Hitachi, Ltd.

Kazuhiro Saito

Kazuo Kobayashi

Fumihiro Endo

Tomoaki Utsumi

Tatsuro Kato

Yukio Kurosawa

Masanori Tsukushi

Osamu Koyanagi

Isao Nishida

Kastuichi Kashimura

Minori Sato

The present invention combines sensor portionsof the device for measuring either current flowing through the line from the power inlet to the power outlet or voltage, or both, and bushingsinstalled at either the power inlet or the power outlet, or both, so as to reduce the size of the gas insulating apparatus. Specifically, the above-mentioned sensor portionsare installed in the space inside the porcelain tubethat constitutes the bushingsAs this space, it is preferable to use the space on the outer-periphery side of the electric field relaxation memberprovided inside the porcelain tube

Gas insulating apparatus and method for locating fault point thereof

The present invention combines sensor portionsof the device for measuring either current flowing through the line from the power inlet to the power outlet or voltage, or both, and bushingsinstalled at either the power inlet or the power outlet, or both, so as to reduce the size of the gas insulating apparatus. Specifically, the above-mentioned sensor portionsare installed in the space inside the porcelain tubethat constitutes the bushingsAs this space, it is preferable to use the space on the outer-periphery side of the electric field relaxation memberprovided inside the porcelain tube 15.

The present invention combines sensor portionsof the device for measuring either current flowing through the line from the power inlet to the power outlet or voltage, or both, and bushingsinstalled at either the power inlet or the power outlet, or both, so as to reduce the size of the gas insulating apparatus. Specifically, the above-mentioned sensor portionsare installed in the space inside the porcelain tubethat constitutes the bushings. As this space, it is preferable to use the space on the outer-periphery side of the electric field relaxation memberprovided inside the porcelain tube

Gas insulated device and failure rating method

In a circuit breaker in which an interrupting device, a resistor device and a capacitor device are connected in parallel, a shield device is arranged to shield the interrupting device and the resistor device and comprises a first shield for shielding the stationary main contact and stationary resistor contact and a second shield for shielding the movable main contact and movable resistor contact. Each of the first shield and the second shield comprises a large shield portion and a small shield portion, and the small shield portions are arranged between the large shield portions. The small shield portion terminates in the vicinity of the top of the main contact and of the top of the resistor contact. The small shield portion comprises wide portions situated substantially in the direction of an axis joining centers of the main contact and resistor contact and narrow portions situated substantially in the direction perpendicular to the axis. The width of the narrow portions is smaller than the width of the wide portions, and at least a part of the capacitor device is arranged over the narrow portions. In the circuit breaker, since the capacitor device is arranged over the narrow portions, the space for arranging the capacitor device is larger than the conventional circuit breaker, the arrangement of the isoelectric liens is not disturbed or disordered locally in the vicinity of the top of the shield of the stationary main contact and in the vicinity of the movable main contact and high dielectric strength between the main contacts is obtained.

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Hitachi, Japan

Kazuhiro Saito