Abstract: This paper studies the characteristics of the melt marks generated by the carbonization path-type short-circuit and the metal short-circuit type under the condition of heat radiation. Considering the electrical appliance power line, RVVB line (copper core PVC sheathed flat shape power line), for the domestic household 220 VAC, compare the time and position of two different types of short circuit, analyze the influence of the melt mark on it. It was found that as the heat radiation intensity increases, the time of short circuit occurs is shortened; The short-circuit position of the wire does not show obvious distribution law; The short-circuited part has strong randomness, and the position of the short-circuit point has no direct correlation with the short-circuit occurrence time; The carbonization path type short-circuit is usually short-circuited by the arrow-shaped melt mark. A typical trace of a short-circuit type is a "工" type melt mark.

Key words: electrical fire; carbonization path type short circuit, metal short circuit type, short circuit mark, fire investigation