Hitachi, Ltd.

Naoki Nakatsugawa

Kenji Tsuchiya

Takumi Ishikawa

Takuya Kurogi

Masato Kobayashi

Ayumu Morita

Toru Tanimizu

Yoshimi Hakamata

Shuichi Kikukawa

Yozo Shibata

Minoru Suzuki

Katsunori Kojima

Yoshitomo Gotoh

Takuya Okada

Makoto Terai

Kenichi Shoda

Nobuyuki Yamada

A switchgear case is partitioned into a high voltage bus bar chamber, which contains bus bars and cable heads, a high voltage device chamber containing circuit breakers and operation mechanisms and a low voltage control chamber containing a relay and measurement devices, etc. A rear wall of the case has a first suction port disposed at a lower part thereof, wherein the high voltage bus bar chamber, high voltage device chamber and the low voltage control chamber are communicated and air passing through the chambers is discharged from a first discharging port of the casing. The bus bars electrically connecting the high voltage devices in the high voltage device chamber and connecting bars connecting the adjoining bus bars and the cable heads are covered with solid insulators for solid-insulation.

Switchgear

A solid insulated bus switchgear including a cabinet having unit and bus rooms, first and second switching units, each having a circuit breaker, current transformer, zero-phase sequence current transformer, and instrument voltage transformer, main buses, a communication bus linked to the main buses, and connected to the first and the second switching units, and first and second leader buses, the first connected to the first switching unit, the second connected to the second switching unit. Each switching unit has a movable cart, the circuit breaker mounted on the cart, and a frame assembly. Two terminals are disposed on the back of the circuit breaker, one connected to a fixed electrode and the other connected to a movable electrode of the circuit breaker. The two terminals are connected to the communication bus and to the first or second leader bus through air bushings.

Solid insulated bus switchgear

Earthing equipment for a switchgear is comprised of a movable carrying cart, a switch portion, a manipulating portion, and a voltage detecting device. The earthing equipment is provided with: an upper conductor connected to any one of the movable electrode and the stationary electrode; a lower conductor connected to the other of the movable electrode and the stationary electrode, an earthing wire connecting the lower conductor to a terminal used for earthing of the switchgear; and an adaptor conductor being selectively connected to either a disconnection portion at a bus bar side or a disconnection portion at a cable side of the switchgear and is permitted to be selectively replaced on either upper or lower face of the upper conductor.

Earthing equipment for switchgear

There is disclosed a vacuum insulation switch provided with a movable electrode, a stationary electrode and an earthing electrode, which are insulated from each other, in a vacuum container made of a conductive material which is earthed, and a switchgear using the same. Since the vacuum insulation, which is excellent in the insulation ability, is utilized, the switch is drastically miniaturized and the number of constituent parts are reduced, whereby the manufacturing cost of the switch and the switchgear can be decreased.

Vacuum switch and a vacuum switchgear using the same

A vacuum insulation switch provided with a movable electrode, a stationary electrode and an earthing electrode, which are insulated from each other, in a vacuum container made of a conductive material which is earthed, and a switchgear using the same.

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Hitachinaka, Japan

Naoki Nakatsugawa