Preliminary real-scale experimental studies on cable fires in plenum

Series fire tests simulating cable fires in plenum caused by exposed and aged combustible cables were carried out in a real-scale flatlet model containing burn room, ceiling plenum, and target room. A special communication cable type insulated with HDPE and sheathed with LLDPE was utilized. A related fire reference scenario was designed to simulate how cables in plenum were involved in a fire from potential fire loads to substantial fuel by the role of an external flaming source and to characterize related fire issues. Major concerns are that how various amounts, various ignition means and different ventilation rates impact on fire performances (heat release rate, smoke temperature, smoke obscuration, combustion products, and toxicity) of cables in plenum. It is found that influences of these parameters are obvious. The burning of exposed tested cables in plenum easily poses a high potential of fire hazard even at a relatively low fire load.