Increased Risk of Electric Service Interruption Associated with Tree Branches Overhanging Conductors

It has long been recognized that branches overhanging conductors represent an interruption risk that is realised during storms with wind and particularly ice loading resulting in branches bridging conductors and causing phase to phase faults. In the event of a whole tree failure, adjacent trees with overhanging branches have a higher probability of interrupting service than similarly proximate trees without overhangs.

This paper develops the mathematics necessary to calculate this difference...