Abstract: Abstract: In order to study the ignition characteristics of overloaded BV wires to surrounding combustibles, the wires with cross-sectional area of 2.5 and 4 mm2 were selected to conduct experiments with overcurrent of 90~180 A and 90~300 A at an interval of 30 A. The temperature change of the wires was measured and the image of arcing and bead splashing were captured. The ignition capacity with the spacing between the wires and cotton cloth of 0.5, 1, 2 cm respectively was studied. The results show that the overload process of wires can be divided into three processes: heating up, arcing and cooling down. In the process of arcing, the arc is generated at the wire gap and gradually grows to both sides until being extinguished, resulting in liquefaction and gasification of wire copper core, molten bead splashing and fluid flame. High temperature arc and bead splashing have the ability to ignite surrounding combustibles.

Key words: Key words: overload wire, igniting combustibles, electric arc, bead splashing, temperature, high speed image