F-3 lead alloy — An improved cable sheathing

OPERATING EXPERIENCES have demonstrated that the attainment of good service reliability of most electric power cables has become substantially more a function of the characteristics of the sheath than of the insulation. Modern underground installations of impregnated-paper-insulated, lead-covered power cable include 1. Solid-type cable with (a). Compound-filled joints without reservoirs. (b). Oil-filled joints with reservoirs. 2. Oil-filled cable operated at 10- to 15-pound gauge pressure. 3. Gas-filled (or pressure) cable operated at (a). Low pressure (10- to 15-pound gauge). (b). Medium pressure (24- to 40-pound gauge). (c). High pressure (150- to 300-pound gauge).