Fire Safety Science Digital Archive

Samples of T.R.S. (1/044), P.V.C. (3/029) and V.I.R. (3/029) cables were subjected to overload currents and it was found that ignition occurred where the currents were greater than 35, 55 and 65 amps respectively. Breakdown of the insuIation between conductors, or between a conductor and a metal earth shield, and the presence of moisture did not appear to be important as causes of fire. Samples of V.I.R. cable over thirty years old appeared to behave similarly to new cable. Only in the case of V.I.R. cable (new and old) did fire or excessive currents reduce the insulation to a conducting material.