5. Comparison of IEC Publication and European Standards (EN) Pag Apparatus groups & temperature classes for common flammable materials Pag.

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2 [Basic concepts for explosion protection] General Index 1. Introduction Pag Group and equipment category Pag North American Standards Pag Conformity Pag Comparison of IEC Publication and European Standards (EN) Pag Types of protection Pag Protection concept Pag Apparatus groups & temperature classes for common flammable materials Pag Temperature Class (group II) Pag Marking Pag SCAME products range Pag. 22 ZENITH P Series Increased Safety Enclosures and Terminal Boxes for Applications in Hazardous Environments Pag. 23 ALUBOX-Ex Series Junction boxes in aluminium alloy Pag. 31 ADVANCE GRP Series Interlocked switch sockets outlets Pag. 32 OPTIMA-Ex Series Industrial plugs Pag. 33 ISOLATORS Series Switch-disconnectors Pag. 34 1

3 1. Introduction Products for use in explosive atmospheres ATEX Here is a simple guide to ATEX, its meaning and how to choose the right products for your application. What is ATEX? ATEX is a European Directive (94/9/EC) valid for products to be used within an explosive atmosphere. The ATEX directive has been in force throughout the European Union since 1 July 2003, replacing the existing different national and European legislation relating to explosive atmospheres. ATEX = ATmosphere EXplosive Why ATEX? An ambience with the potential to become an explosive atmosphere during operating conditions and/or under the influence of the environment is defined as a potentially explosive atmosphere. Products covered by directive 94/9/EC are defined as intended for use in potentially explosive atmospheres. Directive 94/9/EC defines an explosive atmosphere as a mixture of: a) flammable substances gases, vapors, mists or dusts b) with air c) under specific atmospheric conditions d) in which, after ignition has occurred, combustion spreads to the flammable mixture Harmonised European ATEX standard The European Union has adopted two harmonized directives in the field of health and safety. The directives are known as ATEX 100a and ATEX 137. Directive ATEX 100a (94/9/EC) lays down minimum safety requirements for products intended for use in potentially explosive atmospheres in European Union member states. Directive ATEX 137 (99/92/EC) defines minimum requirements for health and safety at the workplace, for working conditions and for the handling of products and materials in potentially explosive atmospheres. This directive divides the workplace into zones and defines criteria by which products are categorized within these zones. ATEX ATEX 94/9/EC (ATEX 100a) ATEX 199/92/EC (ATEX 137) Products directive Covers manufacturers health and safety requirements Workers directive Covers and users minimum requirements for health and safety protection of workers ATEX 100a Product directive ATEX 137 Workers directive Products requirements Product test Quality audit Certificates documentation instructions Risks analysis Zones identification Assessment Explosion protection document 2

4 [Basic concepts for explosion protection] DIRECTIVE 1999/92/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL dated 16 December 1999 on minimum requirements to improve the safety and health protection of workers potentially at risk of explosive atmospheres (15th individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC) Gives the minimum requirements in the field of safety and health protection of workers potentially at risk of explosive atmospheres. Define obligations of the employer Defines Zones and criteria for selection of equipment and protective systems DIRECTIVE 94/9/EC OH THE EUROPEAN PARLIAMENT AND THE COUNCIL dated 23 March 1994 on the approximation of the laws of the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres Applied to equipment and protective systems intended for use in potentially explosive atmospheres. Covers all risk of explosion (not only those from electrical origin) Covers both application for mines and for other application Applied to equipment, components, safety devices, controlling devices and regulating devices. 2. Group and equipment category Group I Mines and surface installations of such mines Category M1 very high level of protection Category M2 high level of protection Group II Other places Category 1 very high level of protection Category 2 high level of protection Category 3 normal level of protection 3

5 Group II - Zones GAS DUST Frequency and duration of the occurrence of an explosive atmosphere 0 20 continuously present or for long periods or frequently 1 21 occasionally 2 22 not likely to occur Potentially explosive atmospheres For an explosive atmosphere to form, the flammable material must be present in a certain concentration. If the concentration is too low (lean mixture) or too high (rich mixture), no explosion occurs, rather there is just a slow combustion reaction or none at all. It is only in the range between the lower and upper explosion limit that the mixture reacts explosively when ignited. The explosion limits depend on the ambient pressure and the proportion of oxygen in the air. Group II Categories - Zones Category GAS DUST Frequency and duration of the occurrence of an explosive atmosphere Continuously present or for long periods or frequently. Level of protection very high 2 means of prot. 2 faults occasionally not likely to occur high 1 mean of prot. 1 fault normal guaranted in normal operation Conformity assessment procedures Category Type of products Procedure 1 M1 2 M2 2 M2 All Electric Not-electric CE type-examination (Annex III) Production quality assurance (Annex IV) or product verification (Annex V) CE type-examination (Annex III) Conformity to type referred (Annex VI) or Product quality assurance (Annex VII) Internal control of production (Annex VIII) and communicate the dossier to a notified body 3 All Internal control of production (Annex VIII) 4

6 [Basic concepts for explosion protection] 3. North American Standards In North America all electrical installations are governed by the National Electric Code (NEC). Electrical equipment used in ordinary, wet and hazardous (or classified) locations must be listed by an accredited approval agency for use in the intended location. The hazardous locations include areas in which flammable, combustible or ignitable substances may occur in hazardous quantities. Article 501 Codes of the NEC use a different way of categorizing the hazardous locations, which is by Class and Division, compared with the European and IEC standards, which have adopted the Zonal method. Electrical apparatus approved in North America for use in hazardous locations must be categorized with an Equipment Class and suitable for a specified Division and Gas Group. Classifications are made in line with the type of combustible material as follows; Class I Flammable gases, vapors or mists Class II Combustible dusts Class III Ignitable fibers and flying In 1996 article 505 was introduced to the NEC which allowed Zonal classification of hazardous areas. This now means that products can be approved as follows: Either, Class, Division & Gas Group For example: Class 1, Division 2, A,B,C,D or Class, Zone & Gas Group For example: Class 1, Zone 2, IIA, IIB, IIC. Although this code change permits the use of products that have a Zonal classification, in a similar way to European practice, the mixing of different forms of equipment approval across zones or divisions is not acceptable. For example products approved for Zone 1 do not necessarily meet the requirements of Division 1, which also encompasses Zone 0. Although no direct equivalents exist between European/IEC and American codes of protection and Area Classification there are similarities and there is a developing acceptance of European/IEC methods in North America and vice versa. The following table shows the basic relationships between the North American and European Classifications. Equivalent Division/Zone NEC Division 1 European/IEC Zone 0 Zone 1 Division 2 Zone 2 As can be seen from the above table, Division 1 covers both the European / IEC Zones 0 & 1. Therefore, care must be taken when using zone classified equipment in a Division 1 area to ensure the suitability of the protection employed. Underwriters Laboratory (UL) and Factory Mutual (FM) are the two main certification bodies in North America and in some cases electrical equipment may also need to meet certain Marine Standards and be separately approved by the US Coast Guards, before it can be used e.g. on an offshore oil rig. 5

7 4. - Conformity The following route to CE conformity for electrical apparatus is prescribed according to Directive 94/9/EC. Depending on the conformity category, it defines which path the manufacturer has to follow towards making the CE declaration of conformity. The overview below shows these paths for the different conformity categories. Conformity-Assessment-Procedure Stages to be followed on the way to CE conformity and the CE mark Equipment of group I & II, category M1 & 1 (*) and autonomous protective systems Equipment of group I & II, category M2 & 2 (*) Equipment of group II, category 3 (*) EC type examination certificate Motor with internal combustion engine, electrical equipment Internal production control AND YES NO QA production OR Product inspection EC type examination certificate Internal production control EC declaration of conformity AND AND EC declaration of conformity EC declaration of conformity Conformity with design OR QA product Forwarding technical documentation to notified bodies CE mark without ID number ( ) CE mark with ID number ( ) CE mark with ID number ( ) EC declaration of conformity EC declaration of conformity EC declaration of conformity CE mark with ID number ( ) CE mark with ID number ( ) CE mark without ID number ( ) (*) and their components if subject to a separate certification. ( ) ID number of the notified body, which certified the QA system or inspected the products. 6

8 [Basic concepts for explosion protection] 5. Comparison of IEC Publication and European Standards (EN) Electrical Apparatus for Explosive Gas Atmospheres IEC publications EN IEC EN General requirements IEC EN Construction and verification test of flameproof enclosures of electrical apparatus IEC A - Method of test for ascertainment of maximum experimental safe gap IEC/TR EN Electrical apparatus, type of protection p IEC EN Spark-test apparatus for intrinsically-safe circuits IEC IEC A - Method of test for ignition temperature IEC EN Powder filling q IEC EN Oil-immersion o IEC EN Increased safety e IEC EN Classification of hazardous areas IEC EN Intrinsic safety i IEC EN Classification of mixtures of gases or vapours with air according to their maximum experimental safe gaps and minimum ignition currents IEC/TR Construction and use of rooms or buildings protected by pressurization IEC EN Electrical installations in hazardous areas (other than mines) IEC pr EN Electrical apparatus with type of protection n IEC/TR Artificial ventilation for the protection of analyser(s) houses IEC EN Inspection and maintenance of electrical installations in hazardous areas (other than mines) IEC EN Encapsulation m IEC pr EN Repair and overhaul for apparatus used in potentially explosive atmospheres (other than mines or explosives) IEC/TR Data for flammable gases and vapours, relating to the use of electrical apparatus Electrical Apparatus for Use in the Presence of Combustible Dust IEC publications EN IEC IEC IEC IEC EN IEC IEC Part 1: Electrical apparatus protected by enclosures Section 1: Specification for apparatus Part 1: Electrical apparatus protected by enclosures Section 2: Selection, installation and maintenance Part 2: Test methods Section 1: Methods for determining the minimum ignition temperatures of dust Part 2: Test methods Section 2: Methods for determining the electrical resistivity of dust in layers Part 2: Test methods Section 3: Methods for determining minimum ignition energy of dust/air mixtures Part 3: Classification of areas where combustible dust are or may be present 7

9 6. Types of protection Flameproof enclosure Marking "Ex d" II 2 G in accordance with IEC Principle A type of protection in which the parts which could ignite an explosive atmosphere are located inside an enclosure which can withstand the pressure of an explosion of the explosive mixture inside, and prevents the transmission of the explosion to the explosive atmosphere surrounding the enclosure. Technically unavoidable gaps are so long and narrow that hot gases jetting out will have lost their power to cause ignition by the time they reach the outside of the enclosure, or, alternatively, if the gaps are only required for the manufacturing process they might be sealed with adhesive. Important design parameters Mechanical strength in accordance with a defined safety factor to withstand internal explosion pressure. As an orientation value, it may be assumed that inside the sphere approx. 0.8 MPa (8 bar) can be generated and that this sphere used as an EEx d enclosure must be able to withstand a pressure of 1.2 MPa (12 bar). Any gap between two parts of the enclosure must be kept so narrow and long that hot gas flowing out will not be able to ignite any explosive atmosphere which may be present in the potentially explosive atmosphere. The parameters for the gaps preventing the transmission of the ignition, width/length, are different for the explosion subgroups IIA, IIB and IIC. The most stringent requirements with regard to the gap parameters apply to enclosures in explosion subgroup IIC. Applications Equipment where, during normal operation, sparks, electric arcs and/or hot surfaces are generated such as switchgear, slip rings, collectors, adjustable resistors, fuses or lamps, heating cartridges, friction brakes. Protection by enclosure Marking "Ex td" II 2 D in accordance with IEC Principle The enclosure is sealed so tight, that no combustible dust can enter. The surface temperature of the external enclosure is limited. Important design parameters Minimum degree of protection in accordance with IEC/EN IP 6X. Consideration of dust accumulating on the surface and reduction of permissible surface temperature with dust layer 5 mm are possible. Applications Various equipment where during normal operation sparks, electric arcs or hot surfaces occur and complex industrial designs (controllers) which by means of this type of protection can be utilized in the potentially explosive atmosphere. 8

10 [Basic concepts for explosion protection] Enclosed break device Marking "Ex nc" II 3 G in accordance with IEC Principle Switchgear as a variant of the Ex n type of protection, with contacts which close and open a circuit potentially able to trigger an explosion, where the enclosure will withstand an internal explosion of a mixture of subgroup IIA, IIB or IIC without being damaged and without transferring the explosion to the external mixture in the surrounding area. Important design parameters Free internal volume 20 cm³. The encapsulation must permit a permanent temperature of 10 K compared to the maximum operating temperature Limited to AC 690 V and 16 A. Applications Contact systems Non-incendive component Marking "Ex nc" II 3 G in accordance with IEC Principle Variant of the Ex n type of protection with contacts which close and open a circuit potentially able to trigger an explosion, where the contact mechanism or the enclosure into which the contacts are enclosed is designed in such a way that the ignition of a mixture of subgroup IIA, IIB or IIC in the surrounding environment is prevented as long as defined operating conditions apply. Important design parameters Free internal volume 20 cm³. The encapsulation must permit a permanent temperature of 10 K compared to the maximum operating temperature. The combination of the parts is tightly sealed or The design of the contacts will extinguish any incipient flame. Limited to AC 254 V and 16 A. L and C are part of the test. Explosion subgroups IIA, IIB and IIC are to be treated differently. Applications Contact systems 9

11 Pressurized apparatus Marking "Ex p" II 2 G in accordance with IEC Marking "Ex pd" II 2 D in accordance with IEC Principle The ingress of the surrounding atmosphere into the enclosure of electrical equipment is prevented by maintaining an ignition shield gas (air, inert or a different suitable gas) inside it at a pressure above atmospheric pressure. The overpressure is maintained with or without constant flushing of the protective gas. Important design parameters Strength of the enclosure; the surrounding, flushed enclosure must withstand 1.5 times the overpressure experienced during normal operation. Flush before commissioning the electrical equipment. Shut-down or alarm if the flushing gas flow or overpressure fails. Applications Equipment where during normal operation sparks, electric arcs or hot surfaces are generated and complex industrial equipment (controls) which must be operated in a potentially explosive atmosphere protected by this type of protection. Large machines, slip ring or collector motors, switch cabinets and control cabinets and analytical apparatus. n-pressurization Marking "Ex pz" II 3 G in accordance with IEC Principle Use of a protective gas preventing ignition inside an enclosure to prevent the formation of an explosive atmosphere inside the enclosure by maintaining a pressure greater than the that in the surrounding atmosphere. Important design parameters The important difference from the pressurized enclosure is the restriction to an enclosure where no internal sources are available and no flammable gases or vapors can be released. Strength of the enclosure. Flush before commissioning the electrical equipment. Shut-down or alarm if the flushing gas flow or overpressure fails. Applications Equipment where during normal operation sparks, electric arcs or hot surfaces are generated and complex industrial equipment (controls) which must be operated in a potentially explosive atmosphere protected by this type of protection. Analytical apparatus without internal sources. 10

12 [Basic concepts for explosion protection] Powder filling Marking "Ex q" II 2 G in accordance with IEC Principle By filling the enclosure with a finely grained powder, an arc within the enclosure is unable, with correct use, to ignite the explosive atmosphere outside. There must be no risk of ignition by flames, nor by increased temperatures at the surface of the enclosure. Important design parameters The filling such as sand, glass balls etc. has to fulfill specific requirements, as must the design of the enclosure. The filling must not be able to leave the enclosure, neither during normal operation, nor as the result of electric arcs or other processes inside the powder-filled enclosure. Applications Capacitors, electronic assembly groups or transformers which are used in a potentially explosive atmosphere. Often components where sparks or hot surfaces occur but whose functioning is not affected by the finely grained filling. Oil immersion 1) Marking "Ex o" II 2 G in accordance with IEC Principle Parts which might ignite an explosive atmosphere are immersed in oil or other non-flammable, insulating liquid so that gases and vapors above the oil level and outside the enclosure cannot be ignited by electric arcs or sparks generated below the oil level, or by hot residual gases from the switching process or by hot surfaces - e. g. on a resistor. Important design parameters Stipulated, insulating liquids, e. g. oil Protection of the liquid from contamination and moisture. Assurance and possibility of monitoring that the oil level is safe - when heated up or cooled - for identification of leaks Restricted to non-portable devices. Applications Large transformers, switchgear, starting resistors and complete starting controllers. 11

13 Increased safety Marking "Ex e" II 2 G in accordance with IEC Principle Additional measures provide a higher level of protection. This ensures reliable prevention of unacceptably high temperatures and sparks or electrical arcs, both on the internal and on the external parts of electrical equipment whose normal operation does not involve unacceptably high temperature sparks or arching. Important design parameters For uninsulated, live parts, special protective requirements apply. Air and creep age gaps are made wider than is generally the case in industry. Special conditions apply to the IP protection degree to be adhered to. For windings, their design, mechanical strength and insulation, higher requirements apply and the windings must be protected from increased temperatures. Minimum cross sections are stipulated for winding wire, the impregnation and reinforcement of coils and for thermal monitoring devices. Applications Installation material such as junction boxes, connection cabinets for heating systems, batteries, transformers, ballasts and cage motors. Non-sparking apparatus Marking "Ex na" II 3 G in accordance with IEC Principle The construction ensures reliable prevention of unacceptably high temperatures and sparks or electrical arcs, both on the internal and on the external parts of electrical equipment whose normal operation does not involve unacceptably high temperature sparks or arcing. Important design parameters For uninsulated, live parts, special protective requirements apply. Air and creepage gaps are specified. Special requirements must be fulfilled by certain types of equipment. Applications Installation material such as junction boxes, connection cabinets, rotating electrical machines, special fuses, lamps, cells and batteries, transformers and low energy equipment. 12

14 [Basic concepts for explosion protection] Encapsulation Marking "Ex m" II 2 G in accordance with IEC Marking "Ex md" II 2 D in accordance with IEC Principle Parts that could ignite an explosive atmosphere by means of sparks or heat are potted so as to prevent ignition of the explosive atmosphere. This is achieved by encapsulating the components in a compound resistant to physical - especially electrical, thermal and mechanical - and chemical influences. Important design parameters Encapsulation: Breakdown strength Low water absorption Resistance to various influences Casting compound must be of the stipulated thickness all round Cavities are only permitted to a limited extent As a rule the casting compound is only penetrated by the cable entries The load on the components is limited or reduced Increased clearance between live parts Applications Static coils in ballasts, solenoid valves or motors, relays and other control gear of limited power and complete PCBs with electronic circuits. Hermetically sealed device Marking "Ex nc" II 3 G in accordance with IEC Principle The equipment may include cavities. It is constructed in such a way that the external atmosphere cannot enter. Important design parameters Sealed by means of a melting process e. g.: Soft solder Hard solder Welding Fusing of glass and metal Applications Spark generating equipment 13

15 Encapsulated device Marking "Ex nc" II 3 G in accordance with IEC Principle The equipment may include cavities which are fully enclosed similar to the encapsulation type of protection e. g. in a casting compound, so that ingress of the outer atmosphere is prevented. Important design parameters It must be impossible to open the equipment during normal operation, internal free volume 100 cm³ External connections, terminals or cables must be available Cast seal must permit permanent operating temperature 10 K compared to the maximum operating temperature It must not be possible for elastic seals to become mechanically damaged under normal operating conditions; they must maintain their sealing properties over the service life of the equipment Applications Contact systems, static coils in ballasts, solenoid valves or motors and complete PCBs with electronic circuits. Sealed device Marking "Ex nc" II 3 G in accordance with IEC Principle The equipment may include cavities, which are fully enclosed similar to the encapsulation type of protection so that ingress of the outer atmosphere is prevented. Important design parameters It must be impossible to open the equipment during normal operation, internal free volume 100 cm³ External connections, terminals or cables must be available It must not be possible for elastic seals to become mechanically damaged under normal operating conditions; they must maintain their sealing properties over the service life of the equipment Applications Contact systems, static coils in ballasts, solenoid valves or motors and complete PCBs with electronic circuits. 14

16 [Basic concepts for explosion protection] Intrinsic safety Marking "Ex i" II 2 G in accordance with IEC Marking "Ex id" II 2 D in accordance with IEC Principle Intrinsically safe electrical equipment contains only circuits that meet the requirements of intrinsically safe circuits. Intrinsically safe circuits are circuits in which no spark or thermal effect occurring under the test conditions laid down in the standard can ignite the explosive atmosphere of subgroups IIA, IIB and IIC or of an air/dust mixture. The test conditions cover normal operation and certain fault conditions stipulated in the standard. Important design parameters Use of certain components for electrical and electronic circuits. Lower permitted load on the components than in ordinary industrial applications with regard to voltage related to electric strength current related to heat Voltage and current, including a safety margin, are kept permanently so low that no impermissible temperatures can occur, and, in the event of open circuit or short-circuit, sparks and electric arcs possess so little energy that they are unable to ignite an explosive atmosphere. An impression of this protection type is provided by the fact that explosive atmospheres of subgroup IIA require only a few hundred μw and those of subgroup IIC only 10μW for ignition. Applications Measuring and monitoring instrumentation and control. Sensors working on the basis of physical, chemical or mechanical principles and at limited power. Actuators working on the basis of optical, acoustic and, to a certain extent, mechanical principles. Energy limited circuit Marking "Ex nl" II 3 G in accordance with IEC Principle These are circuits in which no spark or thermal effect occurring under the test conditions laid down in the standard can ignite the explosive atmosphere of subgroups II A, II B and II C or of an air/dust mixture. The test conditions cover normal operation and certain fault conditions stipulated in the standard. The permissible currents or voltages exceed those stipulated for the intrinsic safety type of protection. Important design parameters The requirements to be fulfilled by the circuit and the loads on the components are lower than those for the intrinsic safety type of protection. Also with regard to errors, lower requirements apply. Applications Measuring and monitoring instrumentation and control. Sensors working on the basis of physical, chemical or mechanical principles and at limited power. Actuators working on the basis of optical, acoustic and, to a certain extent, mechanical principles. 15

17 Restricted breathing enclosure Marking "Ex nr" II 3 G in accordance with IEC Principle The enclosures are designed in such a way that the ingress of gases is restricted. Important design parameters The powerloss in the enclosure may, if it contains sparking components, only lead to a temperature increase compared to the surrounding of 10 K. Equipment with these enclosures must allow monitoring of the vapour tightness and tightness after installation and maintenance. The allocation to the temperature class by the external surface temperature applies to all enclosures with and without sparking components. It must not be possible for elastic seals to become mechanically damaged under normal operating conditions; they must maintain their sealing properties over the service life of the equipment. Cast seals must permit a permanent operating temperature 10 K compared to the maximum operating temperature. Applications Switchgear, measuring and monitoring instrumentation and information systems and devices. 16

18 [Basic concepts for explosion protection] 7. Protection concept Electrical Symbol Gas/Dust Typical Zone(s) IEC/EN Draft Only Due 2006 Standard (status at Jan 2006) Gas Increased safety e 1,21 EN Type n (non-sparking) na 2,22 EN Dust Basic concept of protection } EN No arcs, sparks or hot surfaces Flameproof D 1,21 EN Type n (Enclosed break) nc 2,22 EN Quartz/sand filled Q 1,21 EN Intrinsic safety Ia/iaD 0,20 EN Intrinsically safe Ib/ibD 1,21 EN Type n (Energy limitation) nl 2,22 EN } EN } EN Contain the explosion, quench the flame Limit the energy of sparks and surface temperatures Pressurised p/pd 1,21,22 EN EN Type n (restricted breathing) nr 2,22 EN EN Type n (simple pressurised) np 2,22 EN Encapsulation Ma/maD 0,20 EN Encapsulation Mb/mbD 1,21 EN Oil immersion O 1,21 EN } EN Keep the flammable gas out Enclosure td 20,21,22 EN Protection by enclosure 17

19 8. Apparatus groups & temperature classes for common flammable materials Gas/Vapour Apparatus group Temperature class Dusts Typical Ignition Temperature ( C) Cloud Layer Acetic Acid IIA T1 Aluminium 590 >450 Acetone IIA T1 Coal dust (lignite) Acetylene IIC T2 Flour Ammonia IIA T1 Grain dust Butane IIA T2 Methyl cellulose Cyclohexane IIA T3 Phenolic resin 530 >450 Ethanol (ethyl alcohol) IIA T2 Polythene 420 (melts) Ethylene IIB T2 PVC 700 >450 Hydrogen IIC T1 Soot Kerosene IIA T3 Starch Methane (natural gas) (non-mining) IIA T1 Sugar Methanol (methyl alcohol) IIA T2 Methyl ethyl ketone (MEK) IIB T2 Propane IIA T1 Propan-1-ol (n-propyl alcohol) IIB T2 Propan-2-ol (iso-propyl alcohol) IIA T2 Tetrahydrofuran (THF) IIB T3 Toluene IIA T1 Xylene IIA T1 9.Temperature Class (group II) Maximum surface temperature T. Codes CENELC IEC 450 C T1 300 C T2 200 C T3 135 C T4 100 C T5 85 C T6 N.B. For Group I applications apparatus has rigid 150 C and 450 C limits rather than T classes. 18

20 [Basic concepts for explosion protection] 10. Marking To enable a piece of equipment to be readily identified it needs to be marked. For electrical equipment in hazardous areas the requirements for the label are carefully detailed in the certification standards and this section covers the sort of information that you will find on such labels. The marking must be legible and durable, permanently affixed onto the equipment to which it relates, and in a visible position. Equipment on which the label has fallen off or is illegible should be re-labelled after consulting the documentation or, if necessary, contacting the manufacturer (quoting the type of equipment and its serial number) for labelling details. The rules for the marking of systems, devices and components are uniformly defined in the standards relating to the general technical requirements. Because the European Community has agreed in the future to also formulate uniform requirements and to introduce a uniform classification for devices, systems and components, other than electrical equipment, the marking has also been unified. Additional symbols have been introduced. This has been defined in the Directive 94/9/EC on Devices and protective systems for use in hazardous areas. This Directive introduces electrical equipment, and for this reason the marking are prefixed by additional symbols. The marking on all devices and protective systems for hazardous areas must indicate the area of their designated use. The marking must indicate the following (see the symbol numbers on the example label): N details Typical marking Meaning Variants General informations 1 SCAME Product manufacturer - 2 Via Costa Erta 15 PARRE (BG) ITALY Manufacturer address - 3 Cod. 644.xxx-yyy Product designation Year of manufacture Can be used with the last two year digit 07 5 Conformity mark 6 Specific marking of explosive protection 7 II Apparatus group 8 2 Product category 9 GD Type of explosive atmosphere For category 1 and 2 must be followed by the notified body number - I: electrical apparatus for mines II: electrical apparatus for all remaining potentially explosive atmosphere Depending on the dangerousness of the gas the group II can be; IIA, IIB, IIC (IIC is the most dangerous) 1 for category 1 2 for category 2 3 for category 3 G: gas D: dust GD: gas/dust 19

21 N details Typical marking Meaning Variants Gas 10 Ex Specific marking according European Directive 94/9/EC - 11 e Protection concept Protection concept for gas: d : flameproof enclosure px : pressurized apparatus, level of protection px py : pressurized apparatus, level of protection py pz : pressurized apparatus, level of protection pz q : power filling o : oil immersion e : increased safety ia : increased safety, level of protection ia ib : increased safety, level of protection ib na : type of protection na nc : type of protection nc nl : type of protection nl nr : type of protection nr ma : encapsulation level of protection ma mb : encapsulation level of protection mb 12 Tx Temperature Class (Max. Surface temperature of the enclosure) Tx: Temperature Class (Group II): T1 = 450 C T2 = 300 C T3 = 200 C T4 = 130 C T5 = 100 C T6 = 85 C Ta: range of ambient temperature Dust 13 td Type of protection for dust 14 A21 Suitable Zone for Dust 15 IP66 Protection degree Type of protection for dust: td : protection by enclosure pd : type of protection pressurized pd id : type of protection, intrinsic safety md : type of protection, encapsulation protection The equipment have been tested according EN method A or method B IP6X: apparatus suitable for Zone 22 with presence of conductive dust IP5X: apparatus suitable for Zone 22 with presence of non conductive dust 16 Tyy Max. surface temperature of the enclosure Tyy C: max. surface temperature of the enclosure Ta: range of ambient temperature 20

22 [Basic concepts for explosion protection] N details Typical marking Meaning Variants Additional information 17a U ATEX components (not CE marked) U : component (for example empty enclosure). The customer is required to certify the final assembly 17b X Particular condition for application X : indicates in instruction sheet particular condition for application 18 Ta xx C to +xx C Ambient temperature If not indicated the range is -20 C+40 C 1 17a Cod. 644.xxxx-yyy S/N xxxxxxxxx SIRA08ATEX3042 U Ex e II Tx Ta -xx to +xx C Ex td A21 IP66 Tyy C Via Costa Erta 15 Parre BG ITALY X Year xxxx V xxxx V I xxxx A P max xxxx W DO NOT OPEN WHEN ENERGIZED IN PRESENCE OF EXPLOSIVE ATMOSPHERE 0051 II 2 GD b 21

23 11. SCAME products range ZENITH P Series Increased Safety Enclosures and Terminal Boxes for Applications in Hazardous Environments ALUBOX-Ex Series Junction boxes in aluminium alloy ADVANCE GRP Series Interlocked switch sockets outlets OPTIMA-Ex Series Industrial plugs ISOLATORS Series Switch-disconnectors 22

24 [Basic concepts for explosion protection] Zenith P Series Code Enclosure size H W D Specifications x80x x80x x110x x110x x160x x160x x190x x190x x230x x230x x220x x160x x260x x360x x560x Atex Code: Ex Protection type: II 2GD Ex e II Ex ia IIC Ex td A21 IP6X T80 C (Ta - 50 C+40 C if not marked) Certificates: Empty Enclosure Sira 08ATEX304IU IECEx SIR U Terminal Box Sira 08ATEX3042 IECEx SIR Operating Temperature Range: -60 C to +75 C (limits) Temperature Class and Ambient: Standard Ambient 40 C and T6 Class Optional Ambient 60 C and T6 Class Ambient 60 C and T5 Class Ambient 75 C and T4 Class Degree of Protection: IP66 Material: Glass Reinforced Polyester (SMC) 4 mm thickness Carbon Loaded for Anti-Static protection UV resistant according to ISO Halogen Free and formulated RoHs directive Absolutely corrosion-proof Seawater-proof Surface Resistance: Antistatic properties: < 10⁹ Ω The enclosures do not present a hazard from static electricity Finish: Natural Black RAL 9005 Impact Resistance: The enclosures are designed to withstand an impact of 7 J, and to be used in normal conditions of vibration Empty enclosures Terminal box with glands 23

25 Component As component it is intended the empty enclosure composed by base, cover and gasket. It can be delivered with internal plate, continuity plate, earth stud, hinges, etc. The installer/customer is required to certify the final assembly Components are not CE marked Material of the enclosure: Resin SMC LS3806 R28C NERO Material of the gasket: Silicone rubber gasket without joint (Mesgo MG8446N30) (delivered in the cover) Cod. 644.xxxx S/N xxxxxxxxx SIRA08ATEX3041U Ex e II Ta -60 to +75 C Ex ia IIC Ta -60 to +75 C Ex td A21 IP66 Via Costa Erta 15 Parre BG ITALY Year xxxx 0051 II 2 GD Label placed internally on the base Material of the label: Fasson Transfer PET Matt Chrome TOP/AL170 BG42 White. As option: Label plate in S.S. AISI316 Laser marking Internal fixing: all internal fittings (e.g. DIN rail, backplate) shall be fitted using stainless steel fasteners and suitable antivibration washers Documentation: each components shall be accompanied by: the certificate of conformity instructions in the language or languages of the country in which the equipment or protective system is to be used (availability in internet is not enough) 24

26 [Basic concepts for explosion protection] Equipment As equipment it is intended the empty enclosure composed by base, cover and gasket completed with terminals. It can be delivered with internal plate, continuity plate, earth stud, hinges, holes, cable glands, etc. Scame certifies the final assembly. Material of the enclosure: Resin SMC LS3806 R28C NERO Material of the gasket: Silicone rubber gasket without joint (Mesgo MG8446N30) (delivered in the cover) Via Costa Erta 15 Parre BG ITALY Label placed outside on the cover and internally on the base Cod. 644.xxxx-yyy S/N xxxxxxxxx SIRA08ATEX3042 Ex e II Tx Ta -xx to +xx C Ex td A21 IP66 Tyy C Year xxxx V xxxx V I xxxx A P max xxxx W 0051 II 2 GD Material of the label: Fasson Transfer PET Matt Chrome TOP/AL170 BG42 White. As option: Label plate in S.S. AISI316 Laser marking DO NOT OPEN WHEN ENERGIZED IN PRESENCE OF EXPLOSIVE ATMOSPHERE -50 C o 60 C to +40 C, +60 C o +75 C Year= year of production V= Rated voltage (V) I= Rated current P max= maximum dissipable power depending on Ta and T class (see following tables) T4, T5 o T6 Cod. 644.xxxx-yyy S/N xxxxxxxxx SIRA08ATEX3042 Via Costa Erta 15 Parre BG ITALY Year xxxx V xxxx V I xxxx A P max xxxx W C, 95 C o 130 C Ex e II Tx Ta -xx to +xx C Ex td A21 IP66 Tyy C DO NOT OPEN WHEN ENERGIZED IN PRESENCE OF EXPLOSIVE ATMOSPHERE II 2 GD Tx e Tyy depends on Ta: Ta=40 C we can have T6 e T80 C Ta=60 C we can have T6 o T5 e T95 C Ta=75 C we can have T4 e T130 C 25

27 For T4 equipment the following sentence shall be reported on the label: WARNING - The cable entry point may exceed 101 C Suitable precaution should be taken when selecting the cable For T5 equipment the following sentence shall be reported on the label : WARNING - The cable entry point may exceed 78 C Suitable precaution should be taken when selecting the cable Internal fixing: all internal fittings (e.g. DIN rail, backplate) shall be fitted using stainless steel fasteners and suitable antivibration washers Terminals can be on rail or back-plate mounted If back-plate mounted they must be fixed with 2 screws The following distances shall be respected: Voltage Creepage distance Clearance 250 6, , SEE NOTE 8 SEE NOTE 8 26

28 [Basic concepts for explosion protection] Any suitable ATEX certified terminal can be used with the following limitations: terminals shall comply with EN (2006) terminals shall be fitted in accordance with the manufacturer s instructions and any special condition for safe use that are specified in their certificate Weidmuller WDU1.5 o WDU2.5 must be limited to 15 C T6 Equipment terminals shall be rated for a temperature minimum 80 C T5 Equipment terminals shall be rated for a temperature minimum 111 C T4 Equipment terminals shall be ceramic Ex i Equipment terminals shall be blue coloured Maximum number of terminals to be fitted into the enclosure depends on: dimensions dissipated power P tot = + n [ R ( d )] t 3ρ 20 Where: R t is the terminal resistance d 3 tridimensional internal diagonal of the enclosure r 20 is the resistivity of the connected conductor at 20 C I is the flowing current (if not specified, it is that of the terminal) I 2 SCAME code Enclosure size Maximum Power Dissipation (W) for Cage Type Terminals T6 Ta=+40 C T6 Ta=+60 C T5 Ta=+60 C x80x x80x x110x x110x x160x x160x x190x x190x x230x x230x x220x x160x x260x x360x N/A N/A x560x N/A N/A T4 Ta=+75 C 27

29 SCAME code Enclosure size Maximum Power Dissipation (W) for Screw Type Terminals T6 T6 T5 Ta=+40 C Ta=+60 C Ta=+60 C x80x T4 Ta=+75 C x80x x110x x110x x160x x160x x190x x190x x230x x230x x220x x160x x260x x360x N/A N/A x560x N/A N/A Maximum power calculated with the above formula shall be less or equal to the maximum power indicated in the tables. Enclosure size (HxWxD) Top/Bottom sides A/C Left/Right sides B/D Rear side F M16 M20 M25 M32 M40 M16 M20 M25 M32 M40 M16 M20 M25 M32 M40 75x80x x80x x110x x110x x160x x160x x190x x190x x230x x230x x220x x160x x260x x360x x560x

30 [Basic concepts for explosion protection] Drilling area Enclosure size (WxHxD) Top/Bottom sides A/C W1xD1 Left/Right sides B/D H2xD2 Rear side F H3xW3 75x80x55 48 x x x 48 75x80x75 48 x x x 48 75x110x55 80 x x x 80 75x110x75 80 x x x 80 75x160x x x x x160x x x x x190x x x x x190x x x x x230x55 90 x 34 (x2) 28 x x x230x75 90 x 54 (x2) 27 x x x220x x x x x160x x x x x260x x x x x360x x x x x560x x 65 (x2) 84 x x 240 (x2) Clearances for standard gland sizes Cable gland size a (mm) Clearances b (mm) a GLAND b CLEARANCE Documentation: each equipment shall be accompanied by: the declaration of conformity instructions in the language or languages of the country in which the equipment or protective system is to be used (availability in internet is not enough) Equipments must be CE marked 29

31 Accessories Back plate in zinc plated steel Mounting bracket in stainless steel AISI 316 External hinges in plastic material Earth continuity plate (internal) in zinc plated steel available as option in copper or brass Earth stud (stud, nut and flat washer) in brass available as option in S.S. AISI MIN Final test If junction boxes are fitted with wiring each equipments shall be subjected to a routine dielectric strengh test. 30

32 [Basic concepts for explosion protection] ALUBOX-Ex Series Reference standards EN EN EN EN Technical characteristics Protection degree: Material: IK degree at 20 C: Cable inlets: DIN rail fixing: IP66 Aluminium alloy IK08 Blank sides Yes Colour: RAL 7037 Versions Enclosure Mounting plate Ex classification Atex Code: Ex Protection type: Operating Temperature Range: Maximum permissible surface temperature: Impact Resistance: CE Certificates: II 3GD Ex na II Ex td A22 IP66 T90 C U -20 C +60 C T90 C Low mechanical risk (4J) SCAME ATEX 01U DIN rail kit Junction boxes in aluminium alloy (for Zone 22) Suitable for outdoor use. Supplied with enclosure earthing kit. Use only non-sparking components and cable glands compliant with the ATEX directive. 31

33 ADVANCE GRP Series Reference standards EN EN EN EN EN Technical characteristics Versions with mechanical interlock With switch-disconnector With switch-disconnector and fuse With fuse and switch-disconnector With molded case circuit breaker with thermal magnetic trip unit Rated current: Rated voltage: Frequency: Insulating voltage: Protection degree: Operating temperature according to the reference standard: 125A V~ 50 60Hz 500/690V~ IP66 Max. operating temperature: 60 C Glow wire test: Self-extinguishing UL94: Material: Cable inlets: -25 C+40 C 850 C/960 C V0 Thermoset Top side max 3xM63 Bottom side max 2xM63 Switch-disconnectors: ABB OT 160 Fuse-carriers: Thermal magnetic protection: Thermal magnetic protection: Version with contactor: NH00 Colour: Grey RAL 7037 Molded case circuit breaker ABB Tmax T1B (16kA) with thermal magnetic trip unit TMD (adjustable thermal threshold 0,7 1 x In fixed magnetic threshold 10 x In) Molded case circuit breaker ABB Tmax T1B (16kA) with thermal magnetic trip unit TMD (adjustable thermal threshold 0,7 1 x In fixed magnetic threshold 10 x In) + residual current release trip units RC221/1 (adjustable residual current trip 0,03-0,1-3A and time limit for non-trip instantaneous) Contactor CL09 GE POWER CONTROL With molded case circuit breaker with thermal magnetic and residual current release trip units Versions with electrical interlock With contactor Ex classification Atex Code: Ex Protection type: Operating Temperature Range: Maximum permissible surface temperature: Protection degree: Impact Resistance: Material: II 3D Ex td A22 IP66 T90 C -25 C +60 C T90 C IP66 7J Thermoset CE Certificates: SCAME ATEX 02 32

34 [Basic concepts for explosion protection] OPTIMA-Ex Series Reference standards EN EN EN EN EN Ex classification Atex Code: Ex Protection type: Operating Temperature Range: Maximum permissible surface temperature: Protection degree: Impact Resistance: Material: II 3D Ex td A22 IP66 T90 C -25 C +60 C T90 C IP66/IP67 7J Thermoplastic CE Certificates: SCAME ATEX 03 Versions Plugs Technical characteristics Rated current: Rated voltage: Frequency: Protection degree: Operating temperature according to the reference standard: 125A V~ 50 60Hz IP66/IP67 Max. operating temperature: 60 C Glow wire test: Self-extinguishing UL94: Material: Colour: -25 C+40 C 850 C/960 C V5 Thermoplastic Grey 33

35 ISOLATORS Series Reference standards EN Technical characteristics Polarity: Rated current: Protection degree: Operating temperature according to the reference standard: 2P 3P 4P 20A 32A 40A 63A 80A 125A 160A IP65 Max. operating temperature: 60 C -5 C+40 C Glow wire test: 650 C Material: Metal Colour: Grey RAL 7015 Versions Ex classification Surface mounting Atex Code: Ex Protection type: Operating Temperature Range: Maximum permissible surface temperature: II 3D Ex td A22 IP65 T90 C U -5 C +40 C T90 C Cable inlets UNDER DEVELOPMENT Enclosure 20A 32A and 40A (105x150x82) Upper surface: 1xM20 + 1xM25 Lower surface: 1xM20 + 1xM25 Enclosure 63A 80A and 100A (150x210x106) Upper surface: 2xM32 Lower surface: 2xM32 Enclosure 125A (315x264x122) 160A (410x315x150) Blank side 34

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