Application of Oil-Cooling in High-Pressure Oil-Filled Pipe-Cable Circuits

Circulation of oil in pipe-type feeders has been employed, to a limited extent, to accomplish either of the following two objectives: 1) temperature-averaging to minimize the effect of unknown hot-spot zones, or 2) an increase in circuit capacity above the self-cooled level. This paper reports, in two sections, on both types of application, which were initiated in 1952 and carried out subsequently on an increasing scale. Particular attention is givein to a large program of 138-and 345-kV pipe-type feeder installations.