The R. STAHL Technology Group Worldwide Success with Competence and Customer Support The entrepreneurial basis of the R. STAHL Technology Group follows a long tradition. The product range is aimed at specialised areas with demanding technology requirements. The main emphasis is on electrical equipment for hazardous areas. With a committed workforce who are receptive to new ideas, we are also exploring new areas of activity. R. STAHL The company ranks as one of the world leaders in the supply of units and systems for measurement, control, regulation, power distribution, circuit protection and illumination as well as operating and monitoring in hazardous areas. The products are used in the chemical and pharmaceutical industries, for the exploration, transport, processing and distribution of oil and natural gas. Also refineries, drilling rigs, tank farms, pumping stations, filling stations, plastics and pharmaceutical plants, painting installations, and all areas where solvents are used represent typical areas of use for the Switchgear Division's products. Their use ensures that the highest safety requirements are met. The new harmonisation and standardisation of dust explosion regulations within the European Union has induced us to adapt our product palette to meet these additional requirements. Application areas include grain mills, animal feed suppliers, silos, sugar factories and grinding works as well as malt houses and plants manufacturing synthetic fibres. 21E2 R. STAHL Technology Group The R. STAHL Technology Group has a worldwide sales organisation which guarantees comprehensive technical and applications support. Most sales activity is centred in European markets but those in America and Asia are growing fast. R. STAHL prides itself on its standards of customer service and places high value on using the best possible technology - derived from corresponding investment in research and development. It demands the highest possible quality in products, services and staff qualifications. 22E2 R. STAHL Explosion Protection R. STAHL has been producing explosion-protected equipment over 6 years. The use of innovative designs, particularly - and extensively - moulded plastics, has enabled R. STAHL to achieve a leadingposition in the international market place. The products fulfil the highest safety requirements in Europe and worldwide. Explosion-protected equipment developed and manufactured by R. STAHL complies with ATEX 95 (Directive 94/9/EC) as well as european and international standards EN resp. IEC 6 79 -. for hazardous areas of all explosion groups and temperature classes. What's more, in countries outside Europe, the quality and reliability of our products has been endorsed by licences from international testing institutions. The R. STAHL quality management system is certified to DIN ISO 91 as well as ATEX. The quality of our products and services is assured by the use of state-of-the-art processes from development to despatch. Our comprehensive product range offers the optimum solution for almost every application in the field of explosion protection. Individual components, plus systems for lighting, control and automation are offered. Where explosion protection is concerned, R. STAHL has the best possible references. 224E2 4121E2 /2 Automation 17.4.28
The R. STAHL Technology Group Worldwide Success with Competence and Customer Support Customer Support As experts in explosion protection we attach great importance to technical service and support. The worldwide presence of R. STAHL makes such personal attention and individual problem solutions possible. Our highly trained engineers offer you intensive well-qualified advice in the field of explosion protection. Please consult our branches and representatives. You will find the addresses at the back of the catalogue. We are glad to help you in every way. Just call us. Terms of Sale and Delivery All deliveries are subject to our "General Terms of Sale and Delivery". All data, dimensions, weights, designs and delivery conditions are subject to alteration. The drawings are subject to modification. The prices of the current price list are effective. The automation catalogue is valid from March 28 onwards. 4122E Automation 17.4.28 /3
Explosion Protection; Classification of Zones Flammable gases, mists and dusts, together with oxygen, form explosive atmospheres. If such an atmosphere is ignited, an explosion result, which may cause serious damage to personnel and equipment An explosion can only take place if the following factors are jointly active: flammable substance (gas, vapour, mist or dust) in a suitable distribution and concentration oxygen (from the air) and ignition source An explosion atmosphere only occurs if the substance-air micture lies within a certain concentration range, the explosion limits. The explosion limits depend on the ambient pressure and the oxygen concentration of the air. 227E2 Explosion Protection In order to avoid explosions and associated dangers, an operator must incorporate effective explosion protection precautions into his plant. The principle of integrated explosion requires that explosion protection measures be taken in the following order: Measures to prevent formation of a dangerous explosive atmosphere Measures which prevent dangerous explosive atmospheres from igniting Measures which restrict the effects of an explosion to a safe level So are distinguished: Primary explosion protection: all measures which prevent the formation of an explosive atmoshpere Secondary explosion protection: all measures which restrict the effects of an explosion to an insignificant level Explosion-resistant construction these are the measures taken to reduce the effects of an explosion to a negligible minimum Classification of Zones Hazardous areas are classified into Zones, depending on the composition and presence of an explosive atmosphere. This enables both selection of suitable equipment and appropriate electrical installation. Electrical apparatus for use in hazardous areas are assigned to various categories. The additional character G (gas) or D (dust) specifies whether the electrical apparatus may be installed in gas and dust endangered areas. Zone in accordance with EC directive 99/92/EG Zone Zone 2 Zone 1 Zone 21 Zone 2 Zone 22 Presence of potentially explosive atmospheres continuously or for long periods or frequently occasionally infrequently and for only a short period Safety level of device very high level of protection high level of protection normal level of protection Classification of Zones and use of equipment Zone Zone 1 Zone 2 Equipment category in accordance with EC directive 94/9/EG category 1G category 1D category 2G category 2D category 3G category 3D Equipment with type examination certificate Equipment with type examination certificate Equipment complying with the basic requirements of Directive 94/9/EC (Equipment certified for Zone and 1 can also be used). /4 Automation 17.4.28
Temperature Classes; Explosion Groups Temperature Classes Ignition temperature is the lowest temperature of a surface at which an explosive atmosphere ignites on it. Flammable vapours and gases can be classified into temperature classes according to their ignition temperature. The maximum surface temperature of a piece of equipment must always be lower than the ignition temperature of the gas-air mixture or vapour-air mixture in which it is placed. Temperature Classes to IEC Temperature class IEC / EN NEC 55-1 Maximum permissible surface temperature of the equipment [ C] Ignition temperatures of flammable substances [ C] T1 45 > 45 T1 T2 3 28 26 23 215 T3 2 18 165 16 T4 135 12 > 3 ( 45 > 28 ( 3 > 26 ( 28 > 23 ( 26 > 215 ( 23 > 2 ( 3 > 18 ( 2 > 165 ( 18 > 16 ( 165 > 135 ( 2 > 12 ( 135 T5 1 > 1 ( 135 T5 T6 85 > 85 ( 1 T6 Temperature class NEC 5-3 CEC 18-52 T2 T2A T2B T2C T2D T3 T3A T3B T3C T4 T4A Explosion Groups Explosion protected electrical equipment is divided into 2 groups: Group I Group II Electrical equipment for mining Electrical equipment for all other hazardous areas Electrical equipment of group II os further subdivided in groups IIA, IIB and IIC, depending on the danger level of the gas or vapour atmosphere in which they are operated. Equipment of group IIC is suitable for use in the most dangerous atmospheres. Examples of the Classification of Gases and Vapours into Explosion Groups and Temperature Classes I IIA IIB T1 T2 T3 T4 T5 T6 Methane Acetone Ethane Ethyl acetate Ammonia Benzene (pure) Acetic acid Carbon monixide Methane Methanol Propane Toluene Town gas (coal gas) Ethyl alcohol i-amyl acetate n-butane n-butyl alcohol Ethylene Gasoline Diesel fuel aviation fuel Heating oils n-hexane Acetaldehyde Ethyl ether IIC Hydrogen Acetylene Carbon disulphide There is no classification of dust material into temperature classes or explosion groups. This means that the respective values are to be taken into account. The minimum ignition energy E min (of a gas-air mixture) is the energy of an electrical spark that is capable of igniting the most critical (highest ignition performance) mixture under defined test conditions. Ignition temperature T ign (of a gas-air mixture) is the lowest temperature of a hot wall surface at which the mixture is ignited after short-term contact. The glow temperature T glow (of a dust layer) is the lowest temperature of a hot surface on which ignition occurs in a 5 mm thick layer of dust. The maximum surface temperature of the equipment must be compared with the ignition temperature and the glow temperature while also taking into account the safety factor: temperature limiting regarding dust clouds: T max = 2 / 3 T ign temperature limiting regarding dust layers: T max = T glow - 75 K (5 mm dust layer) The lower of the two values represents the maximum permissible surface temperature of the equipment. Automation 17.4.28 /5
Types of Protection Types of Protection In areas where explosive atmospheres can occur despite the explosion protection measures employed, only explosionprotected electrical equipment may be used. Explosion protected electrical equipment can be manufactured to IEC protection type levels. Types of protection for electrical apparatus in hazardous areas Type of protection Diagram Main application Standard increased safety e terminal and junction boxes, control boxes for EN 6 79-7 installing Ex-components (with different type of IEC 6 79-7 protection), squirrel-cage motors, light fittings UL 6 79-7 FM 36 1198E flameproof enclosure d switchgear and control station and indicating equipment, control systems, motors, transformers, heating equipment, light fittings EN 6 79-1 IEC 6 79-1 UL 6 79-1 FM 36 1199E pressurized apparatus p switchgear and control cabinets, analysers, large motors px = for use in Zone 1, 2 py = for use in Zone 1, 2 pz = for use in Zone 2 EN 6 79-2 IEC 6 79-2 NFPA 496 FM 362 intrinsic safety oil immersion i 111E 1111E FISCO Ex ia IIC T4 FNICO Ex ia IIC T4 o instrumentation technology, fieldbus technology, sensors, actuators ia = for use in Zone, 1, 2 ib = for use in Zone 1, 2 [Ex ib] = associated electrical apparatus - installation in the safe area EN 6 79-11 IEC 6 79-11 intrinsically safe systems EN 6 79-25 IEC 6 79-25 fieldbus intrinsically-safe concept (FISCO) for Zone 1 fieldbus non-incentive concept (FNICO) for Zone 2 EN 6 79-27 IEC 6 79-27 transformers, starting resistors EN 6 79-6 IEC 6 79-6 UL 6 79-11 FM 361 UL 6 79-6 FM 36 1112E powder filling q transformers, capacitors, terminal boxes for heating conductors EN 6 79-5 IEC 6 79-5 UL 6 79-5 FM 36 1113E encapsulation m switchgear with small capacity, control and signalling units, display units, sensors ma = for use in Zone, 1, 2 mb = for use in Zone 1, 2 EN 6 79-18 IEC 6 79-18 UL 6 79-18 FM 36 1114E type of protection optical radiation n_ op_ 1115E all electrical apparatus for Zone 2 na = non-sparking apparatus nc = sparking apparatus, in which the contacts are protected in a suitable way nl = energy limited apparatus nr = restricted breathing apparatus nz = apparatus with n-pressurization op is = inherently safe optical radiation op pr = protected optical radiation op sh = optical radiation interlock EN 6 79-15 IEC 6 79-15 EN 6 79-28 IEC 6 79-28 UL 6 79-15 FM 36 1116E /6 Automation 17.4.28
Types of Protection Types of protection for electrical apparatus in areas with combustible dust Type of protection Diagram Main application Standard protection by enclosure td switchgear and control station, terminal and connection boxes, EN 61 241-1 IEC 61 241-1 control boxes, motors, light fittings td A21 = under procedure A for Zone 21 td B21 = under procedure B for Zone 21 1117E pressurization pd switchgear and control cabinets, motors EN 61 241-4 IEC 61 241-4 1118E intrinsic safety id measurement and control technology, fieldbus technology, sensors, actuators iad = for use in Zone 2, 21, 22 ibd = for use in Zone 21, 22 [Ex ibd] = associated electrical apparatus - installation in the safe area EN 61 241-11 IEC 61 241-11 1119E encapsulation md switchgear with small capacity, control and signalling units, display units, sensors mad = for use in Zone 2, 21, 22 mbd = for use in Zone 21, 22 EN 61 241-18 IEC 61 241-18 1111E Automation 17.4.28 /7
Certification and Marking Certification and Marking Only appropriately certified and marked units may be used in hazardous areas. EC-Directive 94/9/EC Validity from 1.3.1996 Range of validity for equipment in hazardous areas all equipment and protection systems gases, vapours and dusts including mining QM system of manufacturer Certificate of conformity QM certificate of a notified body manufacturers declaration of conformity on the basis of the type examination Marking laid down by the Directive and the standards Name or marking of the manufacturer Type marking, (e.g.) 6/562 Address Marking of explosion protection Distinguishing symbol of the EC with indication of the category D-74638 Waldenburg EEx de IIC T6 EEx oder Ex (ab 12/24) CENELEC marking d, e, ib, [ib],... 1) protection types IIC T6 E II 2 G D Test station, no. of certificate PTB 97 ATEX 231 2) CE-mark, no. of testing authority C 12 Electrical data Ambient temperature, if other than - 2 C... + 4 C 1) 2) II explosion group (for gases) temperature class or, in the case of dust, the max. surface temperature of the equipment Mark according to EC Directive Group of equipment 2 Category of equipment G, D G: gases, vapours or mist; D: dusts V, A, W, Hz Ta ( + 5 C ib for intrinsically safe apparatus, [ib] for associated apparatus with... X if special conditions are indicated for use etc. with... U for Ex-components /8 Automation 17.4.28
Certification and Marking Automation 17.4.28 /9