High-Pressure Gas-Filled Cable Impregnated witn Extra-High-Viscosity Oil

1. The 7-mile circuit of 120-kv high-pressure gas-filled cable installed in 1941 has fulfilled, during seven years of operation, the favorable expectations indicated in an AIEE paper presented in 1942.¹ 2. Several engineering features of high-pressure gas-filled cable, concerning which there has been no previous publication, have been investigated and are described. The results obtained are favorable. 3. It is believed that the characteristics of the high-viscosity saturant used are very significant with respect to the performance which this cable has given and which may be expected from it. Reasons for this are given, and added details of the oil characteristics are shown. 4. Further tests on an experimental field installation are reported. These show favorable results concerning cable operation at high temperature for both the preimpregnated and mass-impregnated types. 5. A new installation of twice the power-carrying capacity and twice the length of the 1941 installation is nearing completion. Half of the cable is made with preimpregnated tapes, and, except for conductor size and for shipment without lead sheath, is substantially the same as that of the 1941 installation. The construction of the other half of the cable involves mass impregnation of the paper with the high-viscosity oil, in a manner generally similar to the impregnation of solid-type cable. 6. The ability of the mass-impregnated cable to meet special loading and other operating conditions has been ascertained by the rigorous tests reported in this paper.