Abstract: A plurality of current detectors are provided in a plurality of prescribed spots of a transmission line for locating a fault caused, e.g. by lightning. A plurality of discriminators are provided in correspondence to the plurality of current detectors. Each discriminator receives detected signals from an arbitrary pair of the plurality of current detectors for detecting a relative difference between arrival times of the detected signals while extracting low-frequency components from the detected signals respectively and for detecting a phase difference between the extracted low-frequency components. A locator receives relative time difference data and phase difference data from the plurality of discriminators, to locate a faulty point in the transmission line on the basis of the received data.

Abstract: A plurality of current detectors are provided in a plurality of prescribed spots of a transmission line for locating a fault caused, e.g. by lightning. A plurality of discriminators are provided in correspondence to the plurality of current detectors. Each discriminator receives detected signals from an arbitrary pair of the plurality of current detectors for detecting a relative difference between arrival times of the detected signals while extracting low-frequency components from the detected signals respectively and for detecting a phase difference between the extracted low-frequency components. A locator receives relative time difference data and phase difference data from the plurality of discriminators, to locate a faulty point in the transmission line on the basis of the received data.

Abstract: A disk, or circular-cone-shaped insulating spacer for gas insulated equipment wherein a portion of the insulating spacer, which is secured to a metal sheath, is greater in thickness than the other portion of the spacer. The insulating spacer is brought into contact with the metal sheath through portions of the metal sheath which are outward of arcuate portions of flanges formed on said metal sheath. The distance between opposed flange surfaces which are formed in said metal sheath may be larger in the outside portion of the metal sheath than that in the inside portion of the metal sheath. The insulating spacer is brought into contact with the metal sheath through the outside portion of the metal sheath.