Forced-Cooling Tests on a 138 kV Pipe Cable Circuit

This paper constitutes an analysis and summary of some of the test data obtained to date in conjunction with the forced-cooling of a full scale, 1.5 mile long, 138 kV, pipe-type cable line. Two methods of forced-cooling are discussed: (1) the return pipe method and (2) mechanical refrigeration. The paper is largely concerned with the return pipe method since the mechanical refrigeration tests are still under way. Design equations for estimating pressure drop and oil temperatures are presented.