Hitachi Cable, Inc.

Chuki Ikeda

Takanori Yamazaki

Kenji Takahashi

Hideki Yagyu

Kiyoshi Watanabe

Kazuo Kotani

Kenichiro Soma

Katsutoshi Hanawa

Takeshi Endoh

Mikio Hagiya

Tomoaki Imai

Nobuju Takaoka

Moritada Marumo

Mamoru Kanaoka

Norio Sato

Naoyoshi Kato

Hiroo Nagano

A bow-tie tree resistant electrical insulating composition comprises 100 parts by weight of at least one polymer selected from polyolefins and ethylene copolymers, 0.005-1.0 part by weight of a metal salt of a fatty acid containing a hydroxyl group in the molecule, and 0.005-1.0 part by weight of a fatty acid or a derivative thereof.

Wire on cable coated with a bow-tie tree resistant electrical insulating

In an electric apparatus such as an electric power cable system, a high frequency pulse is induced on a conductive member such as a metal sheath, where partial discharge occurs in an insulation. The high frequency pulse is detected by means of a bypass lead wire, a metal foil electrode, a detecting coil, and the like provided on the electric apparatus without interrupting a live operation of the electric apparatus.

Method for detecting partial discharge in an insulation of an electric

A power cable such as a rubber or plastic insulated power cable is diagnosed to be detected an insulation deterioration resulted from water tree generated in an insulation material thereof. At first, charging current flowing from the power cable through a grounding conductor connected to a metal shielding layer thereof to the ground is measured under a state that a rated AC voltage is applied to the power cable. In accordance with the charging current, stray current flowing from the ground to the power cable is calculated. Then, a direct current component of the charging current is detected, and an intrinsic direct current component is calculated by subtracting the stray current from the direct current component. The insulation deterioration is diagnosed in accordance with the level of the intrinsic direct current component.

Method for diagnosing an insulation deterioration of a power cable

A device for cross-linking of coating material such as rubber or plastic having a vertical or inclined cross-linking tube including a heating portion and a succeeding cooling portion, said heating portion comprising at the side thereof a gas circulating passage having a gas supply device, a gas heating device, a gas cooling device and a filter, said gas circulating passage communicating with an exhaust port above the heating portion and with a gas supply port below the heating portion so that the gas circulate in a direction opposed to the traveling direction of a conducting strand passing therethrough, whereby said conductive strand is heated and cross-linked while residue emitted from the coating material of said conductive strand is effectively removed.

Device for cross-linking of coating material such as rubber or plastic,

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Ibaraki, Japan

Chuki Ikeda