Abstract: In a method for manufacturing a stranded conductor for an electrical power cable comprising a process for forming cupric oxide films of from 0.3 .mu.m to 3 .mu.m in thickness by passing an uninsulated stranded conductor constituted by a plurality of stranded copper strands through oxidizing liquid, the stranded conductor passing through the liquid is curved in a wave to form gaps between the strands, and the oxidizing liquid is caused to penetrate between the strands through the gaps to form cupric oxide films of from 0.3 .mu.m to 3 .mu.m in thickness on the surfaces of the strands. Also disclosed is a stranded conductor for an electrical power cable constituted by a plurality of stranded copper strands, at least one of the copper strands being covered with a cupric oxide film free from exfoliation.

Abstract: In a method for manufacturing a stranded conductor for an electrical power cable comprising a process for forming cupric oxide films of from 0.3 .mu.m to 3 .mu.m in thickness by passing an uninsulated stranded conductor constituted by a plurality of stranded copper strands through oxidizing liquid, the stranded conductor passing through the liquid is curved in a wave to form gaps between the strands, and the oxidizing liquid is caused to penetrate between the strands through the gaps to form cupric oxide films of from 0.3 .mu.m to 3 .mu.m in thickness on the surfaces of the strands. Also disclosed is a stranded conductor for an electrical power cable constituted by a plurality of stranded copper strands, at least one of the copper strands being covered with a cupric oxide film free from exfoliation.

Abstract: This invention provides an insulating paper sheet produced by mixing synthetic resin flakes with natural fibers to provide a composite paper mass. This insulating paper sheet is favorably accepted as an insulating member for covering the conductor of a power cable.

Abstract: A power cable joint structure in which a sheath isolation is provided in a cable shielding layer in, for instance, each phase of a three-phase circuit. A reinforcing insulation is covered on the connected cable conductors and a shielding layer is covered on the outer periphery of the above-mentioned joint itself. The shielding layer has a pair of mutually opposite layers with a gap therebetween which provides a sheath isolation. A thick sheet-like insulator 12 with a plurality of spherical electrodes distributed therein is contained in the sheath isolation.

Abstract: In the joint structure for a power cable, a cable insulator covers a cable conductor. A reinforcement insulator is mounted on the said cable insulator. In the said reinforcement insulator there are disposed by dispersion a plurality of electrode spheres. The voltage applied in between the said cable conductor and a cable shielding layer covering the said cable insulator is borne by the electrostatic capacities occurring among the said electrode spheres.

Abstract: In a method for manufacturing a stranded conductor for an electric power cable comprising a process for forming insulating films by passing an uninsulated stranded conductor constituted by a plurality of stranded conductive strands through oxidizing liquid, the stranded conductor passing through the liquid is curved at an angle of 3.degree. to 10.degree. in a predetermined path to form gaps between the strands, and the oxidizing liquid is caused to penetrate between the strands through the gaps to form oxide films on the surfaces of the strands.