Power cable failure modes and fault location methods, practices and strategies

During the last 140 years, insulated cables have been applied for power transmission and distribution, as well as signaling and other purposes. While the basic functions of power cables remain unchanged — providing a conductor to carry current and a dielectric insulation to support the line-to-ground voltage — the materials and characteristics used in power cables have evolved. Cables experience faults, and some methods to find those faults have changed as technologies have developed. Classical bridge techniques are still used, often with improved null detectors, but modern methods such as time domain reflectometry and faulted circuit indicators provide novel methods for better accuracy and faster location. This paper summarizes recent work in both areas and provides background on cable failure modes and typical fault location methods.