Protection classes of electrical equipment belonging to group II

Transcription

1 Technica Expanations Contro Soenoids in exposion-proof execution G XX E Contents Terms, definitions, expications Cassification of exposive atmospheres in zones and connection with eectrica equipment Ignition temperature temperature cass Protection casses of eectrica equipment beonging to group II Identification / designation exampes Exposion protection at Production and test of contro soenoids in exposion-proof execution Reguations, standards and specifications actuators in exposion-proof execution Magnet-Schutz GmbH & Co. KG Postfach 1665 D Memmingen Agäuer Straße 30 D Memmingen Teefon ++49 (0) Teefax ++49 (0) info@magnet-schutz.de

2 1. Terms, Definitions, Expications 1.1 Eectrica Equipment A objects serving totay or party to the appication of eectric energy. Objects for generation, transmission, distribution, storage, measuring, controing, transformation and consumption of eectric energy as we as objects for teecommunication beong to this. Eectrica equipment for exposion-proof areas is cassified in:: Group I: Eectrica equipment for mine workings with firedamp exposion risk Group II: Eectrica equipment for a exposive areas without mine workings with firedamp exposion risk Furthermore another cassification in so-caed categories is made, where category 1 and category 2 are used for groups I and II. Category 3 refers ony to group II: Category 1: highest degree of protection, thus very high degree of safety Category 2: increased degree of protection, thus high degree of safety Category 3: norma degree of protection, thus norma degree of safety With the cassification in categories, aso an attribution to the appication area is made (underground, gas-exposive areas, areas with combustibe dust) where the equipment is used: Group I: M1, M2 (mining) Group II: 1G, 2G, 3G (gas) 1D, 2D, 3D (dust) (see point 2) 1.2 Exposive Atmosphere Mixture of air and combustibe gases, steams, mists or dusts under atmospheric conditions in which the combustion process has transferred on the whoe unburnt mixture after effected ignition. Atmospheric conditions mean : - Temperature from -20 C up to +60 C - Pression from 0,9 bar up to 1,1 bar - Air with oxygen content of approx. 21% 1.3 Exposive Area Zone where the atmosphere may become exposive due to the oca and operationa conditions. Generay exposive areas are cassified in zones according to frequency and duration of potentiay exposive atmosphere whereas a differentiation is aso made between combustibe gases, steams and mists, as we as combustibe dusts : Danger areas gas / steam: Zone 0 Zone 1 Zone 2 Danger areas dust: Zone 20 Zone 21 Zone 22 (see point 2) 1.4 Fashpoint Temperature The owest temperature at which a combustibe gas or a combustibe iquid can generate a suitabe quantity of steam at its surface under specia testing conditions so that with an effective ignition source an ignition of the steam-air-mixture might become possibe. 1.5 Ignition Temperature Temperature Cass The ignition temperature of a combustibe materia is the owest temperature at which the combustibe materia just ignites in connection with air. By means of fixed proceedings (EC/EN respectivey IEC/EN ) the ignition temperature of any substances is determined so they can be cassified in temperature casses. (see point 3) Temperature casses Tabe 1.5 Ignition temperature ranges of mixtures [ C] Max. admissibe surface temperature eekof eectrica equipment [ C] T1 > T2 > T3 > T4 > T5 > T6 > Temperature casses and respective temperature ranges 1.6 Exposion Subgroups Cassification of combustibe gases and steams within group II according to their ratio of min. ignition current reated to methane or according to their border gap width. The vaue of the MESG (Maximum Experimenta Safe Gap) is very important for constructions with protection cass fameproof encosures. The vaue of the MIC (minimum ignition current) is very important for constructions with protection cass intrinsic safety. (See point 3) Exposion subgroup Tabe 1.6 Minimum ignition current reated to methane (MIC:CH4) Maximum experimenta safe gap (MESG) Hazardousness IIA > 0,8 > 0,9 mm ow IIB 0, ,8 0,5... 0,9 mm average IIC ,45 < 0,5 mm high Exposion subgroups and their cassification 1.7 Protection Casses Designation for actions which assure that an ambient exposive mixture of gas, air, mist or dust may not ead to an ignition due to different protection principes. (see point 4) A protection casses of the same category are equa concerning safety! Protection principe Protection principe ensures that an ignition source may not incur Protection principe ensures that an ignition source may not become effective Protection principe prevents the exposive atmosphere from reaching the ignition source Protection principe aows ignition but prevents the fame propagation by means of the housing Tabe Protection Cass Eectrica equipment of categories 1G, 2G, 3G Increased safety e Not sparking devices na Protection principe and protection types Intrinsic safety i Energy imited eectric circuits nl Pressurized encosures p Simpified pressurized encosures pz Encapsuation m Oi immersion dans o Hermeticay seaed devices Encapsuated/seaed equipment nc Protection against exposive gases and dusts nr Fameproof encosures d Powder fiing q Encosed contro unit nc Not ignitabe part nc Describes the degree by an encosure. - protection against contact Die IP-Schutzart stet - foreign body protection. (see point 6.4) - protection against ingress of water Eectrica equipment of categories 1D, 2D, 3D Intrinsic safety id Protection by encosures td Pressurized encosures pd Encapsuation md 2

3 2. Cassification of exposive areas and coherence with eectrica equipment Due to the cassification of eectrica equipment in different groups and categories and due to the division of the exposive areas into different zones the equipment can be categorized in reevant exposive areas where they may be appied. For the European community the definition of zones is standardized in reguation 1999/92/EG. Abbidung 2.1 Zoneneinteiung beispiehaft dargestet Necessary marking of the appicabe Rating of exposion hazard equipment Device group Category Operation at exposion hazard Mining I M1 Cut-off at exposion hazard Mining I M1 or M2 Zones for danger by gas / steams Zone where exposive atmosphere as mixture of air, combustibe gases, steams or fogs is aways, for ong periods or often existing Zone where at norma operation an exposive atmosphere as mixture of air, combustibe gases, steams or fogs may form from time to time Zone where at norma operation an exposive atmosphere as mixture of air, combustibe gases, steams or fogs may normay not form or even temporariy Zone 0 II 1G Zone 1 II 2G or 1G Zone 2 II 3G, 2G or 1G Zones for danger of combustibe powder Zone where an exposive atmosphere in form of a coud of combustibe dust contained in the air exists aways, for a ong time or often Zone where an exposive atmosphere in form of a coud of combustibe dust contained in the air exists from time to time at norma operation Zone where at norma operation an exposive atmosphere in form of a coud of combustibe dust contained in the air does not form normay or even temporariy Zone 20 II 1D Zone 21 II 2D or 1D Zone 22 II 3D, 2D or 1D Tabe 2.1 Definition of zones and appicabe equipment 3

4 3. Ignition Temperature Temperature Cass 3.1 Safety-reated identification numbers of combustibe gases and steams for determination of temperature cass and exposion subgroup T1 > 450 C Temperature cass / temperature of mixtures T2 > 300 C C T3 > 200 C C T4 > 135 C C T5 > 100 C C T6 > 85 C C Appicabiity of materia with exposion subgroup IIA IIB IIC Acetone Ammoniac Benzo pure Acetic acid Ethy acetate Ethy choride Carbon monoxide Methane Methano Methyene choride Naphthaine Pheno Propane Touo Ethy acoho i-amy acetate n-butane n-buty acoho Cycohexane Acetit anhydride Benzins generay diese fue kerosine heating oi DIN n-hexane Acetadehyde IIA City (iuminating-)gas Acryon nitrie Ethyene Ethyene oxide Ethyene gyco Hydrosuphide Ethy ether IIB Hydrogene Ethine (Acetyene) Carbon disuphide IIC T1 T2 T3 T4 T5 T6 Appicabiity of materia with temperature cass Fig. 3.1 Exampes for cassification of different gases and steams in temperature casses and exposion subgroups 3.2 Dust deposit: Max. admissibe surface temperatures Fig. 3.2 Reduction of the max. admissibe surface temperature with increasing ayer thickness of the dust ayer (IEC/EN ) 4

5 4. Protection cass of eectrica equipment of group II Protection cass Gases / steams Dusts Marking Principe and constructive measures Appication exampes Fameproof encosures fameproof encosures d The components which may ignite an exposive atmosphere are incorporated in an encosure which withstands the pressure resuting from an exposion of an exposive mixture inside.. Technoogicay necessary gap and notches are designed concerning ength and tightness that a transmission of the exposion on the exposive atmosphere surrounding the encosure is avoided. Contro soenoids with buit-on switch, transformers, contro and switch devices, engines and generators with coector and coector rings, variabe resistors, amps etc. Contro soenoids in particuary soid execution Pressurized encosures pressurized encosures p pd The encosure of eectrica materias is fied with an ignition protection gas (air, inert or other suitabe gas) which is kept under overpressure compared with the ambient atmosphere. So the ambient atmosphere may not penetrate in the encosure. Possiby the overpressure wi be maintained by an ongoing purging with ignition protection gas. Large-scae machines, measuring stations, switch and contro units, anaysis devices, arge-scae engines, heating devices etc. No importance for contro soenoids Powder fiing powder fiing q The fiing of an encosure with fine-grained fi effects that at occurrence of an eectric arc in the encosure an exposive atmosphere surrounding the encosure wi not be ignited. No ignition may occur either by increased temperature on the encosure surface. Contro soenoids, switching devices, power suppy units, eectronic components Oi immersion oi immersion o The parts of eectrica equipment from which an ignition of exposive atmosphere may come are dipped so deepy in a protection iquid (mosty insuating oi) that gases and vapours upside the iquid and outside the encosure may not be ignited by eectric arcs or simiar. Large transformers, switching devices, starting resistances and compete run-up contros. Rarey appied for contro soenoids. Increased safety increased safety e The possibiity of inadmissiby high temperatures and emerging sparks or eectric arcs inside and at externa parts of eectrica equipment are avoided by additiona measures and a higher degree of safety. Contro soenoids, transformers, accumuators, amps, squirre-cage motors, instaation materias, termina and junction boxes Intrinsic safety intrinsic safety ia, ib, ic, iad, ibd Intrinsic materias contain ony eectric circuits which compy with the requirements for intrinsic circuits. Intrinsic circuits are reaized when energy and switching capacity are so ow that no spark or therma effect occurs which may cause (at norma operation and under certain error conditions) an ignition of exposive atmosphere of the subgroups IIA, IIB or IIC resp. of a dust-air-mixture. Measuring / monitoring information systems or devices often appied for contro soenoids Sensors and actors Protection cass n type of protection n nc, na, nr, nl Protection is achieved by different constructive actions which are imiting or avoiding the penetration of externa atmosphere in encosures or which are imiting the energy of eectric circuits in that way that no sparks, eectric arcs or inadmissiby high temperatures occur which may ignite the exposive atmosphere. Contro soenoids, contact systems, batteries, materia with ow energy etc. Encapsuation encapsuation ma, mb mad, mbd The parts of the eectrica materia which coud ignite an exposive atmosphere by sparks or heating are embedded in a mouding mass. So the exposive atmosphere may not be ignited. This is made by an overa coating of the components with a suitabe mouding mass. Printed boards with circuits, reays, switch arrangements, often appied for contro soenoids Schutz durch Gehäuse protection by encosures td The encosure is so tight that no combustibe powder may penetrate inside. The surface temperature of the externa encosure is imited. Contro soenoids, contro systems, diverse materias Tabe 4.1 Protection casses for eectrica equipment of group II 5

6 5. Marking / Designation exampes 5.1 ATEX-Marking 0123 II 2G Ex e mb II T4 TPS EX bzw. PTB -- ATEX -- European Community aex-symbo ATEX EC-type examination certificate TÜV Süd Product Service resp. PTB Braunschweig Ex-symbo ATEX ATEX device group ATEX device category Protection cass(es) Exposion sub-group Temperature cass According to ATEX marking above exampe is a materia beonging to group II suitabe for appication in a gas exposive area, zone 1. Exposion protection of the materia is achieved by means of protection casses e / increased safety) and mb (encapsuation with protection eve mb ); in temperature cass T4 it is suitabe for a gases of group II. As there is no additiona marking for the ambient temperature the materia is designed for a range of ambient temperatures from 20 C up to + 40 C. Fig Marking exampe for exposion proof eectrica materia according to ATEX, suitabe for gas exposive areas 0123 II 2G II 2D Ex e mb II T4 TPS EX bzw. PTB -- ATEX -- Ex td A21 IP67 T130 C European Community ID number of certification authority ATEX Nummer der EG-Baumusterprüfbescheinigung TÜV Süd Product Service bzw. PTB Braunschweig Ex-symbo ATEX ATEX device group Device category ATEX Protection cass(es) Protection cass of the housing (protection cass IP) Max. surface temperature -20 C Ta +50 C Angabe spezieer Umgebungstemperaturbereich According to ATEX marking above exampe is a materia which is identica concerning device group, device category, protection cass, exposion sub-group, temperature cass etc. - with the exampe in fig for appication in gas exposive areas. As per marking it is additionay a materia beonging to group II for appication in an area with danger by combustibe dusts, zone 21. Exposion protection is here achieved by means of protection cass td (protection by encosures) whereas the marking A21 signifies that the materia is designed according to procedure A (see IEC/EN ) and may be appied in zone 21. The encosure is protected according to IP protection cass IP 67; its max. surface temperature is 130 C. The additiona marking of the ambient temperature means that the materia is designed for a range of ambient temperatures from 20 C up to + 50 C. Fig Marking exampe for exposion proof eectrica materia according to ATEX, suitabe for dust exposive areas 6

7 6. Exposion Protection at 6.1 Certificats and Audits For many years has been working in the fied of exposion-proof eectromagnetic actuators and sensors. Since 2000 a vaid certification of the QS-system according to annex VII of the directive no. 94/9/CE (ATEX 95) has existed for devices and protection systems destined for the use in exposive areas. is certified for devices of group II in the categories 2G and 2D in protection casses e, m, d, i, md, td, id zertifiziert. On the base of that ATEX certification a mutitude of approvas (EC-type examination certificate) issued by TÜV Süd Product Service (TPS) and the Physikaisch Technischen Bundesanstat, Braunschweig (PTB federa institute for physics and technoogy in Braunschweig) are aready existing for eectromagnetic devices for diverse appications. To faciitate the wordwide approvas the QA system of been aso audited for IECEx since has Up to now this certificate (Quaity Assemby Report QAR) comprises the protection casses e, mb, td. The enargement of the Quaity Assessment Report with other protection casses is possibe on request by test and approva (Test Report TR) of other devices. The Quaity Assessment Report QAR as we as the Certificate of Conformity CoC can be seen and printed on the homepage of IECEx ( 7

8 6.2 Constructive Assemby of Contro Soenoids in Different Protection Casses Figure 6.2.1: DC soenoid GRCE045 protection cass Increased safety ( e ), encapsuation ( m ) and protection by encosures ( td) for categories II 2G and II 2D Figure 6.2.2: Termina in protection cass increased safety ( e ) Figure 6.2.3: Proportiona soenoid GAAE045 in protection cass Increased safety ( e ), encapsuation ( m ) and protection by encosures ( td ) for categories II 2G and II 2D Figure 6.2.4: Vave soenoid GBXE022 in protection cass intrinsic safety ( i and id ) for categories II 2G and II 2D Figure 6.2.5: Magnetic body FHMPE037 in protection cass encapsuation ( m ) Figure 6.2.7: Vave soenoid GBRE022 in protection cass encapsuation ( m ) for the categories II 2G and II 2D Figure 6.2.6: DC soenoid GAAE050 in protection cass increased safety ( e ) and encapsuation ( m ) 8

9 6.3 Ambient Temperatures, Battery Assemby Generay contro soenoids for exposive areas are designed for the use in an ambient temperature range of -20 C up to +40 C. In this case an additiona identification of the ambient temperature T a is not necessary. If the contro soenoid is designed for the appication in a different temperature range, this is regarded as specia design and the ambient temperature range is indicated by a specia identification. Generay the infuence of vicina heat sources as e.g. for battery assemby of soenoids / vaves (see fig and fig ),has to be considered. Figure 6.3.2: Battery assemby of pneumatic soenoids in exposion-proof design on a vave ine If an arrangement of severa devices is made by a battery assemby in accordance to the distances x and y, the devices may have negative therma infuences against each other. In such cases pease contact us indicating the present case of appication: Dimensions Denomination of the distances x, y Duty cyce of the different soenoids Temperature at the area of appication Temperature of medium (hydrauic oi, air, etc.) Figure 6.3.1: Exampe for battery assemby of pneumatic vave soenoids with distances x and y 9

10 6.4 Protection Cass According to IEC/EN 60529, Corrosion Protection, Mechanica Strength Besides the protection casses described under point 4 the IP protection casses according to IEC/EN (VDE ) are reevant for exposion-proof contro soenoids for protection against contact protection against foreign objects protection against ingress of water concerning operationa safety. 6.5 Limitation of Over-votage Inductance (inductance L) causes high votage peaks when switching off DC contro soenoids. In order to excude these phenomenon and for safety reasons exposion-proof DC contro soenoids are provided with a protective circuit which is integrated in the soenoid and situated in parae to the exciter coi. (see fig and fig ) -Exposion-proof MSM contro soenoids are designed among others for a protection cass of min. IP54 for G (gas exposive areas) resp. IP65 for D (areas with combustibe dust) according to IEC/EN (VDE ). In order to execute the soenoids in exposion-proof design by preventive means in addition to the requested protection type aso with adequate corrosion protection sufficient mechanica strength eventuay higher protection cass concerning the requirements of the area of appication, it is necessary to indicate in inquiries or orders - in addition to the requested protection type according to IEC/EN (VDE ) detaied information about mechanica strength infuence of water infuence of aggressive media and simiar information about the area of appication as e.g.: unprotected instaation outside instaation in a contro cabinet assemby on a deck of ship reative humidity etc. Fig : Wiring diagram for DC version with protective circuit bidirectiona diode AC version with protective circuit diode and rectifier Fig : Wiring diagram for DC version with protective circuit varistor AC version with protective circuit varistor and rectifier If no protective circuit exists the over-votage has to be imited externay with appropriate means. 10

11 7. Production and Test of Exposion-proof Contro Soenoids In -manufacturing the production of individua parts for the soenoids, the assemby and the test according to the reevant reguations and standards are ony carried out by particuary skied and quaified workers. A individua parts which are important for the exposion protection are checked with a testing accuracy of 100%. By means of construction and test prescriptions detais for a reaisation of a safe exposion protection are reiaby verified. After a successfu detaied conformity inspection each device is separatey marked and the test resuts of the individua parts and of the finished devices are accuratey recorded in detaied test reports. For -ATEX executions of exposion-proof contro soenoids an instruction manua is deivered with each device for category 2. This instruction manua contains information about ambient conditions, instaation and starting up as we as information about assemby and detaied technica data. It has to be respected by the user in any case! Figure 7.2: Exampe, ATEX decaration of conformity Additionay a manufacturer s CE certificate of conformity is deivered for and joint to each deivery ot (devices for category 2 and category 3). This certificate of conformity proves that the respective -contro soenoid is conform to the underying EC-Type Examination Certificate (devices for category 2) resp. to the manufacturer s examinations (devices for category 3) and that it fufis the requirements of the respective standards and the prescriptions of the EC directive 94/9/CE. According to directive 1999/92/CE the instruction manua and / or the certificate of conformity have to be respected by the raiser / user and have to be joined to the exposion protection document for documentation. -IECEx executions of exposion-proof contro soenoids are aso deivered with a correspondent instruction manua. The correspondent certificate of conformity (CoC) and the Quaity Assessment Report (QAR) are stored on the homepage of IECEx ( where they can be seen and printed if required. Figure 7.1: Exampe, ATEX operating manua 11

12 8. Reguations, Standards and Provisions For the constructive deveopment, design and test of exposion-proof contro soenoids the foowing points 8.1 up to 8.17 are taken into consideration according to tabe IEC / EN (VDE ) Eectrica equipment for gas exposive areas - Genera requirements 8.2 IEC / EN (VDE ) Eectrica equipment for gas exposive areas - Fameproof encosures 8.3 IEC / EN (VDE ) Eectrica equipment for gas exposive areas - Pressurized encosures 8.4 IEC/EN (VDE ) Exposive atmosphere - Equipment protection by powder fiing 8.5 IEC / EN (VDE ) Exposive atmosphere - Equipment protection by oi immersion 8.6 IEC / EN (VDE ) Exposive atmosphere - Equipment protection by increased safety 8.7 IEC / EN (VDE ) Exposive atmosphere - Equipment protection by intrinsic safety 8.8 IEC / EN (VDE ) Eectrica equipment for gas exposive areas - Construction, test and marking of protection cass n apparatus 8.9 IEC / EN (VDE ) Exposive atmosphere - Equipment protection by encapsuation 8.10 IEC / EN (VDE ) Eectrica equipment for appication in areas with combustibe powder - Genera requirements 8.11 IEC / EN (VDE ) Eectrica equipment for appication in areas with combustibe dust - Protection by encosures 8.12 IEC / EN (VDE ) Eectrica equipment for appication in areas with combustibe - Protection cass «pd» 8.13 IEC / EN (VDE ) Eectrica equipment for appication in areas with combustibe dust - Protection by intrinsic safety IEC / EN (VDE ) IEC / EN (VDE ) IEC / EN (VDE ) IEC / EN (VDE ) IEC / EN (VDE ) Eectrica equipment for appication in areas with combustibe dust - Protection by encapsuation Panning and instaation as we as test and maintenance of eectrica equipment in gas exposive areas and / or areas with combustibe dust 8.16 DIN VDE 0580 Genera reguations for eectromagnetic devices 8.17 IEC / EN (VDE ) Protection casses by encosures Tabe 8.1: Reguations, standards and provisions 12

13 9. -Actuators in Exposion-proof Execution As reputabe and potentia manufacturer of exposion-proof soenoids is abe to provide a wide and manifod programme for contro soenoids in different protection casses according to the effective reguations. Fig. 9.1: Singe-acting soenoids type GTCE for eectromechanic appications II 2G EEx em II T4/T5 Fig. 9.2: Singe-acting soenoids type GMCE for eectromechanic appications II 2G EEx m II T4 Fig. 9.3: Shotbot ock units pu or push type GSCE for eectromechanic appications II 2G EEx m II T4 Fig. 9.4: ON/OFF and proportiona soenoids type GHPE / GRCE for hydrauic appications II 2G EEx m II T4 II 2D IP65 T130 C Fig. 9.5: Proportiona soenoids type GREE 035 AMX A01... for hydrauic appications II 2G EEx m II T4 Fig. 9.6: ON/OFF and proportiona soenoids type GHPE... / GRCE... for hydrauic appications II 2G Ex e mb II T4 II 2D Ex td A21 IP65 T130 C Fig. 9.7: ON/OFF and proportiona soenoid Type GAAE... / GRFE... for hydrauic appications II 2G Ex e mb II T4 II 2D Ex td A21 IP65 T130 C Fig. 9.8: Vave soenoid Type GBRE 022 AMX for pneumatic appications II 2G EEx m II T5 II 2D IP65 T95 C Fig. 9.9: Vave soenoid in intrinsicay safe version Type GBXE 022 AIA A01 for pneumatic appications II 2G EEx ia IIC T6 II 2D Ex iad IP65 T80 C Further information can be taken from our brochure «ATEX 95 exposion-proof actuators». Pease ask the support of our responsibe technica office when required. 13

14 -Technica Expanations G XX G XX E G XX 2. Zusatz G XX V W XX P XX H XX Y XX DC soenoids Exposion-proof contro soenoids DC proportiona soenoids DC shotbot ock units AC soenoids DC or AC ON/OFF soenoids for pneumatic appications DC or AC ON/OFF soenoids for hydrauic appications Vibrators /08 ALT