Abstract: An optic sensor comprises a transparent rod passing through a wall of a sealed enclosure of a gas-insulated electrical installation. The internally protruding end of the rod comprises frustum-shaped reflecting faces of a light ray parallel to the wall. This ray is reflected perpendicularly to an optic fiber which transmits the signal to an alarm device.

Abstract: A metallic three-phase substation has three circuit breaker per two feeders, and includes two busbars (B01, B02) to which a plurality of single-phase cells (14R, 16R, 18R, 14S, 16S, 18S, 14T, 16T, 18T) with separate phases are connected. The cells are provided with circuit breakers (20R, 22R, 24R, 20S, 22S, 24S, 20T, 22T, 24T) which are aligned longitudinally according to a direction parallel to the busbars (B01, B02) and which are housed in vertical enclosures, located at regular intervals along the busbars. The lower and upper transverse connections of the circuit breakers extend respectively in two planes parallel to the bushbars (B01, B02).

Abstract: A metal-clad electric installation for high tension use includes a metallic housing containing a conductor supported by an insulator and surrounded by an insulating gas. The metallic housing has adjacent sections which are joined by pairs of connected flanges. The insulator has an external border which is interposed between the flanges of two successive sections of the housing and is secured thereto by bolts passing through aligned openings in the flanges and external border, thereby partitioning the housing into tight compartments. In order to dismantle a section without affecting the sealed condition of the adjacent section, the bolts are replaced by screws which are screwed into small nut plates inserted into slots provided in the interface of the external border and the flanges.