SR EN 50306-3:2003

EN 50306-3 specifies requirements for, and constructions and dimensions of, multicore cables, rated 300 V to earth, of the following type: Screened (0,5 mm2 to 2,5 mm2, number of cores from 1 to 4) All cables have stranded tinned copper conductors, and thin wall thickness, halogen-free, insulation and sheath. They are for use in railway rolling stock as fixed wiring, or wiring where limited flexing in operation is encountered. The requirements provide for a continuous operational life at temperatures of 90 °C or 105 °C dependent upon the sheath system type. NOTE 1 For cables with type S2 sheath a temperature of 105 °C is only allowed when specifically tested for the higher rating (i.e. by long-term thermal endurance testing to demonstrate a lifetime of at least 20 000 h at 125 °C). The maximum temperature for short-circuit conditions is 160 °C based on a duration of 5 s. Under fire conditions the cables exhibit special performance characteristics in respect of maximum permissible flame propagation (flame spread) and maximum permissible emission of smoke and toxic gases