Arc Tracking Properties of the Aging Wires in Aircraft

A modern commercial aircraft contains hundreds of miles of wiring. This vastly increased use of wiring, in conjunction with decreased insulation thickness, has increased the incidence of wire-related aircraft safety problems. Due to thermal, electrical, mechanical and chemical overstress, the aircraft wiring will be aged and the wire insulation will be decreased. Microscopic cracking occurs in wire insulation as the insulation ages. The Cracking in the wire insulation can lead to arc burning between metal conductors in aircraft wiring system. Aging wiring and associated deterioration of the insulation increases the potential for arc fault phenomenon to occur in aircraft. In order to investigate fault arc behaviour of the aging wire, the arc tracking tests have been performed with typical aircraft wire BMS 13-60. The video of the arc burning and the waveform of the fault arc have been recorded. The primary test results indicate that wire aging has an important influence on the fault arc behaviour.