US Patent 9746512 Arc fault location detection for aircraft wiring

A system for detecting the location of arc faults in an aircraft electrical wiring arrangement is provided. The system comprises a controller, operable to generate a test signal and a directional coupler for coupling the test signal into electrical wiring and for coupling reflected test signals from the electrical wiring to the controller. The electrical wiring comprises one or more wire under test and the controller is further operable to detect test signals reflected from arc faults in the wire under test and to analyze reflected test signals in order to determine one or more arc fault position therefrom. The wire under test may be live and testing can be performed without the need to use invasive in-line components.