Condition Assessment of Belted PILC Cables After 7 to 68 Years of Service

This paper summarizes the results of laboratory evaluation of eight service aged paper-insulated lead-covered belted cables, produced by different manufacturers in the period between 1937 and 1998. Cable performance was evaluated from different perspectives, including partial discharge pattern, ionization factor at room temperature, dissipation factor at elevated temperatures, up to 90 °C, dielectric strength of the cable insulation, analysis of the laminated insulation structure, moisture content, etc. Overall results indicate that unless cable insulation is affected by moisture intrusion, most of the cable characteristics still meet the requirements for new cables. The only exception is dissipation factor at elevated temperature, which suggests that cable ampacity is reduced by cable aging.