Development of extruded dielectric underground transmission cables rated 138 kV, 230 kV and 345 kV, volume 2

Technology to manufacture chemically crosslinked polyethylene insulated power cables in the ac voltage range of 138 kV to 345 kV having insulation thicknesses approximately equal to that of oil impregnated paper insulated cables is developed. The development of field molded splices and terminations for high voltage stress 138 kV cables are also incorporated. After reviewing the main equipment elements, incorporated in the pilot extrusion line, the special features of this system are noted and a step by step description of the cable extrusion process is given. Optimization of the process and introduction of modifications in the equipment culminated with the production of 138 kV cables. Results of laboratory tests to demonstrate the high quality of the cables are given. The development of molded splices and molded stress control cones was initiated with the work on model cables and followed by the making of splices and terminations on 138 kV cables.