Electrical treeing endurance behavior of XLPEcable insulation was investigated by
application of AC voltages on specimens witha pin-plane electrode system. The needle
inserted has a tip radius of 10 μm, and the pin-plane distance is 2 mm. The relation
between applied voltage and tree initiation time, when plotted in a log-log coordinate,
could be approximated by three straight lines, and an electrical threshold stress of about
100 kV/mm was deduced from it in the low field region.