Mitsubishi Denki Kabushiki Kaisha

Ichiro Yamasaki

Toshihiro Suzuki

Toshiaki Yoshizumi

Kiyoshi Hani

Tadao Minagawa

Shigeru Kubota

Takashi Yonezawa

Takeo Yoshioka

Toshimoto Moriwaki

Mamoru Hosomi

Yoshifumi Matsushita

Akira Fukami

Akiyoshi Onuma

Shohei Eto

An element for detecting internal faults in an insulating gas charged electrical apparatus comprises a substrate disposed in the electrical apparatus charged with an insulating gas, a pair of electrodes disposed on the substrate, and a thin metal film covering the pair of electrodes and the exposed surface of the substrate. This film is capable of producing fluorides with low conductivity upon reacting with a decomposed gas produced by internal faults of the electrical apparatus. Since the thin metal film exhibits high response characteristics readily in reaction with even a trace amount of a decomposed gas, it is possible to promptly detect faults occurring in the electrical apparatus, such as a partial discharge or local heating. In addition, a device for detecting internal faults in an insulating gas charge electrical apparatus using the internal fault detection element utilizes an optical signal for transmitting signals. Accordingly, the device is free from electromagnetically induced interference and is capable of remote monitoring because of the low level of loss in signal transmission.

Element and device for detecting internal faults in an insulating gas

In an interrupter, an insulated nozzle is disposed in the vicinity between a pair of contact elements and is adapted to extinguish an arc occurring between the contact elements by blowing an insulating gas thereto. This insulated nozzle is formed from a fluoroplastic and boron nitride mixed thereinto, the mixed proportion of boron nitride being within a range of weight percentages of 0.3 to 1.0.

Insulated nozzle for use in an interrupter

A flame retardant liquid rubber composition comprises a hydrogenated polyhydroxybutadiene polymer and castor oil, which are modified with an isocyanate having the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 respectively represent a lower alkyl group or hydrogen atom and n is an integer of 1 to 4, and alumina hydrate and magnesium hydroxide. The castor oil can be incorporated before adding said isocyanate or can be converted into an isocyanate prepolymer by reacting with said isocyanate before the addition.

Flame retardant liquid rubber composition

Growing community of inventors

Amagasaki, Japan

Ichiro Yamasaki