EN 50306-2 specifies requirements for, and constructions and dimensions of, single core cables, rated 300 V to earth, of the following type:Unscreened(0,5 mm2 to 2,5 mm2 single core)All cables have stranded tinned copper conductors and thin wall thickness, halogen-free insulation. 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 105 °C, and a maximum temperature for short-circuit conditions of 160 °C based on a duration of 5 seconds.NOTE 1 Where these single core cables are used as components of sheathed cables, the temperature for continuous operational life depends upon the type of sheath system used. Sheath systems for either 90 °C for 105 °C are defined in other parts of EN 50306.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. These requirements are specified to permit the cables to satisfy Hazard Levels 2, 3 or 4 of EN 45545-11).NOTE 2 Requirements for the emission of smoke and gases are not specified for cables used for Hazard Level 1 of EN 45545-1.NOTE 3 EN 45545-1 is still under development and should be consulted.EN 50306-2 should be used in conjunction with EN 50306-1, General requirements.