High impedance faults result when an energized primary conductor contacts a quasiinsulating object, such as a tree, a structure or equipment, a pole crossarm, or falls to the ground. Typically, a high impedance fault exhibits arcing and flashing behavior at the point of ground surface contact. The significance of these hard to detect faults is that they represent a serious public safety hazard as well as a risk of arcing ignition of fires. As such, high impedance fault detection has been a major concern of protective relaying for a long time. Relaying engineers and researchers have been challenged for a long time to develop a suitable technique that will detect high impedance faults with a reasonable degree of reliability while being secure against false detection.