A 25 Factorial Experiment Investigating the Effects of Operating Conditions on Cable Insulation Life

The method and interim results of a three-year laboratory investigation are reported on the effects of five in-service environmental factors. These factors include 1) presence or absence of water, 2) ambient air temperature, 4) presence or absence of daily voltage impulses, and 5) presence or absence of currend loading. A 5 kV UniShield R cable was used in the experiment. Through an analysis of variance, the operating conditions that significantly influence cable life are being assessed.