Hiroaki Kurihara, Shozo Kobayashi, Masami Kitaya, Yoshihiro Arashitani, Hiroshi Oda, Toru Serizawa, Toyoaki Tashiro
In the overseas market of power cable accessories for 110-kV rating or over, prefabricated joints (PJs) of on-site assembly type are very often designated in the purchasing specifications due to their simple installation and high reliability. In particular, one-piece rubber block joints (RBJs) featuring simple structure and easy installation are growing in popularity thereby replacing epoxy-unit type PJs comprised of epoxy unit and rubber stress cone. In the domestic market for 66-kV rating also, the RBJ is known for its high quality, low cost, and short installation time so that it is going to supplant tape-wrapping joints (TJs) now dominating the market.
In view of these market needs, the authors have successfully developed a cold shrinkable joint (CSJ) as a class of RBJ, in which one-piece molded rubber block is expanded at the factory in advance followed by installation on the cable at the construction site. This is the world's first achievement of factory expansion, cold shrinkable joints with ultra-high voltage rating.
This paper reports on the first application of this factory expansion, cold shrinkable joint to practical transmission lines.