bsen61241-1-20xxelectricalapparatusforuseinthepresenceofcombustibledust—part1protectionbyenclosures“t—”(文件)

　

【正文】 y enclosures ...................................................... 11 Thermal tests ........................................................................................... . 13 9 Marking .......................................................................................................................... 13 Annex ZA (normative) Normative references to international publications with their corresponding European publications ............................................................................. 14 Annex ZZ (informative) Coverage of Essential Requirements of EC Directives ....................................15 B ibliography.......................................................................................................................... 16 Figure 1 – Plain joints ............................................................................................................. 8 Figure 2 – Spigotted joints ...................................................................................................... 8 Figure 3 – Gasketed joints ......................................................................................................9 Figure 4 – Power shafts for speeds of 100r/min or more ....................................................... 10 Figure 5 – Clearance of bolts ................................................................................................ 11 Table 1 – Plain joints .............................................................................................................. 8 Table 2 – Gasketed joints ....................................................................................................... 9 Table 3 – Power shafts for speeds of 100 r/min or more ....................................................... 10 Table 4 – Power shafts for speeds of less than 100 r/min ..................................................... 10 Page 4 EN 61241?1:2020 INTRODUCTION Many dusts which are generated, processed, handled and stored, are bustible. W hen ignited they can burn rapidly and with considerable explosive force if mixed with air in the appropriate proportions. It is often necessary to use electrical apparatus in locations where such bustible materials are present, and suitable precautions must therefore be taken to ensure that all such apparatus is adequately protected so as to reduce the likelihood of ignition of the external explosive atmosphere. In electrical apparatus, potential ignition sources include electrical arcs and sparks, hot surfaces, and frictional sparks. Areas where dusts, flyings and fibres in air occur in dangerous quantities are classified as hazardous and are divided into three zones according to the level of risk. Generally, electrical safety is ensured by the implementation of one of two considerations, . that electrical apparatus be located where reasonably practicable outside hazardous areas and that electrical apparatus be designed, installed and maintained in accordance with measures remended for the area in which the apparatus is located. Combustible dust can be ignited by electrical apparatus in several ways: ? by surfaces of the apparatus that are above the minimum ignition temperature of the dust concerned. The temperature at which a type of dust ignites is a function of the properties of the dust, whether the dust is in a cloud or layer, the thickness of the layer and the geometry of the heat source。 Europ233。lectriques pour utilisation en pr233。 BSI 2020 ISBN 0 580 45200 X Amendments issued since publication EUROPEAN STANDARD EN 612411 NORME EUROP201。ENNE EUROP196。sence de poussi232。en de Normalisation Electrotechnique Europ228。 ? by arcing or sparking of electrical parts such as switches, contacts, mutators, brushes or the like。 ? any electrical sparking parts, or parts having a temperature above the temperature limit specified in IEC 6124114: are contained in an enclosure which adequately prevents the ingress of dust, or the energy of electrical circuits is limited so as to avoid arcs, sparks or temperatures capable of igniting bustible dust。C and maintaining this temperature for approximately 1 h and subsequently cooling the chamber to 20 176。 – zone 21。 ? by radiated energy (. electromagic radiation)。r Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B 1050 Brussels 169。use tD (IEC 612411:2020) This European Standard was approved by CENELEC on 20200601. CENELEC members are bound to ply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Uptodate lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical mittees of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit233。riels 233。BRITISH STANDARD BS EN 612411:2020 Incorporating corrigenda nos. 1 and 2 Electrical apparatus for use in the presence of bustible dus