Effect of the surface roughness on interfacial breakdown between two dielectric surfaces

Cable splices and accessories are the weak link in an underground power distribution system. Investigation of problems related to cable splices and accessories becomes quite intricate once the simpler causes of failures are dismissed to allow more complex phenomena to be examined. The interfacial breakdown between two internal dielectric surfaces represents one of the major causes of failure for power cable joints. In order to better understand this phenomenon, breakdown experiments were performed at interfaces found in cable splices. An experimental jig was designed to induce breakdown between dielectric surfaces longitudinally along their interface. Effects of surface roughness at EPDM/XLPE and EPDM/EPDM interfaces as well as the presence of silicone grease are taken into account