Principles of Explosion-Protection

Basics

Principles of Ex-Protection The safety you rely on. Delivering world-class reliability and safety in high consequence harsh and hazardous environments

Only Eaton’s Crouse-Hinds can deliver... • Protection and safety of people and assets around the world with unsurpassed reliability and quality in every product we offer • Industry leading innovation and product efficiency • Product solutions designed and certified for global specifications • Best-in-class, global sales, and customer service teams that provide local support

The Eaton advantage.

Crouse-Hinds series remains the brand that stands And now, the next phase in the evolution of the for safety in the harshest of environments when brand you trust: Crouse-Hinds joins the leading power management is most critical. While it all Eaton portfolio of reliable, efﬁcient and safe began with the Condulet®, the Crouse-Hinds electrical power management solutions. brand has grown into the premier name for a comprehensive portfolio of solutions for high- More protection. More technology. consequence harsh and hazardous environments. Expect more. Table of Contents

1 Basics The history of explosion-protection and the legislative provisions ...... 4 Physical principles of explosion-protection ...... 6 Explosion-protection concepts ...... 9 Hazardous areas ...... 10 Gas-Ex areas ...... 11 Dust-Ex areas ...... 12

2 European directives on explosion protection European Ex-directives ...... 13 ATEX directive 2014/34/EU ...... 14 Directive 1999/92/EC ...... 19

3 Explosion protected electrical equipment Explosion-protected Electrical Equipment: Basics ...... 21 Equipment protection level EPL ...... 23 Type of protection to EN 60079 ...... 27 Explosion protected mechanical equipment Explosion-protected Mechanical Equipment; Requirements ...... 50 Safety devices according to EN 50495 Safety devices for the safe operation of equipment with regard to explosion risks ...... 51 Marking Marking of electrical equipment for use in potentially explosive atmospheres ...... 52

4 Erection, operation, maintenance and repair Requirements for the erection, operation, maintenance and repair ...... 55 Design, selection and erection of electrical installations according to EN 60079-14 ...... 55 Operation of installations in hazardous areas ...... 58 EN 60079-17; Explosive atmospheres - Part 17: Electrical installations, inspection and maintenance ...... 59 Continuous supervision ...... 60

5 Marking of degree of protection Marking of degree of protection of electrical equipment for use in explosive atmospheres .....61

6 IECEx and UNECE IECEx Conformity Assessment System...... 63 UNECE ...... 64

7 Wall chart Ex-marking - NEC/CEC code digest - overview ATEX/IECEx and NEC/CEC ...... 65 Explosion-Protected Solutions Global Support & - Worldwide- Manufacturing With the brand of CEAG we develop and Our sales support and manufacturing facilities manufacture electrical products that provide are strategically positioned around the world to safety, productivity, innovation and labour deliver products close to your project. Whenever savings in hazardous, industrial and commercial required we are there on-site during construction, environments - for more than 100 years. commissioning and training. We design, configure and manufacture explosion- Eaton’s Crouse-Hinds Division manufactures in protected electrical equipment for your safety. 5 continents and sells into more than 100 Of course we are certified for all functional areas countries. We have dedicated sales support in according to the latest quality standards every major location with local technical sales and ISO 9001:2015 and in addition for the necessary engineering teams to support your immediate explosion protection according to ISO/IEC 80079-34. needs. As one of the largest oil & gas bulk We will implement consistently your specifications electrical and instrument material suppliers, we according to current national directives and stand- can easily provide you a single source for all the ards at the application site. components to complete your project on time and on budget. In addition to systems and components built to ATEX Directive 2014/34/EU and European Standards, we also provide products with international approvals like IECEx (IEC Ex Scheme), UL and CSA (USA, Canada), INMETRO (Brazil) and NEPSI (China) as well as certifications of Eastern Europe testing and certification organisations and the new TR-CU Customs Union (EAC).

2 EATON www.crouse-hinds.de Preface 0

Preface This publication provides a brief survey of the essential aspects of explosion-protection. The statutory regulations deﬁne the obligatory duties of manufacturers, installers and operators of electrical installations in explosive atmospheres. Important hints you will also ﬁnd in the regulations of the professional associations. Eaton‘s Crouse-Hinds Division seminars imparts expert knowledge in explosion protections in theory and practice. (https://www.crouse-hinds.de/ de/seminar-explosionsschutz/)

www.crouse-hinds.de EATON 3 Principles of Explosion-Protection 1 The history of explosion-protection and the legislative provisions

The history of explosion- Light switches had to be installed protection and the legislative outside of the hazardous loca- provisions tions, and in the case of a failure As early as 1909 Concordia Ele- or the lack of explosion-protected ktrizitäts-Aktiengesellschaft, lat- lighting, access to these loca- er called CEAG, began to manu- tions was only permitted with facture firedamp-protected safety lamps. Therefore, in gen- electrical miners’ lamps for the eral, electrical installations were mining industry. Until then, only not used in hazardous locations. lamps with a naked flame were available. The first contribution Machines with slip rings or to safety was made in1815 by commutators had to be de- the English chemist, Sir Hum- signed in such a way that the phry Davy, who developed an slip ring or commutator was, at oil lamp that prevented the least, enclosed and the enclo- propagation of the flame by sure purged thoroughly under means of a close-meshed overpressure with extraneous screen. The elementary experi- air or a suitable gas. Purging ments carried out by Dr.-Ing. had to start prior to switching e.h. Carl Beyling, a mining engi- on the machine or the machine neer, relating to the specially had to be built into a flameproof protected electrical motors and enclosure. This requirement ap- apparatus in coal mines against plied to all locations where ex- firedamp were a decisive step plosive gas or vapour/air mix- in the development of explo- tures might occur. sion-protection. The governing design principles of firedamp protection devices on electrical The first German regulations on machines, transformers and the subject of the protection of switchgear issued in 1912 were hazardous installations were the based on the results of these “Guiding principles on the instal- Firedamp-proof miner‘s lamps (combustion lamps) experi ments. lation of electrical equipment in The following types of protec- hazardous production areas and specifications and introduced tion were accepted as protec- storage rooms (VDE 0165/1935), the Ex identification marking for tive measures: which were issued in 1935. electrical apparatus built in compliance with it. • Oil immersion • Closed encapsulation The governing principles and • Plate encapsulation specifications of the VDE regula- • Close-meshed screen Flameproof tions 0165 and 0171 were the enclosure basis of the police decree dated • Labyrinth encapsulation } 13.10.1943 for electrical appara- • “Flat joint” encapsulation tus in hazardous locations and in mines subject to the hazard of firedamp. The police decree was From 1924 incandescent lamps The fundamental revision of primarily aimed at the manufac- only were permitted for lighting these regulations began with turers of electrical apparatus. It Research papers by hazardous areas, whereby the the VDE regulations 0171 “Con- specified that explosion-protect- Carl Beyling, mining engineer luminous element was hermeti- structional regulations for explo- ed electrical equipment could cally sealed. The incandescent sion-protected apparatus”, only be placed on the market, in- lamps had to be protected with which came into force in 1943. stalled and operated if it con- a strong glass that also tightly They provided the manufactur- formed to the so-called VDE reg- enclosed the lamp holder. ers of electrical equipment for ulations and had successfully use in potentially ex plosive at- passed the specified type and mospheres with the necessary routine tests. documents for a safe design and construction. The responsible factory inspec- torate division was chosen to be The regulation not only de- the competent authority to described the individual types of fine to what extent a room or Ex protection and the scope of plant might be subject to the their application, but also includ- hazard of explosion. ed a number of constructional

Police degree dated13.10.1943

4 EATON www.crouse-hinds.de Principles of Explosion-Protection The history of explosion-protection and the legislative provisions 1

The “Decree concerning electri- Directive 94/9/EC on the ap- cal installations in potentially ex- proximation of the laws of the plosive atmospheres (ExVO)”, Member States concerning which was issued in 1963, not equipment and protective sys- only introduced the obligation to tems for use in potentially ex- have the explosion-protected plosive atmospheres, issued on apparatus tested by the Federal 23.03.1994 by the European Physico-Technical Institute Parliament and Council, irrevo- (Physikalisch-Technische Bun- cably replaced any previous di- desanstalt PTB) or the Mining rectives concerning explosion- Test Station (BVS), but also the protection that existed on a obligation to obtain the design European level from 01.07.2003. approval from the authorities of the competent federal state. On 12.12.1996, Directive 94/9/ EC was converted into national In 1975 the Council of the Euro- law by the second decree con- pean Community issued frame- cerning the equipment safety ElexV from 1980 work directives on explosion- law and the changes relating to protection. The European the equipment safety law by The BetrSichV replaces the standards for electrical equip- the explosion-protection decree ElexV for explosion protection. ment for use in hazardous areas (ExVO). With this decree, the However, within the scope of were drawn up by CENELEC, acetyl decree (AcetV), the the transitional regulations, the the “European committee for decree on flammable liquids ElexV could still be applied for electro-technical standardiza- (VbF) and the ElexV were also installations that were commis- tion”. In Germany the new Euro- brought into line with the sioned before 03.10.2002. pean standards EN 50 014 to European law. EN 50 020 were adopted in the national standards as VDE On 19.04.2014 Directive standards. These new stand- On 28.01.2000, Directive 2014/34/EU, the successor di- ards DIN EN 50014 to 50020/ 1999/92/EC of the European rective to 94/9/EC came into ef- VDE 0170/0171, Parts 1 to 7, Parliament and Council, dated fect with a two-year transition designated as VDE regulations, 16.12.1999, the second impor- period. This new directive had came into force on 01.05.1978. tant directive concerning explo- become necessary as a result sion protection, was published of the approximation with other in the official gazette of the Eu- EU directives, without revising The application of these Euro- ropean communities. It con- the technical content. On a na- pean standards for the contains minimum requirements tional level, this new ATEX di- struction and testing of explo- for the improvement of the rective was transposed in the sion-protected electrical safety and health protection of 11th Regulation on the Product apparatus was governed employees potentially at risk Safety Act. (ExVO –11. ProdSV). throughout Europe by the “EC from explosive atmospheres. Directive 79/196/EC”. With the This EC directive, also called new regulation, now known as the European Occupational As a result of the reform of na- ElexV, among other things this Safety Directive, lays down the tional and European regulations EC Directive was implemented rules for operational explosion (REACH regulation- 1907/2006/ on 01.07.1980 and explosion pro- protection and is aimed at the EC, the Chemicals Act ChemG tection newly regulated for operators of installations where and the Occupational Safety Act manufacturers and operators. explosion hazards are to be ArbSchG,), it was also neces- Furthermore, the expertise of expected. sary to review the Industrial the testing establishments and Safety Regulation (BetrSichV) the design approval were re- with the set of Technical Regu- placed by a type sample test. The directive was converted lations on Industrial Safety The type sample test was car- into national law on 03.10.2002 (TRBS) and the Ordinance on ried out by authorized testing in the “Decree on health and Hazardous Substances establishments of the member safety protection relating to the (GefStoffV) with the set of states of the EU (Notified Bod- provision of work equipment Technical Rules for Hazardous ies). The certificates of conform- and the use thereof during op- Substances TRGS. ity and inspection granted on eration, safety during the opera- the basis of the said tests were tion of installations requiring su- valid throughout Europe. pervision and the organisation of operational safety provisions (Industrial Safety Regulation – BetrSichV)”.

Explosion-protected electrical equipment from the 60‘s www.crouse-hinds.de EATON 5 Principles of Explosion-Protection 1 Physical principles of explosion-protection

Physical principles of explo- Definition „Explosive atmos- sion-protection phere“ Mixture with air, under atmos- Explosive mixture – pheric conditions, of flammable explosive atmosphere substances in the form of gas, §2 of the Ordinance on Hazardous vapour, dust, fibres or flyings Substances (GefStoffV) contains which, after ignition, permits a the following terms for explosive selfsustaining propagation. mixture / explosive atmosphere. As these terms are not congruent with the definitions according to Standard atmospheric condi- the standards/IEC (International tions (relating to the properties Electrotechnical Vocabulary), of an explosive atmosphere) ac- supplement the terms of the cording to IEC 60079-0, the ba- GefStoffV found there: sic standard for electrical equipment, and ISO 80079-36, the Physical basics of an explosion basic standard for mechanical 1. An explosive mixture is a plosion limits change: For exam- grate quickly or, upon heat- equipment, are specified as fol- ple, as the proportion of oxygen ing, explode when partially mixture of combustible lows: gases, vapours, mists or increases, the upper explosive confined. whirled up dust with air or • Temperature –20 °C to +60 °C, limit is raised. Generally, the ex- 2. oxidizing, if they are not another oxidizing agent, • Pressure 80 kPa (0.8 bar) to plosive limits are indicated in normally inherently combus- whereby, after an ignition 110 kPa (1,1 bar) and percent by volume. The percent tible, but, in contact with source has become active, by volume, abbreviated to %/vol., combustible substances or • air with normal oxygen content, an automatic flame propa- is the content by volume of the preparations, mainly due to generally 21%/vol. gation, which generally in- combustible matter in the mix- the release of oxygen, they volves a sudden rise in This limitation is necessary, as ture with air. The lower explo- enhance the fire hazard and temperature and pressure, the essential safety parameters sive limit of hydrogen is 4.0 % the intensity of a fire consid- takes place. for explosion protection are a by volume, and the upper explo- erably function of the pressure, tem- sive limit 75.6 % by volume. 2. A dangerous explosive 3. highly flammable, if: perature and oxygen content The safety coefficients define mixture is one which arises a) in a liquid state, they have and can only be considered to quantitative data on the proper- in such a quantity that spe- an extremely low flash point be sufficiently constant if they ties of most of the known sub- cial protective measures and a low boiling point, are within the limits of these stances are necessary for the main- b) in a gaseous state, they parameters. The methods for tenance of the health and are flammable in contact determining the safety parame- safety of workers or other Flash point with air at ambient tempera- ters and the characteristics of persons. ture and pressure. combustible substances are Combustible liquids are not the 3. A dangerous explosive at- based, among other things, on actual combustion agent, but 4. highly flammable, if: mosphere is a dangerous the standard series ISO/IEC the vapours that develop above a) they can become hot and mixture with air as the oxi- 80079-20. the liquid, when mixed with air, finally catch fire in contact dizing agent under atmos- form the explosive atmosphere. with air at ambient tempera- A mixture is potentially explo- pheric conditions (ambient ture without any application sive if, under atmospheric con- temperature from -20 °C to of energy, ditions, the concentration is Definition „Flash point“: +60 °C and pressure from b) in a solid state, they can within given, substance-specific lowest liquid temperature at 0.8 bar to 1.1 bar). readily catch fire after brief limits. Here distinction is made which, under certain standard- contact with a source of igni- 4. A hazardous area is the between the upper and lower ized conditions, a liquid gives tion and continue to burn or area in which a dangerous explosion limit, whereby the off vapours in quantity such as to be consumed in a hazard- explosive atmosphere can mixture is still combustible to be capable of forming an ig- ous manner after removal of occur. above the upper explosion limit. nitable vapour/air mixture. the ignition source, Hazardous substances and c) they have a very low flash Combustible substance Definition “Upper explosive preparations are classified in point in a liquid state, mixed with air limit (UEL)” accordance with their proper- d) they develop highly flam- The description of the physical Concentration of flammable gas ties according to §3a, Clause 1 mable gases in dangerous principles presupposes some or vapour in air above which an of the Chemicals Act, i.a. as quantities on contact with basic definitions which are de- explosive atmosphere will not follows: water or damp air. rived, in part, from the norma- be formed. 1. explosive, if, in a solid, tive specifications. The Europe- 5. flammable, if they have a low liquid, pasty or gelatinous an regulations and the flash point in a liquid state. state, they may also react associated national regulations Definition “Lower explosive An explosive atmosphere that exothermically without at- are also based on these specifi- limit (LEL)“ causes damage in the event of mospheric oxygen, thereby cations. The definitions used in an explosion is called a “hazard- Concentration of flammable gas quickly evolving gases, and explosion protection can be ous explosive atmosphere”. It is or vapour in air below which an which, under defined test found in Chapter 426 of the IEV possible to roughly assess explosive atmosphere will not conditions, detonate, defla- (IEC 60050), the International be formed. Electro-technical Vocabulary. Under conditions other than atmospheric conditions, the ex-

6 EATON www.crouse-hinds.de Principles of Explosion-Protection Physical principles of explosion-protection 1

whether or not an atmosphere is the simultaneous occurrence of a Flames and hot gases Mechanical sparks: explosive. In confined spaces, re- hazardous explosive atmosphere (including hot particles) friction; hammering; grinding gardless of their size, a continu- and an effective ignition source. Flames are associated with ous volume of 10 litres of explo- Open flames and electric ignition combustion reactions at temper- sive atmosphere must already be sources have always been con- atures of more than 1000 °C. regarded as hazardous. In the sidered to be extremely critical Hot gases are produced as reac- case of smaller spaces with a and the avoidance of these ignition products and, in the case of volume of <100 m³, this also ap- tion sources by respective pro- dusty and/or sooty flames, glow- plies for smaller quantities. tective measures has already ing solid particles are also pro- been described in past docu- duced. ments. However, in order to be Flames and their hot reaction In addition to the material de- able to prevent the occurrence of products or otherwise highly scription of an explosive atmos- explosions, it is necessary to take heated gases can ignite an ex- phere, it is also necessary to de- all possible effective ignition plosive atmosphere. scribe its local occurrence. sources into consideration. Flames, even very small ones, are among the most effective a) as return currents in power Deﬁnition „Hazardous area“ ignition sources. Ignition sources that can set off generating systems – in parti- Area in which an explosive at- an explosion are: cular in the vicinity of electric mosphere is present, or may be railways and large welding sy- expected to be present, in Mechanically generated Hot surfaces stems - if, for example, conduc- quantities such as to require sparks tive electrical system compo- special precautions for the con- If an explosive atmosphere As a result of friction, impact or nents that are laid in the ground, struction, installation and use of comes into contact with a heat- abrasion processes, such as such as rails and cable shea- electrical equipment. ed surface, ignition can occur. grinding, particles can become Not only can a hot surface itself separated from solid materials thing, lower the resistance of act as an ignition source, but a and become hot due to the en- this return current path; Ignition sources ergy used in the separation pro- Heat: b) as a result of a short circuit or of In addition to the combustible cess. If these particles consist open ﬂames; hot surfaces; a short circuit to earth in the substance and the oxidizing hot gases; gases under pres- of oxidizable substances, e.g. event of faults in the agent, e.g. air, a third partner, sure; sunlight; infrared light; iron or steel, they can undergo electrical installations; namely an ignition source, is re- an oxidation process, thus ultrasonic waves c) as a result of magnetic induction quired for an explosion. EN 1127- reaching even higher tempera- (e.g. near electrical installations 1 specifies 13 types of ignition tures. with high currents or radio sources that shall be taken into These particles (sparks) can ig- frequencies) and; account in connection with explo- nite combustible gases and va- sion protection. pours and certain dust/air mix- d) as a result of lightning. In order to prevent the ignition of tures (in particular metal dust/ If parts of an installation that a hazardous explosive atmos- air mixtures). In deposited dust, can carry stray currents are dis- phere, it is necessary to be aware smouldering can be caused by connected, connected or of all possible ignition sources sparks, and this can become a bridged, even in the case of that may occur and to ensure that source of ignition for an explo- minimal potential differences, these ignition sources cannot be- sive atmosphere. an explosive atmosphere can come effective by applying explo- be ignited as a result of electric dust layer or a combustible sol- sion protection measures. sparks and/or arcs. id in contact with a hot surface Electrical installations and ignited by the hot surface In the case of electrical installa- Here a risk assessment is carried can also act as an ignition tions, electric sparks and hot Static electricity out to analyse the probability of source for an explosive surfaces can occur as sources Incendive discharges of static atmosphere. of ignition. Electric sparks can, electricity can occur under giv- for example, be generated: en conditions. The discharge of charged, insulated conductive

a) when electric circuits are Electric sparks: opened and closed; opening and closing of contacts; short circuits; over voltage; b) by loose connections; static discharges

c) by stray currents.

Stray electric currents, ca- thodic corrosion protection Stray currents can flow in elec- trically conductive systems or parts of systems:

Ignition limit of gases an vapours in air www.crouse-hinds.de EATON 7 Principles of Explosion-Protection 1 Physically principles of explosion-protection

Ionizing radiation Note: Ionizing radiation can ignite ex- In pressure lines of air compres- plosive atmospheres (especially sors and in containers connect- explosive atmospheres with ed to these lines, explosions dust particles) as a result of en- can occur as a result of a com- ergy absorption. Ionizing radia- pression ignition of lubricating tion can cause chemical decom- oil mists e.g. by quick-acting position or other reactions, valves in long pipes. which can lead to the generation of highly reactive radicals or unstable chemical compounds. Exothermic reactions, includ- This can cause ignition. ing self-ignition of dusts Exothermic reactions can act as an ignition source if the rate of Ultrasound heat generation exceeds the When ultrasonic sound waves are rate of heat loss to the sur- used, a large proportion of the roundings. Whether a high energy emitted by the electro- temperature can develop in the acoustic transducer is absorbed event of a reaction is depend- parts can easily lead to incentive All conductive parts located in by solid or liquid substances. As ent, among other parameters, sparks. With charged parts the radiation field function as a result, the sub stance exposed on the volume/surface ratio of made of non-conductive materi- receiving aerials. If the field is to ultrasonics heats up so in- the reacting system, the ambi- als, which include most plastics powerful enough and if the re- tensely that, in extreme cases, ent temperature and the resi- as well as some other materi- ceiving aerial is sufficiently ignition can be induced. dence time. These high temper- als, brush discharges and, in large, these conductive parts atures can lead to both the special cases, during fast sepa- can cause ignition in explosive ignition of explosive atmos- ration processes or due to a Adiabatic compression and atmospheres. shock waves pheres and the initiation of combination of conductive and smouldering and/or burning. In the case of adiabatic or almost non-conductive materials, prop- The received radio-frequency agating brush discharges are adiabatic compression and in power can, for example, make also possible. Cone discharges shock waves, such high tem- thin wires glow or generate Catalysers can also set off reac- from bulk material and cloud peratures can occur that explo- sparks during the contact or in- tions where energy is released, discharges can also occur. sive atmospheres (and deposit- e.g. between hydrogen/air mix- terruption of conductive parts. Brush discharges can ignite ed dust) can be ignited. The tures and platinum, of alkaline The energy picked up by the re- almost all explosive gas and temperature increase depends metals with water, the self-igni- ceiving aerial, which can lead to vapour atmospheres. mainly on the pressure ratio, tion of combustible dusts, the ignition, depends mainly on the not on the pressure difference. self-heating of animal fodder in- distance between the transmit- Lightning duced by biological processes, ter and the receiving aerial as the decomposition of organic If lightning strikes in an explosive well as on the dimensions of peroxides, or polymerization atmosphere, ignition will always the receiving aerial at a given reactions. occur. Moreover, there is also a wavelength and high-frequency possibility of ignition due to the power. high temperature attained by lightning conductors. High currents flow from where the light- Electromagnetic waves with ning strikes and these currents frequencies ranging from 11 15 can produce sparks in the vicinity 3 × 10 Hz to 3 × 10 Hz of the point of impact. Even in Radiation in this spectral range the absence of lightning strikes, can – in particular when fo- thunderstorms can cause high cussed - become a source of ig- induced voltages in equipment, nition due to absorption in ex- protective systems and plosive atmospheres or on solid components. surfaces. Sunlight, for example, can trigger an ignition if objects cause a convergence of the ra- Electromagnetic waves with diation. In the case of laser radi- frequencies ranging from ation, even at great distances 4 12 10 Hz to 3 x 10 Hz (high the energy or power density of frequency) even an unfocused beam can Electromagnetic waves are be so great that ignition is emitted by all systems that gen- possible. Here, too, the process erate and use high-frequency of heating up occurs mainly electrical energy (high-frequen- when the laser beam strikes a cy systems), e.g. radio transmit- solid body surface or when it is ters or industrial or medical RF absorbed by dust particles in generators for heating, drying, the atmosphere or on dirty hardening, welding, cutting, etc. transparent parts. Impact of a dust explosion: Rolandsmühle, Bremen, Germany

8 EATON www.crouse-hinds.de Principles of Explosion-Protection Primary and secondary explosion-protection concepts 1

Primary and secondary explo- Prevention of an ignition the case of liquid substances, nical means is that it needs sion-protection concepts Here distinction is made be- the concentration is usually constant servicing and monitor- Explosion protection measures tween two procedures: kept below the lower explosive ing. In addition to this, precau- shall always be taken if the for- limit, since a large amount of ef- tions have to be taken in case fort is required to keep the con- the installation should operate mation of a hazardous explosive • Raising the flash point atmosphere is to be expected centration in the upper range. at a lower output or fail alto- and, at the same time, an igni- Here the flash point of a flam- gether. mable liquid shall be at least 5 K tion source with sufficient ener- • Inertisation gy is present. In accordance to 15 K above the processing or Secondary explosion If the proportion of oxygen in a with Directive 2014/34/EU, the room tem perature. In the case protection mixture is less than 10 % by measures are divided into pri- of water soluble, flammable volume, then, as a general rule, Once all the possibilities of primary, secondary and tertiary substances this can be a mixture is not explosive. In or- mary explosion protection have measures. achieved by adding water. der to attain such a low propor- been exhausted, there can still tion, so-called inert gaseous be areas where a hazardous ex- substances such as nitrogen, plosive atmosphere occurs. carbon dioxide, water steam or These areas are called hazard- halogenated hydrocarbon are ous areas. Here secondary ex- added to the mixture until the plosion protection with protec- desired concentration is ob- tive measures that render tained. If the percent by volume ignition sources ineffective are of the inert gas to the flamma- applied. All the types of protec- ble gas is in the minimum ratio tion described in the standards of 25:1, an explosive atmos- of the series IEC 60079-0ff for phere cannot form, regardless electrical equipment and ISO/ of the quantity of air added. IEC 80079-36ff for mechanical equipment are secondary explosion protection measures. • Ventilation The formation of a hazardous Constructional (tertiary) explosive atmosphere can be explosion protection prevented or restricted by ventilation. In rooms above ground If, in spite of the measures level and without special venti- named above, ignition sources lation, the air is generally re- and, as a result, explosions are newed by natural ventilation to be expected, e.g. due to once per hour. By way of com- electrostatic discharges or parison, the exchange of air in chemical reactions, construc- cellar rooms takes up to 2.5 tional or tertiary explosion pro- hours. The concentration of the tection measures shall be taken. Primary explosion protection mixture can, however, only be • Lowering the processing calculated if the escaping quan- The avoidance of a hazard is al- temperature tity per unit of time of a flam- ways better than any protection The explosion-protected design mable substance is known and method. Among other things, it With this method it is neces- is, for example, a constructional if an equal distribution can be is possible to prevent an explo- sary to apply technical meas- measure that cannot prevent an assumed. sion by excluding the formation ures (e.g. cooling) to ensure explosion, but can limit the ef- of an explosive atmosphere. Pri- that the processing tempera- fects to a non hazardous degree. ture is always at least 5 - 15 K mary explosion protection can, The natural flow conditions in a The equipment shall be de- lower than the flash point. It is, for example, be achieved by ap- room can be assessed by an ex- signed in such a way that it can however, necessary to keep plying the following measures: pert on ventilation, who will withstand the maximum explo- faults, standstills, leakages and then usually recommend venti- sion pressure and, in extreme other influence factors safely Avoidance of ﬂammable lation by technical means, as cases, even the detonation under control. substances the natural ventilation cannot be pressure. A detonation can hap- pen quickly in pipes and elon- Whenever possible, flammable considered to be a constant. Limitation of the concentration gated constructions. If the substances should be substitut- Compared to natural ventilation, flameproof design is not able to ed by substances that are not The formation of an explosive it ensures the exchange of larg- withstand the increase in pres- capable of forming an explosive atmosphere can be prevented if er quantities of air and a more sure, effective explosion pres- mixture. it is possible to limit the con- carefully directed air flow. centration of a substance to the Moreover, the concentration oc- sure relief measures shall be range below the lower or above curring can be determined with taken. the upper explosive limit. This is a considerably higher degree of often possible with gases. reliability. With technical ventila- However, problems arise if tion, gas clouds that are re- there is a gas leak or if the igni- leased due to faults can be tion range has to be passed quickly diluted to non-critical through when starting up or values. On the other hand, the closing down the installation. In drawback of ventilation by tech- www.crouse-hinds.de EATON 9 Principles of Explosion-Protection 1 Hazardous areas

Hazardous areas probability of the occurrence of The international definition of Zone 20 an explosive atmosphere. zones is given in EN 60079-10. • Area in which an explosive at- Definition In addition, distinction is made For this reason, both defini- mosphere in the form of a An area in which an explosive between flammable gases, va- tions, which are almost identi- cloud of combustible dust in atmosphere is present, or may pours and mists on the one cal, are stated below. air is present continuously, or be expected to be present in hand, and combustible dusts on for long periods or frequently quantities such as to require the other. Information on the Zone 0 (EN 60079-10-2). special precautions for the con- zone classification can also be • Area in which an explosive at- • An area in which a hazardous struction, installation and use of found in the Explosion-Protec- mosphere consisting of a explosive atmosphere in the electrical apparatus tion Rules of the Employers’ mixture of air with flammable form of a cloud of combusti- (IEV 426-03-01). Liability Insurance Association substances in the form of ble dust in the air is present for the Chemical Industry and gas, vapour or mist is present continuously, for long periods EN 60079-10. continuously or for long peri- Note: or frequently (GefStoffV). ods or frequently A hazardous area is a (EN 60079-10-1). Zone 21 three-dimensional region Classification of hazardous • An area in which a hazardous or space (EN 60079-14). areas • Area in which an explosive at- In national law the definition of explosive atmosphere con- mosphere in the form of a zones given in the Ordinance sisting of a mixture of air and cloud of combustible dust in Zone classification on Hazardous Substances flammable gases, vapours or air is likely to occur occasion- In accordance with Directive (GefStoffV) applies. mists is present continuous- ally in normal operation 1999/92 EG, hazardous areas ly, over long periods or fre- (EN 60079-10-2). quently (GefStoffV). are divided into six zones. The • An area in which a hazardous classification is based on the explosive atmosphere in the Zone 1 form of a cloud of combusti- • Area in which an explosive ble dust in the air can only gas atmosphere consisting of form occasionally during nor- a mixture of air with flamma- mal operation (GefStoffV). Gas-Ex-areas ble substances in the form of gas, vapour or mist is likely to Zone 22 occur in normal operation oc- • Area in which an explosive at- Fuel tank casionally (EN 60079-10-1). Zone 2 mosphere in the form of a • An area in which a hazardous cloud of combustible dust in explosive atmosphere con- Valve air is not likely to occur in nor- sisting of a mixture of air and mal operation, but, if it does flammable gases, vapours or occur, it will persist for a Zone 0 mists can form during normal short period only operation (GefStoffV). (EN 60079-10-2).

Zone 1 Zone 2 flammable liquid • Area in which an explosive at- • Area in which an explosive mosphere in the form of a gas atmosphere consisting of cloud of combustible dust in Tank Flange/Pump/Piping a mixture of air with flamma- air does not normally occur; if ble substances in the form of it occurs, then only rarely and Example of the zone classiﬁcation of explosive gas atmospheres to gas, vapour or mist is not like- for a short time (GefStoffV). EN 60079-10-1 ly to occur in normal operation, but if it does occur, will persist for a short period only Note: Dust-Ex-Areas (EN 60079-10-1). Layers, deposits and accumula- • An area in which a hazardous tions of combustible dust are to Sack emptying station explosive atmosphere con- be considered in the same way Zone 22 sisting of a mixture of air and as any other source that forms flammable gases, vapours or an explosive atmosphere. mists does not normally oc- Normal operation is understood cur, and if it occurs, then only Zone 21 as being the state where instal- rarely and for a short time lations are being used within (GefStoffV). their design parameters. Zone 20

Example of the zone classiﬁcation of explosive dust atmospheres to EN 60079-10-2

10 EATON www.crouse-hinds.de Principles of Explosion-Protection Gas-Ex-areas 1

Examples of applications can usually accommodate these Zone 2 and the classification of explosive gases for longer peri- suitable equipment: ods, so that it is also necessary Zone 1 Gas-Ex-areas to expect a Zone 0 area here. With equipment for Zone 0, ig- Gas-Ex-areas nition sources shall be protected against explosion even if the Zone 0 occurrence of failures is only Zone 0 mainly encompasses ar- rare. Hence, the equipment eas such as the inside of en- shall satisfy the following re- closed containers, pipes and ap- quirements: paratus that contain flammable Should one type of protection liquids. fail or should two faults occur Here the respective operating simultaneously, sufficient protection against explosion shall temperature lies above the Zone classification example: Loading/discharging flammable liquids still be ensured. flash point. The hazardous area from a road transporter tanker without stand-alone ventilation. is above the surface of the liq- The constructional require- uid and not in the liquid. Most ments DIN EN 60079-26 (VDE gases of flammable liquids are 0170/0171/Part 12-1) state that type of protection “ia” to EN The chapter „Electrical equip- heavier than air and spread in a the necessary explosion protec- 60079-11, Intrinsic Safety, or ment for use in hazardous are- similar way to liquids. Cavities tion is attained if the equipment satisfies the requirements of as” describes the individual such as pits or pump sumps is built in accordance with the two types of protection of the types of protection. According to series EN 60079, which are ef- Directive 2014/34/EU, Zone 1 fective independently of each equipment shall satisfy the other. requirements for Category 2G. For this reason, for example, flameproof luminaires were ad- Zone 2 ditionally pressurised or intrinsi- Zone 2 encompasses areas cally safe apparatus in the type around Zone 0 and Zone 1, as of protection “ib” potted. well as areas around flanged According to Directive joints on pipes in enclosed 2014/34/EU, equipment for rooms. Furthermore, it includes Zone 0 shall satisfy the require- such areas in which, due to ments for Category 1G. In Zone natural or forced ventilation, 0 the hazard of an ignition due the lower explosive limit is only to electrostatic charges, even attained in exceptional cases, on rare occasions, shall be safe- such as the environment of ly excluded. For this reason, the outdoor installations. Flamma- requirements according to EN ble or explosive substances are 60079-0 for equipment for use manufactured or stored in Zone in Zone 0 exceed those for 2. The probability of the occur- equipment for Zone 1 by far. rence of an ignitable concentration is rare and, if one occurs, it only persists for a short period. Zone 1 Flammable or explosive sub- During normal, trouble-free op- stances are made, processed or eration, ignition sources shall stored in Zone 1. This includes be safely prevented. the proximity of loading flap or filling and discharging facilities, the vicinity of fragile equipment, According to Directive 2014/34/EU, pipes and glands on pumps and equipment for Zone 2 shall sat- slides that do not seal ade- isfy the requirements for Cate- quately. It is likely that an ignit- gory 3G. In addition, all equip- able concentration will occur ment that satisfies the during normal operation. requirements for equipment for use in Zone 0 and Zone 1 is, of course, permitted. Ignition sources that occur during normal, trouble-free operation and those that usually occur in the event of operating disturbances shall be safely prevented.

Example for a Zone 0 application: The inside of a ﬂat-bottom tank of an oil terminal www.crouse-hinds.de EATON 11 Principles of Explosion-Protection 1 Dust-Ex-areas

Dust-Ex-Areas Zone 21 Among others, Zone 21 encompasses mills, warehouses for coal or grain, and the area surrounding filling stations. Here, for example, explosive clouds of dust can develop due to the occasional escaping of dust from the opening. The risk of hazards due to dust deposits is often underestimated.

Explosive dust/air mixtures can Zone 20 develop due to the formation of Zone 20 mainly encompasses a smoulder spot or of a low areas inside closed containers, temperature carbonization gas, pipes and apparatus in which as well as due to the deflagra- combustible dust in the form of tion of a low temperature car- a cloud is present continuously bonization gas or the whirling- or for long periods or frequently. up of dust caused by glowing With equipment for Zone 20, ig- combustion. nition sources shall be protected against explosions, even if the occurrence of a malfunction Ignition sources that occur dur- Example of dust-Ex-Zone 21: Explosion-protected terminal box is rare. For this reason, equip- ing normal, trouble-free opera- ment shall fulfil the following tion and those that normally oc- Zone 22 requirement: cur in the event of malfunctions In Zone 22, under normal oper- shall be safely prevented. In the event of the failure of one ating conditions it is unlikely According to Directive 2014/34/ type of protection or the simul- that an explosive dust/air mix- EU, equipment for Zone 22 shall taneous occurrence of two mal- ture will occur. An explosive at- satisfy the requirements for The individual types of protec- mosphere is only to be expect- functions, it is necessary to tion are described in the chap- Category 3D. ensure adequate explosion pro- ed in the event of malfunctions, ter „Electrical equipment for e.g. due to whirled-up dust. tection. According to Directive use in hazardous areas“. Accord- Detailed information on all 2014/34/EU, equipment for use ing to Directive 2014/34/EU zones can be found in the in Zone 20 shall satisfy the re- equipment for Zone 21 shall Ignition sources shall be safely chapter “Installation and quirements for Category 1D. satisfy the requirements for prevented during normal, trou- operation of electrical Category 2D ble-free operation. installations in hazardous areas”.

12 EATON www.crouse-hinds.de European Ex-Directives European Ex-Directives 2

This directive, which applied to type and content of the con- both electrical and mechanical formity assessment procedure. equipment, encompassed re- Thus, for example, an EC Type quirements relating to the ap- Examination Certificate accord- proval of equipment and the ing to Directive 94/9/EC can be requisite quality assurance sys- used to issue a new CE Decla- tems. These requirements are ration according to Directive graduated according to the 2014/34/EU. In accordance with equipment category. Article 41, § 2, the issue of a new EU Type Examination Certificate according to the new As this new directive was directive is not necessary. drawn up according to the “new approach” of the EC, it Directive 94/9/EC could be ap- also introduced the Declaration plied for the last time on of Conformity to be issued by 19.04.2016. As of 20.04.2016 the manufacturer for explosion- only the new ATEX directive 2014/34/EU applies. European Ex-Directives This symbol was specified as protected equipment and the the distinctive mark for the plac- CE marking of products. Free movement of goods ing of explosion-protected elec- within the European trical equipment on the market Directive 2014/34/EU of the Community throughout the community: European Parliament and Council dated 26.02.2014 – Article 100 of the treaty estab- 2nd ATEX Directive lishing the EEC (European Economic Community) was the Directive 94/9/EC had to be basis for the free movement of adapted to Resolution No. goods within the European 768/2008/EC. This resolution economic area. In 1975, to im- required a common legal frame- plement this article, the Council work for the marketing of prod- of the European Community ucts and contains general prin- issued the Explosion Protection ciples and reference provisions Framework Directive that are to be applied in all sec- (Directive 76/117/EEC). Directive 94/9/EC of the tor-specific legal acts. It was, The issue of European Parliament and therefore, a common basis for a Directive 79/116/EEC by the Council dated 23.03.1994 - revised or new version of exist- European Commission 1st ATEX Directive ing legal provisions. concretised this basis and established a first legal basis. The purpose of this directive This new ATEX directive came A series of European standards was the approximations of the into effect on 20.04.2014, with for explosion- protected appara- laws of the member states of a two-year transitional period. tus was drawn up by the Euro- the European Union for equip- However, this did not mean pean Standards Committee for ment and protective systems that, as was the case with the electrical apparatus (CENELEC) intended for use in potentially transition to the 1st ATEX direc- to provide the basis for the en- explosive atmospheres. As of tive, both directives could be forcement of the requirements. 01.07.2003 it replaced all previ- applied simultaneously. On the In Germany these European ous directives on explosion pro- part of the European Commis- standards, EN 50014 to EN tection on a European level. 50020, were adopted as VDE sion only a legal certainty was The directive, also known as standards in the national stand- provided that, when the transi- the ATEX directive, applied to ards. tion period expired, the new di- equipment and protective sys- rective only in the announced tems that were intended for form was to be applied. Thus, Directive 79/196/EEC was re- use in potentially explosive at- the manufacturers were given stricted to explosion-protected mospheres. Safety devices and the opportunity to adapt their di- electrical equipment and the control systems for use outside rective-specific documents and regulations that were required of potentially explosive atmos- papers within this two year pe- for the free movement of pheres also came under this di- riod. In the case of the notified goods. rective. This also applied when bodies, this meant, for exam- such devices were required for ple, that they had to complete the safe operation of equipment the designation procedure for By strict reference to the Euro- and protective systems in haz- the new ATEX directive within pean standards, the normative ardous areas or contributed to these two years. The major basis for the certification of exit, Furthermore, the directive changes only concern formal plosion-protected electrical ap- now directly included “funda- and legal aspects. No changes paratus was regulated by “noti- mental safety requirements“ for were made to the basic health fied bodies”. explosion-protected equipment. and safety requirements or the www.crouse-hinds.de EATON 13 European Ex-Directives 2 ATEX directive 2014/34/EU

ATEX Directive 2014/34/EU • means of transport, i.e. Directive 2014/34/EU applies to vehicles and their trailers in- products, i.e. equipment and tended solely for transporting protective systems intended for passengers by air or by road, use in potentially explosive at- rail or water networks, as mospheres, with the following well as means of transport in Structure and content of Directive 2014/34/EU definitions, which are new in so far as such means are de- • Chapter 1 part: signed for transporting goods General Provisions (Article 1-5) by air, by public road or rail a) “Equipment” means • Chapter 2 networks or by water. Vehi- machines, apparatus, fixed or Obligations of economic operators (Article 6-11) cles intended for use in a po- mobile devices, control compo- tentially explosive atmos- • Chapter 3 nents and instrumentation phere shall not be excluded Conformity of the product (Article 12-16) thereof and detection or pre- from the scope of this Direc- • Chapter 4 vention systems which, sepa- tive. Notification of conformity assessment bodies rately or jointly, are intended for (Article 17-33) the generation, transfer, storage, measurement, control and d) “making available on • Chapter 5 conversion of energy and/or the the market” means Union market, surveillance and control of products entering processing of material and any supply of a product for dis- the Union market and Union safeguard procedure which are capable of causing an tribution, consumption or use (Article 34-38) on the Union market in the explosion through their own po- • Chapter 6 course of a commercial activity, tential sources of ignition. Committee, transitional and final provisions whether in return for payment b) “Protective systems” means (Article 39-45) or free of charge; devices other than components • Annex I e) “placing on the market” of equipment which are intend- Criteria determining the classification of equipment means ed to halt incipient explosions groups into categories immediately and/or to limit the the first making available of a effective range of an explosion product on the Union market; • Annex II Essential health and safety requirements relating to the and which are separately made f) “manufacturer”’ means available on the market for use design, and construction of equipment and protective any natural or legal person who as autonomous systems. systems for use in potentially explosive atmospheres manufactures a product or has • Annex III c) “Components” means a product designed or manufac- Module B: EU-Type Examination any item essential to the safe tured, and markets that product functioning of equipment and under his name or trade mark or • Annex IV protective systems but with no uses it for his own purposes. Module D: Conformity to type based on quality autonomous function. assurance of the production process This Directive shall not apply to: • Annex V • medical devices intended for Module F : Conformity to type based on use in a medical environ- product verifications ment; • Annex VI • equipment and protective Module C1: Conformity to type based on internal systems where the explosion production control plus supervised product testing hazard results exclusively • Annex VII from the presence of Module E: Conformity to type based on product explosive substances quality assurance or unstable chemical • Annex VIII substances; Module A: Internal production control • equipment intended for use • Annex IX in domestic and non-com- Module G: Conformity based on unit verification mercial environments where potentially explosive atmos- • Annex X pheres may only rarely be EU Declaration of Conformity created, solely as a result • Annex XI of the accidental leakage of Part A: Repealed Directive with a list of the successive fuel gas; amendments thereto (referred to in Article 43) • personal protective • Part B: Time limits for transposition into national law and equipment as covered by dates of application (referred to in Article 43) Directive 89/686/EEC; • Annex XII • seagoing vessels and mobile Correlation table offshore units together with equipment on board such vessels or units;

14 EATON www.crouse-hinds.de European Ex-Directives ATEX directive 2014/34/EU 2

Essential health and safety Equipment groups and Classiﬁcation of explosion protected apparatus in equipment requirements equipment categories groups and categories according to 2014/34/EU The requirements relating to Equipment is subdivided into equipment and protective devic- groups and categories: Equipment Group I for mines endangered by ﬁredamp. es are divided up into general The equipment Group I is subdivided into the Categories M1 and M2: requirements and supplementa- • Equipment group I – applies ry requirements, whereby, above to equipment intended for all, the supplementary require- use in underground parts of The equipment in this category is intended for use in both underground ments are to take both existing mines as well as those parts parts of mines and those parts of surface installations of such mines and potential hazards into con- of surface installations of that are endangered by firedamp and/or combustible dust. sideration. This means that the such mines that can be en- equipment and protective sys- dangered by firedamp and/or The equipment shall continue to remain functional even in the event of tems shall satisfy one or more combustible dust. M1 rare incidents relating to the equipment with an explosive atmosphere requirements at the same time, present, and feature such protective measures that in the event of fail- • Equipment group II – applies inasmuch as this is necessary ure of one means of protection, at least an independent second means to equipment for use in the for their correct operation or provides the requisite level of protection, or the requisite level of protec- remaining areas that can be their intended use. tion is assured in the event of two faults occurring independently of at risk due to an explosive at- each other. Adherence to the health and mosphere. safety protection requirements is absolutely essential to guar- Categories antee the safety of equipment See adjacent tables The equipment in this category is intended for use in both underground and protective devices. These parts of mines and those parts of surface installations of such mines that requirements shall be imple- are endangered by firedamp and/or combustible dust. mented with prudence in order Making available on the mar- to fulfil the latest technological ket and commissioning M2 If an explosive atmosphere occurs, it must be possible to switch off the developments at the time of of products equipment. The constructional explosion-protection measures ensure the making equipment available on The member states must not required degree of safety during normal operation, even under severe oper- the market. This directive only forbid, restrict or impede the ating conditions and, in particular, in cases of rough handling and changing environmental influences. defines general basic require- making available on the market ments. In order to make it easi- and commissioning of equip- er to furnish proof that a piece ment, protective systems and of equipment or a protective devices that conform to the system conforms to these re- terms of this directive. Similarly, Equipment Group II for all other hazardous areas quirements, uniform standards the making available on the mar- The equipment Group II is subdivided into the have been established on a Eu- ket of components accompanied Categories 1, 2 and 3: ropean level. If standards are by a certificate of conformity published by the European according to Article 13, § 3 of Commission in the Official Ga- Directive 2014/34/EU shall not The equipment in this category is intended for use in areas in which an zette of the European Commu- be forbidden, restricted or im- explosive atmosphere is present continuously or for long periods or frequently. nities as assigned to a given di- peded if they are to be built into a piece of equipment or a pro- rective, they are Even if equipment failures only occur infrequently, the equipment must valid as so-called “harmonized tective system in line with this ensure the required degree of safety and feature such explosion protec- standards”. directive. 1 tion measures that If a product meets the requirements of the harmonized stand- • if one constructional protective measure fails, at least one other The EU member states assume independent constructional protective measure ensures the ards, the essential require- conformity with this directive required degree of safety, or ments of the directive are and with the conformity assess- • if two independent faults occur in combination, the required deemed to be fulfilled ment procedures if the appara- degree of safety is still ensured. (presumption of conformity). If tus, protective systems and de- necessary, this list in the official vices are accompanied by the gazette is adapted in line with EU Certificate of Conformity the latest versions of the stand- and if the products are provided The equipment in this category is intended for use in areas in which an ards. These standards are, in with the CE marking. principle, prepared by the Euro- explosive atmosphere occurs occasionally. Even in the case of frequent 2 equipment failures or faulty conditions that are normally to be expected, pean Committee for Standardi- the constructional explosion-protection measures ensure the required zation (CEN) and the European Products that do not yet meet degree of safety. Committee for Electro-technical the requirements of this direc- Standardization (CENELEC). tive may be displayed at exhibi- In the field of explosion protections, fairs and demonstrations tion the standardization is large- if a visible sign clearly indicates ly carried out by Technical Com- that it will not be possible to The equipment in this category is intended for use in areas in which no occurrence of an explosive atmosphere due to gases, vapours, mists or mittee TC31, “Equipment for purchase the product until com- 3 whirled-up dust is to be expected. If, however, it occurs, then in all prob- explosive atmospheres”, of the pliance with the directive has been ensured. ability only rarely or for a short period. During normal operation the equip- International Electro-technical ment ensures the required degree of safety. Commission (IEC).

www.crouse-hinds.de EATON 15 European Ex-Directives 2 ATEX directive 2014/34/EU

Procedure for non-compliant Marking Conformity assessment • EU-type examination by a no- (e.g. unsafe) products In accordance with Annex II, procedures tified body and Should a member state or their Point 1.0.5 of the Directive, Depending upon the conformity either market surveillance authorities each piece of equipment and assessment procedure to be • ensure constructional con- discover that any equipment, each protective system shall be applied, a notified body can be formity or protective systems or devices marked in a clear and indelible active during the design and en- • verification of the quality as- (products) with the CE marking manner with the following gineering phase, during the pro- surance of the products. are unsafe; it can withdraw minimum particulars: duction phase or during both these from the market and for- • name, registered trade name phases. The applicable evalua- In the case of other equipment bid their being made available or registered trade mark, and tion procedure is laid down in in these groups and categories, on the market or commission- address of the manufacturer, the Directive according to the ing, or restrict their free circula- product, the group and the the internal production control • (The contact data shall be tion. equipment category. procedure shall be applied, given in a language that is whereby the technical docu- easily comprehensible for the mentation shall be submitted to The member state is required to end users and the market Equipment groups I and II, a notified body in accordance notify the commission of the surveillance authorities.) equipment categories with Article 13, § 1, Clause b) ii). European Union of such meas- M1 and 1 ures and to give the reasons for • CE marking In order to be permitted to affix its decision. The commission • designation of series or type Equipment group II, the CE mark to his product, the will immediately contact the equipment category 3 • batch or serial number, if any, manufacturer must arrange for economic operators concerned In order to be permitted to affix the following procedures to be (manufacturers, authorized per- • year of construction the CE mark to the product, the carried out: sons, importers or retailers) and • the specific marking of explo- manufacturer shall apply the in- inform all member states if sion protection followed by • EU-type examination by a no- ternal production control proce- these measures are justified. the symbol of the equipment tified body and either dure. group and category, • an audit of the quality assur- Declaration of Conformity Equipment, protective systems • for equipment-group II, the ance for the production or devices (products) are letter ‘G’ (concerning explo- process or In order to make products avail- deemed unsafe if, when used sive atmospheres caused by • an audit of the products. able on the market within the for their intended purpose, they gases, vapours or mists), EU, the EU Declaration of Con- represent an imminent danger and/or formity shall be included with all to the safety of people, domes- Equipment groups I and II, products or batches of identical tic animals or goods. • the letter ‘D’ (concerning equipment categories products. explosive atmospheres M2 and 2 caused by dust). In the case of internal combus- According to Article 38 of the This does not apply to the re- Directive, a product is formally tion motors and electrical equip- Furthermore, and where neces- ment, in order to be permitted port, if available, issued by the deemed non-compliant if, notified body as part of the au- for example: sary, they shall also be marked to affix the CE marking to the with all information essential to product, the manufacturer shall dit of the quality assurance sys- their safe use arrange for the following proce- tem of the manufacturer or the EU-Type Examination Certifi- • the CE marking has not been dures to be carried out and/or cate. affixed; ensure the following measures: • the specific marking of explosion protection, the symbols of the equipment-group and category and, where applicable, the other markings and information have not been affixed in violation of SERIES point 1.0.5 of Annex II; • the identification number of CEAG the notified body, where that D-69412 Eberbach body is involved in the pro- BVS 16 ATEX E 123 / IECEx BVS 16.123 duction control phase, has IP66/67 been affixed wrongly or has II 2G Ex db eb mb ib IIC T4 Gb Ta= -25°C bis +55°C not been affixed; II 2D Ex tb IIIC T80°C Db • the EU declaration of con- AC: 110-254V 50-60Hz formity or the attestation of conformity, as appropriate, DC: 110-250V does not accompany the Lampe: G13-81-IEC www.ceag.de product or has not been issued correctly; or Snr.: D123456 2016 Made in Germany • the technical documentation is not available or not complete. Example for a type label according to the latest standards and directive 2014/34/EU

16 EATON www.crouse-hinds.de European Ex-Directives ATEX directive 2014/34/EU 2

Explosion-protected linear light ﬁtting type eLLK 92 LED 800 with operating instruction and Declaration of Conformity

These operating instructions The operating instructions con- and safety information as well tain the drawings and diagrams as all markings shall be explicit, that are necessary for the put- easily comprehensible and ting into service, maintenance, clearly visible. inspection, checking of correct operation and, when appropri- The maintenance instructions ate, repair of equipment and for use by the specialist person- protective systems, together nel employed by the manufac- with all useful instructions, in turer or his authorized repre- particular with regard to safety. sentative established in the Community may be drawn up in With regard to safety aspects, a single community language the documentation describing that is understood by this per- the equipment or protective sonnel. systems shall not conflict with the operating instructions.

Instructions • details which allow a decision According to Annex II, point to be taken beyond any doubt 1.0.6 of the Directive, all equip- as to whether an item of ment and protective systems equipment in a specific cate- shall be accompanied by in- gory or a protective system structions, including at least the can be used safely in the in- following particulars: tended area under the expected operating conditions, • a recapitulation of the information with which the equip- • electrical and pressure param- ment or protective system is eters, maximum surface tempe- marked, except for the batch ratures and other limit values; or serial number , and, where • where necessary, special appropriate, any additional in- conditions of use, including formation to facilitate mainte- particulars of possible mis- nance (e.g. address of the im- use which experience has porter or service workshop, etc.); shown might occur; and • instructions for safe: • where necessary, the essential - putting into service, characteristics of tools which - use, may be fitted to the equipment - assembling and or protective system. disassembling, - maintenance (servicing The operating instructions shall and emergency repairs), be drawn up by the manufactur- - installation, er or his authorized representa- - adjustment; tive established in the community in one of the community • where necessary, an indication languages in accordance with of the danger areas in front of the decision of the respective pressure-relief devices, member state and it shall be • where necessary, training in- easily comprehensible for the structions , users and other end users.

www.crouse-hinds.de EATON 17 European Ex-Directives 2 European directives

Directive 2006/42/EC: Ma- Directive 2014/35/EU: Directive 89/686/EEC: Per- chinery Directive Low Voltage Directive sonal Protective Equipment Mechanical engineering is an The aim of this directive is to en- (PPE) important technical subsector sure that electrical equipment on For the purposes of this direc- and one of the industrial core ar- the market meets the require- tive, PPE is any device or eas of the economy in the Com- ments that guarantee a high pro- means that is intended to be munity. The social costs caused tective level with regard to the worn or held by a person and by the numerous accidents that health and safety of people, do- protect this person against one occur as a result of the use of mestic animals and livestock and or more risks that might endan- CE-sign machinery can be lowered if the with regard to property, while ger his health or safety. safety aspect is taken into con- guaranteeing the functioning of sideration during the design and the single market. Directive 2014/68/EU: CE-marking construction of machines and if The Directive shall apply to elec- Pressure Equipment Directive The manufacturer shall affix the the machines are installed and trical equipment designed for use (PED) CE marking to products that fall maintained correctly. If the haz- with a voltage rating of between This directive applies to the de- within the scope of given direc- ards presented by machinery 50 V and 1000 V for alternating sign, manufacture and conform- tives. This applies to products stated in Annex I of the Direc- current and between 75 V and ity assessment of pressure that are covered by the directive are covered in total or par- 1500 V for direct current, with equipment and assemblies with tives according to the new con- tially by other Community Direc- the exception of the electrical a maximum permissible pres- cept and include requirements tives, this directive does not equipment and areas listed in An- sure (PS) of more than 0.5 bar. relating to the technical proper- apply to this machine and the nex II, i.a. electrical equipment This directive does not apply to ties of products. These EU di- hazards or no longer applies for use in explosive atmos- equipment that, according to rectives constitute binding regu- from the beginning of the appli- pheres. Article 13 of this directive, lations of the „European Union”. cation of these other directives. would, at most, come under Category I and is covered by This means that compliance Annex I, § 1.5.7 states that; Directive 1999/5/EC: Radio one of the clauses of with these requirements is the “Machinery must be designed and Telecommunications Directive 2014/34/EU. condition for marketing the and constructed in such a way Terminal Equipment (RTTE) products in Europe. as to avoid any risk of explosion This directive regulates the posed by the machinery itself or making available on the market, Directive 2014/29/EU: Simple by gases, liquids, dust, vapours free trade and putting into oper- Pressure Vessels (SPVD) When the CE marking is affixed or other substances produced ation of radio installations and to a product, the conformity of or used by the machinery. Ma- This directive applies to vessels telecommunications transmis- the product with the relevant chinery must comply, as far as that are manufactured in series. sion devices within the Com- basic requirements of all direc- the risk of explosion due to its munity. tives applicable to the products use in a potentially explosive at- is confirmed. The marking is, mosphere is concerned, with therefore, an imperative re- the provisions of the specific quirement for the making avail- Community Directives.” able on the market of products within the Community, as well Directive 2014/30/EU: as in the country of origin. EMC-Directive Subject matter of this directive is The CE marking is only meant the electromagnetic compatibil- as evidence of conformity with ity of equipment. This directive the directives for the supervis- shall be applied to all products ing authorities and is not a qual- that can cause electromag netic ity mark. interferences or whose operation can be affected by these In addition to the CE marking, interference. It is intended to the manufacturer shall also pre- ensure the functioning of the pare a Declaration of Conform- single market for equipment by ity for the product. This Declara- specifying an appropriate level tion of Conformity shall clearly of electromagnetic compatibility. indicate which directive was applied and which standards were taken into account for the verification of conformity. The following directives are also of particular importance for electrical equipment:

18 EATON www.crouse-hinds.de European Ex-Directives Directive 1999/92/EC 2

Directive 1999/92/EC It does not apply to: Structure of the directive 1999/92/EC Directive 1999/92/EC of the Enacting part a) areas used directly for and European Parliament and • Section 1 Council dated 16.12.1999 during the medical treatment of patients; Article 1-2 It defines the minimum require- General Requirements ments for the improvement of • Section 2 the health and safety protection b) the use of appliances burning Article 3-9 of employees potentially at risk gaseous fuels in accordance Duties of employer due to an explosive atmosphere with Directive 90/396/EEC (2); 3: Prevent of and protection against explosions and is also referred to as the 4: Assessment of the explosion risks “European Workplace Directive”. 5: General obligations c) the manufacture, handling, 6: Coordination obligations use, storage and transport of Explosion-protection is of par- 7: Areas with explosive atmospheres explosives or chemically ticular importance to safety. Ex- 8: Explosion-protection document unstable substances; plosions endanger the lives and 9: Special regulations relating to working materials health of workers as a result of and places of work the uncontrolled effects of d) mineral-extracting industries • Section 3 flame and pressure, the pres- covered by Directive 92/91/EEC Article 10-15 ence of noxious reaction prod- or Directive 92/104/EEC; Other requirements ucts and consumption of the oxygen in the ambient air which • Appendix I workers need to breathe; e) the use of means of transport Classification of areas where explosive atmospheres may occur by land, water and air, to 1. Areas where explosive atmospheres may occur which the pertinent provisions 2. Classification of hazardous areas For this reason, in order to es- of the international agree- • Section II A tablish a coherent strategy for ments (e.g. ADNR, ADR, Minimum requirements for the improvement of the safety the prevention of explosions at ICAO, IMO, RID), and the and health protection of employees potentially at risk from the workplace, organisational Community Directives for the explosive atmospheres measures have to be taken. Di- implementation of those 1. Organisational measures rective 89/391/EEC requires the agreements apply. 2. Explosion-protection measures employer to take the necessary measures for the health and • Section II B safety protection of employees, Means of transport intended for Criteria for the selection of equipment and including measures for the pre- use in a potentially explosive at- protective systems vention of occupational hazards, mosphere shall not be excluded. • Section II C to inform and instruct, and to Warning signs for marking areas where explosive provide a suitable organization atmospheres may occur and the necessary means. Reduction and assessment of explosion risks It is the duty of the employer to After assessment of all the re- Zone 0 The directive was issued in ac- carry out measures in the fol- maining explosion risks, where- A place in which an explosive at- cordance with Article 137 of the lowing order of precedence: by the interaction of installations, mosphere consisting of a mixture treaty establishing the EEC and the materials being used, the with air of flammable substances is, as such, only a minimum re- processes and their possible in- 1. Where possible, the prevention in the form of gas, vapour or mist quirement. It states explicitly teractions were taken into con- of explosive atmospheres by is present continuously or for that any provisions issued on sideration, measures for the the substitution of materials. long periods or frequently. the basis of this article shall not safety of employees at work prevent the member states 2. Prevention of the ignition of must be laid down to ensure from maintaining or taking more explosive atmospheres. their health and safety at all Zone 1 stringent protective measures 3. Mitigation of harmful effects. times. Here special require- A place in which an explosive that are compatible with the ments are imposed regarding atmosphere consisting of a mix- treaty. the coordination duties of the ture with air or flammable sub- This concept is already known employer at the place of work stances in the form of gas, va- in Germany due to the explo- Scope pour or mist is likely to occur in sion-protection directives of the normal operation occasionally. This Directive, which is the 15th employers’ liability insurance as- Classiﬁcation of hazardous individual Directive within the sociation and it has been put areas meaning of Article 16(1) of into practice for many years. The areas in which explosive at- Zone 2 Directive 89/391/EEC, lays The new aspect of this directive mospheres can occur are subdi- A place in which an explosive down minimum requirements is the systematic method ac- vided into zones according to atmosphere consisting of a mix- for the health and safety protec- cording to which the measures the frequency and duration of ture with air of flammable sub- tion of workers potentially at are laid down and documented. the occurrence of explosive at- stances in the form of gas, va- risk from explosive mospheres. This classification pour or mist is not likely to atmospheres. determines the scope of the occur in normal operation but, if measures to be taken. it does occur, will persist for a short period only.

www.crouse-hinds.de EATON 19 European Ex-Directives 2 Directive 1999/92/EG

Zone 20 • that the workplace and work • Installation and operation A place in which an explosive equipment, including warning according to the lowest atmosphere in the form of a devices, are designed, oper- explosion risk cloud of combustible dust in air ated and maintained with re- • If necessary, warning of is present continuously, or for gard to due safety; and Ex atmosphere long periods or frequently • that, in accordance with (visual/acoustical) Council Directive 89/655/EEC • Provision of escape facilities Zone 21 (1), arrangements have been made for the safe use of • Initial inspection by qualified A place in which an explosive work equipment. persons atmosphere in the form of a • Measures for risk cloud of combustible dust in air assessment is likely to occur in normal oper- The explosion protection docu- ation occasionally. ment shall be drawn up prior to • Hazards due to power failures commencement of work. • Safe reduction of stored Zone 22 and shall be revised when the energy

A place in which an explosive workplace, work equipment or atmosphere in the form of a organisation of the work under- cloud of combustible dust in air goes significant changes, exten- Annex II B is not likely to occur in normal sions or conversions. Criteria for the selection of operation but, if it does occur, equipment and protective sys- will persist for a short period tems: The employer may combine ex- only. isting explosion risk assess- ments, documents or other Unless otherwise specified in the explosion protection docu- Note: equivalent reports produced under other Community acts. ment, taking into account the 1. Layers, deposits and accu- risk evaluation, equipment and mulations of combustible protective systems are selected dust that can form an ex- in accordance with plosive atmosphere shall be Annex II A Directive 2014/34/EU treated in the same way as Minimum requirements for the any other cause. improvement of the health and Zone Category 2. Normal operation is the state safety protection of employees 0 or 20 1 in which installations are potentially at risk from explo- used within the rated sive atmospheres. 1 or 21 1 or 2 parameters. 2 or 22 1, 2 or 3 1. Organisational measures • Appropriate instruction of Explosion protection Anex III document employees Warning sign for marking areas • Written instructions and work As part of his obligations, the in which explosive atmospheres release notes employer shall ensure that a may occur. document (hereinafter • If necessary, written referred to as the ‘explosion instructions for the work protection document’) is drawn assignment up and kept up to date. • Work release system for hazardous tasks • In particular, the explosion • Work release by authorized protection document shall person demonstrate: • that the explosion risks have 2. Explosion protection been determined and as- measures sessed; • Rendering any escaped Ex • that adequate measures are atmosphere harmless taken to fulfil the aims of this • Design according to the Directive; highest risk potential • which areas which have been • Avoidance of all ignition classified into zones in ac- hazards (e.g. static charge cordance with Annex I; of persons) • the areas where the mini- • Taking into operation if mum requirements set out in authorized in the explosion Annex II apply; document

20 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Basics 3

Electrical equipment for use Subdivision into groups Gap in hazardous areas: Joint width Basics Group I: - Electrical equipment for use Groups A and B General in mines susceptible to fire- Flat joint It would not be economical to damp such as coal mines build all explosion-protected electrical equipment in such a Group II: Groups way that it can be used in all A, B and C hazardous areas. Furthermore, Electrical equipment for use Cylindrical there are also other boundary in explosive gas atmospheres joint conditions that have to be taken into consideration, e.g. relating Group III: to the ignition temperature, Groups Electrical apparatus for use A, B and C flame transmission properties in all explosive dust Threaded and the ignitability of the explo- atmospheres joint sive substances. For the gradation or allocation Maximum experimental Different types of joint in practice: Apparatus for the experimental to the required safety level for safe gap (MESG) • flanged joint testing of the minimum ignition current (MIC) the respective application, it is • cylindrical joint subdivided into; Deﬁnition: • threaded joint • Groups The maximum gap of the joint between the two parts of the • temperature classes interior chamber of a test appa- (surface temperature) ratus which, under specified Minimum ignition Minimum ignition and conditions, when the internal current (MIC) energy gas mixture is ignited, prevents • equipment protection levels A minimum ignition energy is The smallest amount of electrical ignition of the external gas needed to ignite an explosive energy stored in a capacitor mixture by flame propagation With all equipment it is neces- mixture. Due to an external that, in the event of the dis- through a joint measuring sary to observe the further sub- ignition source, e.g. an electric charge of this capacitor across 25 mm in length. division into groups with regard spark, a high temperature a spark gap, is barely able to to the risk of an electrostatic develops in a small volume area ignite the most easily ignitable charge/discharge. In addition, of an explosive atmosphere. fuel/air mixture at atmospheric hazards due to electromagnetic This then leads to combustion. pressure and room temperature. and optical radiation shall also The heat generated by the be taken into account. spark and the subsequent There is a certain relationship combustion heats the immedi- between the safe gap and the Electrical equipment for use ate layers, but, at the same minimum ignition current ratio. time, energy is fed to the out- in gas Ex areas side due to heat conduction. In order to be able to classify Group II gases and vapours to satisfy Group II electrical equipment in If the heat dissipation is greater the explosion-protection re- is subdivided into A, B, and C. than the quantity of heat that is quirements, it is, therefore, suf- supplied and generated, a prop- In the case of flameproof ficient to determine just one of agation of the combustion to enclosures, the classification the two properties of most of the surrounding volume areas is is based on the maximum the mixtures of gas and vapour not possible. Only if, due to the experimental safe gap (MESG) with air that are used in industry. external ignition source, the en- and, in the case of intrinsically ergy input is so great that the safe apparatus on the minimum temperature of the surrounding ignition current (MIC). Apparatus for the experimental layers rises above its ignition determination of the maximum temperature, the combustion is safe gap (MESG) in accordance propagated autonomously and with IEC 60079-20-1 an explosion occurs.

This basic knowledge is used for the type of protection “Intrinsic Safety“. The electric ratings of a circuit are limited to such a degree that the mini- Groups Safe Gap in mm Minimum ignition current mum ignition energy required II A > 0,9 > 0,8 for an ignition is not attained. II B 0,5 to 0,9 0,45 to 0,8 Ignition energy in relation to the concentration of a ﬂammable II C < 0,5 < 0,45 substance in air www.crouse-hinds.de EATON 21 Explosion-protected Electrical Equipment 3 Basics

Ignition temperature and The ignition temperatures of Electrical equipment for use temperature classes the different explosive mixtures in areas with combustible The maximum surface tempera- vary considerably. Whereas a dusts ture of the electrical equipment, mixture of air with town gas will subject to the protective meas- only ignite at 560 °C, a mixture Group III ures on the interior or exterior, of air and petrol will ignite at The subdivision of Group III must not attain the ignition ca. 250 °C. electrical equipment is based temperature of the hazardous The data can be found in on the same principle as the explosive atmosphere. The igni- IEC 60079-20-1. subdivision of Group II electrical tion temperature of a flamma- equipment, whereby the divi- To simplify matters, these ble substance is determined by sion into Groups A, B and C is different properties were means of a test apparatus and based on the properties of the classified and divided into is defined as the lowest tem- „dust“. temperature classes. perature on a heated wall at Groups Substances which the flammable substance IIIA combustible flyings will just ignite in the mixture Explosion-protected portable with air. IIIB non-conductive dusts searchlight in the dust test chamber IIIC conductive dusts To avoid ignition hazards, it is necessary that: Ignition sources Combustible dust can be ignit- ´the temperature of any sur- ed by electrical equipment in faces on which dust deposits various ways: can form or that can come into contact with a cloud of dust are by equipment surface tem- ´ kept at a temperature that is peratures that are higher than lower than the limiting tempera- the ignition or glow temperatures laid down in EN 50028-1-2; ture of the respective dust. The Experimental determination of the temperature at which the dust áll parts with electric sparks ignition temperatures of flammable ignites is dependent on the or with temperatures above the substances to IEC 60079-20-1 properties of the dust, on ignition or glow temperature of whether it is present in the the dust are built into an enclo- form of a cloud or deposits, on sure that prevents the ingress of Tempera- Maximum permissible Ignition temperatures the thickness of the layer and dust in a suitable manner, or ture class surface temperature of of the flammable on the type of heat source; ´the energy of the electric cir- the equipment in °C substances in °C ´by sparks at electrical parts cuits is limited to such a de- T 1 450 > 450 such as switches, contacts, com- gree, that sparks or temperature that could ignite T 2 300 > 300 ≤ 450 mutators, brushes or similar; combustible dust are avoided; T 3 200 > 200 ≤ 300 ´by the discharge of stored electro static energy; áll other ignition sources are T 4 135 > 135 ≤ 200 avoided. ´by radiated energy T 5 100 > 100 ≤ 135 (e.g. electromagnetic radiation); T 6 85 > 85 ≤ 100 ´by mechanic impact or friction sparks or a rise in temperature Classification of gases and vapours in explosion groups and originating from the apparatus. temperature classes T1 T2 T3 T4 T5 T6

I Methane Acetone Ethane Petrol Ethylacetate Ethyl- Diesel Ammonia alcohol fuel Acetal- Benzol i-amyl- Aviation deyde- II A Acetic acid acetate fuel Ethyl- Carbon ox- n-butane Heating ether yde n-butyl- oils Methanol alcohol n-Hexane Propane Toluene Town gas II,B Ethylene (lamp gas) Carbon II C Hydrogen Acetylene disulphide

22 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Equipment protection level EPL 3

Equipment protection level EPL

An alternative method for the risk assessment taking the “Equipment Protection Level“ for Ex-equipment into account.

Historical background Hazardous areas are divided into zones according to the degree of hazard. The degree of hazard is defined according to the probability of the occur- This was carried out on the sta- As an alternative method to the rence of an explosive atmos- The concept of protective levels tistical basis that - depending on prescriptive and relatively rigid phere. Generally, neither the relating to the equipment was the probability or frequency of approach of the association of potential consequences of an first implemented in the Euro- the occurrence of an explosive equipment to zones, a concept explosion nor other factors, pean directive 94/9/EC and atmosphere- the required level that was uncoupled from haz- such as the toxicity of materi- described as categories. of safety against the probability ardous areas was introduced for als, are taken into account. A This concept was adopted in of the presence of an ignition the assessment of hazards for true risk assessment would the standards as Equipment source and the probability of the selection of Ex equipment. consider all factors. Protection Levels (EPL). the occurrence of an explosive The Equipment Protection Level atmosphere has be adapted ac- The ignition hazard posed by Historically, the selection of (EPL) is the level of protection cordingly. the equipment itself was the equipment for each zone is assigned to equipment based defining characteristic, whereby based on a firm link between on its likelihood of becoming At a very early stage the type of it did not matter which protec- the zone and the type of protec- a source of ignition and distin- protection “Intrinsic Safety”, tion measure was being ap- tion to be applied. guishing the differences which was used for the instru- plied. between explosive gas mentation and control technol- atmospheres, explosive dust Not all types of protection pro- ogy, was subdivided into vari- To simplify this, a system of atmos pheres, and the explosive vide the same degree of safety ous “safety categories” while protections levels relating to the atmospheres in mines against the possibility of the oc- maintaining the general explo- equipment was introduced. susceptible to firedamp. currence of an ignitable state. sion protection measures For this reason, specific types (see EN 60079-11 for details). of protection have been allocat- These categories were then as- ed to specific zones. signed directly to zones.

Zone classiﬁ cation / Equipment protection level For most of the situations with the typical possible consequences of an occurring explosion a standard assignment from Zone to equipment protection level is possible.

Minimum requirements for equipment

Standard IEC/EN 60079- Period of presence of the combustible Directive 2014/34/EU Protection Substance Zone 0 substances level Equip- Equipment Equipment ment Group protection group category level EPL

Continuously for long periods or frequently Zone 0 II 1 G II Ga very high

Gas, Occasional occurrence Zone 1 II 2 G II Gb high mist, vapour Not likely, but if it occurs only rarely and for Zone 2 II 3 G II Gc enhanced a short period

Continuously for long periods or frequently Zone 20 II 1 D III Da very high

Dust Occasional occurrence Zone 21 II 2 D III Db high

Not likely, but if it occurs only rarely and for Zone 22 II 3 D III Dc enhanced a short period

Mining I M1 I Ma very high Methane, coal dust Mining I M2 I Mb high www.crouse-hinds.de EATON 23 Explosion-protected Electrical Equipment 3 Equipment protection level EPL

Mines susceptible to ﬁredamp (Group I)

EPL „Ma“ EPL „Mb“ Equipment for installation in a Equipment for installation in a mine susceptible to firedamp, mine susceptible to firedamp, having a “very high” level of pro- having a “high” level of protec- tection, which has sufficient se- tion, which has sufficient secu- curity that it is unlikely to be- rity that it is unlikely to become come an ignition source in a source of ignition in normal normal operation, during expect- operation or during expected ed malfunctions or during rare malfunctions in the time span malfunctions, even when left en- between there being an out- ergized in the presence of an break of gas and the equipment outbreak of gas. being de-energized.

Picture: Ruhrkohle-AG

Gases (Group II)

EPL „Ga“ EPL „Gc“ Equipment for explosive gas at- Equipment for explosive gas atmospheres, having a “very mospheres, having an “en- high” level of protection, which hanced” level of protection, is not a source of ignition in nor- which is not a source of ignition mal operation, during expected in normal operation and which malfunctions or during rare mal- may have some additional pro- functions tection to ensure that it remains EPL „Gb“ inactive as an ignition source in Equipment for explosive gas at- the case of regular expected oc- mospheres, having a “high” level currences (for example failure of protection, which is not a of a lamp) source of ignition in normal operation or during expected malfunctions

Dust (Group III)

EPL „Da“ EPL „Dc“ Equipment for explosive dust Equipment for explosive dust at- atmospheres, having a “very mospheres, having an “en- high” level of protection, which hanced” level of protection, is not a source of ignition in nor- which is not a source of ignition mal operation, during expected in normal operation and which malfunctions, or during rare may have some additional pro- malfunctions. tection to ensure that it remains inactive as an ignition source in the case of regular expected oc- EPL „Db“ currences (for example failure of Equipment for explosive dust a lamp) atmospheres, having a “high” For a large majority of situations level of protection, which is not with the typical possible conse- a source of ignition in normal quences of the occurrence of an operation or during expected explosion, a standard allocation malfunctions. of zones to equipment protection levels is possible.

24 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Equipment protection level EPL 3

Electrical types of protection for explosive atmospheres due to ﬂammable gases, vapours and mists

Protec- Equip- Equipment CENELEC /IEC Type tion Type of protection Group ment protection Protection concept standard level category level (EPL) Explosion containment, prevention d da Flameproof enclosure II 1 G Ga EN 60079-1 / IEC 60079-1 of flame transmission Explosion containment, prevention d db Flameproof enclosure II 2 G Gb EN 60079-1 / IEC 60079-1 of flame transmission Explosion containment, prevention d dc Flameproof enclosure II 3 G Gc EN 60079-1 / IEC 60079-1 of flame transmission p pxb pyb Pressurised enclosure II 2 G Gb EN 60079-2 / IEC 60079-2 Exclusion of Ex-atmosphere p pzc Pressurised enclosure II 3 G Gc EN 60079-2 / IEC 60079-2 Exclusion of Ex-atmosphere q Powder filling II 2 G Gb EN 60079-5 / IEC 60079-5 Prevention of explosion diffusion o ob Liquid immersion II 2 G Gb EN 60079-6 / IEC 60079-6 Exclusion of Ex-atmosphere o oc Liquid immersion II 3 G Gc EN 60079-6 / IEC 60079-6 Exclusion of Ex-atmosphere e eb Increased safety II 2 G Gb EN 60079-7 / IEC 60079-7 No arcs, sparks or hot surfaces e ec Increased safety II 3 G Gc EN 60079-7 / IEC 60079-7 No arcs, sparks or hot surfaces Limitation of spark energy and sur- i ia Intrinsic safety II 1 G Ga EN 60079-11 / IEC 60079-11 face temperature Limitation of spark energy and sur- i ib Intrinsic safety II 2 G Gb EN 60079-11 / IEC 60079-11 face temperature Limitation of spark energy and sur- i ic Intrinsic safety II 3 G Gc EN 60079-11 / IEC 60079-11 face temperature Pressurised Exclusion of Ex-atmosphere / dilu- p/v II 2 G Gb EN 50381 IEC 60079-13 enclosure/ventilation tion nA Non-sparking equipment II 3 G Gc EN 60079-15 / IEC 60079-15 No arcs, sparks or hot surfaces Explosion containment, prevention nC Enclosed equipment II 3 G Gc EN 60079-15 / IEC 60079-15 of flame transmission Restricted breathing Exclusion of Ex-atmosphere for a nR II 3 G Gc EN 60079-15 / IEC 60079-15 enclosure limited period m ma Encapsulation II 1 G Ga EN 60079-18 / IEC 60079-18 Exclusion of Ex-atmosphere m mb Encapsulation II 2 G Gb EN 60079-18 / IEC 60079-18 Exclusion of Ex-atmosphere m mc Encapsulation II 3 G Gc EN 60079-18 / IEC 60079-18 Exclusion of Ex-atmosphere Limitation of spark energy and sur- i Intrinsic system II 2 G Gb EN 60079-25 / IEC 60079-25 face temperature Equipment with protection 1 G Ga II EN 60079-26 / IEC 60079-26 Double protection concept level (EPL) Ga 1 G/2 G Ga/Gb Inherent safe optical radia- op is II 1 G Ga EN 60079-28 / IEC 60079-28 Limitation of radiation energy tion Inherent safe optical radia- op is II 2 G Gb EN 60079-28 / IEC 60079-28 Limitation of radiation energy tion inherent safe optical radia- op is II 3 G Gc EN 60079-28 / IEC 60079-28 Limitation of radiation energy tion op pr Safe/interlocked Limitation or containment of radia- II 2 G Gb EN 60079-28 / IEC 60079-28 op sh optical radiation tion energy op pr Safe/interlocked Limitation or containment of radia- II 3 G Gc EN 60079-28 / IEC 60079-28 op sh optical radiation tion energy s sa Special protection n.a. n.a. Ga IEC 60079-33 Special measures s sb Special protection n.a. n.a. Gb IEC 60079-33 Special measures s sc Special protection n.a. n.a. Gc IEC 60079-33 Special measures

www.crouse-hinds.de EATON 25 Explosion-protected Electrical Equipment 3 Equipment protection level EPL

Electrical types of protection for explosive atmospheres due to combustible dust

Protec- Group Equip- Equipment Type of Type tion ment protection CENELEC /IEC standard Protection concept protection level Direc- Stand- category level (EPL) tive ard Pressurised Exclusion of p pxb II III 2 D Db EN 60079-2 / IEC 60079-2 enclosure Ex-atmosphere Pressurised Exclusion of p pzc II III 3 D Dc EN 60079-2 / IEC 60079-2 enclosure Ex-atmosphere Limitation of spark i ia Intrinsic safety II III 1 D Da EN 60079-11 / IEC 60079-11 energy and surface temperature Limitation of spark i ib Intrinsic safety II III 2 D Db EN 60079-11 / IEC 60079-11 energy and surface temperature Limitation of spark i ic Intrinsic safety II III 3 D Dc EN 60079-11 / IEC 60079-11 energy and surface temperature Exclusion of m ma Encapsulation II III 1 D Da EN 60079-18 / IEC 60079-18 Ex-atmosphere Exclusion of m mb Encapsulation II III 2 D Db EN 60079-18 / IEC 60079-18 Ex-atmosphere Exclusion of m mc Encapsulation II III 3 D Dc EN 60079-18 / IEC 60079-18 Ex-atmosphere Inherent safe Limit of radiation op is II III 1 D Da EN 60079-28 / IEC 60079-28 optical radiation energy Inherent safe Limit of radiation op is II III 2 D Db EN 60079-28 / IEC 60079-28 optical radiation energy Inherent safe Limit of radiation op is II III 3 D Dc EN 60079-28 / IEC 60079-28 optical radiation energy Limitation or containment op pr Safe/interlocked II III 2 D Db EN 60079-28 / IEC 60079-28 of radiation op sh optical radiation energy Limitation or containment op pr Safe/interlocked II III 3 D Dc EN 60079-28 / IEC 60079-28 of radiation op sh optical radiation energy Protection by enclo- tta II III 1 D Da EN 60079-31 / IEC 60079-31 Exclusion of dust sure Protection by ttb II III 2 D Db EN 60079-31 / IEC 60079-31 Exclusion of dust enclosure Protection by ttc II III 3 D Dc EN 60079-31 / IEC 60079-31 Exclusion of dust enclosure s sa Special protection III n.a. Da IEC 60079-33 Special measures Special ssb III n.a. Db IEC 60079-33 Special measures protection Special ssc III n.a. Dc IEC 60079-33 Special measures protection

26 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-0 3

Type of protection to Table 34/1: Ambient temperatures in service and additional marking EN 60079-0 Electrical equipment Ambient temperature in ser- Additional marking vice Explosive atmospheres – Part 0: Equipment – General Normal Maximum: +40 °C None requirements Minimum: −20 °C Electrical equipment for use in Special Specified by the T or T with the special range, e.g. -30 °C explosive atmosphere shall a amb manufacturer ≤ T ≤ +40 °C, or the symbol “X” meet the general requirements a of EN 60079-0 and the specific Temperatures To prevent an electrostatic Special requirements requirements of the type of pro- charge, in the case of plastic Depending on the type of protection in which it is designed. Electrical equipment shall be enclosures, a material with a tection, special requirements Under some circumstances, designed for use in a normal surface resistance of < 1 GOhm apply to particularly harsh operating con- ambient temperature range of -20 to +40°C (see table 34/1). is used if the area specified in ditions, the effects of humidity, the standard is exceeded. fasteners and interlocks, bush- high ambient temperatures and ings and connection pieces ,ro- other special demands require Mechanical strength of tating machines, switchgear, additional measures. equipment fuses, plugs and sockets, The mechanical strength, suit- luminaires and batteries. ability for the intended operat- Some of the main points are ing temperature range and the listed below: resistance to ageing of the materials used are verified by cli- Equipment grouping matic conditioning and tests for resistance to impact and drop Electrical equipment for explosive tests(see table 34/1). atmospheres is divided into the following groups: Electromagnetic and ultrasonic energy-radiating equipment Electrical equipment of Group I is In order to prevent the ignition of intended for use in mines sus- an explosive mixture, the signals ceptible to firedamp. Electrical emitted from equipment shall be equipment of Group II is intended below the values stated in the for use in areas where an explo- standard. The specified limiting sive gas atmosphere is to be ex- values shall also apply to lasers pected, other than mines suscep- and other continuous light tible to firedamp. Electrical sour ces. equipment of Group II is subdivided according to the nature of the explosive atmosphere for which it Enclosures and parts of is intended. enclosures If plastics and light alloys are used, special requirements list- Group II subdivisions ed in the standard that apply • IIA, a typical gas is propane specifically to enclosures shall • IIB, a typical gas is ethylene be met. • IIC, a typical gas is hydrogen Tests for resistance to impact of an explosion-protected junction box Table 34/2 Electrical equipment of Group III is intended for operation in Drop height h 0 with mass areas with an explosive dust at- +0,01 mosphere, other than mines Tests for resistance to impact 1 0 kg susceptible to firedamp. Elec- +0,01 m trical equipment of Group III is subdivided according to the na- Equipment grouping Group I Group II or III ture of the explosive atmos- Risk of mechanical danger high low high low phere for which it is intended a) Enclosures and external accessible parts of 2 0,7 0,7 0,4 enclosures (other than light-transmitting parts) Group III subdivisions b) Guards, protective covers, fan hoods, cable glands 2 0,7 0,7 0,4 • IIIA, combustible flyings c) Light-transmitting parts without guard 0,7 0,4 0,4 0,2 • IIIB, non-conductive dust d) Light-transmitting parts with guard having individual • IIIC, conductive dust openings from 625 mm² to 2 500 mm²; see 21.1 0,4 0,2 0,2 0,1 (tested without guard)

www.crouse-hinds.de EATON 27 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079...

Cable entries Operating instructions Cable entries must not render The operating instructions shall the special properties of the type include all the information re- of protection of the electrical quired for the installation, com- equipment to which they are missioning, use, assembly and mounted ineffective and shall ful- dismantling and, where neces- fil the requirements laid down in sary, special instructions for use the standard. and a list of the standards, including the date of issue, with which the electrical equipment Marking Ex-components is declared to comply. An Ex component is a part of The electrical equipment shall electrical equipment or a mod- be marked legibly on the main ule that is marked with the part on the exterior of the enclo- symbol “U” must not be used sure. The minimum require- alone and requires additional ments for the marking can be consideration when incorporat- found in the standard. The fol- ed into electrical equipment or lowing is an example of a mark- systems for use in explosive ating. mospheres.

Example for a type label

Name or registered trade mark (CEAG) and 4 address of the manufacturer 2. Serial number including year of manufacture SERIES 3. Certificate number, 7 CEAG may end with “X“ or “U” 1 D-69412 Eberbach - “X“ indicates that special conditions 3 11 for safe use apply BVS 16 ATEX E 123 / IECEx BVS 16.123 IP66/67 II 2G Ex db eb mb ib IIC T4 Gb -“U” is used for 8 Ta= -25°C bis +55°C 12 component certificates II 2D Ex tb IIIC T80°C Db 9 AC: 110-254V 50-60Hz 4. Additional IECEx certification 13 10 DC: 110-250V 5. Marking according to directive: Lampe: G13-81-IEC www.ceag.de Equipment group (II) 2 Snr.: D123456 2016 Made in Germany and equipment category (2); type of explosive atmosphere 5 6 G (Gas, vapour or mist) D (dust) 10. Other essential information (depends on the standard, e.g. lamp) 6. Marking according to standard: IEC/EN 7. Equipment name/type 11. Other optional information (e.g. degree of protection) 8. CE marking and number of the 12. Permissible ambient temperature (-25°C to +55°C); ”notified body” no marking required for temperatures from -20°C to 40°C responsible for monitoring the quality system (standard values for all equipment) (0158 = EXAM Germany) 13. Marking according to EU-directive 2002/96/EC 9. Electrical parameters (WEEE-directive: Waste of Electrical and Electronic Equipment)

28 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-1 3

EN 60079-1 Requirements for level of Explosive Atmospheres– Part protection “da” 1: Equipment protection by The level of protection “da” only flameproof enclosures “d” applies to catalytic sensors or W portable combustible gas detec- Scope tors. The maximum free internal This part 1 of EN 60079 contains volume shall not exceed 5 cm³. specific requirements for the I construction and testing of Requirements for level of electrical equipment in the protection “db” type of protection The new level of protection “db” Flameproof Enclosure “d” replaces and describes the previ- Principle of flameproof enclosures intended for use in explosive gas ous flameproof enclosure “d”. atmospheres. It supplements and modifies the general Requirements for level of requirements of EN 60079-0. protection “dc” The level of protection “dc” de- Definition scribes a simplified flameproof Type of protection where the encapsulation without the cons- parts which can ignite an explo- tructional requirements for, for sive gas atmosphere are built example, the geometry of gaps. into a flameproof enclosure that The maximum free internal vo- can withstand the pressure de- lume shall not exceed 20 cm³. veloped during an internal explosion of an explosive mixture General requirements and prevents the transmission of the explo sion to the explosi- The flameproof encapsulation ve atmosphere surrounding the can be seen as a one-way enclosure. street. An explosive atmosphere can enter into the enclosure, but, in the event of an explosion inside the enclosure, the transmission of the explosion to the explosive atmosphere surrounding the enclosure. As, due to the construction principle, there are normally gaps in flameproof enclosures, these gaps shall be such that an arc- through through these gaps is prevented. In particular, it is necessary to ensure that the gaps are not damaged mechanically. The geometry of gaps, the gaps and the width of joints shall vary according to the respective group (A, B, C).

The ﬂanged/threaded joint pre- Application example: Ex-d enclosure solution for the chemical industry vents a transission of an explosion

Equipment Protection Level (EPL) The flameproof enclosure shall Special attention shall be given be able to safely withstand the to the fact that, as the ambient Electrical equipment with flame- pressure resulting from an explo- temperature changes, there may proof enclosure “d” can be desi- sion inside the enclosure. De- also be negative changes to the gned in various levels of protec- pending upon the size, group stability of enclosure parts. tion, which determine the overall and geometry, the pressures ari- Because, when the internal equipment protection level: sing in the event of an explosion compartment is divided up (e.g. a) Level of Protection “da” can vary considerably (<5 bar to by built-in equipment) and , in (EPL “Ma” or “Ga”); > 40 bar). If flameproof enclosu- the event of an explosion, a pre- res are used outside of the stan- compaction of the remaining b) Level of Protection “db” dard ambient temperature range mixture and, as a result, increa- (EPL “Mb” or “Gb”); or The values stated in the stan- (-20 °C to +40 °C), the suitability ses in pressure may occur, the c) Level of Protection “dc” dard are only minimum require- shall be tested in accordance worst case scenarios shall be (EPL “Gc”). ments. The suitability shall be with the method specified in taken into consideration during verified by experimental tests. EN 60079-1. experiments. www.crouse-hinds.de EATON 29 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079-1

Walls and obstructions that could Cable entries lead to a dynamic pressure with In addition to the requirements flange joints shall feature a mini- of EN 60079-0, cable entries in mum clearance from the joints Ex-d enclosures shall satisfy the requirements for flameproof en- Oil and liquids that can form an ex- closures. plosive mixture with the air on de- Depending on the chosen con- composition must not, under any cept, entry into the enclosure circumstances, be used in equip- can either be made: ment in flameproof enclosures. directly ( Ex-d cable entry or conduit) Ex-d Emergency light ﬁtting with self-contained battery for direct entry Equipment of Group IIC may or into the ﬂameproof enclosure also be used in the areas for Groups IIB and IIA, equipment indirectly ( Ex-e connection box of Group IIC may be used in ar- combined with Ex-d flameproof eas for Group IIA. The tempera- bushings). ture class of equipment de- notes the permissible limiting temperature up to which the external surface of the equipment may heat up.

Minimum distance of obstructions from flameproof “d” flange openings Gas group Minimum distance IIA 10 mm IIB 30 mm IIC 40 mm NOTE IEC 60079-14 limits the installation of equipment employing type of protection “d” that incorporates flanged (flat) joints. Specifically, the flanged joints of such equipment are not permitted to be installed closer to solid objects that are not part of the equipment, than the dimensions shown in Table 11, unless the equipment is so tested Ex-d pendant light fitting with indirect entry by an Ex-e connection box with Ex-d flameproof bushing

Empty enclosures Cells and batteries for use in The enclosures shall be marked flameproof enclosures in the in accordance with the require- type of protection “d” ments for the marking of Ex Irrespective of the type of components according to electro-chemical cell used, the EN 60079-0. The Ex marking main task is to prevent the re- must not be affixed to the exte- lease of a combustible mixture rior. The exterior of the enclo- of electrolysis gases (normally sure may only be marked with hydrogen and oxygen) inside the name of the manufacturer the flameproof enclosure. and identification features (e.g. type or serial number). For this reason, the use of cells and batteries where the release of electrolysis gases (either due to natural ventilation or with a pressure-relief valve) is to be Ex-d empty enclosures, connected to each other by an Ex-d flameproof expected during normal opera- bushing tion is not permitted. Examples of flameproof enclosure “d” applications • Motors with slip rings and commutators • Three-phase cage induction motors • Switchgear with N/C and N/O contacts such as manual motor starters, circuit breakers, air-break contactors • Control devices • Plugs and sockets • Luminaires

30 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-2 3

EN 60079-2 Equipment protection level Explosive atmospheres – Part (EPL) 2: Equipment protection by Protection by pressurised enclo- pressurised enclosure “p” sures is subdivided into three levels of protection („pxb“, Scope „pyb“ and „pzc“) that, due to This part 2 of EN 60079 con- the equipment protection level tains the specific requirements („Mb“, „Gb“, „Db“, „Gc“ or „Dc“) for the construction and testing required for the respective exter- p of electrical equipment with nal explosive atmosphere, are Q pressurised enclosures, of type selected according to whether of protection “p”, intended for there is potential for an internal use in explosive gas atmos- release and whether the equip- Principle of pressurisation pheres or atmospheres with ment inside the pressurised en- combustible dust. It specifies closure is ignition-capable (Table Protective gas Monitoring requirements for pressurised 1). The type of protection then As a rule, air is used as the pro- It is necessary to monitor the enclosures containing a limited defines the design criteria for tective gas. The protective gas maintenance of the overpres- release of a flammable sub- the pressurised enclosure and shall enter into or exit the enclosure and, if the pressure should stance. It supplements and the pressurisation system sure outside of the hazardous fall, to issue a warning or switch modifies the general require- (Table 2). area. off the system. ments of EN 60079-0. General requirements Cells and batteries for Level Purging criteria Deﬁnition A minimum overpressure of 50 of Protection „pxb“ and Level A method that prevents the in- Pa for the level of protection a) For Level of Protection “pxb” of Protection „pyb“ gress of the surrounding atmos- “pxb” or the level of protection or Level of Protection “pyb”, the Only the cells listed in EN phere into an enclosure, where- “pyb” and 25 Pa for the level of minimum purge flow and time 60079-0 for which there is an by a protective gas is kept at a protection “pzc” shall be main- shall be specified. For simple EN(IEC) standard may be used pressure that is higher than the tained at every point inside the geometries the minimum purge in pressurised enclosure. pressure of the surrounding at- pressurised enclosure and the flow and time may be based mosphere. associated conduit where leak- upon a five-enclosure-volume Secondary cells and batteries ages may occur. purge. may be used if

b) For Level of Protection “pzc”, • the individual cells are sealed the minimum purge flow and cells (either gastight sealed time shall be specified to en- cells or valve- sure that the pressurised enclo- regulated cells) sure is purged by a quantity of or protective gas equivalent to five • if the volume of the battery enclosure volumes. does not exceed 1 % of the free volume inside the pressurised enclosure

Examples of pressurised enclosure ”p” applications • Electrical machines with a higher rating • Control panels and cabinets • Control rooms • Measuring and analysing equipment Terminal in pressurised stainless steel enclosure • Special machines and equipment www.crouse-hinds.de EATON 31 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079-2

Table 1 – Determination of protection level Is there an internal release Highest Equipment Protection Does enclosure contain Level of Protection condition? Level requirement for external ignition-capable equipment? explosive atmosphere

No „Mb”, „Gb” or „Db” Yes or no Level of protection „pxb“ No „Gb” or „Db” No Level of protection „pyb“ No „Gc” or “Dc” Yes or no Level of protection „pzc“ Yes, gas/vapour „Mb”, „Gb” or „Db” No or Yes and the ignitioncapable equipment Level of protection „pxb“ is not located in the dilution area Yes, gas/vapour „Gb” and „Db” Yes or no Level of protection „pyb“ Yes, gas/vapour „Gc” or „Dc” Yes and the ignitioncapable equipment Level of protection „pxb“ is not located in the dilution area Yes, gas/vapour „Gc” or „Dc” No Level of protection „pyb“ Yes liquid „Gb” or „Db” Yes or no Level of protection „pxb“ (inert) Yes liquid „Gb” or „Db” No Level of protection „pyb“ (inert) Yes liquid „Gc” or „Dc” Yes or no Level of protection „pzc“ (inert) REMARK 1 If the flammable substance is a liquid, normal release is never permitted. REMARK 2 The protective gas shall be inert if “(inert)” is shown after the pressurisation level; see Clause 13

Table 2 – Design criteria based upon level of protection Design criteria Level of protection Level of protection Level of protection Level of protection „pxb“ „pyb“ with indicator „pzc“ with alarm„pzc“ Degree of enclosure protection according IP4X minimum IP4X minimum IP4X minimum IP3X minimum to IEC 60529 or IEC 60034-5 Impact resistance of the enclosure IEC 60079-0 applies IEC 60079-0 applies IEC 60079-0 applies apply half the value shown in IEC 60079-0 Verifying purge period for Group I and Requires a timing device and Time and flow marked Time and flow marked Time and flow marked Group II monitoring of pressure and flow

Preventing incandescent particles from ex- Spark and particle barrier re- No requirement a) Level of protection pzc” does Level of protection pzc” does iting a normally closed relief vent into an quired, see unless incandes- not apply to areas requiring not apply to areas requiring area requiring EPL Mb, Gb or Db cent particles not normally EPL Mb, Gb or Db EPL Mb, Gb or Db produced

Preventing incandescent particles from ex- No requirement b) No requirement b) No requirement b) No requirement b) iting a normally closed relief vent into an area requiring EPL Gc or Dc Preventing incandescent particles from ex- Spark and particle barrier re- Spark and particle barrier re- Level of protection pzc” does Level of protection pzc” does iting a vent that opens during normal oper- quired quired not apply to areas requiring not apply to areas requiring ation, to an area requiring EPL Mb, Gb or EPL Mb, Gb or Db EPL Mb, Gb or Db Dc

Preventing incandescent particles from ex- Spark and particle barrier re- No requirement a) Spark and particle barrier re- Spark and particle barrier re- iting a vent that opens during normal oper- quired, see unless incandes- quired, see unless incandes- quired, see unless incandes- ation, to an area requiring EPL Mb, Gb or cent particles not normally cent particles not normally cent particles not normally Dc produced produced produced Door or cover opens only with use of a tool Warning b)ii) Warning b) Warning Warning c) Door or cover opens only with use of a tool Interlock (no internal hot Warning a) Warning Warning parts) Internal hot parts that require a cool-down Comply with ii No requirement a) Warning Warning period before opening enclosure a) point ii) is not applicable for Level of Protection “pyb” since neither hot internal parts nor normally created incandescent particles are permitted. b) There is no requirement for spark and particle barriers since in abnormal operation, where the relief vent opens, it is unlikely that the external atmosphere is within the explosive limits. c) There is no requirement for tool accessibility on a Level of Protection “pzc” enclosure since in normal operation the enclosure is pressurised with all covers and doors in place. If a cover or door is removed, it is unlikely that the atmosphere is within the explosive limits

32 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-5 3

EN 60079-5 pressure test. Enclosures of Explosive atmospheres – electrical equipment protected Part 5: Equipment protection by the type of protection “q“ by powder fi lling “q” shall be filled, closed and sealed during production. It shall not Scope be possible for it to be opened h This part 5 of EN 60079 con- without leaving visible signs. tains specific requirements for Electrical equipment where re- the construction, testing and pairing is possible shall be fitted d marking of electrical equipment, with suitable fasteners that can parts of electrical equipment be opened without damaging and Ex components in the type the enclosure. After completion of protection powder filling “q”, of repair work, the equipment Principle of powder fi lling intended for use in explosive shall be resealed and marked gas atmospheres. It supple- accordingly. Cells and batteries (Accumulators) ments and modifies the general The built-in electrical compo- requirements of EN 60079-0. nents shall be adequately insu- Containers of electrical equip- lated, irrespective of the insulat- ment, parts of electrical equipment or Ex components pro- Defi nition ing effect of the filling material. In the case of bare, live parts, tected by powder filling ”q” A type of protection in which there must be sufficient space that contain cells or batteries the parts capable of igniting an between the parts themselves shall feature a venting device explosive gas atmosphere are and between the parts and the that leads to the outside atmos- fixed in position and completely enclosure wall. The filling mate- phere, except if the cells or bat- surrounded by filling material to rial is compressed, whereby, teries prevent the ignition of an exter- depending on the built-in com- nal explosive gas atmosphere. ponents and requirements, the a) have a capacity of 1.5 Ah layers of filling material shall or less or Equipment Protection Level have a specified thickness. b) do not release any gas under The EPL provided by the type of normal operating conditions and protection powder filling “q” is they meet the requirements “Gb” or “Mb”. according to EN 60079-7 for primary and secondary bat- General requirements teries with a capacity up to With this type of protection the 25 Ah for the level of enclosure is normally filled with protection “eb”. solid glass or quartz particles that have to meet specific requirements relating to the grain size, purity, moisture content and disruptive strength. The stability of the enclosure shall be verified by means of a static

Examples of powder ﬁ lling “q” applications

• Capacitors • Small transformers Application example: Powder ﬁ lled capacitor • Electronic equipment www.crouse-hinds.de EATON 33 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079-6

EN 60079-6 Requirements for Level of Explosive atmospheres – Protection “ob” Part 6: Equipment protection • Rated voltage max. 11 kV by liquid immersion „o“ alternating or direct voltage. • Liquid level indication Scope h This part of EN 60079 specifies • Switching devices rated at the requirements for the de- 2 kVA per contact or less, are sign, construction, testing and permitted without further marking of Ex Equipment and testing. Where the switching Ex Components with type of device is rated above 2 kVA protection liquid immersion “o” per contact, neither pressure intended for use in explosive increases nor excessive de- Principle of liquid immersion “o” gas atmospheres. It supple- composition products shall ments and modifies the general invalidate the type of General requirements Protective liquid requirements of EN 60079-0. protection. With this type of protection the The protective liquid can be a electrical equipment or parts of mineral oil to EN 60296, a sili- Deﬁnition the electrical equipment are im- cone liquid to EN 60836, a syn- Requirements for Level of A type of protection in which mersed in a protective liquid in thetic organic ester (Type T1) to Protection “oc” the electrical equipment or such a way that an explosive EN 61099 or a liquid that com- parts of the electrical equip- • Rated voltage max. 15 kV gas atmosphere which may be plies with the specification in ment are immersed in a protec- alternating or direct voltage. above the liquid or outside the the standard. tive liquid in such a way that an • Switching devices rated at enclosure cannot be ignited. explosive gas atmosphere 10 kVA per contact or less, which may be above the liquid are permitted without further This requires that the thermal or outside the enclosure cannot testing. For switching devices output fed to the protective liq- be ignited. rated above 10 kVA per con- uid, the thermal energy and the tact, neither pressure increas- resulting energy density be takes nor excessive decomposi- Equipment Protection Level en into account. In addition to tion products shall invalidate (EPL) ensuring that the level of the the type of protection. Electrical equipment and Ex protective liquid is sufficient in components in the type of pro- all operating positions of the tection liquid immersion “o” equipment, the use of a suita- can be designed with various ble type of protective liquid is levels of protection which de- important. It shall not decom- termine the overall equipment pose under the influence of, for protection level. example, switching arcs. More- over, by means of adequate di- a) Level of Protection “ob” mensioning, i.a. the dimension- (EPL Gb or Mb); ing of the protective liquid, it or shall be ensured that the equip- b) Level of Protection „oc“ ment does not exceed the per- (EPL „Gc“). mitted temperature. The long term quality of the liquid shall also be monitored. Due to the use of high-performance electronics in explosive atmospheres, in the future the significance of liquid immersion could become far more significant than it is today. Here the protective liquid would fulfil two functions – namely an explosion protection and a cooling medium.

Examples of liquid immersion “o” applications • Switchgear • Transformers • Electronics

34 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-7 3

EN 60079-7 General requirements Explosive atmospheres – Part 7: Equipment protection by Electrical connections increased safety „e“ In accordance with the requirements, electrical connections Scope are subdivided into those for field wiring and factory wiring This part 7 of IEC 60079 speci- and into permanent types and fies the requirements for the reconnectable/rewireable types. design, construction, testing Each type shall, as applicable, and marking of electrical equip- be constructed in such a way ment and Ex Components with that the conductors cannot slip out from their intended location type of protection increased during the tightening of a screw Principle of the type of protection “Increased Safety” safety “e” intended for use in or after insertion, provide a explosive gas atmospheres. means to avoid self-loosening It supplements and modifies of the connection in service, be Degree of protection provided Electrical machines the general requirements of designed in such a way that by enclosures Every insulating material is sub- IEC 60079-0. contact is assured without damage to the conductors and to Enclosures containing bare ject to a natural ageing process. provide a positive compression conductive live parts shall To extend the service life of insu- Deﬁnition force to assure contact pres- provide at least the degree lating materials used for wind- A type of protection applied to sure in service. If intended for of protection IP54. ings, the limiting temperature is electrical equipment in which stranded conductors, employ a lowered compared to conven- The degree of protection IP44 additional measures are applied means to protect the conduc- tional windings. This reduces the tors and distribute the contact is sufficient for enclosures that so as to give increased security risk of damage to the windings against the possibility of exces- pressure evenly. only contain insulated conduc- and, consequently, the formation sive temperatures and against tive parts. If rotating electrical of arcs and sparks due to earth the occurrence of arcs and machines in clean environments sparks during the intended op- Clearances and creepage faults and shorted windings. are monitored regularly by quali- eration and under given ex- distances fied personnel, the degree of traordinary conditions. The clearances and creepage protection IP 20 is sufficient for To protect the winding and to distances are specified subject maintain the maximum permis- Equipment protection level Group II. to the level of protection. The sible surface temperatures, cur- (EPL)) basis for this is EN 60644 for rent-dependent safety devices Electrical equipment and Ex the use of equipment in outside Surface temperatures that respond in the event of components in the type of pro- areas, which is decisive for in- With this type of protection the heavy starting or malfunctions tection “e” can be designed dustrial equipment. To achieve ingress of an explosive gas at- are generally used in motors. with various levels of protection an “increased safety“ and ex- mosphere cannot be excluded. With motors with the level of which determine the overall clude flashovers and the forma- This reason, the maximum per- protection “eb”, this protective equipment protection level. tion of creepage paths, the missible surface temperatures device shall ensure that a motor a) Level of Protection „eb“ clearances were increased con- also apply to all surfaces inside that has reached its con tenuous (EPL „Mb“ or EPL „Gb“) siderably for the Level of Pro- an enclosure. service temperature after sever- tection „eb“ (in the first in- or al hours of operation at rated stance by a factor of 1.5). load is still switched off safely b) Level of Protection „ec“ before it reaches the permissi- (EPL Gc“). ble limiting temperature if a rotor blocks due to a malfunction Level of Protection „eb“ and, as a result, the consump- Rated voltage 11 kV rms AC or tion of an increased current. DC Electrical motors in the type of protection „Increased Safety“ This applies to the equipment may generally only be used in specified in the standard and continuous operation and for connections, conductors, wind- normal, not frequently recurring ings, lamps and batteries, but starts, so that the temperature not to electronic components. increases occurring at the start do not exceed the permissible Level of Protection „ec“ limiting temperatures. Rated voltage 15 kV rms AC or DC Luminaires

This applies to the equipment The requirements of the stand- specified in the standard and ard apply to all luminaires (fixed, connections, conductors, wind- portable, or transportable), hand ings, lamps and batteries, in- lights, and caplights (other than cluding semiconductors or elec- for Group I); intended to be sup- trolytic capacitors. plied by mains (with or without galvanic isolation) or powered by batteries. Explosion-protected electrical machine www.crouse-hinds.de EATON 35 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079-7

Permissible light sources for the All luminaires shall feature a lamp In addition, the following requirements apply for the use of lamps Levels of protection „eb“ and cover of sufficient strength with bi-pin holders: „ec“ are defined explicitly: Type of Type of protection Temperature Temperature Maximun lamp of luminaire class cathode • For Level of Protection “eb” “eb” “ec” or “ec”, fluorescent lamps of power the cold starting type in ac- ≤ cordance with EN 60081 with T8/T10/T12 Permissible Permissible 40 °C T4 10 W single-pin caps (Fa6) in ac- T8/T10/T12 Permissible Permissible ≤ 60 °C T4 8 W cordance with EN 60061-1; T8/T10/T12 Permissible Permissible ≤ 60 °C T3 10 W • For Level of Protection „eb“ or „ec“ tubular fluorescent LED luminaire in the type of protection T5 (8 W) Permissible Permissible ≤ 40 °C T4 4 W bi-pin lamps in accordance „e“, in Level of Protection „eb“ with ≤ with EN 60081 with G5 or LEDs in the type of protection „m“ T5 (8 W) Permissible Permissible 60 °C T3 4 W G13 lamp caps in accordance T5-HE (8 W Not Permissible ≤ 60 °C T4 5 W with EN 61195 with pins Note: bis 35 W) permissible made of brass. Lamp holders LEDs are currently not permitted and sockets shall conform to as a source of light in the Level 5.3.5.3. Such lamps shall be of Protection “eb”, as these semi- Junction and connection connected in a circuit in conductor devices are not yet boxes: which they start and run with- considered to be sufficiently de- Rated data shall be specified for out preheating of the cath- fined, with respect to safety fac- junction and terminal boxes to odes; only T8, T10, or T12 tors and, therefore have to be ensure adherence to the limit- lamps shall be used. T5 lamps protected by other suitable pro- ing temperature during opera- shall be permitted only up to tective measures. tion. 8 watts. • For the Level of Protection These can, for example, be • For Level of Protection „ec“, “eb“ the lamp holders shall specified by determining the tubular fluorescent bi-pin either meet the requirements load data in relation to the ter- lamps in accordance with for the type of protection Flame- minal cross section (wire cross- EN 60081 with G5 or G13 proof Enclosure „db“ or the section) and the number of con- lamp caps in accordance with type of protection Increased nected wires. EN 61195 with pins made of Safety “eb”, whereby, with the Stainless-steel terminal box, brass. Lampholders and sock- latter the is not live during type of protection „e“ ets shall conform to 5.3.5.3. con nection or disconnection. Such lamps may be connected in a circuit in which they start Batteries and cells Type of Capacity Permitted activity in Remarks and run with preheating of the cell or of cell or hazardous area cathodes; only T5-type HE ac- Only those types of cells named battery battery Dis- Char- Additional cording to EN 60081 sheet explicitly in the standard are per- char- ging equipment in 6520 (14 W), sheet 6530 (21 missible. Here distinction is ging the same com- W), sheet 6640 (28 W), sheet made between: partment 6650 (35 W), T8, T10, or T12 • Sealed cells lamps shall be used. sealed ≤ 25 Ah yes yes yes - • Valve-regulated cells and bat- • For Level of Protection „eb“ teries Valve- No yes no Yes Equipment with Type or „ec“ tungsten filament regulated restriction Only of Protection “d”, “í”or • Vented cells and batteries lamps in accordance with “e” “m” “o” “q” shall be located in a separate compartment EN 60064 and EN 60432-1.; During transport in an explosive • For Level of Protection „eb“ atmosphere the live parts of a a Vented No yes no tungsten-halogen lamps in battery shall have a minimum restriction accordance with EN 60432-2, degree of protection IP 30. restricted to max. 100 W. • For Level of Protection „ec“ tungsten-halogen lamp in accordance with EN 60432-2.; without power limitation. Examples of Increased Safety “e“ applications • For Level of Protection „ec“ discharge lamp in • Three-phase cage rotors accordance with EN 62035 • Transformers • for Level of Protection „ec“ • Current and voltage transformers LEDs • Measuring instruments • Luminaires • Terminal compartments for all electrical equipment • Connections for plugs and sockets

36 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-11 3

EN 60079-11 60079-0, where the intrinsic Explosive atmospheres – safety of the electrical circuits in Part 11: Equipment protection the explosive atmosphere may R L by intrinsic safety “I” depend upon the design and construction of such electrical Scope equipment or parts of such U C One of the more recent types electrical equipment. The cur- of protection against explosion rent standard supplements and hazards due to electrical appara- modifies the general requirements of EN 60079-0. tus and installations is called RL ”Intrinsic Safety”. The most common types of protection Deﬁnitions were conceived for electrical Principle of the type of protection Intrinsic Safety “I” power engineering applications. Intrinsic Safety „i“ non-intrinsically safe circuits Equipment Protection Level As a result of increasing auto- Type of protection based on the cannot adversely affect the in- (EPL) mation in hazardous areas, restriction of electrical energy trinsically safe circuits. Electrical apparatus in the type there has been an ever growing within equipment and of inter- of protection Intrinsic Safety demand for explosion-protected connecting wiring exposed to „i“ can be subdivided into vari- measurement and control de- the explosive atmosphere to a Note: ous levels of protection that vices. This part of EN 60079 level below that which can determine the overall equip- specifies the requirements for cause ignition be either spark- Associated apparatus may be ment protection level: the construction and testing of ing or heating effects. either: intrinsically safe apparatus in- Electrical equipment which has a) level of protection „ia“ tended for use in an explosive Intrinsically safe circuit another type of protection for (EPL „Ma“; „Ga“ or „Da“); atmosphere and for associated Circuit in which any spark or use in the appropriate explosive b) level of protection „ib“ apparatus, which is intended for thermal effect produced in the atmosphere; (EPL „Mb“; „Gb“ or „Db“); connection to intrinsically safe conditions specified in this Electrical equipment not so pro- oder circuits which enter such at- standard, which include normal tected and which, therefore, is mospheres. operation and specified fault not normally used within an ex- c) level of protection „ic“ This type of protection is appli- conditions, is not capable of plosive atmosphere, e.g. a re- (EPL „Gc“ or „Dc“). cable to electrical equipment in causing the ignition of a given corder which is not itself in an which the electrical circuits explosive atmosphere. explosive atmosphere, but is Level of protection „ia“ themselves are incapable of connected to a thermocouple With UM and UI applied, the in- causing an explosion in the sur- situated within an explosive at- Intrinsically safe apparatus trinsically safe circuits in electri- rounding explosive atmos- mosphere where only the re- cal apparatus of level of pheres. It is also applicable to Electrical equipment in which all corder input circuit is electrical equipment or parts of circuits are intrinsically safe. intrinsically safe. protection “ia” shall not be ca- electrical equipment located pable of causing ignition in each outside the explosive atmos- of the following circumstances: Associated apparatus phere or protected by another a) in normal operation and with Electrical equipment which con- Type of Protection listed in IEC Diode safety barriers the application of those non- tains both intrinsically safe and Assemblies that incorporate countable faults which give the non-intrinsically safe circuits shunt diodes or diode chains most onerous condition; and is constructed so that the (including Zener diodes) pro- b) in normal operation and with tected by fuses or resistors or a the application of one countable combination of these, manufac- fault plus those non-countable tured as an individual apparatus faults which give the most on- rather than as part of a larger erous condition; apparatus. c) in normal operation and with the application of two countable faults plus those non-countable faults which give the most onerous condition.

Associated electrical apparatus www.crouse-hinds.de EATON 37 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079-11

Level of protection „ib“ Ignition limit curves 5 A With Um and Ui applied, the in- In the intrinsically safe circuit the energy released, even in the trinsically safe circuits in electri- 2 A cal apparatus of level of protec- event of a fault, shall be limited tion “ib” shall not be capable of to such an extent that no igni- causing ignition in each of the tion can occur. To simplify mat- 1 A following circumstances: ters, the ignition limit curves for the individual groups were de- 500 mA • In normal operation and with I the application of those non- termined using a standardized II A countable faults which give spark test apparatus. II B 200 mA the most onerous condition; As the probability of the ignition of a mixture is also dependent • In normal operation and with 100 mA the application of one count- on the number of makes and able fault plus the application breaks, in accordance with of those non-countable faults EN 60079-11 it is necessary to 50 mA II C which give the most onerous carry out up to 1000 makes and condition. breaks, whereby no ignition shall occur under any circum- 20 mA stances. Level of protection „ic“ Depending on the design of the Resistive circuit With UM and UI applied, the in- intrinsically safe circuit, it is nec- trinsically safe circuits in electri- essary to expect the presence μ cal apparatus of level of protec- of energy stores. If the event of .000 F tion “ic” shall not be capable of capacitances in the intrinsically 3000 μF causing ignition in normal oper- safe circuit, they are charged to ation and under the conditions 000 μF the voltage of the circuit. If specified in this standard. there is a short in the circuit, in 300 μF addition to the energy supplied Note: by the associated apparatus, 100 μF the energy stored in the capaci- The concept of countable faults C = 40 Ω (Cd) tor is also released. The same 30 μF does not apply to this level of C = 15 Ω (Cd) applies if the event of induct- C =5,6 Ω (Cd) protection. 10 μF ances in the circuit. • For the reasons stated above, 3 μF with intrinsically safe circuits (Sn) 1,0 μF General requirements it is necessary to take the (Cd)

On principle, as with all other three limiting cases: 0,3 μF types of protection, the associ- - resistive ated electrical apparatus used in 0,1 μF intrinsically safe circuits and the - capacitive 0,03 μF intrinsically safe apparatus shall - inductive circuit be tested and certified. Accord- 0,01 μF into consideration. ing to EN 60079-0, only such Capacitive circuit apparatus where, according to the details given by the manu- 1 H facturer, no value exceeds 1.2 V; 0.1 A; 20 μJ or 25 mW, is ex- 00 mH empted. Simple intrinsically safe apparatus where the elec- 00 mH trical parameters and the ther- 00 mH mal behaviour can be clearly defined and that conforms to the 50 mH applicable constructional re- I 20 mH II A quirements need not be tested II B or certified. The general require- 10 mH ments according to EN 60079-0 and the design of enclosures 5 mH and connection boxes with re- II C gard to the surface resistance 2 mH or the selection of the alumini- 1 mH um alloy (surface resistance for moulded plastic enclosures 500 μH <109 Ohm) shall, however, be observed here. 200 μH

Inductive circuit

38 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-11 3

Separation of intrinsically safe Intrinsically safe circuits with When using measuring instru- circuits from non-intrinsically Zener barriers ments, it is necessary to bear in safe circuits Normally intrinsically safe cir- mind that they might contain an In order to avoid any mix-ups as cuits shall be insulated. They internal energy store (e.g. the a result of the loosening of con- may be earthed if this is re- inductance of a moving coil indi- nection cables during connec- quired for functional reasons. cator) that could nullify the in- tion or bridging, the terminals of They must, however, be earthed trinsic safety. intrinsically safe circuits shall al- if this is mandatory for safety ways be safely segregated from Example of the separation of reasons. The earth connection Reduced separation distances the terminals of non-intrinsically intrinsically safe circuits from may only be made at one point Under certain conditions speci- safe circuits. non-intrinsically safe circuits with by connection with the potential fied in the standard, it is possi- a minimum distance of 50 mm equalization, which has to be This can, for example, be achieved ble to design printed circuit available throughout the area in by positioning the connection boards with separation distanc- which the intrinsically safe cir- terminals of intrinsically safe the conductors of the intrinsical- es that are smaller than the cuit is installed. As, in the case circuits at least 50 mm away ly safe cores can withstand a standard distances that normally of safety barriers, there is no from the connection terminals test voltage of 2000 V. apply, thus enabling the use of galvanic isolation of the intrinsi- of non-intrinsically safe circuits smaller, more effective It is also necessary to ensure cally safe circuit from the or by separating the two circuits that there can be no inductive electronic elements. using an insulating partition or non-intrinsically safe circuit, for or capacitive influences from safety reasons there has to be an earthed metal partition. These the non-intrinsically safe circuit a faultless earth connection. Fieldbus intrinsically safe partitions shall either extend to into the intrinsically safe circuit. within 1.5 mm from the enclo- concept (FISCO) sure wall or they shall ensure a Working on and testing of The requirements for apparatus Planning of intrinsically safe minimum clearance of 50 mm intrinsically safe circuits and systems for use with the circuits Fieldbus Intrinsically Safe Con- between the connection On principle, working on live cept (FISCO) are based on con- terminals. When setting up an intrinsically intrinsically safe circuits is cepts of Manchester encoded, safe circuit with just one intrin- allowed, as, due to their design, bus powered systems designed Separation of insulated con- sically safe apparatus and one no ignition can take place. How- in accordance with IEC 61158-2, ductors of intrinsically safe associated apparatus, the limit- ever, the generally valid require- the “physical layer standard” and non-intrinsically safe ing values for the permissible ments for work on live parts for Fieldbus installations. The clearance between the con- external capacitance and the shall be observed. ductors of insulated cables shall permissible external inductance satisfy given requirements. shall be taken from the type label of the associated apparatus. With the exception of varnishes They are defining for the circuit. and similar coatings, this insulation is considered to be a solid Then, based on the maximum Typical system insulation. The separation dis- possible power supply of the tance is determined by the ad- associated apparatus, it is only dition of the radial thickness of necessary to check the heat the insulation on the wires. The rise behaviour of the intrinsically minimum clearances are speci- safe apparatus. However, when fied in EN 60079-11: several intrinsically safe circuits are interconnected (e.g. several This clearance is not necessary if: pieces of associated apparatus the cores of the intrinsically safe for one intrinsically safe appara- and non-intrinsically safe circuits tus), a further verification of the are fitted with an earthed screen intrinsic safety is necessary. The verification of the intrinsic safe- Hazardous area Non-hazardous area or if, in the case of electrical ty of a circuit shall be docu- Legend apparatus with the level of pro- mented in detail. 1 Terminating resistor 5 Field devices tection ib or ic, the insulation of 2 Supply unit 6 Main line 3 Data 7 Branch line 4 Handheld controller

PROFIBUS IS ﬁeld equipment DP, DPV1 MODBUS

1 24 24 V DC 24 V DC supply supply

memory memory I/O I/O

Bus Bus Bus Bus Bus Bus

FB Remote I/O Example of an intrinsically safe application: 4-wire PT 100 www.crouse-hinds.de EATON 39 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079-13

EN 60079-13 Deﬁnitions

Explosive atmospheres – Pressurised room Part 13: Equipment protection A room volume protected by by pressurised room “p” and pressurisation and of sufficient artificially ventilated room “v” size to permit the entry of a person who may occupy the room. Scope This part of EN 60079 gives re- Artificially ventilated room p Q quirements for the design, con- A room volume protected by struction, assessment, verifica- artificial ventilation and of suffi- tion and marking of rooms: cient size to permit the entry of Principle of protection by a pressurised room „p” and an artificially • located in an explosive at- a person who may occupy the ventilated room mosphere protected without room. General requirements Artificial Ventilation “v” an internal source of release Rooms with artificial ventilation and is protected by pressuri- Pressurisation “p” “v” shall be in the level of pro- sation or artificial ventilation; Equipment protection level The described concept can be Rooms with pressurisation “p” tection “v” or “vc” (EPL Gc), • located in a non-hazardous subdivided into various levels of shall be in the level of protec- area or Zone 2 area, contain- tion “pb” (EPL “Gb” or “Db”), protection that determine the Level of protection “vc” ing an internal source of re- overall equipment protection whereby the pressurised room lease and protected by artifi- The ventilated room maintains level. maintains an internal overpres- cial ventilation; sure preventing the ingress of artificial ventilation to dilute a • Rooms with pressurisation release of flammable substance • located in an explosive at- an explosive atmosphere and is Level of protection “pb” to reduce a hazardous area mosphere, containing an in- suitable for use in an area re- (EPL “Gb” or “Db”). such that the required EPL is ternal source of release and quiring EPL “Gb” or” Db”, per- reduced from either “Gb” or protected by pressurisation • Rooms with pressurisation mitting unprotected equipment “Gc” to non-hazardous, or from and artificial ventilation. Level of protection “pc” to be installed within the pres- (EPL “Gc” or “Dc”) surised room except for pres- “Gb” to “Gc”, and is suitable for surisation defined safety devic- use in an area requiring EPL “Gc”. • Rooms with artificial ventilation The term “room” used in this es, or level of protection “pc” Level of protection “v” ( “Gb” document includes single (EPL “Gc” or ”Dc”), whereby Level of protection “v”, rooms, multiple rooms, a com- or “Gc”), ventilated room the pressurised room maintains The ventilated room maintains plete building or a room con- with an internal source of re- an internal overpressure pre- artificial ventilation to dilute a tained within a building and in- lease and suitable only for venting the ingress of an explo- release of flammable substance cludes inlet and outlet ducts. use in a non-hazardous area. sive atmosphere and is suitable to reduce a hazardous area • Rooms with artificial ventilation for use in an area requiring EPL such that the required EPL is A room assembled or construct- Level of protection “vc”. (EPL “Gc” or “Dc”, permitting unpro- reduced from either “Gb” or ed on site, may be either on “Gb” or “Gc”), ventilated tected equipment to be in- “Gc” to non-hazardous or from land or off-shore, and designed room with or without an inter- stalled within the pressurised “Gb” to “Gc” and is suitable to facilitate the entry of person- nal source of release and suit- room except for pressurisation only for use in a non-hazardous nel. The room is primarily in- able for use in Zone 2 areas. defined safety devices. area. tended for installation by an end-user but could be constructed and assessed at a manufacturer’s facility, where the final construction such as ducting is to be completed on site.

Rooms may be located in an explosive gas atmosphere requiring Equipment Protection Levels (EPL) Gb or Gc. or a combustible dust atmosphere requiring Equipment Protection Levels (EPL) Db, or Dc.

40 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-15 3

EN 60079-15 Deﬁnitions

Explosive atmospheres - Type of protection “n” Part 15 Equipment protection Type of protection applied to by type of protection “n” electrical equipment that, during normal operation and under Scope specified fault conditions, is not This part 15 of EN 60079 speci- capable of igniting a surround- fies requirements for the con- ing explosive gas atmosphere. struction, testing and marking of Group II electrical equipment Non-sparking device „nA“ in the type of protection “n” for use in explosive gas atmos- A device designed to minimize Principle of the type of protection „non-sparking“ „n“ pheres. This standard applies to the risk of the occurrence of arcs electrical equipment where the or sparks capable of creating an Note: General requirements rated voltage does not exceed ignition hazard during normal In the meantime this protection The classification of electrical 15 kV r.m.s. a.c.or 15 kV d.c. It operation. concept has been incorporated equipment into groups and applies to both non-sparking Note: in EN 60079-1 as Level of temperature classes shall com- electrical equipment and equip- ply with the classification of In the meantime this protection Protection “dc” ment with circuits or parts pro- electrical equipment into groups concept has been incorporated in ducing arcs or sparks or having and temperature classes in ac- EN 60079-7 as Level of Hermetically sealed device hot surfaces which, if not pro- cordance with EN 60079-0. Dur- Protection”ec”. ”nC” tected in one of the methods ing normal operation and under A device that is so constructed given in this standard , could be given fault conditions, as speci- that the external atmosphere capable of igniting a surround- Enclosed break device “nC“ fied in this standard, the equip- cannot gain access to the inte- ing explosive gas atmosphere. A device incorporating electrical ment must not: contacts that are made and bro- rior and in which the seal is This standard describes several a) give off any arcs or sparks ken and that will withstand an made by fusion, e.g. by solder- different methods by which this during operation unless internal explosion of the flamma- ing, brazing, welding or the fu- can be achieved which may be measures have been taken to ble gas or vapour which may en- sion of glass to metal. combined with other methods prevent the ignition of the ter it without suffering damage described in IEC 60079 0. This surrounding explosive atmos- and without communicating the standard supplements and Non-incendive component phere as a result of these internal explosion to the external modifies the general require- “nC” arcs or sparks; ments of IEC 60079 0. flammable gas or vapour. A component with contacts for b) develop a maximum surface making or breaking a specified temperature that exceeds the ignition capable circuit , but in maximum values for the re- which the contacting mechanism spective temperature class of is designed and constructed in the equipment such a way that the component is not capable of causing ignition The surface to be taken into of a specified explosive gas consideration is: atmosphere. – equipment in the types of protection nR and nC: Sealed device “nC“ the external surface of the A device that is constructed in equipment; such a way that it cannot be – equipment in the type of pro- opened during normal service tection nA: the surface of any and is sealed effectively to part of the electrical equip- prevent the ingress entry of an ment, including the surface of external atmosphere. parts located inside the equipment, where the in- Restricted-breathing enclo- gress of an explosive gas at- sure “nR” mosphere is possible. An enclosure designed to restrict the ingress of gases, vapours and mists.

Equipment Protection Level Group II electrical equipment in the type of protection “n” provides equipment with Equip- ment Protection Level (EPL) Gc.

Electrical machines: Plug-in connected pump drives by type of protection „nA“ www.crouse-hinds.de EATON 41 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079-15

Supplementary requirements Restricted-breathing In the meantime the require- enclosures “nR” Overview ments for equipment in the type Restricted-breathing equipment Temperature Deﬁnition Test port Routine test of protection “nA” have been in- shall be limited with regard to limitation corporated in the Level of Pro- the dissipated power, so that tection “ec” in EN 60079-7. the temperature measured on Sparking Ta + 20 K Yes Required In the meantime the requirements the outside does not exceed the maximum permissible sur- for non-sparking equipment with a Non-sparking T-class No Required low power rating have been incor- face temperature. porated in the Level of Protection Restricted-breathing equipment Non-sparking T-class Yes Depends on type test “ec” in EN 60079-7. with built-in components that In the meantime the requirements give off arcs or sparks during for enclosed break devices have normal operation or equipment been incorporated in the Level with hot surfaces designed for Type test Test port Routine test of Protection “dc” in EN 60079-1. frequent temperature changes shall be limited with regard to 0.3 kPA - 0.15 kPA/360 s Yes No In the meantime the type of pro- the power dissipation, so that tection “nL” that is still included the temperature measured on 0.3 kPA - 0.15 kPA/180 s in older editions of EN 60079-15 the outside of the enclosure 0.3 kPA - 0.15 kPA/180 s No 0.3 kPA - 0.27 kPA/27 s has been incorporated as Level does not exceed the external 3.0 kPA - 2.7 kPA/27 s of Protection “ic” in EN 60079-11. ambient temperature by more 0.3 kPA - 0.15 kPA/90 s than 20 K. 0.3 kPA - 0.15 kPA/90 s Yes 0.3 kPA - 0.27 kPA/14 s Hermetically sealed and Restricted-breathing electrical 3.0 kPA - 2.7 kPA/14 s sealed devices “nC” equipment that does not nor- Hermetically sealed and sealed mally give off arcs or sparks, devices shall be designed in but does produce hot surfaces such a way that they are sealed during normal operation shall be routine maintenance work. in a way that the ingress of an limited with regard to the dissi- Luminaires may be exempted explosive atmosphere into the pated power, so that the tem- from the fitting of a test port if device is not to be expected perature measured on the out- the following conditions are and that they can be opened side does not exceed the values met: during normal operation. Her- for designated temperature a) there are no devices that nor- metically sealed devices are class. sealed by means of a fusion mally give off arcs or sparks process, whereas a suitable Restricted-breathing equipment in the restricted-breathing seal is used for sealed devices. shall normally be fitted with a enclosure test port to allow the testing of The free internal volume must and not exceed 100 cm³. the restricted-breathing properties after installation and during b) resilient gasket seals are protected mechanically in such a way that they are not subject to mechanical damage during field installation or replacement and c) the gaskets or seals exposed during a re-lamping are of a type that can be readily replaced during the re-lamping process. Equipment that does not have a test port shall be marked with the symbol “X” and the specific conditions of use shall be specified in the documentation.

Test port

42 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-18 3

EN 60079-18 mable or toxic gas from the Explosive atmospheres – dust. It supplements and modi- Part 18: Equipment protection fies the general requirements of by encapsulation “m” IEC 60079-0.

Scope Deﬁnition h This part 18 of IEC 60079 gives Type of protection whereby the specific requirements for parts that are capable of igniting the construction, testing and an explosive atmosphere by ei- marking of electrical equipment, ther sparking or heating are fully parts of electrical equipment enclosed in a compound or oth- and Ex components with the er permitted non-metallic enclo- Principle of encapsulation “m” type of protection encapsulation sure with adhesion in such a “m” intended for use in explo- way as to avoid ignition of a Additional requirements for Permissible free space in the sive gas atmospheres or explo- dust layer or explosive atmos- le vels of protection “ma” and encapsulation sive dust atmospheres. It only phere under operating or instal- “mb” With Group III equipment the applies for encapsulated electri- lation conditions. Components without additional sum of the free spaces is not cal equipment, encapsulated protection shall be used only if limited, but the volume of each parts of electrical equipment they cannot damage the encap- individual free space is limited and encapsulated Ex compo- Equipment protection level sulation mechanically or ther- to 100 cm3. The thickness of the nents (hereinafter always re- (EPL) mally in the case of any fault compound surrounding such ferred to as “m” equipment) Electrical equipment in the type conditions specified in this free spaces shall meet the re- where the rated voltage does of protection encapsulation “m” standard. quirements laid down in the not exceed 11 kV. The use of can be designed with various standard. electrical equipment in atmos- levels of protection which de- pheres, which may contain ex- termine the overall equipment Additional requirements for With Group I and Group II plosive gas as well as combusti- protection level: level of protection “ma” equipment the sum of the free spaces shall not exceed: ble dust simultaneously, may a) Level of protection „ma“ The working voltage at any point require additional protective (EPL „Ma“ or „Ga“); in the circuit shall not exceed 1 • 100 cm3 for level of protection measures.. This standard does kV. Cells and batteries shall ad- „mb“ and „mc“, not apply to dusts of explosives b) Level of protection „mb“ ditionally comply with the cell 3 which do not require atmos- (EPL „Mb“ or „Gb“); or and battery requirements of • 10 cm for level of protection pheric oxygen for combustion c) Level of protection „mc“ IEC 60079-11.; however, parallel „ma“ or to pyrophoric substances and (EPL „Gc“). cells are not permitted. does not take account of any Cells and batteries risk due to an emission of flam- General requirements Cells and batteries that can re- Duromers, thermoplasts and lease gas during normal opera- elastomers with and without tion are not permitted. If for lev- fillers and/or other additives els of protection “ma” and may be used as the compound. “mb” the release of gas in the The selection of the compound event of a fault cannot be pre- for a particular application de- cluded, the gassing shall be pends on the function to be ful- minimised by a control device filled by the compound in the With secondary cells, the con- equipment. The encapsulation trol device shall be effective not shall ensure the effectiveness only during charging, but also of the type of protection subject during discharging. to the level of protection, even in the event of permissible over- loads and given faults. Voids in the compound for accommodat- ing components such as relays, transistors, etc. are permissible. Specially designed multilayer circuit boards are also classed as encapsulated.

Examples of encapsulation “m”: • Relays, signal and control devices • Electronic devices Electrical components in encapsulation „m“ • Components, small transformer and solenoid valves. www.crouse-hinds.de EATON 43 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079-25

EN 60079-25 Definitions Explosive atmospheres – Part 25: Intrinsically safe Intrinsically safe electrical R L electrical systems system An assembly of interconnected Scope items of electrical apparatus, U C This part 25 of EN 60079 con- specified in a descriptive sys- tains the specific requirements tem document, in which the cir- for the construction and assess- cuit or parts of circuits intended ment of intrinsically safe electri- for use in an explosive atmos- RL cal systems, type of protection phere are intrinsically safe cir- “i“, intended for use as a whole cuits. or in part in locations in which Principle of protection „intrinsic safety“ „i“ the use of Group I,II or III appa- Certified intrinsically safe Uncertified intrinsically safe General requirements ratus is required. It supplements electrical system electrical system and modifies the general re- A descriptive system document quirements of EN 60079-0 and An intrinsically safe electrical An intrinsically safe electrical sys- shall be created for all systems. the intrinsic safety standard system for which a certificate tem for which the knowledge of The document shall provide an EN 60079-11. has been issued confirming that the electrical parameters of the adequate analysis of the level of the electrical system complies items of certified electrical appa- protection achieved by the sys- with the standard. ratus, certified associated appa- tem. The minimum require- ratus and simple apparatus and ments are: the knowledge of the electrical • a block diagram of the sys- and physical parameters of the tem listing all the items of interconnecting wiring, permit apparatus within the system; the unambiguous deduction that the intrinsic safety is preserved. • a statement of the group subdivision, the level of pro- Equipment protection level tection for each apparatus, (EPL) the temperature classification and the ambient temperature Each part of an intrinsically safe rating of the system; electrical system intended for use in an explosive atmosphere • the requirements and permis- has a level of protection in sible parameters of the inter- accordance with EN 60079-11: connecting wiring; a) level of protection „ia“ • details of the earthing and (EPL „Ma“; „Ga“ or „Da“) bonding points of the system; b) level of protection „ib“ • where applicable, the justifi- (EPL „Mb“; „Gb“ or „Db“) cation of the assessment of c) level of protection „ic“ (EPL the apparatus as “simple ap- „Gc“ or „Dc“). paratus” in accordance with EN 60079-11. The complete system need not necessarily have a single level of protection.

Typical system

Hazardous area Non-hazardous area Legend 1 Terminating resistor 5 Field devices 2 Supply unit 6 Main line 3 Data 7 Branch line 4 Handheld controller Components for intrinsically safe systems

44 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-26 3

EN 60079-26 and Ex “da”) cannot be applied. This standard also applies to Explosive atmospheres – equipment mounted across a Part 26: Equipment with boundary wall where different Equipment Protection Level Equipment Protection Levels (EPL) Ga may be required. When operated within the oper- Scope ational parameters specified by This part 26 of EN 60079 speci- the manufacturer, this electrical fies alternative requirements for equipment ensures a very high p Q the construction, testing and level of protection, even in the marking of electrical equipment in the event of the occurrence Principle of the combination of two independent types of protection for use in explosive atmospheres of rare malfunctions or of two in which explosive mixtures of malfunctions occurring indepen- air with gases, vapours or mists dently of each other. Equipment Protection Level General requirements are present continuously, for (EPL) This standard supplements and In order to exclude ignition haz- long periods or frequently that modifies the general require- If the marking states several ards that can occur in connec- provides the Equipment Protec- ments of EN 60079-0. EPLs for the equipment (e. g. tion with electrical circuits, the tion Level (EPL) Ga when sin- Ga/Gb), it is necessary to state requisite level of protection gle, standardised types of pro- which parts of equipment have shall either be ensured by one tections (e.g. Ex “ia”, Ex “ma” which EPL. means of equipment protection, even in the event of the occurrence of two independent mal- Application of a type of protection providing EPL “Gb” and a separation element functions, or, in the event of the The table shows the possible combinations of partition walls with types of protection for applications failure of one means of equip- using separation elements. ment protection, by a second independent means of equipment protection.

Single type of equipment protection The following are permitted as single types of equipment protection: Equipment and circuits in accordance with the requirements of EN 60079-11, level of protection “ia”, and encapsulated equipment in accordance with the requirements of EN 60079-18, level of protection “ma”. Note: Also valid is the protection level “da”, not yet embodied in this standard.

Combined types of equipment protection Electrical equipment shall comply with the requirements of two independent types of protection that provide EPL “Gb”. The independent types of protection shall not have a common mode of failure that can result in the simultaneous failure of both types of protection. Combined types of protection providing EPL “Gb” shall depend on different physical protection principles. In addition, the equipment and parts thereof in Zone 0 shall be designed in such a way that ignition sources due to sparks caused by an impact or friction are excluded and ignition hazards due to hazardous electrostatic charges cannot occur. www.crouse-hinds.de EATON 45 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079-28

EN 60079-28 This standard contains require- Deﬁnitions ments for optical radiation in • Inherently safe optical Explosive atmospheres - the wavelength range from radiation “op is” Part 28: protection of equip- 380 nm to 10 μm. It covers the Visible or infrared radiation ment and transmission sys- following ignition mechanisms: that is incapable of producing tems using optical radiation sufficient energy under normal or specified fault condi- • optical radiation is absorbed Scope tions to ignite a specific by surfaces or particles, caus- This part of EN 60079 specifies explosive atmosphere. ing them to heat up, and un- the requirements, testing and der certain circumstances • Protected optical radiation marking of equipment emitting this may allow them to attain “op pr” Warning of optical radiation optical radiation intended for a temperature which will ig- Visible or infrared radiation that use in explosive atmospheres. nite a surrounding explosive is confined inside optical fibre It also covers equipment locat- atmosphere. or other transmission medium ed outside the explosive atmos- under normal constructions or • In rare special cases, direct phere or protected by a type of constructions with additional laser induced breakdown of protection listed in IEC 60079-0, mechanical protection based the gas at the focus of a but which generates optical ra- on the assumption that there is strong beam, producing plas- diation that is intended to enter no escape of radiation from the ma and a shock wave both an explosive atmosphere. It confinement. covers Groups I, II and III, and eventually acting as ignition EPLs Ga, Gb, Gc, Da, Db, Dc, source. These processes can • Optical system with inter- Ma and Mb. be supported by a solid mate- lock “op sh” rial close to the breakdown System to confine visible or point. infrared radiation inside optical fibre or other transmission This standard supplements and medium with interlock cut-off modifies the general require- provided to reliably reduce the ments of EN 60079-0 and ap- unconfined beam strength to plies to optical fibre equipment safe levels within a specified and optical equipment, includ- time in case the confinement ing LED and laser equipment. fails and the radiation be- comes unconfined.

Equipment Protection Level EPL EPL EPL Ga, DA, Ma Gb, Db, Mb Gc, Dc Inherently safe optical radiation “op is” safe with two faults or using optical source based on the thermal failure characteristic yes yes yes safe with one fault or using optical source based on the thermal failure characteristic no yes yes safe in normal operation no no yes Protected ﬁbre optic media with ignition capable beam “op pr” with additional mechanical protection no yes yes according to fibre manufacturers specification for normal industrial use, no no yes but without additional mechanical protection Fibre optic media with ignition capable beam interlocked in case of ﬁbre breakage “op sh” Protected fibre optic cable “op pr” for Gb/Db/Mb + shutdown functional safety system yes yes yes based on ignition delay time of the explosive gas atmosphere Protected fibre optic cable “op pr” for Gc/Dc + shutdown functional safety system based on no yes yes eye protection delay times (IEC 60825-2) Unprotected fibre optic cable (not “op pr”) + shutdown functional safety system based on no no yes eye protection delay times (IEC 60825-2) None (unconfined, ignition capable beam) no no no Shutdown system safe with one fault

46 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-28 3

General requirements Optical equipment shall be subjected to a formally documented ignition hazard assessment using the principles stated in the standard. This assessment shall be made to determine which possible optical ignition source can arise in the equipment under consideration, and which measures may need to be taken to mitigate the risk of ignition. If a source of optical radiation is inside an enclosure providing a protection of minimum IP 6X, after the tests specified in IEC 60079-0 for enclosures, the ingress of absorb- ing targets from the outside of the enclosure need not be taken into consideration, but the existence of internal targets shall be taken into consideration. However, where the optical radiation may leave such an enclosure, the requirements of this standard also apply to the emitted optical radiation.

Safe optical power and irradiance for explosive atmosphere, categorized according to equipment group and temperature class

Equipment group I IIA IIA IIB IIC

Temperature class T3 T4 T4 T4 T6

Temperature (°C) <150 °C <200 °C <135 °C <135 °C <135 °C <85 °C

Radiated power (mW) 150 mW 150 mW 35 mW 35 mW 35 mW 15 mW

Irradiance (mW/mm”) 20 mW/mm² 20 mW/mm² 5 mW/mm² 5 mW/mm² 5 mW/mm² 5 mW/mm² (Surface up to 400 mm²) For irradiated areas of more than 30 mm² where combustible materials can enter the beam, an irradiance limit of 5 mW/mm² applies

www.crouse-hinds.de EATON 47 Explosion-protected Electrical Equipment 3 Type of protection to EN 60079-29 and EN 60079-30-1

EN 60079-29 EN 60079-30-1

Explosive atmospheres - Explosive atmospheres - Part 29-1 Gas detectors – Part 30-1 Electrical resistance Performance requirements of trace heating – General and detectors for ﬂammable gases testing requirements

Scope Scope This part of the series EN 60079- This standard specifies general 29 contains general requirements and testing requirements for for the construction, testing and electrical resistance trace heat- performance and describes the ers for use in explosive gas at- test methods that apply to port- mospheres. able, transportable and fixed ap- It covers trace heaters that paratus for the detection and comprise either factory or field- measurement of flammable gas assembled units, e.g. series or or air concentrations with air. parallel trace heater cables, trace heater pads or trace heat- Further standards of series er panels that have been as- EN 60079-29 sembled and/or terminated in EN 60079-29-2: accordance with the manufacturer’s instructions. The electri- Explosive atmospheres - Part cal resistance trace heating 29-2 Gas detectors – Selection, shall be designed and con- installation, use and mainte- structed in such a way that it nance of detectors for flamma- Example of a trace heating can be operated safely in the system ble gases and oxygen explosive gas atmosphere, EN 60079-29-3: whereby the components used shall comply with the relevant Explosive atmospheres - Part type of protection. 29-3 Guidance on the functional safety of fixed gas detection systems Furthermore, it is necessary to EN 60079-29-4: ensure that, under all circumstances and maintaining the Explosive atmospheres - Part safety clearance, the surface 29-4 Gas detectors – Perfor- temperature of the resistance mance requirements of open trace heating remains below path detectors for flammable the ignition temperature of the gases explosive mixture. If this cannot be ensured by the design of the heating cable, suitable safety thermostats shall be used as limiters.

Application example: Gas detector with plug-in connection in a waste- water treatment plant

48 EATON www.crouse-hinds.de Explosion-protected Electrical Equipment Type of protection to EN 60079-31 3

EN 60079-31 Definition Dust ignition protection by en- Explosive atmospheres – closure “t” is a type of protec- Part 31: Equipment dust tion for explosive dust atmos- ignition protection by pheres where electrical enclosure “t“ equipment is provided with an enclosure providing dust in- Scope gress protection and a means This part 31 of IEC 60079 is ap- to limit surface temperatures. plicable to electrical equipment protected by enclosure and sur- Principle of the type of protection Principle of the type of protection face temperature limitation for “t” level of protection „ta“ “t” level of protection „tb“ use in explosive dust atmospheres. It specifies require- Requirements for electrical Requirements for electrical ments for design, construction equipment with level of equipment with level of and testing of electrical equip- protection „ta“ protection “tb” and electri- ment and Ex Components. It For electrical equipment with cal equipment with level of supplements and modifies the level of protection “ta”, the max- protection “tc” general requirements of imum surface temperature stat- For electrical equipment with EN 60079-0. ed on the exterior of the enclo- levels of protection “ta” and This standard does not apply to sure and on the surfaces of the “tb”, the marked maximum sur- dusts of explosives which do internal components of the Dust- ignition protection by enclo- face temperature shall be not require atmospheric oxygen sure “t”: fluorescent light fitting in electrical equipment shall be measured on the external sur- for combustion, or to pyrophoric explosive dust atmosphere measured. The highest of the faces of the enclosure with no substances. Similarly, this measured temperatures shall dust layer on the external sur- standard does not apply to be the basis for the maximum faces under normal operating electrical equipment or Ex Com- Equipment Protection Level surface temperature marking. conditions . Before testing for ponents intended for use in un- (EPL) For electrical equipment with dust exclusion, a positive inter- derground parts of mines as Electrical equipment in the type level of protection “ta”, the max- nal pressure of 2kPa shall be well as those parts of surface of protection „t“ can be de- imum surface temperature shall applied to the enclosure to veri- installations of such mines en- signed in various levels of pro- be determined by installing the fy that the seal fits tightly, ex- dangered by firedamp and/or tection which determine the equipment in accordance with cept where the design of the combustible dust. overall Equipment Protection the manufacturer’s instructions electrical equipment is such The use of electrical equipment Level and surrounded by at least a that gaskets or seals are physi- 200 mm layer of dust on all cally constrained from moving in atmospheres which may con- • Level of Protection „ta“ sides. e.g. an “O” ring in a groove. tain both combustible dust and (EPL „Da“) or explosive gases, whether simultaneously or separately, may re- • Level of Protection „tb“ Before testing for dust exclu- quire additional protective (EPL „Db“) or sion, a positive internal pres- measures not specified in this • Level of Protection „tc“ sure of 4kPa shall be applied to standard. (EPL „Dc“). the enclosure to verify that the seal fits tightly. For normal applications, equipment with level IP test of protection “ta” shall be rated The following table shows the for connection to a circuit with a relationship between the level of prospective short circuit current protection, group and required of not more than 10 kA. ingress protection against dust.

Required IP protection

Level of protection Group IIIC Group IIIB Group IIIA

„ta“ IP6X IP6X IP6X

„tb“ IP6X IP6X IP5X

„tc“ IP6X IP5X IP5X

Ingress protection shall be determined in accordance with degree of protection (IP) of enclosures as specified in IEC 60079-0 for level of protection “tb” and “tc”. For level of protection “ta” the level of depression shall be increased to at least 4 KPa for a period of least 8 h. Any grease in the joints shall be removed before the IP test is performed. When IP5X is required, all enclosures including rotating machines shall satisfy the test and acceptance requirements of IP5X as specified in IEC 60529. Dust deposits in an industrial plant www.crouse-hinds.de EATON 49 Explosion-protected Mechanical Equipment 3 Requirements; / type of protection to ISO 80079...

Explosion protection of me- basic philosophy and methodo- chanical equipment logy for assessing the ignition Unlike the earlier directive for hazard have not changed, be- equipment for use in hazardous cause the ISO standards are areas (Directive79/196/EC), based on the European stand- which was restricted to electri- ards. Analogously, it is also cal equipment, ATEX Directive possible to apply the electrical 2014/34/EU and its precursor, standards, e.g. the types of pro- Directive 94/9/EC, apply to all tection Flameproof Enclosure products (electrical and me- “d” or Pressurization “p”. chanical). For this reason, ana- Further purely mechanical log to electrical equipment at standards are currently being CENELEC TC 31, a series of prepared by IEC SC31M. standards with constructional and testing requirements has However, special mention shall also been compiled for be made of one change, namely mechanical equipment by the marking: CEN TC 305, the responsible committee. Marking On an international level, All mechanical equipment IEC TC 31 is the standards body shall only be marked with the for explosion protection, where- letter “h”, irrespective of ISO 80079-37: The measures applied can be as the standards body responsi- whether only the general part Types of protection construc- initiated automatically by direct ble for mechanical equipment ISO 80079-36 was applied or tional safety “c”, control of connections between the sen- on an international level I, in whether it was applied in ignition source “b” and liquid sors and the protective system fact, ISO. In 2007 ISO and IEC combination with one of the immersion “k” or manually after a warning has agreed to form the subcommit- types of protection from part (Previous standards in Europe: been given to the operator of tee SC 31M at IEC TC 31 and ISO 80079-37. EN 13463-5, -6 and -8) the equipment (with the aim not to have an independent In the case of Protection by con- that the operator carries out the The EPL (equipment protection ISO committee. This subcom- structional safety the equipment protective measure e.g. by level) for the complete equip- mittee can issue both ISO and is dimensioned and designed in shutting down the equipment). ISO/IEC standards. The num- ment shall be included at the such a way (e.g. by a special Equipment in the type of pro- bering of these standards is end of the marking, e.g. tightness and over-dimensioning) tection Liquid Immersion fea- 80079 (instead of 60079) to Ex h IIB T4 Gb or that no ignition sources can tures potential ignition sources make it clear that these stand- Ex h IIIC T120°C Db. form during the service life of that are either rendered ineffec- ards were drawn up by SC the equipment or in the event tive by submersing it in a pro- 31M. These standards are ISO 80079-36: of any malfunctions that are to tective liquid or by continuously agreed on at both CEN and Basic methods and require- be expected. This type of pro- coating it with a flowing film of CENELEC parallel to ISO and ments (Previous standard in tection is used, for example, for protective liquid, e.g. oil-im- IEC and can then also be Europe: EN 13463-1) bearings and couplings. mersed disc brakes or oil-filled published as EN standards This part specifies the base gearboxes where the gear and harmonized by the methods and requirements for With the type of protection wheels are partially immersed, EU commission. the hazard assessment of me- Control of Ignition Sources it is but continuously coated by a chanical equipment. The aim These requirements for me- assumed that many types of viscous film of oil. here is to prevent the formation chanical equipment are laid non-electrical equipment for of mechanical ignition sources. down in the standards of the use in explosive atmospheres ISO 80079-38: If this is not possible by applying series EN 13463 (as European do not feature effective ignition Equipment and components in constructional measures, other standards only) and, as of 2016, sources during normal opera- underground mines (Group I) measures shall be applied to en- also in standards of the series tion. However, there is a risk of This part specifies the require- sure that these ignition sources ISO 80079-36, -37 and -38. The the formation of an ignition ments for equipment with an cannot become effective. In addi- source if there is a malfunction equipment protection level tion, measures are applied to pre- in the moveable parts or if a “Ma” and “Mb”. vent the coming into contact of process is not carried out cor- effective ignition sources with rectly. In order to prevent poten- The fundamental requirements the explosive atmosphere. An- tial ignition sources from be- according to 60079-0 (if cited) other measure is to confine a coming effective during normal and 80079-36 apply. This stand- possible explosion in such a way operation, a malfunction or a ard describes additional require- that it cannot spread to the out- rare malfunction, it is possible ments that take special hazards side. This standard can be applied to fit sensors in the equipment. due to the hybrid mixture of on its own for a testing and as- These detect any imminent haz- coal dust and firedamp into sessment, but in some parts it ardous conditions and counter- consideration. The marking cor- also refers to EN 60079-0, the measures can be initiated at an responds to that for mechanical general requirements for early phase of the malfunction equipment, e.g. Ex h I Mb. electrical equipment. before potential ignition sources become effective.

50 EATON www.crouse-hinds.de Safety devices Safety devices for the safe operation of equipment with regard to explosion risks 3

EN 50495 Safety devices where the safety Table 1: Safety devices for the safe function cannot be adequately Minimum requirements for safety devices for risk reduction operation of equipment with specified with the existing regard to explosion risks standards of the series Group IIIC Group IIIB Group IIIA EN 60079 shall also meet the Scope requirements of this standard. Equipment suitable Equipment suitable Equipment suitable for EPL Ga / Da for EPL Ga / Da for EPL Gb / Db This standard specifies the safety where an ignition where an ignition where an ignition requirements for electrical safety Deﬁnitions EUC source can become source can become source can become devices used for monitoring ig- effective in the effective in the effective in the nition hazards with equipment Safety device event of rare faults event of faults to event of faults to in explosive atmospheres. This Safety devices, control and reg- be expected be expected also includes safety devices op- ulating devices lead to the safe Minimum risk re- erated outside the explosive at- functioning of equipment with duction factor of 10 100 10 mospheres to ensure the safe regard to explosion risks. Safety safety device functioning of equipment or devices provide explosion pro- EPL of the com- protective systems by monitor- Ga IP5X IP5X tection by carrying out a safety bined equipment ing explosion risks. function that operates indepen- Electrical equipment intended dently of the normal function of for use in explosive atmos- the equipment. pheres are dependent on the Safety function General requirements Function performed by a safety correct functioning of the safety Safety instrumented system When specifying (selecting) a device to ensure the safe state devices, such as, for example, (SIS) safety device, the EUC, includ- devices for ensuring adherence of the EUC and, by doing so, ing the potential ignition source System for carrying out one or to given characteristics of the provide explosion protection. to be monitored, shall be taken more safety-related functions. equipment within permissible into consideration. An SIS system consists of limits. sensor(s), logic solver and General requirements The safety device shall satisfy actuator(s). General concept the level of operational safety Examples of safety devices in- During the ignition source risk dependent on the reduction of clude motor protection devices analysis of electrical equipment, the ignition source risk for the Safety component (limitation of the rise in tempe- it is necessary to assess all equipment under control (EUC) rature if the motor blocks) and Part of the system or device potential ignition sources, inclu- subject to the EPLs. control devices for the protec- for specific safety functions. ding the faults to be considered, tion of the pressure compensa- in relation to the EPL. By apply- tion. Ignition sources can be Example of an application: Equipment under control ing the types of protection of avoided with the aid of control According to EN 60079-7, the (EUC) the series of standards or monitoring devices. For this EN 60079 ff, the ignition risks rise in temperature of a motor Equipment, machinery, appara- reason, these devices shall car- covered by these standards are in EPL “Gb” shall also be limit- tus or components that contain ry out the respective measures minimized. EN 50495 provides ed under fault conditions a potential ignition source and within the appropriate reaction solutions for ignition risks that (blocked rotor). This can be are monitored by a safety time, for example, the activation cannot be eliminated by apply- achieved by using a current device. of an alarm or an automatic ing the classic types of measuring device that can be switch-off. protection. installed outside the explosive atmosphere. The safety function comprises the monitoring of the current and the switching off of the motor in the event of an in- admissibly high current under the fault condition to be expected (blocked rotor). To ensure the required level of safety for EPL “Gb”, the minimum risk reduction factor of the safety device shall be 10 (see table).

Working group 42 of IEC TC 31 is currently preparing a new standard that, once completed, (not to be expected before 2019), will replace the previous European standard.

www.crouse-hinds.de EATON 51 Marking of electrical equipment 3 Marking of electrical equipment for use in potentially explosive atmospheres

Marking of electrical equip- Rules and conditions for 1.0.5. Marking Example of marking accord- ment for use in potentially afﬁxing the CE marking and All equipment and protective ing to the Directive explosive atmospheres due other markings systems must be marked legibly 1 Name or registered trade to ﬂammable gases, vapours and indelibly with the following mark (CEAG) and address and mists as well as dusts Article 16: Excerpts minimum particulars: of the manufacturer • name, registered trade name 2 Serial number including year The requirements for the mar- or registered trade mark, and of manufacture king of explosion-protected (1) The CE marking shall be af- address of the manufacturer, equipment are laid down in the fixed visibly, legibly and indel- 3 Certificate number, may end European Directive 2014/34/EU ibly to the product or to its • CE marking (see Annex II to with “X“ or “U” - “X“ indica- and the standard EN 60079-0. data plate. Where that is not Regulation (EC) No tes that special conditions for possible or not warranted on 765/2008), safe use apply“U” is used account of the nature of the for component certificates Directive 2014/34/EU • designation of series or type, product, it shall be affixed to 4 Additional IECEx certification All the applicable directives for the packaging and to the ac- • batch or serial number, if any, 5 Marking according to direc the respective product shall be companying documents. • year of construction, observed when marking electri- tive: Equipment group (II) and cal equipment. In the case of • he specific marking of explo- equipment category 2); type explosion-protected equipment, (3) The CE marking shall be sion protection followed by of explosive atmosphere Directive 2014/34/EU is mainly followed by the identification the symbol of the equipment- G (Gas, vapour or mist) – applied. number of the notified body, group and category, D (dust) where that body is involved in • for equipment-group II, the 6 Marking according to This directive contains several the production control phase articles (e.g. Article 6, 15 and letter ‘G’ (concerning explo- standard: IEC/EN (for Category I and Category sive atmospheres caused by 16) and Annex II (1.0.5) where II electrical equipment) 7 Equipment name/type the minimum requirements for gases, vapours or mists), 8 CE marking and number of the marking of explosion-pro- the ”notified body” tected equipment are outlined and/or (4) The CE marking and, where responsible for monitoring explicitly. applicable, the identification the quality system number of the notified body (0158 = EXAM Germany) shall be followed by the • the letter ‘D’ (concerning specific marking of explosion explosive atmospheres 9 Electrical parameters CE marking caused by dust). protection, the symbols of 10 Other essential information „CE marking“ shall mean a the equipment-group and (depends on the standard, marking by which the manu- category and, where applica- Furthermore, where necessary, e.g. lamp) facturer indicates that the ble, the other markings and they must also be marked with 11 Other optional information product is in conformity with information referred to in all information essential to their (e.g. degree of protection) the applicable requirements point 1.0.5 of Annex II. safe use. set out in Community harmo- 12 Permissible ambient tem-

nisation legislation providing perature (-25°C to +55°C); for its affixing. Marking in accordance with no marking required for Annex II, No.1.0.5 temperatures from -20°C The directive requires a special to 40°C (standard values This CE marking indicates the and clear marking of this equip- for all equipment) conformity of a product and is ment and these protective sys- 13 Marking according to the visible result of a complete tems that identifies their suita- EU-directive 2002/96/EC process that includes the con- bility for use in explosive (WEEE-directive: Waste of formity assessment in the broa- atmospheres and goes above Electrical and Electronic der sense. The general princip- and beyond the CE marking. les for the CE marking are laid Equipment) down in Regulation (EC) 765/2008. The C marking according to Directive 2014/34/EU 4 shall only be applied for equipment and not components. SERIES 7 CEAG 1 D-69412 Eberbach 3 BVS 16 ATEX E 123 / IECEx BVS 16.123 IP66/67 11 II 2G Ex db eb mb ib IIC T4 Gb 8 Ta= -25°C bis +55°C 12 II 2D Ex tb IIIC T80°C Db 9 AC: 110-254V 50-60Hz 13 10 DC: 110-250V Lampe: G13-81-IEC www.ceag.de 2 Snr.: D123456 2016 Made in Germany

5 6

Example of marking according to the Directive

52 EATON www.crouse-hinds.de Marking of electrical equipment Marking of electrical equipment for use in potentially explosive atmospheres 3

Marking according to Marking for explosive gas „nA“: Type of Protection n, II 2G Ex db eb mb ib IIC T4 Gb EN 60079-0 atmospheres: type nA (for EPL Gc) II 2D Ex tb IIIC T80°C Db In addition to the marking ac cor- „nC“: Type of Protection n, c) the symbol for the group: ding to the directive, equipment II 2G Ex db eb mb ib IIC T4 Gb type nC (for EPL Gc) – I for electrical equipment for shall also be marked with the II 2D Ex tb IIIC T80°C Db „nR“: Type of Protection n, mines susceptible to firedamp marking specified in EN 60079-0, a) the symbol Ex, which indi- type nR (for EPL Gc) to ensure a safe selection and a cates that the electrical – IA, IIB or IIC for electrical safe use of the equipment. This equipment corresponds to „ob“: Liquid Immersion equipment for places with an marking shall be clearly legible one or more of the types of (for EPL Gb) explosive gas atmosphere other than mines susceptible and affixed to the “main part” protection; „oc“: Liquid Immersion to firedamp of the equipment. b) the symbol for the type of (for EPL Gc) With the exception of enclosu- protection used „pxb“: Pressurization res that have only been issued II 2G Ex db eb mb ib IIC T4 Gb (for EPL Gb or Mb) II 2D Ex tb IIIC T80°C Db with a component certificate II 2G Ex db eb mb ib IIC T4 Gb (U certificate) where the Ex II 2D Ex tb IIIC T80°C Db „pyb“: Pressurization, d) for Group II electrical equip- (for EPL Gb) ment, the symbol indicating marking may only be affixed to „da“: Flameproof Enclosure the temperature class. the interior, the marking shall be (for EPL Ga or Ma) „pzc“: Pressurization affixed to the exterior. Further (for EPL Gc) „db“: Flameproof Enclosure requirements for the marking II 2G Ex db eb mb ib IIC T4 Gb (for EPL Gb or Mb) „q“: Powder Filling are laid down in Clause 29 of II 2D Ex tb IIIC T80°C Db (for EPL Gb or Mb) the standard named above. „dc“: Flameproof Enclosure e) the equipment protection lev- (for EPL Gc) “op is”: Inherently safe el, “Ga”, “Gb”, “Gc”, “Ma”, or optical radiation “Mb” as appropriate „eb“: Increased Safety (for General (for EPL Ga or Ma) EPL Gb or Mb) The marking shall include the “op pr”: Protected following: „ec“: Increased Safety (for optical radiation EPL Gc) a) the name of the manufacturer (for EPL Gb or Mb) or his registered trade mark; „ia“: Intrinsic Safety “op sh”: Optical system (for EPL Ga or Ma) b) the manufacturer’s type with interlock identification; „ib“: Intrinsic Safety (for EPL Ga or Ma) (for EPL Gb or Mb) c) a serial number, except for „ic“: Intrinsic Safety – connection accessories (ca- (for EPL Gc) ble glands, blanking element, thread adaptor and bushings); „ma“: Encapsulation (for EPL Ga or Ma) – very small electrical equipment on which there is limit- „mb“: Encapsulation ed space; (for EPL Gb or Mb) d) the name or mark of the cer- „mc“: Encapsulation tificate issuer and the certifi- (for EPL Gc) cate reference e) if it is necessary to indicate specific conditions of use, the symbol “X” shall be placed after the certificate reference. An advisory marking may ap- pear on the equipment as an alternative to the requirement for the “X” marking; SERIES f) the specific Ex marking for CEAG explosive gas atmospheres, see 29.3, or for explosive D-69412 Eberbach dust atmosphere. The Ex BVS 16 ATEX E 123 / IECEx BVS 16.123 IP66/67 marking for explosive gas at- II 2G Ex db eb mb ib IIC T4 Gb mospheres and explosive Ta= -25°C bis +55°C dust atmospheres shall be II 2D Ex tb IIIC T80°C Db separate and not combined; AC: 110-254V 50-60Hz g) any additional marking pre- DC: 110-250V scribed in the specific standards for the types of protec- Lampe: G13-81-IEC www.ceag.de tion Snr.: D123456 2016 Made in Germany

Example for a Gas-Ex marking www.crouse-hinds.de EATON 53 Marking of electrical equipment 3 Marking of electrical equipment for use in potentially explosive atmospheres

Marking for explosive dust „Ga“ equipment using two atmospheres: independent “Gb” types of protection

II 2G Ex db eb mb ib IIC T4 Gb II 2G Ex db eb mb ib IIC T4 Gb Where two independent types II 2D Ex tb IIIC T80°C Db II 2D Ex tb IIIC T80°C Db (or levels) of protection with a) the symbol Ex, which indi- c) the symbol for the group EPL Gb, are employed for the cates that the electrical IIIA, IIIB or IIIC for electrical same piece of electrical equip- equip ment corresponds to equipment for places with an ment in order to achieve one or more of the types of explosive dust atmosphere EPL Ga, the Ex marking shall in- protection clude the symbols for the two types (or levels) of protection

II 2G Ex db eb mb ib IIC T4 Gb II 2G Ex db eb mb ib IIC T4 Gb employed with the symbols for II 2D Ex tb IIIC T80°C Db II 2D Ex tb IIIC T80°C Db the types (or levels) of protec- b) the symbol for each type of d) the maximum surface tem- tion joined with a “+” protection used: perature in degrees Celsius (See EN 60079-26). „ta“: Protection by enclosure and the unit of measurement °C preceded with the letter (for EPL Da) Alternate marking of equip- “T”, (e.g. T 90 °C) „tb“: Protection by enclosure ment protection levels (EPL) (for EPL Db) The currently valid standard II 2G Ex db eb mb ib IIC T4 Gb „tc“: Protection by enclosure II 2D Ex tb IIIC T80°C Db EN 60079-0 contains an alternate marking that has scarcely (for EPL Dc) e) the equipment protection been used. As the use of this level, “Da”, “Db”, or “Dc”, „ia“: Intrinsic safety marking caused problems with as appropriate (for EPL Da) regard to the differentiation be- „ib“: Intrinsic safety tween the level of protection of (for EPL Db) The Ex marking for explosive the type of protection and the overall equipment protection „ic“: Intrinsic safety gas atmospheres and explosive level, it will be deleted in the (for EPL Dc) dust atmospheres must not be combined, but shall be indicat- future. „ma“: Encapsulation ed separately. (for EPL Da) “mb”: Encapsulation (for EPL Db) „mc“: Encapsulation (for EPL Dc) „pxb“ Pressurization (for EPL Db), „pyb“ Pressurization (for EPL Db), „pzc“ Pressurization (for EPL Dc), “op is”: Inherently safe optical radiation (for EPL Da) “op pr”: Protected optical radiation (for EPL Db) SERIES “op sh”: Optical system with interlock (for EPL Da) CEAG D-69412 Eberbach BVS 16 ATEX E 123 / IECEx BVS 16.123 IP66/67 II 2G Ex db eb mb ib IIC T4 Gb Ta= -25°C bis +55°C II 2D Ex tb IIIC T80°C Db AC: 110-254V 50-60Hz DC: 110-250V Lampe: G13-81-IEC www.ceag.de Snr.: D123456 2016 Made in Germany

Example of Dust-Ex marking

54 EATON www.crouse-hinds.de Erection, Operation, Maintenance and Repair of electrical installations in explosive atmospheres 4

Requirements for the erection, • The relevant technical rules Design, selection and erection For example, most flammable operation, maintenance and – Operational Safety (TRBS) of electrical installations materials and many materials repair of electrical installa- and Hazardous Substances according to EN 60079-14 which are not normally regard- tions in explosive (TRGS) ed as non-flammable might atmospheres • On principle, the following Explosive atmospheres – Part burn vigorously under condi- VDE regulations apply for the 14: Electrical installations de- tions of oxygen enrichment. Fur- Rules, regulations and erection of electrical installa- sign, selection and erection ther precautions might also be necessary for the use of electri- ordinances tions: This standard contains the cal equipment under conditions The following shall be observed VDE 0100, 0101, 0107, specific requirements for the with extremely high tempera- for the erection and operation of 0113, 0141, 0185, 0190, design, selection, erection and tures and extreme pressure. electrical installations in hazard- 0800 Parts 1 – 4. initial inspection of electrical Such measures are not within ous areas: installations in explosive atmos- • In addition, the following VDE the scope of this standard. • Ordinance on protection regulations shall be taken into pheres. Where the equipment is As part of the risk assessment against hazardous substances consideration for hazardous required to meet other environ- these additional measures as (Gefahrstoffverordnung – areas: mental conditions, e.g. against well as the requirements for hy- GefStoffV) VDE 0165 and the ingress of water and resist- VDE 0170 (all parts). ance to corrosion, additional brid mixtures must be determi- • Ordinance governing the protection requirements may be ned. health and safety aspects of • The following applies for the necessary. If additional protec- This EN 60079-14 standard ap- the provision of work equip- operation and servicing of ex- tive measures are applied, they plies to all electrical equipment, ment and use of materials at isting installations shall not have an adverse effect including fixed, portable, trans- work, the operation of equip- VDE 0105 Operation of on the suitability of the portable and personal equipment requiring supervision electrical installations enclosure. ment, and permanent or tempo- and the organisation of occu- – Part 1: General rary installations. It applies to pational health and safety stipulations installations for all voltages. precautions (Betriebssicher- The requirements of this stand- heitsverordnung - BetrSichV) ard only apply to the use of • Ordinance concerning the equipment under normal or al- This EN 60079-14 standard placing on the market of most normal atmospheric con- does not apply to: ditions. For other conditions, equipment and protective • electrical installations in additional precautions may be systems intended for use in mines susceptible to necessary. hazardous areas – Explosion firedamp; protection decree (ExVO) • inherently explosive • Directive on the harmonisa- situations, e. g. the tion of the laws of the Mem- manufacture and ber States relating to equip- processing of explosives; ment and protective systems • rooms used for medical intended for use in potentially purposes; explosive atmospheres (2014/34/EU) • Directive on the minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres (1999/92/EC) • Explosion protection rules (EX – RL) with examples from the “BG-Chemie“ (Employ- ers’ Liability Association for the Chemical Industry) • Rule for the avoidance of ignition hazards due to electrostatic charges issued by the Confederation of the Insur- ance Liability Associations • Accident prevention regulations of the Employers’ Liabil- ity Association DGUV, Regula- tion 4 “Electrical installations and equipment”

www.crouse-hinds.de EATON 55 Erection, Operation, Maintenance and Repair 4 of electrical installations in explosive atmospheres

The following Table of Contents • 6.7 Electromagnetic radiation • 13.2 Temperature monitoring • 19.1 General provides an overview of the • 6.8 Cathodically protected • 13.3 Limiting temperature • 19.2 External connections requirements found in the metallic parts standard: • 13.4 Safety devices • 20 Additional requirements for the type of protection “q” • 6.9 Ignition by optical radiation • 13.5 Electrical trace heating • 1 Scope – Powder filling • 7 Electrical protection systems • 2 Normative references • 21 Additional requirements • 8 Switch-off and electrical • 14 Additional requirements for the type of protection • 3 Terms and definitions isolation for type of protection “d” – “m” – Encapsulation • 4 General • 8.1 General Flameproof enclosures • 22 Additional requirements • 4.1 General requirements • 14.1 General • 8.2 Switch-off for the type of protection • 14.2 Solid obstacles • 4.2 Documentation • 8.3 Electrical isolation “op” – Optical radiation • 14.3 Protection of flameproof • 4.3 Initial inspection • 9 Cable and wirings systems • 23 Additional requirements joints for the type of protection “t” • 4.4 Assurance of equipment • 9.1 General conformity • 14.4 Conduit systems – Protection by enclosure • 9.2 Aluminium conductors • 4.5 Qualification of personnel • 15 Additional requirements • Annex A (normative) Knowl- • 9.3 Cables for the type of protection “e” edge, skills and competen- • 5 Selection of electrical equip- cies of responsible persons, • 9.4 Conduit systems – Increased Safety ment operatives/technicians and • 15.1 General • 5.1 Information requirements • 9.5 Additional requirements designers • 15.2 Maximum dissipated po- • 5.2 Zones • 9.6 Installation requirements • Annex B (informative) Safe wer of terminal box enclosures work procedure guidelines for • 5.3 Relationship between • 10 Cable entry systems and • 15.3 Conductor terminations explosive gas atmospheres Equipment Protection Levels blanking elements (EPLs) and zones • 10.1 General • 15.4 Maximum number of • Annex C (normative) Initial conductors in relation to the inspection – Equipment- • 5.4 Selection of equipment • 10.2 Selection of cable glands cross-section and the permis- specific inspection schedules according to EPLs • 10.3 Connections of cables to sible continuous current • Annex D (informative) Electri- • 5.5 Selection according to equipment • 16 Additional requirements cal installations in extremely equipment group • 10.4 Addition requirements for the type of protection “i” low ambient temperatures • 5.6 Selection according to the for entries other than “Ex d”, – Intrinsic Safety • Annex E (informative) Restric- ignition temperature of the Ex “t” or Ex “nR” • 16.1 General ted breathing test for cables gas, vapour or dust and the • 10.5 Unused openings ambient temperature • 16.2 Installations to meet the • Annex F (informative) Installa- • 10.6 Additional requirements requirements of EPL “Gb” or tion of electrical trace heating • 5.7 Selection of radiating for type of protection “d” – “Gc” and EPL “Db” or “Dc” systems equipment Flameproof enclosures • 16.3 Installations to meet the • Annex G (normative) Potential • 5.8 Selection of ultrasonic • 10.7 Additional requirements requirements of EPL stator winding discharge risk equipment for type of protection “t” – “Ga” or “Da” assessment – Ignition risk • 5.9 Selection taking other in- factors Protection by enclosure • 16.4 Simple apparatus fluences into consideration • Annex H (normative) Verifica- • 10.8 Additional requirements • 16.5 Terminal boxes • 5.10 Selection of transporta- for type of protection “nR” – tion of intrinsically safe circuits ble, portable and personal Restricted breathing enclosure • 16.6 Special applications with more than one associat- equipment ed apparatus with linear cur- • 11 Rotating electrical machines • 17 Additional requirements • 5.11 Rotating electrical for pressurized enclosures rent/voltage characteristics • 11.1 General machines • 17.1 General • Annex I (informative) Meth- • 11.2 Motors with type of ods of determining the maxi- • 5.12 Luminaires • 17.2 Type of protection “p” protection “d” – Flameproof mum system voltages and • 5.13 Plugs and sockets enclosures • 17.3 Type of protection “pD” currents in intrinsically safe • 5.14 Cells and batteries • 11.3 Motors with type of pro- • 17.4 Rooms for explosive circuits with more than one associated apparatus with lin- • 5.15 RFID tags tection „e“ – Increased safety gas atmosphere ear/current /voltage character- • 5.16 Gas detection equipment • 11.4 Motors with types of • 18 Additional requirements istics (as required by Annex H) protection „p“ and „pD“ – for the type of protection “n” • 6 Protection from dangerous Pressurized enclosures • Annex J (informative) Deter- (incendive) sparking • 18.1 General mination of cable parameters • 11.5 Motors with type of • 18.2 “nR” equipment • 6.1 Light metals as protection „t“ – Protection by • Annex K (normative) Addition- construction materials enclosures supplied at vary- • 18.3 Combinations of al requirements for the type • 6.2 Danger from live parts ing frequency and voltage terminals and conductors of protection “op” – Optical for general connection and radiation • 6.3 Danger from exposed and • 11.6 Motors with type of pro- junction boxes extraneous conductive parts tection „nA“ – Non-sparking • Annex L (informative) Exam- • 18.4 Conductor terminations ples of dust layers of exces- • 6.4 Potential equalization • 12 Luminaires • 19 Additional requirements sive thickness • 6.5 Static electricity • 13 Electric heating systems for the type of protection “o” • Annex M (informative) • 6.6 Lightning protection • 13.1 General – Liquid Immersion Hybrid mixtures

56 EATON www.crouse-hinds.de Erection, Operation, Maintenance and Repair of electrical installations in explosive atmospheres 4

Brief information on selected Electrostatic charges hazardous area shall be installed closed conduit systems must points Parts of the construction shall outside the hazardous area. not be laid unless, due to their also be designed in such a way specific design, they are suitable for hazardous areas. Potential equalization that no dangerous charges can Electrical isolation occur when they are used for Potential equalization is required In addition, to allow work to be their intended purpose. For the for installations in hazardous ar- carried out safely, a suitable The transmission of gases or limitation of surface areas, it is eas to avoid incendive sparking. means of isolation with a label liquids through cables shall be necessary to take both the sur- All conductive parts of the con- to identify the respective circuit prevented by applying suitable rounding zone and the explo- struction or installation where a shall be provided for each cir- measures (e.g. potting, sion group into consideration. hazardous potential shift is to cuit (or each group of circuits). completely filled cables, etc.). be expected shall be incorporat- Further useful requirements can ed in the equipotential bonding be found in TRGS 727. system. Cables and wiring systems Additional requirements Lightning protection Wiring systems shall always be In addition to the basic require- A functioning lightning protec- selected so as to ensure that ments already described, de- Examples where additional po- tion system is required in haz- they withstand the mechanical, pending on the type of protec- tential equalization measures ardous areas according to the electrical, chemical and thermal tion and/or equipment, the may be required: zone. The individual require- stresses that are to be expect- standards also contain further • via compensators ments can be found in VDE ed. Cables that are not laid in requirements. (non-conductive) 0185. EN 60079-14 only states earth or in sand-filled cable the objective of reducing the ef- trenches/ducts shall be protect- • insulated conduit Commissioning of electrical fects of lightning strikes to a ed against flame propagation. installations in hazardous • insulated gaskets non-hazardous level. A surge areas The following need not be in- protector is only required for in- Unused cores of multi-core ca- After erection, in accordance corporated in the equipotential trinsically safe circuits leading bles shall be connected safely with §15 of BetrSichV, the opera- bonding system: into Zone 0. to the earth potential or ade- tor shall have the proper state of • conductive window frames quately isolated by using a an installation inspected by an • conductive door frames suitable connected terminal. authorized person in accordance Emergency switch-off Bushings for cables into non- with Annex 2, Clause 3, No. 3.3 Enclosures need not be addi- or a notified monitoring body For emergencies where the hazardous areas shall be ade- tionally connected to the equi- prior to commissioning or after spreading of a hazard is to be quately sealed (e.g. sand seals potential bonding system if they modifications requiring testing. are mounted in such a way that expected, devices for switching or mortar sealing). Where cables they have reliable contact to off the electrical supply of the are subject to particular stresses, parts of the installation that are they shall be specially protected incorporated in the equipoten- (e.g. by conduit). However, tial bonding system.

www.crouse-hinds.de EATON 57 Erection, Operation, Maintenance and Repair 4 of electrical installations in explosive atmospheres

Operation of installations in When work is being carried out Avoidance of formation of Here a distinction is made be- hazardous areas in hazardous areas, the safety sparks tween two types of tools, tools of persons and installations is With the electrical equipment where only single sparks occur After an installation has been dependent to a large degree on used, the respective types of during use, e.g. screwdrivers or erected correctly, it shall be op- the strict adherence to all safety protection ensure that no spanners, and tools that give off erated in accordance with the regulations. incendive sparks or hot a shower of sparks during use, state of the art technology. The company management and surfaces come into contact e.g. grinders. The use of tools that may give off sparks is gen- In accordance with §6 GefStoffV, the operating and maintenance with the explosive personnel shall work together in atmosphere. erally not permitted in Zones 0 (Ordinance on Protection against and 20. Hazardous Substances) the re- an optimal way to ensure the If no further organizational sponsible operator shall observe maximum possible degree of measures have been taken, According to EN 1127, only the following important princi- safety. Thus, the maintenance only explosion-protected meas- those steel tools that might ples and document them before staff that works in such installa- uring instruments may be used give off a single spark can be operation: tions bears a special responsi- to measure electrical values. used in Zones 1 and 2 if no bility. Group IIC substances are pre- Sparks capable of causing igni- 1. Hazards during operations sent. The use of steel tools that with hazardous substances tion may also occur when con- give off single sparks is permit- Maintenance necting or disconnecting cables, 2. Result of a test for the substi- ted in Zones 21 and 22. tution of the hazardous sub- Maintenance encompasses all even though no voltage source On principle, tools that give off stance and for the forgoing of measures (inspection, servicing is connected. sparks may only be used to- a possible technical substitu- and repair) for maintaining and The reasons for this can be gether with a “safe work per- tion with protective restoring the required state and stored energy in electrical in- mit” if the location has been as- measures. for determining and assessing stallations or external influences sessed to ensure that an the actual state. Inspections or such as induction of electro- 3. Safety measures to be explosive atmosphere is not the supervision of installations magnetic fields. The electrician carried out present for the duration of the helps to prepare for upcoming shall, at all times, be aware of work in hand. The requisite 4. Reasons for deviation from maintenance tasks and to iden- whether or not sparks capable safety measures shall be speci- the known rules and findings tify trends with regard to possi- of causing ignition are to be ex- fied in the safe work permit. 5. Verification of the effective- ble damages. pected. ness of the protective A visual inspection shows the A possible spark formation shall measures experienced specialist, e.g. due also be taken into account Subject to the development of to the formation of droplets on when using hand-operated a hazard due to explosive mix- switch cabinets, whether more tools. tures, the hazards shall be stat- intensive inspections are neces- ed specifically in the explosion sary. protection document. Determi- nation and assessment of an Special safety measures explosion hazard Whenever work is carried out in 1. Appropriate measures for hazardous areas, it is necessary achieving the explosion to ensure that neither incendive protection goals sparks nor hot surfaces occur that, in combination with an ex- 2. Zone classification plosive atmosphere, can lead to 3. Areas for which explosion an explosion. protection measures have On principle, work on live elec- been taken trical installations and equip- 4. Measures for the safe ment is strictly forbidden. By collaboration with various way of exception, work on in- companies trinsically safe circuits and, in certain cases, on other electri- 5. Tests for explosion protection cal installations is permitted. in accordance with the health and safety ordinance In this case, the company man- (BetrSichV) agement shall issue a safe work permit to confirm in writing that no explosion hazard exists at After commissioning, it is nec- the work site for the duration of essary to ensure that the proper the work in hand (e.g. monitor- state is maintained. For this the ing by a gas detector). installations shall be inspected The absence of voltage may at given intervals on a recurrent only be measured with explo- basis according to §16 of Be- sion-protected measuring in- trSichV, at the least every 3 struments. The two special cas- years. EN 60079-17/ VDE 0165 es named above are the only Part 10 can be referred to for exceptions. details relating to the execution of these inspections. Example of a safety work permit

58 EATON www.crouse-hinds.de Erection, Operation, Maintenance and Repair of electrical installations in explosive atmospheres 4

EN 60079-17 Contents of standard Terms and deﬁnitions Continuous supervision Explosive atmospheres - (excerpt) Frequent attendance, inspecti- Part 17: Electrical installations 1 Scope Visual inspection on, service, care and main- inspection and maintenance 2 Normative references Inspection which identifies, wi- tenance of the electrical installation by skilled personnel who 3 Terms and definitions thout the use of access equip- Electrical installations in explo- ment or tools, those defects, have experience in the specific sive atmospheres feature speci- 4 General requirements such as missing bolts, which installation and its environment in order to maintain the explosi- al characteristics that allow their 4.1 Documentation will be apparent to the eye. correct operation in these on protection features of the in- 4.2 Qualification or personnel areas. For safety reasons it is stallation in a satisfactory condi- Close inspection essential for these special cha- 4.3 Inspections tion. Inspection which encompasses racteristics to remain effective 4.4 Periodic inspections those aspects covered by a vi- throughout the service life of Skilled personnel 4.5 Continuous supervision by sual inspection and, in addition, such installations. Additional to Persons whose training has in- an initial inspection this requires skilled personnel identifies those defects, such as loose bolts, which will be ap- cluded instruction on the vari- regular periodic inspections du- 4.6 Maintenance requirements ous types of protection and in- ring plant operation. parent only by the use of ac- 4.7 Environmental conditions cess equipment, e.g. steps and, stallation practices, the This standard, which is directed requirements of this standard, 4.8 Isolation of equipment (where necessary), tools. at the operator, only deals with the relevant national regulati- aspects directly related to the 4.9 Earthing and equipotential Note: ons/company rules applicable to inspection and maintenance of bonding lose inspections do not normal- the installation and on the gene- electrical installations 4.10 Specific conditions of use ly require the enclosure to be ral principles of area classificati- opened, or the equipment to be on. It does not include: 4.11 Movable equipment and its de-energized. • other fundamental installation connections and inspection requirements 4.12 Inspection schedules Documentation for electrical installations (Tables 1 to 3) Detailed inspection For the purposes of inspection • the verification of electrical Inspection which encompasses and maintenance, an up-to-date equipment those aspects covered by a documentation for the following close inspection and, in additi- items shall be available: • the repair and reclamation of on, identifies those defects, explosion protected equip- such as loose terminations, ment (see EN 60079-19) which will only be apparent by It does not apply to: opening the enclosure, and/or • underground mining areas, using, where necessary, tools and test equipment. • areas in which a hazard can occur due to the presence of hybrid mixtures , • dusts of explosives that do not require atmospheric oxygen for combustion, • pyrophoric substances.

Explosion-protected handlamps ensures a ﬂexible and safe illumination of the working area for inspection and maintenance work www.crouse-hinds.de EATON 59 Erection, Operation, Maintenance and Repair 4 of electrical installations in explosive atmospheres

a) zone classification of areas Continuous supervision So that possible weak points Continuous supervision shall be and, if included, the equip- “Continuous supervision” is the can be identified at an early carried out by a technical per- ment protection level (EPL) frequent attendance, inspection, stage, it is necessary to have a son with executive function (re- required for each location service, care and maintenance specific knowledge of the instal- sponsible engineer). With re- (see EN 60079-10); In Europe of electrical installations by lation and the demands on it. gard to the qualification of this the respective equipment cat- skilled personnel with experi- In the course of their normal responsible engineer, impor- egories apply ence in the environment to en- work, for example, control oper- tance is placed on the function- sure the fast detection and im- ations, inspections, mainte- al description and not the edu- mediate elimination of any nance work, cleaning work, cational background. Here the b) for gases: equipment group person in question is a respon- (IIA, IIB or IIC) and tempera- faults that may occur and the checking for faults, switching early recognition of any changes operations, making terminal sible person with an executive ture class requirements for function that, for example, can the equipment used and the initiation of appropriate connections and disconnec- countermeasures. tions, setting and adjustment be performed by a trained tech- c) for dusts: equipment group work, alterations and erection nician with the necessary ex- (IIIA, IIIB or IIIC) and maxi- For the realization of a continu- pertise. Based on this expertise, ous supervision, the responsible work, skilled personnel shall de- mum surface temperature re- tect faults or changes at an ear- he controls the qualification of quirements for the equip- operator of the installation shall skilled personnel and the execu- permanently employ qualified ly stage so that the necessary ment used maintenance measures can be tion of the continuous supervi- personnel and allow them suffi- sion by specifying appropriate d) equipment characteristics carried out in good time. cient freedom to supervise the operational procedures, and e.g. temperature ratings, type installation. Here training as a analyses changes in environ- of protection, IP rating, corro- skilled electrician is the mini- mental conditions, the feedback sion resistance mum requirement. In addition, from maintenance measures e) records sufficient to enable it is necessary to have an ade- and results of random individual the explosion protected quate knowledge of the field of tests , so that necessary meas- equipment to be maintained explosion protection. ures for the adaptation of elec- in accordance with its type of trical installations can be carried protection (for example list out at an early stage. and location of equipment, spares, certificates, technical information) Table : Testing plan for Ex „d“, „e“ and „n“ (D = Detailed inspection; N = Close inspection; S = Visual inspection) f) copies of previous inspection records g) copy of the initial inspection records according to EN 60079-14

Inspections Before an installation or equipment can be put into service, it shall be subjected to an initial inspection. These initial inspections are carried out following the erection according to EN 60079-14. The inspection requirements are specified in this standard. To ensure that the installations in the hazardous area are maintained in the state required for their further operation, according to this standard it is necessary for a) regular periodic inspections b) or continuous supervision by skilled personnel and, if necessary, maintenance and repair work to be carried out The Annex to EN 60079-17 contains information on tests for the implementation of these inspection requirements.

60 EATON www.crouse-hinds.de Marking of degree of protection of electrical equipment for use in explosive atmospheres 5

Marking of degree of protection Degree of protection of explo- of electrical equipment for Table 1: IP-Code according to IEC/EN 60529 sion-protected equipment use in explosive atmospheres Unlike industrial equipment FIRST NUMBER SECOND NUMBER In the relevant IEC(EN) Protection against the ingress of Protection against the ingress of where testing of the degree of standards distinction is made foreign bodies water with adverse effect protection may be carried out between on new test sample, with explo- No protection 0 0 No protection sion-protected equipment, if the degree of protection is a con- IEC 60529 Vertically dripping ≥ 50 mm diameter 11stituent element of the type of Degree of protection by enclo- water sure (IP Code) and protection, tests shall be carried ≥ 12,5 mm Dripping water out on “aged” and mechanically IEC 62262 diameter 22 15° angle stressed test samples. Mechanical protection by ≥ 2,5 mm EN 60079-0 specifies this aging enclosure (IK Code) diameter 3 3 Sprayed water process where, among other ≥ 1,0 mm things, the aging of plastics and 4 4 Splashed water diameter the resistance to aging of seals SERIES is tested. This is followed by a Dust-protected 5 5 Water jets mechanical test that simulates CEAG IP56 a prolonged use of the equip- Powerful water D-69412 Eberbach Dust-tight 66ment for the application and is jets IP66/67 / IK 10 fundamentally different to the T4 Gb Temporary Ta= -25°C bis +55°C 7 tests for equipment for industri- Db immersion al applications only. Continuous 8 The following chart shows that immersion the test for the degree of pro- ww.ceag.de High pressure & high tection comes at the end of the in Germany 9 temp. of water jets test chain. An impact piece with a considerably smaller diameter IP-Code - Degrees of protection is used for the mechanical test to IEC/EN 60529 IK Code - Mechanical degree to EN 60079-0. of protection to IEC/EN 62262 This standard describes a system This standard describes a sys- with fixed gradations and test tem with fixed gradations and methods for classifying the de- test methods for classifying the grees of protection provided by mechanical degree of protec- enclosures of electrical equip- tion (resistance to impact) pro- ment against the ingress of solid vided by enclosures. The speci- foreign objects and the ingress fied test is a type test and is of water (see Table 1). The carried out on clean and new Impact test of an explosion specified test is a type test and equipment at temperatures protected junction box is carried out on clean and new ranging from 15 °C to 35 °C. equipment at temperatures Table 2: Combined designation if requirements for ranging from 15°C to 35°C. The several applications are met first digit of the IP Code describes the protection of persons Enclosure passes test for: against access to hazardous Temporary/conti- Water jets nuous immersion parts and, at the same time, Table 3: Impact piece and second character- second charac- Designation and Range of the protection of the enclosure test to IEC 62262 istic numeral teristic numeral marking application against the ingress of foreign bo- Impact IK Code 5 7 IPX5/IPX7 Versatile dies. The second digit specifies energy (J) the protection of the enclosure 5 8 IPX5/IPX8 Versatile with regard to harmful effects -- IK 00 6 7 IPX6/IPX7 Versatile due to the ingress of water. With 0.14 J IK 01 6 8 IPX6/PX8 Versatile the second number, numbers up to 6 indicate that the require- 0.2 J IK 02 9 7 IPX7/IPX9 Versatile ments for all the lower numbers 0.35 J IK 03 9 8 IPX8/IPX9 Versatile are met. With numbers > 6 the protection for lower numbers is 0.5 J IK 04 5 and 9 7 IPX5/IPX7/IPX9 Versatile not necessarily given. The code 0.7 J IK 05 5 and 9 8 IPX5/IPX8/IPX9 Versatile number for the lower degrees 1 J IK 06 6 and 9 7 IPX6/IPX7/IPX9 Versatile of protection need not be stated in the code. If an enclosure 2 J IK 07 6 and 9 8 IPX6/IPX8/IPX9 Versatile meets the requirements for 5 J IK 08 - 7 IPX7 Restricted both areas, this shall be indicat- 10 J IK 09 - 8 IPX8 Restricted ed using a combined marking (see Table 2). 20 J IK 10 9 - IPX9 Restricted

www.crouse-hinds.de EATON 61 Marking of degree of protection 5 of electrical equipment for use in explosive atmospheres

Flow chart for tests on equipment for use in explosive atmospheres

Group I or II or III

4 samples 26.4.1.2. 2 samples

Thermal endurance to heat 26.8 Thermal endurance to heat 26.8

Wärme Thermal endurance to cold 26.9 Thermal endurance to cold 26.9

and Resitance to impactTmax 26.4.2

2 samples Tmax 2 samples Tmin Drop testT20 °C 26.4.3

Resitance tound impact 26.4.2 Resitance to impactTmin 26.4.2

Drop test 26.4.3 Drop testTmin 26.4.3

Any joint that is intended to be opened is opened and re-closed

Degree of protection (IP) 26.4.5

Test required by type of protection

Additional group I test

and

2 samples 2 samples Resistance to oil/greasses 26.11 Resistance to hydraulic liquids 26.11

Resitance to impact 26.4.2

Prüfungen, gefordert von den einzelnen Zündschutzarten Drop test 26.4.3

Degree of protection (IP) 26.4.5

Test requirements by type of protection

62 EATON www.crouse-hinds.de IECEx Conformity Assessment System 6

The IECEx Conformity Assessment System

In the early 1990s an IEC working group, the WGEx, was formed. This was the starting point for the investigation of a possible implementation of a global certification system for the field of explosion protection based on the IEC standards for equipment for use in explosive atmospheres, which were in existence worldwide. The first official meeting for the estab- lishment of a new IEC conformity assessment system (IECEx) took place in June 1996. When it was established, in line with the IECEE System, the IECEx System only focussed on the drafting and mutual accept- However, it was not long before Unlike the existing national and In the meantime the IECEx ance of test reports for equip- the IECEx Conformity Assess- regional approvals systems, Conformity Assessment System ment that had been tested for ment System was extended to where the paper original of the not only a system for the use in explosive atmospheres allow the preparation of full a approval certificate is the deci- testing and approval of elec- (IECExTest Reports (ExTRs)) of pprovals. The first IECEx Certifi- sive document, the IECEx Sys- trical equipment for use in the participating IECEx testing cate of Conformity (CoC) for Ex tem used an EDP supported ap- explosive atmospheres, but it organisation. equipment was issued in 2002. provals system from the outset. has extended its activities to include international services Each CoC contains a test report or systems. The basis for this Certificate of (ExTR), the associated Quality Only the document shown in Conformity (CoC) issued by an Assessment Report (QAR) with the system is the original. The rulings now cover: IECEx certification body (ExCB) detailled information on the re- • the certification of Ex equip- was the test report (ExTR) of an sults of the assessment and ment , IECEx test laboratory (ExTL), testing of a product and its • the certification of Ex service and, as an added element, an manufacture by an IECEx providers and audit of the manufacturer’s certification body (ExCB) quality management system. and test laboratory (ExTL). • the certification of Ex personnel competence.

IECEx System www.iecex.com Choice between:

IECEx Certificate of Conformity IECEx Equipment Scheme Certification of IECEx Component Ex Equipment and Systems Certificate IECEx Unit Verification Cert.

IECEx Conformity Mark License Scheme

IECEx Services Scheme Certification of Ex Service Providers, eg. repair and overhaul workshops

IECEx Certified Persons Scheme(CoPC) Competeny for work in Ex field (NEW) www.crouse-hinds.de EATON 63 UNCE 6 United Nations Economic Commission for Europe

The UNECE Working Party on Objectives Regulatory Cooperation and The UNECE Working Party 6 UNECE Standardization Policies (WP. 6) established a “sectoral has worked in close coopera- initiative” to tackle existing tion with the International Formation challenges in this sector. Electro-technical Commission Specifically, the project aimed The Economic Commission for (IEC) and the IEC System for at: Europe (UNECE) was set up Certification to Standards nearly two years after the end relating to Equipment for Use in of the Second World War by the Explosive Atmospheres (IECEx) • Fostering the use of relevant Economic and Social Council of to develop a model for legisla- IEC and ISO International the United Nations. The aim was tion in the sector of equipment Standards by the industry. to aid economic reconstruction used in environments with an in Europe, in particular the eco- explosive atmosphere. After the • Promoting a globally nomic relations amongst them- model was adopted In the first harmonized legislation. selves and worldwide. On the Explosion protection step, the text was published. • Ensuring mutual acceptance same day the Economic and The United Nations, through the The model provides for ade- of test procedures and test Social Commission for Asia and United Nations Economic Com- quate risk mitigation, without results among the test the Pacific was set up with the mission for Europe (UNECE), is creating excessive costs or red houses. same aim. tape for business. a multilateral platform that facili- • Striving for comparable instal- The Economic Commission for tates greater economic integra- lation, maintenance and re- Latin America and the Caribbe- tion and cooperation among Any Member State that has no pair procedures of the an, the Economic Commission Member States and promotes regulatory framework in the ex- equipment. for Africa and the Economic and sustainable development and plosive equipment sector can Social Commission for Western economic prosperity Asia followed later. Based on the use the model as a blueprint for objectives of the ECE and the si- legislation. If countries already tuation at that time with regard have such a framework, they to economic force and power, it could consider gradually was almost inevitable that the converging towards this USA and the Soviet Union were international model. among the founder members.

Structure The Commission is made up of an Executive Committee and Sectoral Committees: Includes • Economic cooperation and United Nations 193 Nations integration • Competitiveness, entrepre- neurship, market regulation UNECE One of Five Regional • Environmental protection United Nations Economic Commissions Commission for Europe 56 Nations • Forests and forest industry • Housing and town planning • Sustainable energy Working Party 6 One of X Work Groups • Norms, standards, trade barriers • Inland waterways, railways, SIEEE One of Four roads Sector Initiative Equipment Innitiatives • Statistics Explosive Environment

Common Regulatory Objectives

64 EATON www.crouse-hinds.de ATEX/IECEx & NEC Wall chart global reference guide , page 7

Wall-chart Global Reference Guide

The wall chart in A1 format (folded to A4) is available in English and German languages. Further information about These comprehensive basic guides and further information can be Printed on both sides it shows NEC/CEC Standards found on the net under: the EU / ATEX / IECEx standard More information on the defini- www.cooperindustries.com/content/public/en/crouse-hinds/ on the front and the NEC / CEC tion of hazardous areas accord- resources/Library/technical_documents.html standard for North America on ing to NEC/CEC and the require- the back page. ments of explosion-protected The wall chart with the order-No. 300 8000 2154 can be ordered by equipment for use in North Eaton’s Crouse-Hinds Division / Customer Center / Eberbach So the wall chart can be used America you will find in the 2014 as required. If both sides should Code Digest (NEC) and the Haz- or online via following link: be seen, two wall charts can be ardous Location Guide (CEC). www.crouse-hinds.de/en/new-ex-poster-according-directive-201434eu/ fixed side by side. www.crouse-hinds.de EATON 65 Eaton’s Crouse-Hinds Business The safety you rely on. See the complete offering of Hazardous and Industrial Products at www.crouse-hinds.de.

U.S. (Global Headquarters): Australia Korea The Netherlands Eaton‘s Crouse-Hinds Phone +61-2-8787-2777 Phone +82-2-3484-6783 Phone +31-10-2452145 Division Fax +61-2-9609-2342 Fax +82-2-3484-6778 Fax +31-10-2452121 [email protected] [email protected] [email protected] 1201 Wolf Street Syracuse, NY 13208 Mexico/Latin America/ Norway China Caribbean Phone +1 (866) 764-5454 Phone +47-32-244600 Phone +86-21-2899-3600 Phone +52-555-804-4000 FAX +1 (315) 477-5179 Fax +47-32-244646 Fax +86-21-2899-4055 Fax +52-555-804-4020 FAX Orders Only: [email protected] [email protected] +1 (866) 653-0640 [email protected] Singapore: [email protected] Great Britain Spain Phone +65-6645-9888 Phone +44-247-630-89 30 Phone +34-9-37362710 Fax +65-6297-4819 Fax +44-247-630-10 27 Fax +34-9-37835055 [email protected] [email protected] sales.CCH.es@ cooperindustries.com For more information: Tu rke y India Phone +90-216-464-20-20 If further assistance is Middle East (Dubai) Phone +91-124-4683888 Fax +90-216-464-20-10 required, please contact Phone +971-4-80-66-100 Fax +91-124-4683899 [email protected] an authorized Eaton [email protected] Fax +971-4-889-48-13 [email protected] Distributor, Sales Ofﬁce, Russia or Customer Service Canada Phone +7-495 510-24-27 Toll Free +1-800-265-0502 Department. Fax +7-495 510-24-28 Fax +1-800-263-9504 [email protected] Fax orders only: www.cooper-russia.ru +1-866-653-0645

Eaton Neuer Weg – Nord 49 D-69412 Eberbach

Phone +49 (0) 6271/806-500 Fax +49 (0) 6271/806-476 E-mail [email protected] Internet www.crouse-hinds.de

Changes to the products, to the information contained in this document, and to prices are Eaton reserved; so are errors and omissions. Only order confirmations and technical documentation 1000 Eaton Boulevard by Eaton is binding. Photos and pictures also do not warrant a specific layout or functionality. Cleveland, OH 44122 Their use in whatever form is subject to prior approval by Eaton. The same applies to United States Trademarks (especially Eaton, Moeller, and Cutler-Hammer). The Terms and Conditions of Eaton.com Eaton apply, as referenced on Eaton Internet pages and Eaton order confirmations.

© 2017 Eaton Corporation All Rights Reserved Eaton’s Crouse-Hinds Division Printed in Germany 1201 Wolf Street Eaton is a registered trademark. Publication No. BR 1258 Syracuse, NY 13208 Article No. 300 8000 1258 +1-866-764-5454 All other trademarks are property August 2017 [email protected] of their respective owners.

66 EATON www.crouse-hinds.de