Experimental Study on Fire and Thermal Characteristics of Cable DC Arc at Different Breaking Speeds

The direct current (DC) arc generated in the electrical system will lead to high temperature, which will cause the cable to burn and cause an electrical fire. When the cable is broken, a DC arc will be generated in the narrow gap of the cable. This paper established an experimental platform for the DC arc with controllable breaking speed to explore the fire and thermal characteristics of the DC arc generated by copper core cable breaking at different speeds when a 48 V DC power supply is used. At the same time, the arc voltage and arc current are collected to study the characteristics of carbonization reconnection during cable breaking, and the characteristic parameters of fire, such as HCl, smoke, and flame released by the cable skin due to high-temperature arc, are collected. The experimental results show that increased breaking speed and load resistance weakened the carbonization reconnection, HCl, smoke, and cable flame. Studying the difference in fire and thermal characteristics of cable DC arcs at different breaking speeds can provide a reference for the prevention and control of electrical fires and the detection standards of arc faults.