The effects of an inert central core on the thermal pyrolysis of an electrical cable

A mathematical model is formulated to simulate pyrolysis of the insulation layer of an electrical cable. The cable is vertically orientated and the mo del resembles a cable flammability test similar to IEC 60332-1 (Test on Ele ctrical Cables Under Fire Conditions). Only nonflaming pyrolysis is investi gated in this paper. The composition of the cable is idealised such that it consists of an inert central core and an insulation layer. The configurati on of the external heat source is also simplified such that only the trunca ted end of the cable sample receives heat. Pyrolysis is modelled as ablatio n which assumes a single constant critical pyrolysis temperature. Investiga tions are concentrated on the effect of the thermal properties of the centr al core on the pre-heating time and the initial stage of pyrolysis. (C) 200 0 Elsevier Science Ltd. All rights reserved.