BS EN 14986:2017

1.1 This European Standard specifies the constructional requirements for fans constructed to Group II G (of explosion groups IIA, IIB and hydrogen) categories 1, 2 and 3, and Group II D categories 2 and 3, intended for use in explosive atmospheres. NOTE1 Operation conditions for the different categories of fans used in this European Standard are defined in Clause4. NOTE2 Technical requirements for category1D fans are not given in this document. Where explosive dust atmospheres are regularly conveyed, explosion protection measures as described in EN1127‑1 are required if this specific us is needed. 1.2 This European Standard does not apply to group I fans (fans for mining), cooling fans or impellers on rotating electrical machines, cooling fans or impellers on internal combustion engines. NOTE1 Requirements for group I fans are given in EN1710 . NOTE2 The requirements for electrical parts are covered by references to electrical equipment standards. 1.3 This European Standard specifies requirements for design, construction, testing and marking of complete fan units intended for use in potentially explosive atmospheres in air containing gas, vapour, mist and/or dusts. Such atmospheres may exist inside (the conveyed atmosphere (flammable or not)), outside, or inside and outside of the fan. 1.4 This European Standard is applicable to fans working in ambient atmospheres and with normal atmospheric conditions at the inlet, having absolute pressures ranging from 0,8 bar to 1,1 bar, and temperatures ranging from−20°C to+60°C, and maximum volume fraction of 21%oxygen content, and an aerodynamic energy increase of less than 25kJ/kg. NOTE1 25kJ/kg is equivalent to 30kPa at inlet density of 1,2kg/m 3. This European Standard may also be helpful for the design, construction, testing and marking of fans intended for use in atmospheres outside the validity range stated above or in cases where other material pairings need to be used. In this case, the ignition risk assessment, ignition protection provided, additional testing (if necessary), manufacturer\'s marking, technical documentation and instructions to the user, should clearly demonstrate and indicate the equipment\'s suitability for the conditions the fan may encounter. This European Standard should not apply to integral fans as a part of Diesel engines, vehicles or electric motors. NOTE2 Where undated references are used in the body of the standard the latest edition applies.