Study on Prevention Method of Snow Lump Shedding from Overhead Ground Wire Focusing on its Surface Temperature

Lumps of snow shed from overhead ground wires occasionally damage plastic greenhouses, vehicles and so on. The overhead ground wires are wrapped with PTFE (Poly-tetra-fluoro-ethylene) tape to prevent the accretion of the snow lumps, however, it cannot be prevented completely. In this paper, an artificial snow accretion test was performed to study occasional conditions of the shedding of snow lumps focusing on the wire-surface temperature. When the wire-surface temperature is kept higher than about 2-3 degree Celsius, no accretion of snow lumps is found. And when the wire-surface temperature is kept higher than about 4 degree Celsius, no accretion of snow lumps is found for various outside natural snow conditions. Furthermore, a method for estimation of the wire surface temperature under various environmental conditions is proposed.