UNE-EN 50306-3:2020

This document specifies requirements for, and constructions and dimensions of, multicore cables,rated voltage U0/ U = 300/500 V, of the following type:- Screened(0,5 mm2 to 2,5 mm2, number of cores from 1 to 8).All cables have stranded tinned copper conductors, and thin wall thickness, halogen-free, insulationand sheath. They are for use in railway rolling stock as fixed wiring, or wiring where limited flexing inoperation is encountered.These cables are rated for occasional thermal stresses causing ageing equivalent to continuousoperational life at a temperature of 90 °C. For standard cables this is determined by the acceptancetest defined in EN 50305, using accelerated long-term (5 000 h) thermal ageing indicating a110 °C/20 000 h temperature index. Should the customer require lifetime predictions this should bedemonstrated based on the temperature index of the product as supplied by the manufacturer. Themaximum temperature for short circuit conditions is 160 °C based on duration of 5 s.Under fire conditions the cables exhibit special performance characteristics in respect of maximumpermissible flame propagation (flame spread) and maximum permissible emission of smoke and toxicgases. These requirements are specified to permit the cables to satisfy Hazard Level 3 of EN 45545-1.prEN 50306-3:2018 has to be used in conjunction with prEN 50306-1:2018, General Requirements,and prEN 50306-2:2018, Single core cables.