A coaxial cable includes a central conductor, a plurality of insulating twisted threads or insulation strings wound therearound, each insulating twisted thread including a plurality of insulating strings twisted together, a cover layer provided around the insulating twisted threads or the insulation strings to form a gap to the insulating twisted threads or the insulation strings, and an outer conductor and a jacket provided on the outer periphery of the cover layer.

A wire harness has: wires each including a core wire that is formed from a conductor and an insulating covering that covers the outer periphery of the core wire; and an exterior material and a braided member, into which the wires are inserted. Each wire has a removed-covering section where the insulating covering has been removed partway in the longitudinal direction. The removed-covering section is covered by a webbed covering member, the outer periphery of which has insulating properties.

Provided are a core electric wire for multi-core cable that is superior in flex resistance at low temperature, and a multi-core cable employing the same. A core electric wire for multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer that covers an outer periphery of the conductor, in which, in a transverse cross section of the conductor, a percentage of an area occupied by void regions among the element wires is from 5% to 20%. An average area of the conductor in the transverse cross section is preferably from 1.0 mm.sup.2 to 3.0 mm.sup.2. An average diameter of the element wires in the conductor is preferably from 40 m to 100 m, and the number of the element wires is preferably from 196 to 2,450. The conductor is preferably obtained by twisting stranded element wires obtained by twisting subsets of element wires. The insulating layer preferably comprises as a principal component a copolymer of ethylene and an -olefin having a carbonyl group.

Provided are a core electric wire for multi-core cable that is superior in flex resistance at low temperature, and a multi-core cable employing the same. A core electric wire for multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer that covers an outer periphery of the conductor, in which, in a transverse cross section of the conductor, a percentage of an area occupied by void regions among the element wires is from 5% to 20%. An average area of the conductor in the transverse cross section is preferably from 1.0 mm.sup.2 to 3.0 mm.sup.2. An average diameter of the element wires in the conductor is preferably from 40 m to 100 m, and the number of the element wires is preferably from 196 to 2,450. The conductor is preferably obtained by twisting stranded element wires obtained by twisting subsets of element wires. The insulating layer preferably comprises as a principal component a copolymer of ethylene and an -olefin having a carbonyl group.

A wire harness has: wires each including a core wire that is formed from a conductor and an insulating covering that covers the outer periphery of the core wire; and an exterior material and a braided member, into which the wires are inserted. Each wire has a removed-covering section where the insulating covering has been removed partway in the longitudinal direction. The removed-covering section is covered by a webbed covering member, the outer periphery of which has insulating properties.

An electric power cable and a process for the production of the cable including a metal conductor and an electric insulation system surrounding the conductor coaxially and radially outwards of the conductor having improved electric properties. The insulation system includes an inner semi-conducting layer surrounded radially outwards by an insulation layer and wherein the insulation layer is surrounded radially outwards by an outer semi-conducting layer. The electric power cable further includes an inner water blocking material arranged in the conductor and/or to surround the conductor radially outwards and an outer water blocking material arranged radially outwards from the insulation system. An inner barrier layer is arranged as a diffusion hindering layer between the inner water blocking material and the insulation system and an outer barrier layer is arranged as a diffusion hindering layer between the insulation system and the outer water blocking material.

A wire cable comprising a ground conductor and an insulated conductor wherein the insulated conductor comprises a metal conductor, an insulated material surrounding the metal conductor, and a nylon jacket surrounding the insulated material. A binder surrounds the ground conductor and the insulated conductor and a jacket surrounds the binder.

A shrinkable cable joint includes a joint insulating layer that surrounds a connection region configured to house two connected cable ends. A joint semiconductive layer surrounds the joint insulating layer. A joint screen layer surrounds the joint semiconductive layer. A joint sheath surrounds the joint screen layer. A capacitive voltage sensor is arranged between the joint screen layer and the joint semiconductive layer. The capacitive voltage sensor includes a sensor insulating layer having a first side and an opposite second side; a sensor electrode and a guard electrode arranged on the second side and directly contacting the joint semiconductive layer; and a sensor conductive layer arranged on the first side. The sensor conductive layer includes a first conductive layer portion in direct contact with the joint screen layer and electrically coupled to the guard electrode and a second conductive layer portion electrically coupled to the sensor electrode.

An insulated electric wire includes a linear conductor and an insulating film disposed to surround the periphery of the conductor. The insulating film includes a polyimide layer formed of a polyimide that has a molecular structure including a PMDA-ODA-type repeating unit A and a BPDA-ODA-type repeating unit B, the mole fraction [B100/(A+B)] (% by mole) represented by the percentage of the number of moles of the repeating unit B to the total number of moles of the repeating unit A and the repeating unit B being 25% or more by mole and 95% or less by mole. The polyimide layer has a plurality of pores. The pores occupy 5% or more by volume and 80% or less by volume of the polyimide layer.

An electric wire includes a conductor, and an insulating film that is configured to cover the conductor and that includes a porous layer having a porous therein, and a non-porous layer in which no porous is formed, wherein the non-porous layer is disposed as an outermost layer of the insulating film.