An experimental study about the fire resistance of low voltage cables

An experimental study, aimed at the identification of specific cable behaviour during "burn tests" was implemented by performing suitable tests at different temperatures. The adopted fire-resistance test end-point criterion was the short-circuit between the energized conductors or between a conductor and a grounded screening tape. The variation with time of the insulation resistance, measured between the conductors and the cable external overall screen was investigated during the tests, while a mechanical shock was cyclically applied to the cable and to its support. This measurement was carried out to look for a significant parameter representative of the degradation process. Finally, the combined electrical and mechanical effect on the degradation process was studied as both stresses were applied to the specimens during the tests