在火灾现场中经常可以发现由于电流作用而熔化形成的短路熔痕。从火灾原因调查角度出发，按照其形成时间又可以分为一次短路熔痕和二次短路熔痕两类。二次短路熔痕是指在火灾过程中产生的熔痕，它是由于通电状态的导线或保护装置绝缘被烧毁，发生短路时所形成的熔痕。二次短路 In the scene of a fire, short-circuit melting marks that melt due to the action of current can often be found. From the perspective of fire investigation, according to the formation time, it can be divided into a short-circuit melting trace and a secondary short-circuit melting trace. The secondary short-circuit melting mark refers to a melting mark generated during a fire, which is caused by the burn of a conducting wire or protective device insulation in the energized state, and the formation of a melting mark when a short-circuit occurs. Secondary short circuit