Models of horizontal electric cables and cable trays exposed to a fire plume

Abstract

Models are developed to describe horizontal insulated cables and cable trays exposed to a fire plume. The models also apply to cables protected by fire-retardant coatings. A cable or coated cable can ignite when its surface is hot enough to generate flammable gas, unless the level of O 2 available is insufficient for ignition. Then the gas can often accumulate elsewhere and burn later. A first set of models predicts the delay time to the onset of gasification. Other models estimate the attainable mass flux of flammable gas generated by a tray of cables when the cables do not ignite directly. Longitudinal heat flow is identified as a factor tending to prevent direct ignition of single-conductor cables in the cool plumes encountered over cable-tray fires.