Accelerated aging of XLPE and EPR cable insulations in wet conditions and its influence on electrical characteristics

This paper presents the results of an investigation into changing of crosslinked polyethylene (XLPE) ethylene-propylene rubber (EPR) cable insulations on electrical characteristics due to water absorption. The experimental set up was made for the following XLPE and EPR cable insulations: steam and dry cured with water tree retardant crosslinked polyethylene (TR-XLPE) and steam cured EPR. During tests, the tap water was injected (1) into the cable conductor with cable ends closed, (2) into the cable conductor with cable ends opened and into the metallic screen with the cable ends closed. The presence of water in TR XLPE and EPR cables was subjected to electrical stress and heating. The tests of electrical characteristics of TR XLPE and EPR cable insulations were performed as a function of aging time at different aging temperatures.