The effect of high oil rressure upon the electrical strength of cable insulation

IMPROVEMENT in cables, which combine liquid and solid dielectrics, has come largely through the study and control of gaseous electrical phenomena. This is because through circumstances of use in the field, gases enter the cable structure and the resulting electrical discharges in these gas layers cause deterioration ultimately leading to failure. The steps in improvement have successively led first to the abandonment of the heavy solids or petrolatums as treating materials and then to the oil filled cable, where the possibility of entrapped and dissolved gases is reduced to the minimum possible.