Study on the Ignition Capacity of Overloaded BVV Wires to Combustibles

Abstract

To clarify the ignition characteristics of BVV copper wires on different types of combustibles under overload conditions and provide theoretical support for electrical fire investigation and fire safety, this study took 1.5mm² BVV copper wires as the research object. Under the overload condition of 6 times the rated current (108A), the ignition capacity and phenomena of the wires on debris materials (paper scraps, wood chips), fiber materials (cotton yarn, polyester), and foam materials(polyurethane foam, polystyrene foam)were systematically studied through different contact methods including single-sided contact, full wrapping, half wrapping, and 5mm spacing. Key parameters such as temperature change, smoke emission time, ignition time, and combustion duration were collected using thermocouples, high-speed cameras and other equipment. The experimental results show that: for debris materials, the ignition risk of spaced contact is the highest, and wood chips are more easily ignited than paper scraps with stronger combustion persistence, for fiber materials, the ignition risk of full wrapping contact is the highest, and cotton yarn has a lower ignition point and more intense fire, being more easily ignited than polyester, for foam materials, double-sided contact (full wrapping) is more dangerous, and polystyrene foam burns more violently and tends to sustain combustion, posing higher risks than polyurethane foam. The differences in ignition characteristics of different types of combustibles are closely related to their ignition points, thermal conductivity, structural properties, as well as heat accumulation and oxygen supply caused by contact methods.