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1 Hazardous Areas Technical GuideHazardous AreasTechnical GuideAn Introduction to ATEX Terminology & RegulationsOrder number:1261090000/01/2011 BahrainBelarusBelgiumBosnia andHerzegovinaBrazilBulgariaCanadaChileC hinaColombiaCosta RicaCroatiaCzech RepublicDenmarkEcuadorEgyptEstoniaFinlan dFranceGermanyGreat BritainGreeceHong KongHungaryIcelandIndiaIndonesiaIranIrel andIsraelItalyJapanJordanKazakhstanKorea KuwaitLatviaLebanonLithuaniaLuxembourgMa cedoniaMalaysiaMaltaMexicoMoldovaNetherl andsNew ZealandNorwayOmanPakistan PeruPhilippinesPolandPortugalQatarRomani aRussiaSaudi ArabiaSerbiaSingaporeSlovakiaSloveniaSou th AfricaSpainSwedenSwitzerlandTaiwanThaila ndTunisiaTurkeyUkraineUnited ArabEmiratesUnited StatesUruguayUzbekistanVenezuelaVietnamW eidm ller is a leading international provider of solutionsfor electrical connectivity, transmission and conditioningof power, signal and data in industrial environments.

2 The company with headquarters in Detmold / Germanydevelops, produces and sells products in the field ofelectrical connectivity and electronics all over the a network of application specialists Weidm ller offersengineering services and develops application specificsolutions. The complete product and service portfolio consistentlyassures both Weidm ller and its customers ofcompetitive advantages and an increase in ller Interface GmbH & Co. KG Klingenbergstra e 16 32758 Detmold Phone +49 5231 14-0 Fax +49 5231 14-2083 AreasTechnical GuideAn Introduction to ATEX Terminology & Regulations2 ContentsIntroduction ..5 Directives, Standards and Regulations ..EC Directives .. directive 94/9/EC ATEX 95 .. directive 1999/92/EC ATEX 137 ..North America ..International IECEx Scheme ..IECEx Scheme Objective ..IECEx International Certification Scheme ..12 Basic Principles of Explosive Atmospheres.

3 Explosive atmosphere ..Ignition sources ..The Hazard Triangle ..15 Gases and Vapours ..Characteristics of gases and vapours ..Principles ..Explosion Group ..Temperature classification ..Area classification ..General ..Definitions of zones..Sources of release ..Equipment protection level (EPL) ..Gas explosion protection concepts for electrical equipment ..Zones of use..Protection concepts ..Installation ..Selection of equipment ..Protection against dangerous incendive sparking ..Electrical protection ..Wiring systems ..Additional requirements for flameproof enclosures d ..Additional requirements for Increased Safety e ..Inspection and Maintenance ..General requirements ..Inspections ..Regular periodic inspections ..Continuous supervision by skilled personnel ..Maintenance ..Repair ..47 Combustible dusts ..Definitions and Dust characteristics ..General ..Directives and standards relevant to dust.

4 Dust definitions ..49 ..Dust characteristics ..Area classification ..Definitions of zones..Grades of release, Extent of zones, Housekeeping ..Dust explosion protection measures ..Protective systems ..Protection by enclosures t ..Protection by pressurisation pD ..Protection by encapsulation mD ..Protection by intrinsic safety iD ..Other protection concepts ..Selection of apparatus ..Installations ..Types of cables ..Cable installation ..Cable entry devices ..Inspection and maintenance ..Inspection ..Maintenance ..Repair ..60 Explosion Protection in North America ..Overview of Regulations in North America (USA and Canada) ..USA: the National Electrical Code (NEC) ..Canada: the Canadian Electrical Code (CEC) ..Class I, II, and III Hazardous Locations ..Class I Locations ..Class II Locations ..Class III Locations ..Protection Techniques ..Protection Techniques under Class-Division.

5 Enclosure Types to IP Designations ..Equipment ..Material Groups for Class-Division ..Temperature Ratings for Class-Division ..Equipment Marking ..66 Appendices ..68 Appendix I .. Definitions and Abbreviations ..69 Appendix II ..Ingress and Impact protection for enclosures ..72 Appendix III ..Terminal Content using the Defined Arrangement Method ..73 Appendix IV ..Inspection schedules for gas atmospheres ..76 Appendix V ..Inspection schedules for dust atmospheres ..79 Appendix VI ..Environmental Type designations for enclosures ..81 Appendix VII ..Harmonised standards for ATEX 95 ..82 Appendix VIII .Certifications ..874 Introduction51 IntroductionSection 1 IntroductionWeidm ller is a leading international provider of solutions for electrical connectivity, transmission and conditioning of power, signal and data in industrial environments. The company with headquarters in Detmold / Germany develops, produces and sells products in the field of electrical connectivity and electronics all over the world.

6 Within the European Union we offer products designed and manufactured to the European standards for Electrical Apparatus for Potentially Explosive Atmospheres, the new ATEX directive , which has been in use since 1996 and has been mandatory throughout the EU since July ller offers the most comprehensive range of ATEX certified enclosures, rail mounted terminals and accessories. Outside the European area, which is not controlled by the ATEX directive , our products are in line with the IECEx scheme. IECEx will have a growing importance for the future as a leading standard all over the world and the national standards follow the IECEx rules more and more. For other local installation requirements for hazardous areas we offer the relevant approvals based on the related local standards. In addition to our leading manufacturing competence in the precision mechanics sector we offer a market and customer orientated portfolio of products for our target groups in industrial and process technology as well as transportation publication provides a brief overview of the essential aspects of explosion protection.

7 Ultimately, safety in a potentially explosive atmosphere is a team effort. Manufacturers have a responsibility to ensure only safe equipment is placed on the market. Installers must follow the instructions provided and use the equipment only for its intended purpose. Finally, the user has a duty to inspect and maintain the equipment in a safe working order. The directives, and national and international standards provide a basis for a safer 2 Section 2 Directives, Standards and Regulations2 .1 EC DirectivesFree movement of goods is a cornerstone of the common market. The mechanisms in place to achieve this aim are based on prevention of new barriers to trade, mutual recognition and technical New Approach to product regulation and the Global Approach to conformity assessment take New Approach directives are based on the following principles: Harmonisation is limited to Essential Health and Safety Requirements (EHSR) Only products fulfilling the EHSR may be placed on the market and put into service Harmonised standards which are transposed into national standards, are presumed to conform to the corresponding EHSR Application of harmonised standards or other technical specifications remains voluntary, and manufacturers are free to choose any technical solution that provides compliance with the EHSR Manufacturers may choose between different conformity assessment procedures provided for in the applicable directiveEquipment that complies with the new Directives may carry the CE mark.

8 The CE mark together with the related EC Declaration of Conformity is like a passport to the common requirements apply for Components than to Equipment. The CE marking is not applied to a Component, and there is a different document of conformity which has to be made and supplied, called an Attestation of two Directives concerned with hazardous areas are called the ATEX 95 and ATEX 137. The names are related to articles 95 and 137 of the EC treaty. ATEX is an abbreviation from the French Atmosph res Explosibles . 2 .1 .1 directive 94/9/EC ATEX 95 directive 94/9/EC on the approximation of the laws of the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheresEquipment, protective systems, and the devices to which this directive applies must meet the essential health and safety requirements set out in Annex II of the directive which apply to them, account being taken of their intended.

9 1 .1 .1 Scope and general definitionsATEX 95, formerly known as ATEX 100a, is aimed at manufacturers. It applies to equipment and protective devices intended for use in potentially explosive atmospheres. Safety and controlling devices for use outside the hazardous area but essential for the safe operating of equipment inside it are also covered. The directive applies to electrical as well as mechanical equipment and applies to gases, vapours, mists and dust , Standards and Regulations72 Directives, Standards and Regulations Equipment means machines, apparatus, fixed or mobile devices, control components and instrumentation thereof and detection or prevention systems which, separately or jointly, are intended for the generation, transfer, storage, measurement, control and conversion of energy for the processing of material and which are capable of causing an explosion through their own potential sources of ignition.

10 Protective systems means devices other than components of the equipment defined above which are intended to halt incipient explosions immediately and/or to limit the effective range of an explosion and which are separately placed on the market for use as autonomous systems. Components means any item essential to the safe functioning of equipment and protective systems but with no autonomous function. Safety devices, controlling devices and regulating devices means devices intended for use outside potentially explosive atmospheres but required for or contributing to the safe functioning of equipment and protective systems with respect to the risks of explosion. Assembly means a combination of two or more pieces of equipment, together with components if necessary, and placed on the market and/or put into service as a single functional unit. Assemblies can be placed on the market in different ways.