Effect of ultra violet irradiation on low voltage cable insulation

To connect the low voltage (1.1 kV rating) underground XLPE and PVC insulated power cables with the overhead distribution network, short lengths of the core insulation are used with their ends often exposed to the atmosphere. Such exposed insulation is reported to develop cracks and become brittle within a few months of installation. Experimental investigation with accelerated UV irradiation in the laboratory revealed significant aging effect on the mechanical properties of XLPE core insulation material. The aging process was found to be faster when the insulation material was under mechanical stress.