Development of 22-kV XLPE cable and joint with reduced insulation thickness having water-impervious aluminum layer

Electric power supply using 22-kV systems is expanding aiming at reduction of electric power distribution costs through upgrading the efficiency of facilities. It was thus required to develop a cable with joint that enabled maintaining the reliability as well as suppressing the cost of electric power supply. In response to this requirement, the authors have developed a new cable having a water-impervious layer of aluminum laminated tape together with its joint, whereby the thickness of the insulating layer was reduced to 4.5 mm - including the inner semiconductive layer - by devising a novel method of terminating the end of the outer semiconductive layer. Moreover, a cold shrinkable straight joint has been developed thus improving the working efficiency at the site. This paper reports on the structure, performance, and working efficiency of this cable and the joint.