BS EN 50355:2013 pdf download
BS EN 50355:2013 pdf download.Railway applications —Railway rolling stock cable shaving special fire performance-Guide to use.
4.2.6 Consideration shall be given to protection against aggressive agents other than those for which the cables are designed
4.2.7 Green-and-yellow coloured cores shall be used for protective earthing purposes only.
4.3 Requirements for installation of cables
4.3.1 Cables shall not be installed in contact with or close to hot surfaces unless the cables are intended for such conditions.
4.3,2 Cables shall be adequately supported, Recommended maximum spacing of supports is given in EN 50343.
In deciding the actual spacing, the weight of the cable between the supports shall be taken Into account so that the limiting value of mechanical tension is not exceeded.
The cable shall not be damaged by any mechanical restraint used for its support
4.3.3 Cables which have been in use for long periods may be damaged if they are disturbed. This can arise from the effect of natural ageing on the materials used for cable insulation and sheathing, which ultimately results in detenoration of the physical properties of these materials.
4.3.4 Cables shall not be subject to excessive abrasion, crushing. kinking. and tensile load (see 6.4) particularly at the point of connection to the fixed equipment. Any strain relief or clamping device shall not damage the cable.
4.3.5 An earthing core in multicore cables, if present, shall be of such a length that in case of cable breakage due to tension applied to the cable this core breaks after all other cores.
4.3.6 It should be noted that the use of a class 5 conductor in cables to EN 50284. EN 50306 and EN 50382 does not indicate that the cable is suitable for repeated flexing.
4.4 El.ctromagn.tlc compatibility (EMC)
If essential circuits are liable to be subject to electromagnetic interference, screens or shielding shall be provided and connected using an appropriate method. (See also EN 50121-1 and EN 50343).
5 Fire
5.1 General
Attention shall be given to the application for which the rollin9 stock will be used when assessing requirements of testing for fire.
Rolling stock cables for power, control and associated circuits will, in the event of fire, limit the risk to people and improve the safety on railways in general. These cables are designed with halogen free materials. In the event of a fire, they will have limited flame spread and limited emission of toxic gases. In addition, these cables when burnt produce limited amounts of smoke This last characteristic will minimise loss of visibility in the event of a fire and will aid reduced evacuation times.
5.2 Resistance to fire
Where in the event of a fire, the integrity of a circuit is essential for personnel and equipment safety. fire resisting (limited circuit integrity) cable shall be used.
6.3 Current carrying capacity
6.3.1 The cross sectional area of every conductor size shall be such that its current carrying capacity 5 not less than the maximum sustained current which will normally flow through it
For the purpose of this European Standard, the operating temperature to which the current carrying capacity is related shall not exceed that appropriate to the type of cable insulation or sheath concerned.
6.3.2 The recommended basis for continuous current carrying capacities for railway rolling stock wiring is given In Annex A. Those tabulated in Table A.1 for cables of 90 C maximum conductor temperature are denved from IEC 60287. These ratings are based on an ambient temperature of 45 C. Table A.2 contains derating factors for other ambient temperatures. Table A.3 contains correction factors For the other maximum conductor temperatures covered by this guide to use.
Use of the tabulated values of current rating given will cause a rise in conductor temperature from that of the ambient air temperature to that of the stated operating temperature. Care shall be taken to ensure the heat generated can be dissipated and does not cause an unacceptable rise In the ambient air temperature.
6.3.3 Recommended short circuit current ratings for railway rolling stock wiring are given in Annex B For cables of 90 C maximum conductor temperature these are given in Table Bi, Table B.2 gives correction factors for the other conductor temperatures covered by this guide to use. The insulation on these cables is thermally capable of withstanding a short circuit current condition of 200 C for 5 s.
Consideration shall be given to the mechanical forces that can be generated in a cable during a short circuit.
