SR EN 50303:2003

1.1 This standard specifies the design, construction, testing and marking requirements for Group I, Category M1 equipment intended to remain functional in underground parts of mines, as well as those parts of surface installations of such mines endangered by firedamp and/or coal dust clouds under normal atmospheric conditions of pressures ranging from 0,8 bar to 1,1 bar and temperatures ranging from 20 °C to + 60 °C. 1.2 It applies to all electrical and non-electrical equipment capable of causing an explosion through its own potential source of ignition. 1.3 It also applies to cables, pipes and optical fibres, when such items are used to carry energy sources and form part of equipment intended to remain functional in an atmosphere endangered by firedamp and/or coal dust. 1.4 It does not apply to category M1 Miners' Caplights, which are dealt with in prEN 62013-1 (in preparation). NOTE 1 As the energy needed to ignite a coal dust /air cloud is in excess of 600 times* that needed to ignite a firedamp /air mixture, this standard assumes that provided intrinsically safe 'ia' c