Ngk Insulators, Inc.

The Tokyo Electric Power Company, Incorporated

Takashi Irie

Yoshio Hasegawa

Kenji Sato

Takashi Ohashi

Keiji Wakamatsu

Masahiro Akizuki

Tsuruo Yorozuya

Shigeru Ogawa

Sadao Mori

A suspension insulator having a shed including an upper surface and an under surface has a pin fitting arranged at its center portion and projected from the under surface and a plurality of circular ribs arranged around the pin fitting in a concentric manner. In a first aspect of the invention, a resistance zone having a surface resistance (1 cm&times;1 cm) of not greater than 4 M&OHgr; and arranged on the under surface at an inner portion continuing from the pin fitting and a conductive zone arranged on the under surface at an outer peripheral portion of the resistance zone. In a second aspect of the invention, a resistance zone arranged on the under surface at an inner portion continuing from the pin fitting and existing between the pin fitting and an inner root portion of the rib.

Suspension insulator

An arresting insulator is provided which includes an insulator body made of an insulative material and a non-linear resistor. The insulator body includes a head for linking the insulator to an adjacent insulator, and a shed formed integrally with the head. The resistor is secured in the insulator body and has a non-linear relation between residual voltage and current. More specifically, the resistor has a characteristic that satisfies the equation:

Suspension-type line arrester

A current limiting horn device for a transmission line supported by sets of insulators suspended from arms of steel towers. The device includes horns located respectively at charging and earthing portions of each set of the insulators and spaced horizontally apart a predetermined distance from a vertical axis of the set of the insulators. At least one of the horns is provided with an arrester element of a resistance having a non-linearity. According to the invention, a ratio Z/Zo of a distance Z between the horns to a total length Zo of the one set of insulators is not more than 0.5, thereby when extraordinary voltage caused by lightening surge is applied to the transmission line, securely causing flash-over between horns to prevent any earthing accident which would otherwise occur in the transmission line.

Current limiting horn device for transmission line

Growing community of inventors

Kani, Japan

Takashi Irie