Abstract: A medium voltage circuit breaker, including first and second arcing contacts, the first arcing contact being longitudinally slidable with respect to the second arcing contact between open and closed positions, first and second main contact, the first main contact being movable with respect to the second main contact between open and closed positions, a sealed enclosure filled with a high dielectric strength gas and housing the first and second arcing and main contacts, and operating mechanism for closing the first and second arcing contacts before the first and second main contacts close and for opening the first and second arcing contacts after the first and second main contacts open. The operating mechanism is mechanically coupled to the first arcing and the first main contacts and comprises a compressible linkage coupled to the first arcing contact.

Abstract: The installation is designed for automatic surveillance of the radiation dose absorbed by an individual carrying a dosimeter during his stay in a specific zone. Each access point to this zone comprises a reader able to transmit a radioelectric wave carrying a proximity signal and possibly other data to the dosimeter. This signal is received by the dosimeter, and the latter retransmits a wave carrying measuring and identification data, and so on, to the reader.

Abstract: A test connector for connection to two test inputs of a trip device. The test connector includes a fixed component made of electrically insulating material, wherein the fixed component includes a sleeve defining an inner space. A movable component is provided within the inner space and is axially movable therein. The movable component includes a protruding portion which extends from the fixed component. A spring is provided between the movable component and the fixed component to provide a biasing force to urge the movable component in an outward axial direction. Two testing needles are housed within two longitudinal passages within the movable component. Upon insertion of the test connector into a recessed portion of a face of an electronic trip device, the movable component is urged rearwardly to expose the two testing needles which pass through orifices int he recessed portion to contact the two test inputs of the trip device.

Abstract: A first control loop enables the inverter to be made to operate as a current generator when it recharges the batteries of a back-up power supply. Two other control loops enable the inverter to compensate on the one hand the harmonics, and on for other hand for the reactive part of the current absorbed by the load, when the inverter is on stand-by.

Abstract: The front panel of the trip device is formed by a flat screen display, for example liquid crystal, controlled by the trip device microprocessor. The display provides a permanent display of the information relating to the type of trip device, the tripping parameters and measured values, from data entered in the trip device memory. Display is in alphanumeric and/or graphic form.

Abstract: To improve the electrical withstand of a low voltage circuit breaker for high currents having multiple contacts of the same length and a stationary arc guiding horn having an intermediate edge extending over a short distance in the direction of movement of the front extensions of the contact fingers, a stationary arcing contact is arranged between the edge of the arc guiding horn and the stationary main contact. The stationary main contact is designed to cooperate with a movable arcing contact of at least one contact finger. At the beginning of the opening travel, closing of the arcing contacts takes place before the main contacts separate. The stationary arcing contact is located in the immediate vicinity of the edge.

Abstract: A runner (20) for mechanical assembly between two miniature molded cases (10,11) performs at the same time the electrical connection of the control circuits of the two cases (10,11). For this purpose, contact pads (27) are arranged in the bottom of the slide (19) in which the runner (20) slides, the runner (20) bearing a contact bridge cooperating with contact pods (27).

Abstract: The short time delay circuit comprises a counter which is zero reset when the signal representative of the current is greater than or equal to a threshold, and controls count-down of an up-down counter, when the content of the counter reaches a preset value. A clock circuit controls the count-up and count-down frequency of the counter and up-down counter.

Abstract: An electronic device including a card having first and second faces opposite each other, electrical devices including at least one of a printed circuit and a plurality of components fixed to the first face of the card, a metal plate spaced apart from the card such that a gap is formed therebetween, a pulp filled within the gap which is more thermally conductive than air, and a plastic insulating film disposed between the pulp and the card. The card, electrical components, the plastic insulating film and the metal plate form an integrated assembly.

Abstract: A protective case with an electronic device, including an assembly which includes a support cradle fixed to and supporting the electronic device, a sealed metal housing enclosing the assembly, the support cradle being fixed to the sealed metal housing via mechanical dampers to isolate the assembly from external disturbances including shocks, wherein a gap is formed between the assembly and the sealed metal housing, and a fan fixed to the cradle for generation of air flow in the gap to promote convection heat transfer from the electronic device to the sealed metal housing.

Abstract: The framework of a switchgear cabinet is formed by identical frame sections in the shape of corner-pieces whose edges are folded at right angles to form folded ends. The edges of the corner-pieces are moreover joined together by a diagonal sealing partition which provides the sealing between the two panels of the cabinet forming the angular junction. The panels with folded edges are fixed to the frame sections by parts.

Abstract: To perform the long delay function of an electronic trip device, a quantity (TLR1) representative of the thermal current state varies proportionally to the difference (I.sup.2 -Is.sup.2) between the square of a value (I) representative of the current flowing in a conductor to be protected and the square of a current threshold (Is). This first quantity (TLR1) is used in combination with a second value (TLR2) to produce a tripping signal when the second value exceeds a preset value (TLR2max). The second quantity preferably increases proportionally to the square (I.sup.2) of the value representative of the current, when the first quantity exceeds a preset threshold (STLR1) and decreases, preferably exponentially, when the first quantity is lower than this threshold.

Abstract: A neutron detection device is housed in a metal enclosure containing a first detector with a high-sensitivity fission chamber, and a second detector having a low-sensitivity fission chamber and a boron-lined ionization chamber compensated for gamma radiation. The detection device is useful for extended range measurement of the neutron fluence rate outside the core of a nuclear reactor.

Abstract: A high-voltage circuit breaker includes a first compartment with SF6 under pressure having stationary and movable contacts therein, and a second sealed compartment housing having an operating mechanism with a pneumatic jack actuated by the gas contained in the first compartment via closing and opening valves. The second sealed enclosure is at low pressure playing the role of expansion volume of the gas expelled from the jack at the end of travel of the piston. The gas pressure in the jack is controlled by means of a control device sensitive to the temperature variation of the gas under pressure in the first compartment.

Abstract: A disconnecting switch for a high voltage electrical substation, including a plurality of articulated arms pivotally connected together to define a movable system, one end of the movable system connected to a stationary support. The switch includes a contact head connected to an opposite end of the movable system, a main conducting bar suspended from a high voltage conductor, such that the contact head is movable between the main conducting bar and the stationary support via the movable system, and a stationary arcing contact electrically connected to the main conducting bar.

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 three-phase circuit breaker with self-extinguishing expansion and rotating arc structures comprises an arc extinguishing chamber per pole and housing a pair of contacts, one stationary and one moveable, a coil to rotate the arc, and an exhaust channel in at least one contact to provide an opening a communication and gas outflow between the extinguishing chamber and the expansion volume of an enclosure filled with SF6. The extinguishing chamber has a square or rectangular cross-section to resorb the gas plug after braking of the gas rotation movement, and improve stirring of the gas in the extinguishing chamber.

Abstract: The differential tripping threshold of the trip device is a polynomial function of an order greater than or equal to two of the highest phase current flowing in the power system protected by the circuit breaker comprising the trip device.

Abstract: A connection process by welding a braided strip to a contact finger defined by side by side stacking of two elementary blades. The first blade is provided with a semi-open notch cooperating with the juxtaposed flat face of the second blade to define a housing receiving a compacted end of the braided strip, said end being hot encrusted in the housing by welding under pressure, without local deformation of the blades. The second blade comprises an overspill aperture located facing the notch to enable the molten copper from the compacted end to be transferred during the welding operation, the surface of the aperture being smaller than that of the notch. Assembly is performed in a single operation without addition of solder.

Abstract: A cabinet for housing modular electrical switchgear is formed essentially by a case on which a cover is tightly fitted, and by a window disposed on the cover to seal an opening arranged on the cover. The window bears on the edge opposite its rotation axis, a lug having a recess receiving a clip-in locking button. The locking button has clip-in fingers which exert a return force on the button in the locked position. The button comprises holes coming in the locked position opposite conjugate holes of the cover for a sealing wire to be fitted. The fixing screws of the cover to the case have holes for the passage of a sealing wire which emerges in an outwardly curved passage, for ease of insertion of the sealing wire.