard locking . 22
6.9.3 Emergency release of guard locking . 23
6.10 Interlock blocking . 23
7 Selection of an interlocking device .23
7.1 General . 23
7.2 Selection of a guard-locking device . .24
7.2.1 Overall system response time and access time .24
7.2.2 Specific requirements for selection of guard-locking devices .24
7.2.3 Selection of supplementary guard-locking releases . 25
7.3 Environmental conditions considerations . 26
7.3.1 General . 26
7.3.2 Influence of dust on Type 2 and Type 5 interlocking devices. 26
7.4 Considerations for the application of trapped key interlocking systems . 26
8 Design to minimize the motivation to defeat .26
8.1 System design . 26
8.2 Methodology procedure .27
8.3 Additional measures to minimize possibility of defeat . 28
8.4 Additional measures to minimize possibility of defeat for Type 5 devices .32
8.4.1 General .32
8.4.2 Key retention .32
iii
ISO 14119:2024(en)
8.4.3 Reproduction of keys . 33
9 Requirements for the control system .33
9.1 General . 33
9.2 Assessment of faults and fault exclusions . 33
9.2.1 Assessment of faults . 33
9.2.2 Fault exclusion . 34
9.2.3 Examples for measures to prevent common cause failures through direct and
non-direct mechanical action of the position switches of Type 1 interlocking
devices . 36
9.2.4 Energy source diversity . 38
9.3 Release of guard-locking device . . 38
9.4 Series connection of electro-mechanical interlocking devices . 38
9.5 Electrical and environmental conditions . 38
9.5.1 General . 38
9.5.2 Performance considerations . 39
9.5.3 Immunity from disturbance . 39
9.5.4 Electrical operating conditions . 39
9.5.5 Clearances and creepage distances . 39
10 Information for use .39
10.1 General . 39
10.2 Information for use given by the manufacturer of interlocking devices . 39
10.2.1 Marking . . 39
10.2.2 Instructions . 40
10.3 Information for use given by the manufacturer of the machine .41
Annex A (informative) Type 1 interlocking device — Examples .42
Annex B (informative) Type 2 interlocking device — Examples . 47
Annex C (informative) Type 3 interlocking device — Example .49
Annex D (informative) Type 4 interlocking devices — Examples .51
Annex E (informative) Example of guard-locking devices .54
Annex F (informative) Application examples of interlocking devices used within a safety
function .59
Annex G (informative) Motivation to defeat interlocking devices (defeating of protective
devices) .65
Annex H (informative) Examples for maximum static action forces .69
Annex I (normative) Test procedures .71
Annex J (normative) Evaluation of fault masking in series connections of interlocking devices
with potential free contacts .73
Annex K (normative) Trapped key interlocking systems .89
Bibliography .106
iv
ISO 14119:2024(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 199, Safety of machinery, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 114, Safety of machinery,
in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 14119:2013), which has been technically
revised.
The main changes are as follows:
— ISO/TS 19837 has been integrated as new Annex K with specific requirements for Type 5 interlocking
devices – “trapped key interlocking devices” (see definition 3.18.1);
— trapped key interlocking systems and Type 5 interlocking devices have been defined;
— Table 5 has been improved and renamed;
— test procedures are described in new Annex I;
— ISO/TR 24119 has been integrated into new Annex J.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO 14119:2024(en)
Introduction
The structure of safety standards in the field of machinery is as follows:
a) type-A standards (basic safety standards) giving basic concepts, principles for design, and general
aspects that can be applied to all machinery;
b) type-B standards (generic safety standards) dealing with one safety aspect or one type of safeguard
that can be used across a wide range of machinery:
— type-B1 standards on particular safety aspects (e.g. safety distances, surface temperature, noise);
— type-B2 standards on safeguards (e.g. two-hand controls, interlocking devices, pressure-sensitive
devices, guards);
c) type-C standards (machine safety standards) dealing with detailed safety requirements for a particular
machine or group of machines.
This document is a type-B2 standard as stated in ISO 12100.
This document is of relevance, in particular for the following stakeholder groups representing the market
players with regard to machinery safety:
— machine manufacturers (small, medium and large enterprises);
— health and safety bodies (regulators, accident prevention organizations, market surveillance).
Others can be affected by the level of machinery safety achieved with the means of the document by the
above-mentioned stakeholder groups:
— machine users/employers (small, medium and large enterprises);
— machine users/employees (e.g. trade unions, organizations for people with special needs);
— service providers, e.g. for maintenance (small, medium and large enterprises);
— consumers (in case of machinery intended for use by consumers).
The above-mentioned stakeholder groups have been given the possibility to participate in the drafting
process of this document.
In addition, this document is intended for standardization bodies elaborating type-C standards.
The requirements of this document can be supplemented or modified by a type-C standard.
For machines which are covered by the scope of a type-C standard and which have been designed and built
according to the requirements of that standard, the requirements of that type-C standard take precedence.
This document has been prepared to give guidance to machinery designers and writers of product safety
standards on how to design and select interlocking devices associated with guards.
Relevant clauses of this document, used alone or in conjunction with provisions from other standards, may
be used as a basis for verification procedures for the suitability of a device for interlocking duties.
Annexes A to E describe the technology and the typical characteristics of the defined interlocking devices
types 1 to 4. Other solutions may be adopted, provided that they are in conformity with the principles of this
document.
Annexes F to H give information on particular aspects such as interlocking devices used within safety
functions, risk assessment considering the motivation to defeat and static action forces.
Annex I describes a locking force test and an impact resistance test for guard-locking devices.
vi
ISO 14119:2024(en)
Annex J provides information on the masking of faults in series connection of interlocking devices with
potential free contacts.
Annex K provides requirements for trapped key interlocking systems and describes their technology.
vii
International Standard ISO 14119:2024(en)
Safety of machinery — Interlocking devices associated with
guards — Principles for design and selection
1 Scope
This document specifies principles for the design and selection (independent of the nature of the energy
source) of interlocking devices associated with guards and provides guidance on measures to minimize the
possibility of defeat of interlocking devices in a reasonably foreseeable manner.
This document covers principles for the design, selection and application of the following:
— parts of the guards which actuate interlocking devices;
— trapped key interlocking devices and systems for machinery applications.
NOTE ISO 14120 specifies general requirements for the design and construction of guards provided primarily
to protect persons from mechanical hazards. The processing of the signal from the interlocking device to stop the
machine and prevent unexpected start up is covered in ISO 14118, ISO 13849-1 and IEC 62061.
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.
ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 13849-1:2023, Safety of machinery — Safety-related parts of control systems — Part 1: General principles
for design
ISO 13849-2:2012, Safety of machinery — Safety-related parts of control systems — Part 2: Validation
1)
ISO 13855:— , Safety of machinery — Positioning of safeguards with respect to the approach speeds of parts of
the human body
ISO 14118:2017, Safety of machinery — Prevention of unexpected start-up
IEC 60204-1:2016+AMD1: 2021, Safety of machinery — Electrical equipment of machines — Part 1: General
requirements
IEC 60947-1:2020, Low-voltage switchgear and controlgear — Part 1: General rules
IEC 60947-3, Low-voltage switchgear and controlgear — Part 3: Switches, disconnectors, switch-disconnectors
and fuse-combination units
IEC 60947-5-1:2016+COR: 2016, Low voltage switchgear and controlgear — Part 5-1: Control circuit devices
and switching elements — Electromechanical control circuit devices
IEC 60947-5-3, Low-voltage switchgear and controlgear — Part 5-3: Control circuit devices and switching
elements — Requirements for proximity devices with defined behaviour under fault conditions (PDDB)
IEC 62061:2021, Safety of machinery — Functional safety of safety-related control systems
1) Under preparation. Stage at the time of publication: ISO/FDIS 13855.
ISO 14119:2024(en)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12100:2010, ISO 13849-1 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
interlocking device
interlock
mechanical, electrical or other type of device, the purpose of which is to prevent the operation of hazardous
machine functions under specified conditions (generally as long as a guard is not closed)
Note 1 to entry: See Figure 1 and Table 2.
[SOURCE: ISO 12100:2010, 3.28.1, modified — Note 1 to entry and Figure 1 were added.]
Key
1 guard 4 position switch
2 interlocking device 5 actuating system
3 actuator 6 output system
a
Direction of opening.
Figure 1 — Example of an interlocking device
3.2
interlocking guard
guard associated with an interlocking device such that, together with the control system of the machine,
prevents the:
— operation of the hazardous machine functions associated with the guard until the guard is closed;
— if the guard is opened while hazardous machine functions are operating, a command to bring the machine
to a safe state (a stop command) is given
Note 1 to entry: An interlocking guard can contain/be equipped with one or more interlocking devices. These
interlocking devices can also be of different types.
Note 2 to entry: The generation of the (stop) command to bring the machine to a safe state when the guard is open
does not apply to guards locked with a trapped key interlocking system.
ISO 14119:2024(en)
3.3
guard-locking device
device intended to lock a guard in the closed position and to be linked to the control system
Note 1 to entry: A guard-locking device may be a separate device or integrated in an interlocking device.
Note 2 to entry: See Annex E for detailed examples.
3.4
interlocking guard with guard-locking function
guard associated with an interlocking device and a guard-locking device so that, together with the control
system of the machine, the following functions are performed:
— the hazardous machine functions associated with the guard cannot operate until the guard is closed
and locked;
— the guard remains closed and locked until the risk due to the hazardous machine functions associated
with the guard has ceased; and
— when the guard is closed and locked, the hazardous machine functions associated with the guard
can operate (the closure and locking of the guard do not by themselves start the hazardous machine
functions)
[SOURCE: ISO 12100:2010, 3.27.5, modified — Note 1 to entry was deleted and in the first and second list
item, "associated" replaces "covered", in the second list item "ceased" replaces "disappeared".]
3.5
defeat
defeat in a reasonably foreseeable manner
reasonably foreseeable action, either manually or by using readily available objects, that makes interlocking
devices inoperative or bypasses them with the result that a machine is used in a manner not intended by the
designer or without the necessary protective measures
Note 1 to entry: This definition includes the removal of position switches or actuators using tools that are needed for
the intended use of the machine or that are readily available (screwdrivers, wrenches, hexagon keys, pliers).
Note 2 to entry: Readily available objects for substitute actuation include:
— screws, needles and sheet-metal pieces;
— objects in daily use, e.g. keys, coins, adhesive tape, string and wire.
Note 3 to entry: Uncontrolled spare and master keys for Type 5 interlocking devices (see also 8.4.3) and spare actuators
(for all types) are also considered as readily available objects.
3.6
automatic monitoring
diagnostic function, which initiates a fault reaction function if the ability of a component or an element to
perform its function is diminished, or if the process conditions are changed in such a way that hazards are
generated
3.7
direct mechanical action
positive mechanical action
movement of a mechanical component, which arises inevitably from the movement of another mechanical
component either by direct contact or via rigid elements
ISO 14119:2024(en)
3.8
direct opening action
direct opening action of a contact element
achievement of contact separation as a direct result of a specified movement of the switch actuator through
non-resilient members (for example not dependent upon springs)
[SOURCE: IEC 60947-5-1:2016 + COR1: 2016, K 2.2.]
3.9
position switch
part of interlocking device comprising the actuating system and the output system
3.10
actuator
separate part of an interlocking device, which transmits the state of the guard (closed or not closed) to the
actuating system
EXAMPLE Guard-mounted cam, shaped tongue, reflector, magnet, RFID tag.
Note 1 to entry: See also Annexes A to E and Annex K.
Note 2 to entry: For type 1 and Type 3 interlocking devices the actuator can be a part of the guard itself.
Note 3 to entry: Examples of actuators are shown in Figure 2.
Note 4 to entry: A key as used in a trapped key system is not covered by this definition.
3.11
coded actuator
actuator which is specially designed (e.g. by shape) to actuate a certain position switch
3.11.1
low-level coded actuator
coded actuator for which 1 to 9 variations in code are available and the different codes are evaluated by the
interlocking device
3.11.2
medium-level coded actuator
coded actuator for which 10 to 1 000 variations in code are available and the different codes are evaluated
by the interlocking device
3.11.3
high-level coded actuator
coded actuator for which more than 1 000 variations in code are available and the different codes are
evaluated by the interlocking device
3.12
actuating system
part of the interlocking device which transmits the position of the actuator or the key and changes the state
of the output system
EXAMPLE Roller plunger, cam mechanism, and optical, inductive or capacitive sensor.
Note 1 to entry: Examples of actuating systems are shown in Figure 2.
3.13
output system
part of the interlocking device that signals the state of the actuator or the key to the control system
EXAMPLE Contact element (electromechanical), semiconductor output, valve.
ISO 14119:2024(en)
3.14
Type 1 interlocking device
interlocking device with mechanically actuated position switch with uncoded actuator
EXAMPLE Hinged interlocking devices.
Note 1 to entry: See Annex A for detailed examples.
3.15
Type 2 interlocking device
interlocking device with mechanically actuated position switch with coded actuator
EXAMPLE Tongue-actuated position switches.
Note 1 to entry: See Annex B for detailed examples.
3.16
Type 3 interlocking device
interlocking device with non-contact
...
SIST EN ISO 14119:2025는 기계의 안전성을 확보하기 위한 중요한 기준으로, 보호장치와 연결된 인터록 장치의 설계 및 선택에 대한 원칙을 규정하고 있습니다. 이 표준은 에너지 원의 종류에 관계없이 이러한 인터록 장치의 설계 및 선택 원칙을 구체화하며, 인터록 장치의 패배 가능성을 최소화하기 위한 조치에 대한 지침을 제공합니다. 이 문서는 보호장치의 일부에서 인터록 장치를 작동시키는 원칙, 그리고 기계 응용을 위한 인형 키 인터록 장치 및 시스템에 대한 설계, 선택 및 적용 원칙을 포괄합니다. 이러한 범위는 기술적인 안전성을 확보하는 데 필수적이며, 기계의 작동 과정에서 발생할 수 있는 고위험 요인을 효과적으로 관리하는 데 도움을 줍니다. SIST EN ISO 14119:2025의 강점은 기계 안전을 위한 최선의 설계 및 선택 원칙을 제시함으로써, 기계 운영자와 유지보수 인력의 안전을 보장하는데 기여하는 점입니다. 특히, 인터록 장치의 패배를 방지하기 위한 주의 깊은 설계를 요구하여 사고 발생 가능성을 줄이는 데 중요한 역할을 합니다. 또한 이 표준은 ISO 14120(기계 보호에 관한 일반 요구 사항) 및 ISO 14118, ISO 13849-1, IEC 62061(기계의 작동을 중지하고 예기치 않은 시작을 방지하는 신호 처리)에 대한 내용을 보완합니다. 이러한 연계성을 통해 보다 포괄적이고 일관된 안전 기준을 제공하며, 기계 안전에 대한 전반적인 이해를 돕습니다. 따라서 SIST EN ISO 14119:2025는 기계 안전의 중요한 지침으로, 사용자가 안전한 설계 및 선택을 통해 기계 위험 요소를 최소화할 수 있도록 지원하는 데 매우 관련성이 높습니다.
SIST EN ISO 14119:2025は、機械の安全性に関する重要な基準であり、ガードと関連するインターロック装置の設計と選定に関する原則を明示しています。この標準は、エネルギー源の性質に依存せず、インターロック装置の設計および選択に関する指針を提供し、予測可能な範囲内でインターロック装置の妨害の可能性を最小限に抑えるための措置を示しています。 この標準の強みは、ガードの一部がインターロック装置を作動させる原則、そして機械用途に特化したトラップキーインターロック装置とシステムに関する具体的な設計、選択、適用の基準が含まれている点です。これにより、技術者や設計者は安全な機械の実現に向けて、明確かつ適切なガイダンスを受けることができます。 さらに、SIST EN ISO 14119:2025は、ISO 14120やISO 14118、ISO 13849-1、IEC 62061と統合されており、全体として機械の安全性を高めるための包括的なフレームワークを提供しています。これにより、企業や工場は、効果的に機械の安全性を確保しつつ、生産性を向上させるための基準を満たすことができます。このように、標準は機械安全における現代的なニーズに合わせた、高い relevancy（関連性）を持ち、設計者やユーザーにとって多くの利点を提供するものとなっています。
The SIST EN ISO 14119:2025 standard outlines vital principles for the design and selection of interlocking devices associated with guards in machinery safety. The scope of this standard is broad, encompassing various aspects of interlocking devices regardless of their energy source, which makes it highly relevant across different industries. Its emphasis on minimizing the risk of defeating these critical safety mechanisms ensures that machinery operates securely, protecting operators and maintenance personnel from mechanical hazards. One of the key strengths of this standard is its comprehensive approach to the design and application of interlocking devices. It includes guidelines for the design of guard components that engage with interlocking devices, ensuring seamless integration. Additionally, the standard addresses trapped key interlocking devices and systems, providing clarity on functionality and safety in machinery applications. By doing so, it enhances the overall safety framework by establishing clear directives on how these devices should be utilized within machinery operations. The relevance of SIST EN ISO 14119:2025 extends beyond mere compliance; it fosters an environment where safety is prioritized in the design phase of machinery. With the guidance offered for selecting and implementing interlocking devices, manufacturers can better ensure safety measures are effectively integrated from the outset. This proactive stance not only promotes compliance with regulatory requirements, as outlined in related standards such as ISO 14120 and ISO 14118, but also facilitates the development of safer machinery that better protects users. In summary, the SIST EN ISO 14119:2025 standard serves as an essential reference for professionals involved in machinery safety. It provides a solid foundation for understanding the principles of interlocking device design and selection, enhancing safety while effectively reducing the likelihood of defeat in safety mechanisms. The comprehensive nature of its guidelines makes it an indispensable resource for ensuring that machinery operates with maximum safety and effectiveness.
Die SIST EN ISO 14119:2025 ist ein entscheidendes Dokument, das umfassende Prinzipien für das Design und die Auswahl von Verriegelungseinrichtungen in Verbindung mit Schutzvorrichtungen vorgibt. Der Umfang dieses Standards reicht von den Bauteilen der Schutzvorrichtungen, die die Verriegelungseinrichtungen betätigen, bis hin zu spezifischen Anforderungen an gefangene Schlüssel und deren Systeme für Maschinenanwendungen. Eine der herausragenden Stärken dieses Standards ist seine Unabhängigkeit von der Art der Energiequelle, was ihn universell anwendbar macht. Dies bedeutet, dass die Prinzipien zur Gestaltung und Auswahl von Verriegelungseinrichtungen für eine Vielzahl von Maschinen und Anwendungen genutzt werden können, wodurch das Dokument für Hersteller und Betreiber von Maschinen von großer Bedeutung ist. Ein weiterer wesentlicher Vorteil der SIST EN ISO 14119:2025 liegt in den präventiven Maßnahmen, die empfohlen werden, um die Möglichkeit der Umgehung von Verriegelungseinrichtungen zu minimieren. Dies ist besonders relevant, um Sicherheitsrisiken zu reduzieren und den Schutz von Personen, die mit oder in der Nähe von Maschinen arbeiten, zu gewährleisten. Darüber hinaus kann dieses Dokument nahtlos mit anderen relevanten Standards wie ISO 14120, ISO 14118, ISO 13849-1 und IEC 62061 kombiniert werden, welche zusätzliche Anforderungen zur Konstruktion und zum Betrieb von Schutzvorrichtungen und deren Signalverarbeitungsmechanismen festlegen. Dies unterstützt die Schaffung eines umfassenden Sicherheitsrahmens für Maschinen, der nicht nur die physische Sicherheit der Arbeitnehmer verbessert, sondern auch zur Effizienz und Zuverlässigkeit der Maschinenbetrieb beitragen kann. Insgesamt ist die SIST EN ISO 14119:2025 ein unverzichtbarer Standard für alle, die im Bereich Maschinenbau und Maschinenbetrieb tätig sind. Ihre Relevanz erstreckt sich über verschiedene Industrien, da sie die Sicherheit und Effizienz in der Maschinenanwendung fördert und somit einen wesentlichen Beitrag zu einer sicheren Arbeitsumgebung leistet.
Le document SIST EN ISO 14119:2025 établit des principes fondamentaux pour la conception et la sélection des dispositifs de verrouillage associés aux dispositifs de protection, s'appliquant indépendamment de la nature de la source d'énergie. Ce standard est crucial car il permet d'assurer la sécurité des machines en minimisant la possibilité de contournement des dispositifs de verrouillage de manière prévisible. Parmi les points forts de ce standard, on trouve son approche exhaustive qui inclut non seulement les parties des dispositifs de protection qui actionnent les dispositifs de verrouillage, mais également les systèmes de verrouillage à clé piégée spécifiquement adaptés aux applications de machines. Cela démontre une attention particulière aux détails et à la flexibilité nécessaire pour diverses configurations industrielles. La pertinence de SIST EN ISO 14119:2025 dans le domaine de la sécurité des machines ne peut être sous-estimée. La directivité qu'il fournit sur la conception et l'application des dispositifs de verrouillage renforce la protection des opérateurs, ce qui est primordial face aux dangers mécaniques. Ce standard s'inscrit également dans un cadre plus large, en interagissant avec d'autres documents normatifs tels que ISO 14120 pour les exigences générales de conception de dispositifs de protection et ISO 14118 pour le traitement des signaux de sécurité. En somme, SIST EN ISO 14119:2025 constitue une référence essentielle pour les professionnels du secteur, en veillant à ce que les dispositifs de verrouillage soient correctement conçus et sélectionnés, garantissant ainsi un environnement de travail conforme et sécurisé.
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