EN IEC 60079-14:2024

Explosive atmospheres - Part 14: Electrical installation design, selection and installation of equipment, including initial inspection

IEC 60079:2024 contains the specific requirements for the design of electrical systems, selection, installation and the required initial inspection of electrical installations of Ex Equipment in, or associated with, explosive atmospheres including requirements for documentation and personnel competency. These requirements are in addition to the requirements for installations in non-hazardous areas. This document applies to all electrical Ex Equipment including fixed, transportable, portable and personal, and installations, permanent or temporary. This document does not apply to: • electrical installations in mines susceptible to firedamp; • inherently explosive situations and dust from explosives or pyrophoric substances (for example explosives manufacturing and processing); • rooms used for medical purposes; • electrical installations in areas where the hazard is due to flammable mist; and • installation of non-electrical Ex Equipment (unless being part of an equipment assembly according IEC TS 60079-46). No account is taken in this document of the toxic hazards that are associated with flammable gases, liquids and dusts in concentrations that are usually very much less than the lower flammable limit. In locations where personnel could be exposed to potentially toxic concentrations of flammable material, appropriate precautions are necessary. Such precautions are outside the scope of this document. This sixth edition cancels and replaces the fifth edition published in 2013. This edition constitutes a technical revision. Edition 6 is a major restructure and introduces a number of technical changes from the previous edition (2013), see Table 1 of the foreword for detailed information.

Explosionsgefährdete Bereiche - Teil 14: Projektierung, Auswahl und Installation der Geräte sowie Erstprüfung elektrischer Anlagen

Atmosphères explosives - Partie 14: Conception des installations électriques, sélection et installation des appareils, comprenant l’inspection initiale

IEC 60079-14:2024 contient les exigences spécifiques relatives à la conception de systèmes électriques, à la sélection, à l’installation et à l’inspection initiale exigée des installations électriques des appareils Ex électriques situés dans des atmosphères explosives, ou associées à celles-ci, comprenant les exigences relatives à la documentation et à la compétence du personnel. Ces exigences complètent celles relatives aux installations dans les emplacements non dangereux. Le présent document s’applique à tout appareil Ex électrique, comprenant les appareils fixes, transportables, portables, et personnels, et aux installations, permanentes ou temporaires. Le présent document ne s’applique pas: • aux installations électriques situées dans des mines grisouteuses; • aux situations intrinsèquement explosives et aux poussières issues de substances explosives ou pyrophoriques (la fabrication et le traitement d’explosifs, par exemple); • aux salles utilisées à des fins médicales; • aux installations électriques situées dans des emplacements où le danger provient d’un brouillard inflammable; et • à l’installation d’appareils Ex non électriques (sauf s’ils font partie d’un assemblage d’appareils conformément à l’IEC TS 60079-46). Le présent document ne tient pas compte des dangers toxiques associés aux gaz, liquides et poussières inflammables présents dans des concentrations habituellement bien inférieures à la limite inférieure d’inflammabilité. Sur les sites où le personnel est susceptible d’être exposé à des concentrations potentiellement toxiques de matières inflammables, des précautions appropriées sont nécessaires. Ces précautions ne relèvent pas du domaine d’application du présent document. Cette sixième édition annule et remplace la cinquième édition parue en 2013. Cette édition constitue une révision technique. La 6e édition constitue une restructuration majeure et introduit plusieurs modifications techniques par rapport à l’édition précédente (2013). Le Tableau 1, voir AVANT-PROPOS "Tableau des modifications majeures", est fourni afin de mettre en avant les modifications techniques ainsi que les principales modifications rédactionnelles par rapport à l’édition précédente.

Ekspolozivne atmosfere - Načrtovanje, izbira in namestitev električnih inštalacij, vključno z začetnim pregledom (IEC 60079-14:2024)

Standard IEC 60079:2024 vsebuje posebne zahteve za načrtovanje električnih sistemov, izbiro, namestitev in zahtevan začetni pregled električnih inštalacij opreme s protieksplozijsko zaščito v eksplozivnih atmosferah ali v povezavi z njimi, vključno z zahtevami za dokumentacijo in usposobljenost osebja.
Te zahteve so dodatne k zahtevam za inštalacije v nenevarnih območjih.
Ta dokument se uporablja za vso električno opremo s protieksplozijsko zaščito, vključno s fiksno, premično, prenosno in osebno, ter stalne ali začasne inštalacije.
Ta dokument se ne uporablja za:
• električne inštalacije v rudnikih, kjer se lahko pojavijo eksplozivni plini;
• situacije, v katerih lahko že samo po sebi pride do eksplozije, in prah iz eksplozivov ali pirofornih snovi (npr. proizvodnja in predelava eksplozivov);
• prostore za zdravstvene namene;
• električne inštalacije na območjih, kjer obstaja nevarnost zaradi vnetljive meglice; ter
• namestitev neelektrične opreme s protieksplozijsko zaščito (razen če je del sklopa opreme v skladu s standardom IEC TS 60079-46).
V tem dokumentu niso zajete nevarnosti zastrupitve, povezane z vnetljivimi plini, tekočinami in prahom v koncentracijah, ki so običajno precej pod spodnjo mejo vnetljivosti. Na območjih, kjer je lahko osebje izpostavljeno toksičnim koncentracijam vnetljivega materiala, je treba upoštevati ustrezne previdnostne ukrepe. Taki previdnostni ukrepi ne spadajo na področje uporabe tega dokumenta.
Šesta izdaja razveljavlja in nadomešča peto izdajo, objavljeno leta 2013. Ta izdaja je tehnično popravljena izdaja. Šesta izdaja je bila obsežno preoblikovana in uvaja številne tehnične spremembe glede na prejšnjo izdajo (2013); za podrobnejše informacije glej preglednico 1 v predgovoru dokumenta.

General Information

• Status: Published
• Publication Date: 10-Oct-2024
• ICS: 29.260.20 - Electrical apparatus for explosive atmospheres
• Technical Committee: CLC/TC 31 - Electrical apparatus for explosive atmospheres - General requirements
• Drafting Committee: IEC/SC 31J - IEC_SC_31J
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 11-Oct-2024
• Completion Date: 11-Oct-2024
• Ref Project: SIST EN IEC 60079-14:2025 - Explosive atmospheres - Part 14: Electrical installation design, selection and installation of equipment, including initial inspection (IEC 60079-14:2024)

Relations

• Replaces: EN 60079-14:2014 - Explosive atmospheres - Part 14: Electrical installations design, selection and erection
• Effective Date: 24-Dec-2019
• Replaces: EN 60079-14:2014/AC:2016 - Explosive atmospheres - Part 14: Electrical installations design, selection and erection
• Effective Date: 24-Dec-2019

Overview

EN IEC 60079-14:2024 (identical to IEC 60079-14:2024, Edition 6) specifies requirements for the design, selection and installation of electrical equipment and systems intended for use in or associated with explosive atmospheres (Ex). It covers fixed, transportable, portable and personal Ex Equipment and both permanent and temporary installations, including initial inspection, documentation and personnel competency. These requirements supplement normal electrical installation rules for non‑hazardous areas.

This sixth edition is a major restructure and technical revision of the 2013 edition and focuses on modernising guidance for hazardous‑area design and safe installation practice.

Key Topics and Technical Requirements

• Zone classification and Equipment Protection Levels (EPLs): Guidance on matching equipment types and protection concepts to gas/dust zones.
• Design principles: Requirements to prevent incendive sparks, manage surface temperatures, and reduce ignition sources (static electricity, optical radiation, RF, lightning).
• Selection & installation of Ex Equipment: Rules for choosing appropriate protection concepts (flameproof "d", increased safety "e", intrinsic safety "i", pressurization "p", etc.) and correct installation practices.
• Cables and wiring systems: Selection, routing, segregation, surface temperature considerations, and crossing of hazardous areas.
• Earthing and bonding: Protective equipotential bonding, handling of extraneous conductive parts and cathodic protection interactions.
• Electrical machines & motors: Specific installation guidance for motors with various protection types.
• Electrical protection, isolation and emergency stop: Requirements for safe isolation, protective devices and emergency stop arrangements compatible with Ex requirements.
• Initial inspection & documentation: Mandatory documentation (site information, equipment data, installation records) and a structured initial inspection process.
• Personnel competency: Requirements for qualified personnel responsible for design, installation and inspection of Ex installations.
• Scope exclusions: Mines susceptible to firedamp; inherently explosive manufacturing (explosives/pyrophoric substances); medical rooms; areas dominated by flammable mist; non‑electrical Ex equipment installation (unless part of an assembly per IEC TS 60079-46).

Practical Applications & Who Should Use It

• Plant and process engineers in oil & gas, chemical, petrochemical and pharmaceutical industries
• Electrical designers and contractors installing Ex systems in hazardous areas
• Safety managers, asset owners and maintenance teams responsible for compliance and inspection
• Certification bodies and notified bodies assessing Ex installations
• Consultants providing hazardous‑area zoning, documentation and competency frameworks

Related Standards

Key related IEC/CENELEC documents referenced include: IEC/EN IEC 60079 series (Parts 0, 1, 7, 11, 15, 17, 19, 25, 28, 29‑1, 31, etc.), and other standards for cables, enclosures, lightning protection and electrical safety.

EN IEC 60079-14:2024 is essential for ensuring safe, compliant electrical installations in explosive atmospheres and for meeting regulatory and industry best practices.

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2025
Ekspolozivne atmosfere - Načrtovanje, izbira in namestitev električnih inštalacij,
vključno z začetnim pregledom (IEC 60079-14:2024)
Explosive atmospheres - Part 14: Electrical installation design, selection and installation
of equipment, including initial inspection (IEC 60079-14:2024)
Explosionsgefährdete Bereiche - Teil 14: Projektierung, Auswahl und Errichtung
elektrischer Anlagen (IEC 60079-14:2024)
Atmosphères explosives - Partie 14: Conception des installations électriques, sélection
et installation des appareils, comprenant l'inspection initiale (IEC 60079-14:2024)
Ta slovenski standard je istoveten z: EN IEC 60079-14:2024
ICS:
29.260.20 Električni aparati za Electrical apparatus for
eksplozivna ozračja explosive atmospheres
91.140.50 Sistemi za oskrbo z elektriko Electricity supply systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60079-14

NORME EUROPÉENNE
EUROPÄISCHE NORM October 2024
ICS 29.260.20 Supersedes EN 60079-14:2014;
EN 60079-14:2014/AC:2016
English Version
Explosive atmospheres - Part 14: Electrical installation design,
selection and installation of equipment, including initial
inspection
(IEC 60079-14:2024)
Atmosphères explosives - Partie 14: Conception des Explosionsgefährdete Bereiche - Teil 14: Projektierung,
installations électriques, sélection et installation des Auswahl und Errichtung elektrischer Anlagen
appareils, comprenant l'inspection initiale (IEC 60079-14:2024)
(IEC 60079-14:2024)
This European Standard was approved by CENELEC on 2024-10-04. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60079-14:2024 E

European foreword
The text of document 31J/366/FDIS, future edition 6 of IEC 60079-14, prepared by SC 31J
"Classification of hazardous areas and installation requirements" of IEC/TC 31 "Equipment for
explosive atmospheres" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 60079-14:2024.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2025-07-04
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2027-10-04
document have to be withdrawn
This document supersedes EN 60079-14:2014 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60079-14:2024 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 standard indicated:
IEC 60034-1 NOTE Approved as EN 60034-1
IEC 60034-5 NOTE Approved as EN IEC 60034-5
IEC 60064 NOTE Approved as EN 60064
IEC 60079 (series) NOTE Approved as EN IEC 60079 (series)
IEC 60079-1 NOTE Approved as EN 60079-1
IEC 60079-2 NOTE Approved as EN 60079-2
IEC 60079-5 NOTE Approved as EN 60079-5
IEC 60079-6 NOTE Approved as EN 60079-6
IEC 60079-10-1 NOTE Approved as EN IEC 60079-10-1
IEC 60079-10-2 NOTE Approved as EN 60079-10-2
IEC 60079-13 NOTE Approved as EN 60079-13
IEC 60079-14 NOTE Approved as EN 60079-14
IEC 60079-18 NOTE Approved as EN 60079-18
IEC 60079-26 NOTE Approved as EN IEC 60079-26
IEC 60079-29-2 NOTE Approved as EN 60079-29-2
IEC 60079-29-3 NOTE Approved as EN 60079-29-3
IEC 60079-31 NOTE Approved as EN 60079-31
IEC 60079-33 NOTE Approved as CLC/TR 60079-33
IEC 60081 NOTE Approved as EN 60081
IEC 60192 NOTE Approved as EN 60192
IEC 60195 NOTE Approved as EN 60195
IEC 60204 (series) NOTE Approved as EN 60204 (series)
IEC 60332-1-2 NOTE Approved as EN 60332-1-2
IEC 60332-3 (series) NOTE Approved as EN IEC 60332-3 (series)
IEC 60332-3-22 NOTE Approved as EN IEC 60332-3-22
IEC 60364 (series) NOTE Approved as HD 60364 (series)
IEC 60364-5-51 NOTE Approved as HD 60364-5-51
IEC 60432-1 NOTE Approved as EN 60432-1
IEC 60432-2 NOTE Approved as EN 60432-2
IEC 60079-14:2024 NOTE Approved as EN IEC 60079-14:2024 (not modified)
IEC 60529 NOTE Approved as EN 60529
IEC 60626-1 NOTE Approved as EN IEC 60626-1
IEC 60654-4 NOTE Approved as EN 60654-4
IEC 60664-1 NOTE Approved as EN IEC 60664-1
IEC 60721-3 (series) NOTE Approved as EN IEC 60721-3 (series)
IEC 60950 (series) NOTE Approved as EN 60950 (series)
IEC 61008-1 NOTE Approved as EN 61008-1
IEC 61010-1 NOTE Approved as EN 61010-1
IEC 61439-1 NOTE Approved as EN IEC 61439-1
IEC 61558-2-6 NOTE Approved as EN 61558-2-6
IEC 61285 NOTE Approved as EN 61285
IEC 61914 NOTE Approved as EN IEC 61914
IEC 61936 (series) NOTE Approved as EN IEC 61936 (series)
IEC 62035 NOTE Approved as EN 62035
IEC 62485-2 NOTE Approved as EN IEC 62485-2
IEC/IEEE 60079-30-1 NOTE Approved as EN 60079-30-1
IEC/IEEE 60079-30-2 NOTE Approved as EN 60079-30-2
ISO/IEC 80079-20-2 NOTE Approved as EN ISO/IEC 80079-20-2
ISO 4892-1 NOTE Approved as EN ISO 4892-1

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.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60060-1 - High-voltage test techniques - Part 1: EN 60060-1 -
General definitions and test
requirements
IEC 60079-0 - Explosive atmospheres - Part 0: EN IEC 60079-0 -
Equipment - General requirements
IEC 60079-1 - Explosive atmospheres - Part 1: EN 60079-1 -
Equipment protection by flameproof
enclosures "d"
IEC 60079-7 - Explosive atmospheres - Part 7: EN 60079-7 -
Equipment protection by increased
safety "e"
IEC 60079-11 - Explosive atmospheres - Part 11: EN 60079-11 -
Equipment protection by intrinsic safety
"i"
IEC 60079-15 - Explosive atmospheres - Part 15: EN IEC 60079-15 -
Equipment protection by type of
protection "n"
IEC 60079-17 - Explosive atmospheres - Part 17: EN IEC 60079-17 -
Electrical installations inspection and
maintenance
IEC 60079-19 - Explosive atmospheres - Part 19: EN IEC 60079-19 -
Equipment repair, overhaul and
reclamation
IEC 60079-25 - Explosive atmospheres - Part 25: EN IEC 60079-25 -
Intrinsically safe electrical systems
IEC 60079-28 - Explosive atmospheres - Part 28: EN 60079-28 -
Protection of equipment and
transmission systems using optical
radiation
IEC 60079-29-1 - Explosive atmospheres - Part 29-1: Gas EN 60079-29-1 -
detectors - Performance requirements of
detectors for flammable gases
IEC 60079-29-4 - Explosive atmospheres - Part 29-4: Gas EN 60079-29-4 -
detectors - Performance requirements of
open path detectors for flammable
gases
IEC 60228 - Conductors of insulated cables EN IEC 60228 -
IEC 60245-4 - Rubber insulated cables - Rated - -
voltages up to and including 450/750 V -
Part 4: Cords and flexible cables
IEC 60364-4-41 - Low-voltage electrical installations - Part HD 60364-4-41 -
4-41: Protection for safety - Protection
against electric shock
IEC 61557-8 - Electrical safety in low voltage EN 61557-8 -
distribution systems up to 1 000 V a.c.
and 1 500 V d.c. - Equipment for testing,
measuring or monitoring of protective
measures - Part 8: Insulation monitoring
devices for IT systems
IEC 62262 - Degrees of protection provided by EN 62262 -
enclosures for electrical equipment
against external mechanical impacts (IK
code)
IEC 62305-3 - Protection against lightning - Part 3: EN 62305-3 -
Physical damage to structures and life
hazard
IEC/TS 60079-32-1 - Explosive atmospheres - Part 32-1: CLC/TR 60079-32-1 -
Electrostatic hazards, guidance
IEC/TS 60079-47 - Explosive atmospheres - Part 47: CLC IEC/TS 60079-47 -
Equipment protection by 2-wire
intrinsically safe ethernet concept (2-
WISE)
IEC 60079-14 ®
Edition 6.0 2024-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 14: Electrical installation design, selection and installation of equipment,

including initial inspection
Atmosphères explosives –
Partie 14: Conception des installations électriques, sélection et installation des

appareils, comprenant l’inspection initiale

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.260.20  ISBN 978-2-8322-9300-3

– 2 – IEC 60079-14:2024 © IEC 2024
CONTENTS
FOREWORD . 10
INTRODUCTION . 16
1 Scope . 19
2 Normative references . 20
3 Terms and definitions . 21
3.1 General . 21
3.2 Hazardous areas . 22
3.3 Flameproof enclosure . 24
3.4 Increased safety . 24
3.5 Intrinsic safety . 25
3.6 Intrinsic safety parameters . 26
3.7 Pressurization . 26
3.8 Type of Protection "n" . 26
3.9 Type of Protection "o" . 27
3.10 Type of Protection "q" . 27
3.11 Type of Protection "m" . 27
3.12 Type of Protection "t" . 27
3.13 Electrical supply systems . 27
3.14 Equipment . 28
3.16 Cable(s) . 28
4 General . 30
4.1 General requirements . 30
4.1.1 Zones and Equipment Protection Levels . 30
4.1.2 Requirements for all Ex Equipment . 31
4.1.3 Electrical ratings . 31
4.1.4 Conditions of control for exceptional circumstances . 31
4.2 Conditions of Use . 32
4.2.1 General . 32
4.2.2 Specific Conditions of Use . 32
4.2.3 Use of Ex Components . 32
4.3 Ignition sources that have an influence on the installation . 33
4.3.1 General . 33
4.3.2 Static electricity . 33
4.3.3 Optical radiation . 33
4.3.4 Lightning protection . 33
4.3.5 Radio frequency received and transmitted in hazardous areas . 33
4.3.6 RFID tags . 34
5 Documentation . 34
5.1 General . 34
5.2 Site information . 35
5.3 Ex Equipment information . 35
5.4 Installation information . 35
5.5 Personnel competency . 36
6 Design . 36
6.1 General . 36
6.2 Protection from dangerous (incendive) sparking . 36

IEC 60079-14:2024 © IEC 2024 – 3 –
6.2.1 Equipment (other than Ex Equipment) above hazardous areas . 36
6.2.2 Wiring systems traversing a hazardous area . 37
6.2.3 Construction materials . 37
6.2.4 Danger from live parts . 37
6.2.5 Danger from exposed and extraneous-conductive-parts . 38
6.2.6 Protective equipotential bonding . 39
6.2.7 Cathodically protected metallic parts . 40
6.3 Electrical protection . 41
6.4 Emergency stop . 41
6.5 Electrical isolation . 41
6.6 Cables . 42
6.6.1 External surface temperature . 42
6.6.2 Cables subjected to thermal insulation . 42
6.6.3 Overhead wiring . 42
6.7 Electrical machines . 42
6.7.1 General . 42
6.7.2 Electrical machines with Type of Protection "d" – Flameproof
enclosures, "p" – Pressurized enclosures and "t" – Protection by
enclosures . 43
6.7.3 Electrical machines with Level of Protection "eb" – Increased safety . 44
6.7.4 Electrical machines with Level of Protection "ec" and Type of Protection
"nA" . 46
6.7.5 Switching electrical machines above 1 kV AC . 47
6.7.6 Prevention of falling bodies . 48
6.8 Electric heating systems . 48
6.8.1 General . 48
6.8.2 Earth fault protection . 48
6.8.3 Limiting temperature . 49
6.8.4 Temperature safety device . 49
6.9 Plugs, socket outlets and couplers . 50
6.9.1 Specific requirements for explosive dust atmospheres . 50
6.9.2 Location . 50
6.10 Cells and batteries . 51
6.10.1 Charging of secondary cells and batteries . 51
6.10.2 Ventilation . 51
6.11 Gas detection systems . 51
6.12 Type of Protection "d" – Flameproof enclosures . 51
6.13 Type of Protection "e" – Increased safety . 51
6.13.1 Maximum dissipated power of junction boxes . 51
6.13.2 Maximum number of conductors . 52
6.14 Type of Protection "i" – Intrinsic safety . 53
6.14.1 General . 53
6.14.2 Cables . 54
6.14.3 Verification of intrinsically safe circuits . 54
6.14.4 Earthing of conducting screens . 56
6.14.5 Cable armour bonding . 57
6.14.6 Marking of cables . 57
6.14.7 Cables carrying more than one intrinsically safe circuit . 58
6.14.8 Types of cables carrying more than one intrinsically safe circuit and
applicable fault considerations . 58

– 4 – IEC 60079-14:2024 © IEC 2024
6.14.9 Earthing of intrinsically safe circuits . 58
6.14.10 Installations to meet the requirements of EPL Ga or EPL Da . 60
6.14.11 Simple apparatus . 61
6.14.12 Junction boxes . 62
6.14.13 Plugs and sockets used for external connections . 63
6.14.14 Special application: Combining intrinsically safe and non-intrinsically
safe circuits . 63
6.15 Type of Protection "m" – Encapsulation . 63
6.16 Type of Protection "n" . 63
6.16.1 General . 63
6.16.2 Type of Protection "nR" . 64
6.17 Type of Protection "o"– Liquid immersion (former Oil immersion) . 64
6.18 Type of Protection "p" . 64
6.18.1 General . 64
6.18.2 Ducting . 65
6.18.3 Action to be taken on failure of pressurization . 65
6.19 Pressurized rooms and artificially ventilated rooms . 69
6.20 Analyser houses . 69
6.21 Type of Protection "q" – Powder filling . 69
7 Selection . 69
7.1 General . 69
7.2 Assurance of conformity of Ex Equipment . 69
7.2.1 Ex Equipment based on IEC standards . 69
7.2.2 Ex Equipment not based on IEC standards . 69
7.2.3 Selection of used or repaired Ex Equipment . 70
7.3 Selection of Ex Equipment . 70
7.3.1 Information requirements . 70
7.3.2 External influences . 70
7.3.3 Selection of radiating equipment . 71
7.3.4 Selection of ultrasonic equipment . 72
7.3.5 Selection for pollution degree . 73
7.3.6 Selection for specific process hazards . 73
7.3.7 Selection of Ex Equipment according to EPLs . 74
7.3.8 Selection according to equipment grouping . 76
7.3.9 Selection according to the ignition temperature of the gas, vapour or
dust . 77
7.3.10 Selection according to the temperature range . 80
7.4 Selection of cables . 80
7.4.1 General . 80
7.4.2 Wiring systems for installation in areas requiring EPL Ga or EPL Da . 81
7.4.3 Cables for direct entries into flameproof enclosures . 81
7.4.4 Cables for direct entries into restricted breathing enclosures . 81
7.4.5 Resistance to flame propagation or flame spread . 81
7.4.6 UV or solar radiation . 81
7.4.7 Non-flexible cables for fixed equipment . 81
7.4.8 Flexible cables for fixed and transportable equipment (excluding
intrinsic safety circuits) . 81
7.4.9 Flexible cables for use for portable equipment . 82
7.4.10 Cables for intrinsic safety circuits . 82

IEC 60079-14:2024 © IEC 2024 – 5 –
7.4.11 Single insulated wires (excluding intrinsically safe circuits) . 82
7.4.12 Aluminium conductors. 82
7.5 Selection of entry devices and other fittings . 83
7.5.1 General . 83
7.5.2 Cable entry devices . 83
7.5.3 Adapters and Blanking Elements . 84
7.5.4 Breathing and draining devices . 84
7.5.5 Entry devices for fibre optic cables . 85
7.5.6 Other entry devices . 85
7.5.7 Cable entry device for Type of Protection "d" . 85
7.5.8 Cable entry device for Type of Protection "nR" . 86
7.6 Conduits . 87
7.6.1 Group II . 87
7.6.2 Group III . 87
7.7 Luminaires and lamps . 88
7.7.1 Luminaires . 88
7.7.2 Lamps . 88
7.8 Rotating electrical machines . 88
8 Installation of equipment . 88
8.1 General . 88
8.2 Cables and wiring systems . 88
8.2.1 Avoidance of damage . 88
8.2.2 Equipotential bonding connections . 89
8.2.3 Terminations . 89
8.2.4 Penetrations in structures . 90
8.2.5 Passage and collection of flammables . 90
8.2.6 Group III ‒ Accumulation of dust . 90
8.2.7 Jointing . 90
8.3 Entry devices and other fittings . 90
8.3.1 General . 90
8.3.2 Cable entry devices . 91
8.3.3 Additional entries . 93
8.3.4 Unused openings . 93
8.4 Conduit systems . 93
8.4.1 General . 93
8.4.2 Group II . 94
8.4.3 Group III . 94
8.4.4 Additional requirements for flameproof sealing devices for conduit . 95
8.5 Electrical heating systems. 95
8.5.1 General . 95
8.5.2 Trace heating system . 95
8.6 Protective coating of Ex Equipment . 95
8.7 Type of Protection "d" – Flameproof enclosures . 96
8.7.1 General . 96
8.7.2 Solid obstacles . 96
8.7.3 Protection of flamepaths . 96
8.8 Types of Protection "e" and "nA" . 97
8.8.1 Conductor terminations . 97

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8.8.2 Combinations of terminals and conductors for general connection and
junction boxes . 97
8.9 Types of Protection "i" – Intrinsic safety . 97
8.9.1 Earthing of conducting screens . 97
8.9.2 Cable armour bonding . 97
8.9.3 Installation of cables and wiring . 98
8.10 Type of Protection "nR" . 99
8.11 Type of Protection "o"– Liquid immersion (formerly Oil immersion) . 99
9 Initial inspection . 99
Annex A (normative) Knowledge, skills and competencies of designers, electricians
and technicians . 100
A.1 Scope . 100
A.2 Knowledge and skills . 100
A.2.1 Designers . 100
A.2.2 Electricians and technicians. 100
A.3 Competencies . 101
A.3.1 General . 101
A.3.2 Designers . 101
A.3.3 Electricians and technicians. 101
A.4 Assessment . 101
Annex B (informative) Safe work procedure guidelines for explosive gas atmospheres . 102
Annex C (normative) Pressure test procedure for cables into Ex "d" enclosures . 103
C.1 General . 103
C.2 Test apparatus . 103
C.3 Test method . 103
C.4 Test report . 104
Annex D (normative) Potential stator winding discharge hazard assessment – Ignition

risk factors . 106
Annex E (normative) Verification of intrinsically safe circuits with more than one
intrinsically safe power source with linear current/voltage characteristics . 107
E.1 General . 107
E.2 Intrinsic safety with Level of Protection "ib" . 107
E.3 Intrinsic safety with Level of Protection "ic" . 107
Annex F (informative) Methods of determining the maximum system voltages and
currents in intrinsically safe circuits with more than one intrinsically safe power source

with linear current and voltage characteristics . 108
F.1 Intrinsically safe circuits with linear current and voltage characteristics . 108
F.2 Intrinsically safe circuits with non-linear current or voltage characteristics . 109
Annex G (informative) Determination of intrinsic safety cable parameters . 110
G.1 Measurements . 110
G.2 Cables carrying more than one intrinsically safe circuit . 110
G.2.1 General . 110
G.2.2 Type A cables . 110
G.2.3 Type B cables . 111
G.2.4 Type C cables . 111
G.3 FISCO . 111
Annex H (informative) Hybrid mixtures . 112
H.1 General . 112
H.2 Concentration limits . 112

IEC 60079-14:2024 © IEC 2024 – 7 –
H.3 Electrostatic hazard . 112
H.4 Energy/temperature limits . 112
H.5 Selection of equipment . 112
H.6 Use of flameproof equipment . 112
H.7 Installation requirements . 112
Annex I (informative) Transportable, portable and personal equipment . 113
I.1 General . 113
I.2 Transportable and portable equipment . 113
I.3 Personal equipment . 114
Annex J (informative) Electrical machines operated from converters . 115
J.1 General . 115
J.2 Earthing, bonding and cabling . 116
J.2.1 Objectives of earthing . 116
J.2.2 Bonding of machines . 116
J.2.3 Machine power cables . 116
J.2.4 Cable terminations . 118
J.2.5 Interruption of the shielded machine supply line . 119
Annex K (informative) Surge protection of an intrinsically safe circuit . 120
K.1 General . 120
K.2 Installation to be protected . 120
K.3 Lightning induced surges . 120
K.4 Preventive measures . 120
K.5 Supporting documentation . 121
K.6 Further protection . 121
Annex L (informative) Adverse environmental conditions . 122
L.1 Climate classifications . 122
L.2 Cables and cable entry devices. 122
L.3 Seals and sealing materials . 122
L.4 Storage and transportation . 122
L.5 Low temperatures . 122
L.5.1 General . 122
L.5.2 Electrical machines . 123
L.6 High humidity . 123
L.7 Solar radiation . 123
L.7.1 General . 123
L.7.2 Equipment protection . 124
L.7.3 Cables and cable entry devices . 124
L.8 Atmospheres containing salt and chlorides .
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