IEC TS 60079-46:2017

Explosive atmospheres - Part 46: Equipment assemblies

IEC TS 60079-46:2017 specifies requirements for the design, construction, assembly, testing, inspection, marking, documenting and assessment of equipment assemblies for use in explosive atmospheres under the responsibility of the manufacturer of the equipment assembly. The requirements of this document apply to individual items according to the IEC 60079 series or ISO 80079 series that comprise the assembly and that have individual certificates. These individual items are then integrated as part of the equipment assembly. Also included are requirements to address aspects for the assembly which may be beyond the certificates of the individual items forming the assembly. The scope of this document includes assessment of the additional requirements for assemblies for hazardous areas and does not include requirements for non-hazardous areas. It is assumed that compliance with other electrical or mechanical requirements that are applicable for non-hazardous areas will be verified by either the same or different party in addition to the requirements of this document. This document does not apply to:
- equipment which is covered, in its entirety, by one or more IEC 60079 and ISO 80079 equipment types of protection;
- pressurized rooms, “p”, in accordance with IEC 60079-13, artificial ventilation for the protection of analyzer(s) houses in accordance with IEC TR 60079-16, and other standards addressing specific Ex assemblies;
- installation at the end-user site under the scope of IEC 60079-14;
- classification of the hazardous area;
- equipment assemblies for mines susceptible to firedamp (Group I applications);
- 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.
The specification is only intended to provide validation for the initial supply of an assembly.
Keywords: equipment assemblies for use in explosive atmospheres

Atmosphères explosives - Partie 46: Assemblages d'appareils

IEC TS 60079-46:2017 spécifie les exigences relatives à la conception, à la construction, à l’assemblage, aux essais, aux inspections, au marquage, à la documentation et à l’évaluation des assemblages d’appareils destinés à être utilisés en atmosphères explosives, sous la responsabilité du fabricant de l’assemblage d’appareils.
Les exigences du présent document s’appliquent aux éléments individuels conformément aux séries IEC 60079 ou ISO 80079 qui composent l’assemblage et qui disposent de certificats individuels. Ces éléments individuels sont ensuite intégrés en tant que partie de l’assemblage d’appareils. Sont également incluses des exigences concernant des aspects de l’assemblage qui peuvent aller au-delà des certificats des éléments individuels formant l’assemblage.
Le domaine d’application du présent document inclut l’évaluation des exigences supplémentaires applicables aux assemblages pour des emplacements dangereux et n'inclut pas d’exigences pour les emplacements non dangereux. Il est supposé que la conformité à d’autres exigences électriques ou mécaniques applicables pour des emplacements non dangereux sera vérifiée par la même partie ou par une autre partie, en complément des exigences du présent document.
Le présent document ne s’applique pas:
- aux appareils qui sont couverts, dans leur intégralité, par un ou plusieurs modes de protection d’appareils conformes à l’IEC 60079 et à l’ISO 80079;
- aux salles à surpression interne, «p», conformes à l’IEC 60079-13, à la ventilation artificielle pour la protection des bâtiments pour analyseur(s) conforme à l’IEC TR 60079 16, et à d’autres normes traitant d’assemblages Ex spécifiques;
- à l’installation sur le site de l’utilisateur final, qui relève du domaine d’application de l’IEC 60079-14;
- au classement de l’emplacement dangereux;
- aux assemblages d’appareils pour les mines grisouteuses (applications du Groupe I);
- 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.
La spécification est destinée uniquement à assurer la validation de la fourniture initiale d'un assemblage.

General Information

• Status: Published
• Publication Date: 30-Aug-2017
• ICS: 29.040.10 - Insulating oils
• ICS: 29.080.20 - Bushings
• ICS: 29.080.99 - Other standards related to insulation
• ICS: 29.260.20 - Electrical apparatus for explosive atmospheres
• Technical Committee: TC 31 - Equipment for explosive atmospheres
• Drafting Committee: MT 60079-46 - TC 31/MT 60079-46
• Current Stage: PPUB - Publication issued
• Start Date: 31-Aug-2017
• Completion Date: 26-Sep-2017

Overview

IEC TS 60079-46:2017 - Explosive atmospheres, Part 46: Equipment assemblies - provides requirements for the design, construction, assembly, testing, inspection, marking, documentation and assessment of pre‑manufactured equipment assemblies for use in explosive atmospheres. The Technical Specification applies when assemblies are formed from individual items already certified under the IEC 60079 or ISO 80079 series and when integration creates additional hazards or assessment needs beyond the individual certificates. It is intended to validate an assembly at initial supply and does not replace installation or site‑classification standards.

Key topics & technical requirements

This TS focuses on the practical steps manufacturers and assessors must consider when producing Ex assemblies. Major technical topics include:

• Design and integration: requirements for combining individually certified Ex items and non‑Ex components into a single assembly.
• Explosion protection specifications: ensuring the assembly maintains required protection levels when items are integrated.
• Wiring systems and interfaces: assessment of wiring methods, cable routing and system interfaces that may affect ignition risk.
• Ignition hazard assessment: evaluating new ignition sources that can arise from assembly layout, temperature rise or interaction of parts.
• Inspection, testing & validation: inspection regimes, functional and type testing, and validation documentation required for initial supply.
• Marking & documentation: assembly marking (group, temperature class/maximum surface temperature, Equipment Protection Level (EPL), ambient range, IP rating) and the certificates and schedule documents needed.
• Drawings and calculations: requirement for clear drawings, bill of materials and calculations relevant to safety and temperature limits.
• Competency and responsibilities: specifying manufacturer responsibilities for assessment and declarations.
• Scope exclusions: explicit exclusions (e.g., assemblies wholly covered by other IEC/ISO Ex protection types; pressurized rooms; end‑user site installation; Group I mining; inherently explosive manufacturing; medical rooms; hazards from flammable mist).

Applications and who uses it

IEC TS 60079-46 is used primarily by:

• Manufacturers of pre‑manufactured or modular Ex equipment assemblies (panels, skids, packaged machines).
• Design and compliance engineers who integrate certified Ex components into assemblies.
• Certification bodies and testing laboratories performing assembly validation and issue of certificates.
• System integrators and procurement teams verifying that supplied assemblies meet hazardous‑area requirements at initial supply.

Typical applications include packaged control panels, instrument skids, and functional machines intended for hazardous areas where component interaction (e.g., wiring, temperature rise) requires additional assessment.

Related standards

• IEC 60079 series (all relevant parts)
• IEC 60079-0, -10-1, -10-2, -14, -25
• ISO 80079 series (including ISO/IEC 80079-34, ISO 80079-36)

Keywords: IEC TS 60079-46:2017, equipment assemblies, explosive atmospheres, Ex assemblies, hazardous areas, IEC 60079, ISO 80079, EPL, assembly marking.

Standards Content (Sample)

IEC TS 60079-46 ®
Edition 1.0 2017-08
TECHNICAL
SPECIFICATION
Explosive atmospheres –
Part 46: Equipment assemblies
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 20 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
IEC TS 60079-46 ®
Edition 1.0 2017-08
TECHNICAL
SPECIFICATION
Explosive atmospheres –
Part 46: Equipment assemblies
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.260.20 ISBN 978-2-8322-4763-1

– 2 – IEC TS 60079-46:2017 © IEC 2017
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 7
4 General requirements for equipment assemblies . 8
4.1 General specifications . 8
4.2 Explosion protection specifications . 8
4.3 Hazardous area classification related to the equipment assembly . 8
4.3.1 General . 8
4.3.2 Equipment assembly with its own source of release . 9
4.4 Competencies . 9
5 Design of equipment assemblies . 9
5.1 General . 9
5.2 Ex Equipment . 9
5.2.1 Individual items . 9
5.2.2 Specific Conditions of Use as specified on certificates . 10
5.2.3 Item list . 10
5.3 Other items . 10
5.4 Wiring system . 10
5.5 Drawings. 11
6 Construction and assembly . 11
6.1 General . 11
6.2 Disassembly and reassembly . 11
6.3 System interfaces . 12
6.4 Ignition hazard assessment . 12
6.5 Calculations . 12
6.6 Inspection & testing . 12
6.7 Validation and documentation . 13
6.7.1 General . 13
6.7.2 Other material specifications . 14
6.7.3 Schedule Documents . 14
6.8 Instructions . 14
7 Certificate . 14
8 Marking . 15
8.1 General . 15
8.2 Determining Group marking . 15
8.3 Determining temperature class or maximum surface temperature marking . 16
8.4 Determining Equipment Protection Level (EPL) marking. 16
8.5 Determining ambient temperature range marking . 16
8.6 Determining ingress protection (IP Code) rating . 16

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHERES –
Part 46: Equipment assemblies
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC TS 60079-46, which is a technical specification, has been prepared by IEC technical
committee TC 31: Equipment for explosive atmospheres.

– 4 – IEC TS 60079-46:2017 © IEC 2017
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
31/1312/DTS 31/1327/RVDTS
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60079 series, published under the general title Explosive
atmospheres, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

INTRODUCTION
The provision of products into end markets for installation by end users may take the form of
either individual items of equipment or pre-manufactured assemblies comprising many items
of equipment. Pre-manufactured equipment assemblies may be as either subsystems
requiring integration as part of an installation at a site or complete functional machines which
require little or no additional reassembly on site.
This document is applied when assembly of Ex Equipment(s) results in an assembly that
creates a need for additional assessment that is not already completely covered by the
individual equipment certificates. Additional assessment might include (but is not limited to)
evaluation of wiring methods used to connect the equipment(s) or temperature rise within the
assembly.
This document provides requirements for the design, construction, assembly, testing,
inspection, marking, documenting and assessment of equipment assemblies such that the
items of Ex Equipment and the interconnection of the items of equipment form an assembly
that also meets other parts of the ISO 80079 and IEC 60079 series.
This document is intended to be used for verification of assemblies to assist in ensuring
products are in compliance with the requirements of the ISO 80079 and IEC 60079 series at
the time of initial installation at the end user site.
After the initial installation, the assembly is considered as part of the site installation in
accordance with other parts of the ISO 80079 and IEC 60079 series.

– 6 – IEC TS 60079-46:2017 © IEC 2017
EXPLOSIVE ATMOSPHERES –
Part 46: Equipment assemblies
1 Scope
This part of IEC 60079, which is a technical specification, specifies requirements for the
design, construction, assembly, testing, inspection, marking, documenting and assessment of
equipment assemblies for use in explosive atmospheres under the responsibility of the
manufacturer of the equipment assembly.
The requirements of this document apply to individual items according to the IEC 60079
series or ISO 80079 series that comprise the assembly and that have individual certificates.
These individual items are then integrated as part of the equipment assembly. Also included
are requirements to address aspects for the assembly which may be beyond the certificates of
the individual items forming the assembly.
The scope of this document includes assessment of the additional requirements for
assemblies for hazardous areas and does not include requirements for non-hazardous areas.
It is assumed that compliance with other electrical or mechanical requirements that are
applicable for non-hazardous areas will be verified by either the same or different party in
addition to the requirements of this document.
This document does not apply to:
– equipment which is covered, in its entirety, by one or more IEC 60079 and ISO 80079
equipment types of protection;
– pressurized rooms, “p”, in accordance with IEC 60079-13, artificial ventilation for the
protection of analyzer(s) houses in accordance with IEC TR 60079-16, and other
standards addressing specific Ex assemblies;
– installation at the end-user site under the scope of IEC 60079-14;
– classification of the hazardous area;
– equipment assemblies for mines susceptible to firedamp (Group I applications);
– 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.
The specification is only intended to provide validation for the initial supply of an assembly.
NOTE 1 Additional guidance on the requirements for hazards due to hybrid mixtures of dust or flyings and
flammable gas or vapour is provided in IEC 60079-14.
Where a requirement of this document conflicts with a requirement of either IEC 60079-0 or
ISO 80079-36, the requirement of this document takes precedence.
NOTE 2 For this first edition, the only requirements of this document that take precedence over IEC 60079-0 or
ISO 80079-36 are the markings for equipment assemblies.

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 60079 (all parts), Explosive atmospheres
IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements
IEC 60079-10-1, Explosive atmospheres – Part 10-1: Classification of areas – Explosive gas
atmospheres
IEC 60079-10-2, Explosive atmospheres – Part 10-2: Classification of areas – Explosive dust
atmospheres
IEC 60079-14, Explosive atmospheres – Part 14: Electrical installations design, selection and
erection
IEC 60079-25, Explosive atmospheres – Part 25: Intrinsically safe electrical systems
ISO 80079 (all parts), Explosive atmospheres
ISO/IEC 80079-34, Explosive atmospheres – Part 34: Application of quality systems for
equipment manufacture
ISO 80079-36, Explosive atmospheres – Part 36: Non-electrical equipment for explosive
atmospheres – Basic method and requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60079-0,
IEC 60079-14, ISO 80079-36 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
3.1
equipment assembly
pre-manufactured combination of Ex Equipment, together with other parts as necessary, that
are electrically or mechanically interconnected that are pre-assembled prior to being placed
into service at the end-user site, and that can be disassembled and then re-assembled at the
end-user site
3.2
equipment assembly certificate
document that conveys the assurance of the conformity of an equipment assembly with
specified requirements
Note 1 to entry: The certificate is either the supplier’s declaration of conformity or the purchaser’s recognition of
conformity or certification (as a result of action by a third party) as defined in ISO/IEC 17000:2004, definition 2.

– 8 – IEC TS 60079-46:2017 © IEC 2017
3.3
pre-manufactured
equipment assembly produced at any location(s) other than the end-user site
4 General requirements for equipment assemblies
4.1 General specifications
The equipment assembly shall be verified for suitability against the requirements of this
document, IEC 60079-0, IEC 60079-14 and ISO 80079-36 as applicable.
The general specifications may be provided by the end-user or by the manufacturer for the
intended use of the equipment assembly and shall cover the following as a minimum:
– manufacturer’s unique equipment assembly identifier (e.g. serial number);
– input and output ratings;
– intended environmental conditions, including ambient temperature range and ingress
protection;
– applicable explosion protection codes, standards and regulations;
– utility-related issues, including power supply;
– any requirements for items to be used in the equipment assembly;
– process conditions, including fluids, pressures, duty;
– external sources of heating and cooling;
– external interface parameters (e.g. for intrinsic safety, controls, shutdowns and interlocks,
including details regarding failure modes).
These general specifications related to the application of the equipment assembly shall be
documented by the manufacturer.
4.2 Explosion protection specifications
In addition to the general specifications of 4.1, if not specified as part of them, the
manufacturer shall document the following specifications related to the installation of the
equipment assembly by the end-user:
– default equipment protection level (EPL) as defined in IEC 60079-14, as a minimum
requirement;
– equipment Group;
– temperature classification or maximum surface temperature;
– allowances for dust layers as applicable;
– Specific Conditions of Use (“X” conditions).
4.3 Hazardous area classification related to the equipment assembly
4.3.1 General
There are two aspects of area classification that can impact equipment assemblies. The first
is due to the area in which the equipment assembly is to be installed, and the second is due
to any source of release from the equipment assembly.
It is not a requirement of this document to verify either of these area classifications.
The manufacturer shall document the suitability of the equipment assembly for the intended
end-site hazardous area classification and for the defined installation conditions.

4.3.2 Equipment assembly with its own source of release
If the equipment assembly has its own source of release, the manufacturer shall also
document:
– the hazardous area classification identifying any source of release, factors relevant to the
sources of release (e.g. relea
...

IEC TS 60079-46 ®
Edition 1.0 2017-08
TECHNICAL
SPECIFICATION
SPECIFICATION
TECHNIQUE
Explosive atmospheres –
Part 46: Equipment assemblies
Atmosphères explosives –
Partie 46: Assemblages d’appareils

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient 21 000 termes et définitions en anglais
Spécifications techniques, Rapports techniques et autres
et en français, ainsi que les termes équivalents dans 16
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.

Recherche de publications IEC -
Glossaire IEC - std.iec.ch/glossary
webstore.iec.ch/advsearchform
67 000 entrées terminologiques électrotechniques, en anglais
La recherche avancée permet de trouver des publications IEC et en français, extraites des articles Termes et Définitions des
en utilisant différents critères (numéro de référence, texte, publications IEC parues depuis 2002. Plus certaines entrées
comité d’études,…). Elle donne aussi des informations sur les antérieures extraites des publications des CE 37, 77, 86 et
projets et les publications remplacées ou retirées. CISPR de l'IEC.

IEC Just Published - webstore.iec.ch/justpublished Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just Si vous désirez nous donner des commentaires sur cette
Published détaille les nouvelles publications parues. publication ou si vous avez des questions contactez-nous:
Disponible en ligne et aussi une fois par mois par email. [e-mail].

IEC TS 60079-46 ®
Edition 1.0 2017-08
TECHNICAL
SPECIFICATION
SPECIFICATION
TECHNIQUE
Explosive atmospheres –
Part 46: Equipment assemblies
Atmosphères explosives –
Partie 46: Assemblages d’appareils

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.260.20 ISBN 978-2-8322-6108-8

– 2 – IEC TS 60079-46:2017 © IEC 2017
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 7
4 General requirements for equipment assemblies . 8
4.1 General specifications . 8
4.2 Explosion protection specifications . 8
4.3 Hazardous area classification related to the equipment assembly . 8
4.3.1 General . 8
4.3.2 Equipment assembly with its own source of release . 9
4.4 Competencies . 9
5 Design of equipment assemblies . 9
5.1 General . 9
5.2 Ex Equipment . 9
5.2.1 Individual items . 9
5.2.2 Specific Conditions of Use as specified on certificates . 10
5.2.3 Item list . 10
5.3 Other items . 10
5.4 Wiring system . 10
5.5 Drawings. 11
6 Construction and assembly . 11
6.1 General . 11
6.2 Disassembly and reassembly . 11
6.3 System interfaces . 12
6.4 Ignition hazard assessment . 12
6.5 Calculations . 12
6.6 Inspection & testing . 12
6.7 Validation and documentation . 13
6.7.1 General . 13
6.7.2 Other material specifications . 14
6.7.3 Schedule Documents . 14
6.8 Instructions . 14
7 Certificate . 14
8 Marking . 15
8.1 General . 15
8.2 Determining Group marking . 15
8.3 Determining temperature class or maximum surface temperature marking . 16
8.4 Determining Equipment Protection Level (EPL) marking. 16
8.5 Determining ambient temperature range marking . 16
8.6 Determining ingress protection (IP Code) rating . 16

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHERES –
Part 46: Equipment assemblies
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC TS 60079-46, which is a technical specification, has been prepared by IEC technical
committee TC 31: Equipment for explosive atmospheres.
This bilingual version (2018-10) corresponds to the monolingual English version, published in
2017-08.
– 4 – IEC TS 60079-46:2017 © IEC 2017
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
31/1312/DTS 31/1327/RVDTS
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
The French version of this technical specification has not been voted upon.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60079 series, published under the general title Explosive
atmospheres, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
INTRODUCTION
The provision of products into end markets for installation by end users may take the form of
either individual items of equipment or pre-manufactured assemblies comprising many items
of equipment. Pre-manufactured equipment assemblies may be as either subsystems
requiring integration as part of an installation at a site or complete functional machines which
require little or no additional reassembly on site.
This document is applied when assembly of Ex Equipment(s) results in an assembly that
creates a need for additional assessment that is not already completely covered by the
individual equipment certificates. Additional assessment might include (but is not limited to)
evaluation of wiring methods used to connect the equipment(s) or temperature rise within the
assembly.
This document provides requirements for the design, construction, assembly, testing,
inspection, marking, documenting and assessment of equipment assemblies such that the
items of Ex Equipment and the interconnection of the items of equipment form an assembly
that also meets other parts of the ISO 80079 and IEC 60079 series.
This document is intended to be used for verification of assemblies to assist in ensuring
products are in compliance with the requirements of the ISO 80079 and IEC 60079 series at
the time of initial installation at the end user site.
After the initial installation, the assembly is considered as part of the site installation in
accordance with other parts of the ISO 80079 and IEC 60079 series.

– 6 – IEC TS 60079-46:2017 © IEC 2017
EXPLOSIVE ATMOSPHERES –
Part 46: Equipment assemblies
1 Scope
This part of IEC 60079, which is a technical specification, specifies requirements for the
design, construction, assembly, testing, inspection, marking, documenting and assessment of
equipment assemblies for use in explosive atmospheres under the responsibility of the
manufacturer of the equipment assembly.
The requirements of this document apply to individual items according to the IEC 60079
series or ISO 80079 series that comprise the assembly and that have individual certificates.
These individual items are then integrated as part of the equipment assembly. Also included
are requirements to address aspects for the assembly which may be beyond the certificates of
the individual items forming the assembly.
The scope of this document includes assessment of the additional requirements for
assemblies for hazardous areas and does not include requirements for non-hazardous areas.
It is assumed that compliance with other electrical or mechanical requirements that are
applicable for non-hazardous areas will be verified by either the same or different party in
addition to the requirements of this document.
This document does not apply to:
– equipment which is covered, in its entirety, by one or more IEC 60079 and ISO 80079
equipment types of protection;
– pressurized rooms, “p”, in accordance with IEC 60079-13, artificial ventilation for the
protection of analyzer(s) houses in accordance with IEC TR 60079-16, and other
standards addressing specific Ex assemblies;
– installation at the end-user site under the scope of IEC 60079-14;
– classification of the hazardous area;
– equipment assemblies for mines susceptible to firedamp (Group I applications);
– 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.
The specification is only intended to provide validation for the initial supply of an assembly.
NOTE 1 Additional guidance on the requirements for hazards due to hybrid mixtures of dust or flyings and
flammable gas or vapour is provided in IEC 60079-14.
Where a requirement of this document conflicts with a requirement of either IEC 60079-0 or
ISO 80079-36, the requirement of this document takes precedence.
NOTE 2 For this first edition, the only requirements of this document that take precedence over IEC 60079-0 or
ISO 80079-36 are the markings for equipment assemblies.

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 60079 (all parts), Explosive atmospheres
IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements
IEC 60079-10-1, Explosive atmospheres – Part 10-1: Classification of areas – Explosive gas
atmospheres
IEC 60079-10-2, Explosive atmospheres – Part 10-2: Classification of areas – Explosive dust
atmospheres
IEC 60079-14, Explosive atmospheres – Part 14: Electrical installations design, selection and
erection
IEC 60079-25, Explosive atmospheres – Part 25: Intrinsically safe electrical systems
ISO 80079 (all parts), Explosive atmospheres
ISO/IEC 80079-34, Explosive atmospheres – Part 34: Application of quality systems for
equipment manufacture
ISO 80079-36, Explosive atmospheres – Part 36: Non-electrical equipment for explosive
atmospheres – Basic method and requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60079-0,
IEC 60079-14, ISO 80079-36 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
3.1
equipment assembly
pre-manufactured combination of Ex Equipment, together with other parts as necessary, that
are electrically or mechanically interconnected that are pre-assembled prior to being placed
into service at the end-user site, and that can be disassembled and then re-assembled at the
end-user site
3.2
equipment assembly certificate
document that conveys the assurance of the conformity of an equipment assembly with
specified requirements
Note 1 to entry: The certificate is either the supplier’s declaration of conformity or the purchaser’s recognition of
conformity or certification (as a result of action by a third party) as defined in ISO/IEC 17000:2004, definition 2.

– 8 – IEC TS 60079-46:2017 © IEC 2017
3.3
pre-manufactured
equipment assembly produced at any location(s) other than the end-user site
4 General requirements for equipment assemblies
4.1 General specifications
The equipment assembly shall be verified for suitability against the requirements of this
document, IEC 60079-0, IEC 60079-14 and ISO 80079-36 as applicable.
The general specifications may be provided by the end-user or by the manufacturer for the
intended use of the equipment assembly and shall cover the following as a minimum:
– manufacturer’s unique equipment assembly identifier (e.g. serial number);
– input and output ratings;
– intended environmental conditions, including ambient temperature range and ingress
protection;
– applicable explosion protection codes, standards and regulations;
– utility-related issues, including power supply;
– any requirements for items to be used in the equipment assembly;
– process conditions, including fluids, pressures, duty;
– external sources of heating and cooling;
– external interface parameters (e.g. for intrinsic safety, controls, shutdowns and interlocks,
including details regarding failure modes).
These general specifications related to the application of the equipment assembly shall be
documented by the manufacturer.
4.2 Explosion protection specifications
In addition to the general specifications of 4.1, if not specified as part of them, the
manufacturer shall document the following specifications related to the installation of the
equipment assembly by the end-user:
– default equipment protection level (EPL) as defined in IEC 60079-14, as a minimum
requirement;
– equipment Group;
– temperature classification or maximum surface temperature;
– allowances for dust layers as applicable;
– Specific Conditions of Use (“X” conditions).
4.3 Hazardous area classification related to the equipment assembly
4.3.1 General
There are two aspects of area classification that can impact equipment assemblies. The first
is due to the area in which the equipment assembly is to be installed, and the second is due
to any source of release from the equipment assembly.
It is not a requirement of this document to verify either of these area classifications.
The manufacturer shall document the suitability of the equipment assembly for the intended
end-site hazardous area classification and for the defined installation conditions.

4.3.2 Equipment assembly with its own source of release
If the equipment assembly has its own source of release, the manufacturer shall also
document:
– the hazardous area classification identifying any source of release, factors relevant to the
sources of release (e.g. release rate, orifice size, operating mode, failure mode,
recommendation for management of the hazard) and any other information relevant to
quantifying the hazard and the methodology and any references used to arrive at the
classification;
– any conditions defined by the manufacturer such that the suitability of the equipment
assembly for the hazardous area classification remains valid.
The classification of hazardous areas shall be in accordance with IEC 60079-10-1 or
IEC 60079-10-2 as applicable. This classification may be provided by the end-user.
4.4 Competencies
For equipment assemblies subjected to type verification, the manufacturing process and the
competency of the related personnel shall conform to ISO/IEC 80079-34.
For equipment assemblies subjected to unit verification, competency of the personnel
performing the production processes is verified by conformity of the equipment assembly with
this document. The verifying party shall be competent in the explosion protection aspects of
the assembly being verified.
When equipment assemblies are subjected to unit verification, the verifying party shall have
evidence of competency through an independent party or system.
Documentation regarding the above shall be included with each equipment assembly.
NOTE An example of suitable documentation to demonstrate the competency required for type verification would
be a record of current assessment to ISO/IEC 80079-34 by a competent third-party assessor, and for unit
verification it could be a current certificate issued by a competent third-party assessor.
5 Design of equipment assemblies
5.1 General
The selection, installation and inspection of the electrical equipment in an assembly shall be
in accordance with IEC 60079-14, except as modified by this document.
5.2 Ex Equipment
5.2.1 Individual items
Individual items that comprise the equipment assembly shall conform to the IEC 60079 series
or ISO 80079 series standards based on the associated ignition risks, and shall have
individual Ex Equipment certificates or be assessed as part of the assembly.
All individual items shall be suitably rated for the application and be utilized in accordance
with the manufacturer’s instructions.
Where items other than suitably rated Ex Equipment were not separately assessed as part of
Ex Equipment, an assessment, including further tests according IEC 60079 series or
ISO 80079 series standards if necessary, shall be made as part of the equipment assembly
evaluation.
NOTE Items other than Ex Equipment can include, for example, Ex Components, simple apparatus, general
industrial products within an Ex “d” or Ex “p” enclosure, Group I equipment used in a Group II application.

– 10 – IEC TS 60079-46:2017 © IEC 2017
5.2.2 Specific Conditions of Use as specified on certificates
All Specific Conditions of Use as specified on equipment certificates shall be considered and
their application documented by the manufacturer as follows:
– If directly related to the equipment assembly, how they were satisfied in the equipment
assembly.
– If directly related to the equipment assembly, but not satisfied in the equipment assembly,
how they will be able to be satisfied in the end-user site installation.
– If not directly related to the equipment assembly, why they were not directly related.
Specific Conditions of Use that are related to items of equipment forming the equipment
assembly, that are not satisfied in the equipment assembly, but able to be satisfied in the
end-user site installation, shall be included or addressed, on the equipment assembly
certificate.
5.2.3 Item list
An item list shall be prepared by the manufacturer of the equipment assembly and included as
part of each equipment assembly certificate.
This list shall include an inventory of all Ex Equipment, including Ex Components that were
assessed as part of this equipment assembly, incorporated into the equipment assembly.
Regarding each item on this list, details shall be provided that indicate the:
– description (type of device);
– manufacturer's name and model or part number (type designation);
– identification number of each item (e.g. tag number);
– Ex Equipment certificate number, including issue number;
– Ex Component certificate number, including issue number, for Ex Components that were
assessed as part of this equipment assembly;
– type of protection, Group and temperature classification (which may be provided as the
complete Ex marking string);
– ambient temperature range;
– ingress protection (IP Code), if applicable.
5.3 Other items
Regarding other items that may be relevant to explosion protection for the equipment
assembly (e.g. non-metallic parts such as housings, handles, cable trays, rollers, fluid tubing),
details shall be provided that indicate the:
– description (type of device);
– manufacturer's name and model or part number (type designation);
– description of any explosion risk involved and how the risks are mitigated.
NOTE ISO 80079-36 provides guidance regarding ignition risk assessments applicable to both non-electrical and
electrical ignition risks.
5.4 Wiring system
Design of the wiring system for the equipment assembly that interconnects the Ex Equipment
shall incorporate wiring methods that conform to IEC 60079-14.
Information shall be provided by the manufacturer for each wiring method, including
termination means, used as part of each equipment assembly.

Regarding this information, details shall be provided that indicate the:
– type of cable or conduit construction designation (e.g. tray cable, marine cable, rigid metal
conduit, flexible conduit);
– number and size of conductor cores, if applicable;
– temperature ratings, if applicable;
– electrical parameters (such as inductance and capacitance per meter, inductance to
resistance ratio) for intrinsically safe systems;
– environmental compatibility in accordance with 4.1 (such as outdoor use, moisture,
flexibility, vibration, chemical compatibility);
– verification that entry devices and fittings (e.g. cable glands, conduit sealing devices,
conduit elbows) are appropriate for the Type of Protection of the interconnected item of Ex
Equipment.
It is not a requirement of this document that the conformity of the cable specifications be
verified by testing, except as required by IEC 60079-14.
5.5 Drawings
Drawings shall be provided by the manufacturer to cover all relevant information for the
assembly including details found in other ISO 80079 and IEC 60079 series standards. This
information may include, as applicable:
– layouts;
– mechanical details;
– single line diagrams;
– interconnection diagrams including wire and core designations;
– cable and conduit details;
– for intrinsically safe wiring systems a “systems descriptive document” as defined in
IEC 60079-25 and IEC 60079-14.
6 Construction and assembly
6.1 General
The manufacturer shall provide mechanical layout drawings of the equipment assembly.
6.2 Disassembly and reassembly
The following is permitted to be performed by the manufacturer of the equipment assembly,
as long as it is documented in the equipment assembly assessment records:
– disassembly in the factory of a completed equipment assembly;
– transportation of the disassembled equipment assembly to the end-user site, and;
– reassembly of the equipment assembly at the end-user site.
Alternatively, the reassembly activity is permitted to be performed under the responsibility of
the manufacturer, as long as this is documented in the equipment assembly assessment
records.
NOTE Local regulations might consider the reassembly of an equipment assembly in the field at the end-site as
an installation activity, and therefore reassembly could be subject to local installation regulations.

– 12 – IEC TS 60079-46:2017 © IEC 2017
6.3 System interfaces
The need for system interfaces related to the explosion protection shall be addressed by the
manufacturer as part of the equipment assembly documentation. See 4.1.
When these interfaces are integral to the equipment assembly, they are addressed as
indicated in this document.
When these interfaces are to be located remotely from the equipment assembly, the
manufacturer shall include instructions as to the necessary characteristics of these interfaces.
6.4 Ignition hazard assessment
The manufacturer shall perform and document an assessment of all ignition hazards that
might have been caused by the combination of the Ex Equipment in accordance with
ISO 80079-36 for both non-electrical and electrical risks. Additionally, a risk assessment
methodology specified by the end-user may also be performed.
The documentation shall address the risks as follows:
– ignition hazards directly related to the equipment assembly, and how they were mitigated
in the equipment assembly;
– ignition hazards directly related to the equipment assembly, not mitigated in the equipment
assembly, but able to be mitigated in the end-user site installation.
For ignition hazards that are not mitigated in the equipment assembly, but that are able to be
mitigated in the end-user site installation, the equipment assembly certificate number shall include
the "X" suffix in accordance with the marking requirements of IEC 60079-0 and the Specific Conditions
of Use shall be listed on the certificate and in the instructions.
Ignition hazards for each item of Ex Equipment are addressed by the Ex Equipment
certificates, and therefore need not be reassessed.
The verifier shall confirm that the manufacturer has carried out an ignition hazard assessment
and documented control measures and any residual risk.
6.5 Calculations
The manufacturer shall provide all calculations and safety parameters (such as trip settings
on a motor overload, explosion relief calculations, etc.) relevant to the explosion protection of
equipment assembly in accordance with IEC 60079-14, and the applicable Type of Protection
standards if not addressed by IEC 60079-14.
Calculations relevant to the explosion protection of equipment assemblies may include
maximum power dissipation for increased safety “e” enclosures, cable rating with the settings
of the overload protecting circuit breakers and intrinsically safe loop analysis (also referred to
as descriptive system documents or control drawings).
NOTE It is not a requirement of this document that the calculations for remotely located items be verified.
6.6 Inspection & testing
Inspection and testing of the entire equipment assembly after assembly shall be performed
and documented by the manufacturer.
The electrical aspects of the assembly shall be inspected and tested in accordance with
IEC 60079-14, with the non-electrical aspects addressed in accordance with the ignition
hazard assessment in 6.4.
When disassembly and reassembly is involved, the equipment assembly shall be subjected to
an inspection and testing and documented either entirely after reassembly, or partially prior to
disassembly and partial after reassembly.
6.7 Validation and documentation
6.7.1 General
Verification of an equipment assembly’s conformity to the design drawings and specifications
shall include:
– confirmation that all Ex Equipment on the assembly is identified in the documentation and
that the documentation matches the assembly;
– verification of the content of the item list (see 5.2.3)
Assessment of the assembly shall include:
– confirmation that each Ex Equipment, including Ex Components that were assessed as
part of this equipment, is appropriate for the application (e.g. ratings match operating
conditions);
– confirmation that Specific Conditions of Use for Ex Equipment are either addressed in the
assembly or passed on to the end-user;
– confirmation that the Schedule of Limitations for Ex Components that were assessed as
part of this equipment assembly are either addressed in the assembly or passed on to the
end-user, including details regarding the assessment;
– inspection of the assembly is completed in accordance with 6.6, and that
non-conformances are corrected;
– inspection of the assembly to ensure that it can be installed in accordance with
IEC 60079-14 (including any local installation criteria);
– review of the instructions for each piece of Ex Equipment to confirm proper application of
the Ex Equipment.
The final documentation package for an equipment assembly shall include the following:
- general specifications related to the application of the equipment assembly (see 4.1);
- explosion protection specifications related to the installation of the equipment assembly by
the end-user (see 4.2);
- suitability of the equipment assembly for the end-site hazardous area classification and for
the installation conditions defined by the end-user (see 4.3.1);
- details regarding any sources of release (see 4.3.2);
- competencies associated with the related manufacturing process personnel or verifying
party as applicable (see 4.4);
– details regarding items relevant to the explosion protection of the equipment assembly as
follows:
• actions regarding all Specific Conditions of Use as specified on equipment (5.2.2)
• item list of all Ex Equipment (see 5.2.3)
• details regarding other items that may be relevant to the explosion protection of the
equipment assembly (see 5.3);
– information regarding each wiring method, including termination means, used as part of
the equipment assembly (see 5.4);
– drawings of the equipment assembly (see 5.5);
– mechanical layout drawings of the equipment assembly (see 6.1);
– any provisions for earthing and bonding of the equipment assembly as required for
end-user site installation;
– 14 – IEC TS 60079-46:2017 © IEC 2017
– details regarding disassembly and reassembly at the end-user site of the equipment
assembly, either directly by the manufacturer of the equipment assembly or under the
responsibility of the manufacturer, if applicable (see 6.2);
– the need for system interfaces related to the explosion protection, either integral to the
equipment assembly or located remotely, if applicable (see 6.3);
– any residual risk identified by the ignition hazard assessment (see 6.4);
– all calculations and safety parameters relevant to the explosion protection of equipment
assembly (see 6.5);
– results of the inspection and testing (see 6.6);
– other material specifications (see 6.7.2);
– instructions for each piece of Ex Equipment;
– instructions for the equipment assembly (see 6.8);
– access to equipment;
– environmental controls;
– allowances for field cabling;
– Ingress Protection assessment results.
6.7.2 Other material specifications
Materials used other than materials that are part of an item of Ex Equipment, including Ex
Components that were assessed as part of this equipment assembly, and that are related to
the explosion protection of the equipment assembly, shall be verified for compliance with the
applicable requirements of IEC 60079-0 and ISO 80079-36.
6.7.3 Schedule Documents
Documents sufficient to define the equipment assembly shall be referenced on the equipment
assembly certificate (e.g. general assembly drawing that identifies the Ex Equipment used).
6.8 Instructions
In addition to the requirements in IEC 60079-0, IEC 60079-14 and ISO 80079-36, the
manufacturer of the equipment assembly shall prepare instructions that address the following,
as applicable:
– specific conditions of use that are not satisfied in the equipment assembly, but that are
able to be satisfied in the end-user site installation;
– characteristics of interfaces that are related to the explosion protection and that are to be
located remotely from the equipment assembly;
– any identified risks that are not mitigated in the equipment assembly, and that are able to
be satisfied in the end-user site installation;
– user-specified design requirements;
– all required markings of the assembly and locations of these markings;
– explosion protection specifications related to the installation of the equipment assembly by
the end-user (see 4.2).
7 Certificate
In addition to the requirements in IEC 60079-0 and ISO 80079-36, the certificate for the
equipment assembly shall address the following, as applicable:
– assembly at the factory by the manufacturer of the equipment assembly;
– assembly at the end-site directly by the manufacturer or under the responsibility of the
manufacturer of the equipment assembly;

– disassembly of an equipment assembly at the factory and reassembly at the end-site
directly by the manufacturer or under the responsibility of the manufacturer;
– where the assembly has an internal source of release, the certificate shall state that the
classification for the internal source of release has not been verified by the assessor, if
such is the case;
– the specific clauses of IEC 60079-14 that have been satisfied;
– the level of inspection completed on the equipment assembly;
– where items other than Ex equipment were included as part of the assembly, the
certificate shall list each such item and indicate the applicable marking on each item.
8 Marking
8.1 General
The equipment assembly shall be marked in accordance with IEC 60079-0 and ISO 80079-36,
except for the symbol for each type (or level) of protection used, which is replaced by
‘60079-46’. As the types of protection are not included on the marking, the equipment
protection level (EPL) for the complete equipment assembly shall be marked.
The manufacturer’s name that appears on the assembly marking shall be that of the
equipment assembler.
The Equipment Group, temperature classification (or maximum surface temperature),
equipment protection level (EPL), and ambient temperature range, along with optio
...