Abstract: The purpose of this study is to investigate the influence of bending angle and cross-sectional area on the combustion characteristics of suspended cables. A flat three-copper-core cross-linked insulated polyethylene cable with the same length was selected as the research object, and 20 groups of cable combustion tests were carried out. The effects of different bending angles and cross-sectional areas on the fire spread behavior of the cable were analyzed by measuring key parameters such as flame temperature, droplet temperature, cable fire spread time and fire spread speed. The results show that when the bending angle decreases, the flame spread velocity increases first and then decreases, and reaches the peak at θ=90°. The flame spread velocity at this peak state is about 1.6 times that at θ=180°. The cross-sectional area is negatively correlated with the flame spread speed. The flame spread speed of the cross-sectional area 2.5 mm2 cable is 1.9 times that of the 16.0 mm2 cable. At the same time, the smaller the bending angle, the larger the cross-sectional area, the more the number of droplets flowing on the attached cable, and the higher the droplet temperature. In addition, the maximum flame temperature at the bend increases with the decrease of the bending angle. When the cross-sectional area increases, the maximum flame temperature increases first and then decreases.

Key words: cable fire, suspended cable, bending angle, cross-sectional area, fire spread