Abstract: A vacuum circuit-breaker including, for each phase, at least one vacuum bottle housed inside a closed enclosure, wherein said circuit-breaker includes at least one scintillation fiber disposed in the space between said enclosure and the outside surface of the vacuum bottle(s), said fiber being connected outside the circuit-breaker to an opto-electronic device.

Abstract: A high-voltage circuit-breaker has an interrupting chamber comprising a gas-tight cylindrical casing filled with a gas having good insulative properties such as sulfur hexafluoride. The casing contains a fixed permanent contact, a fixed arc contact and a mobile assembly comprising permanent contacts and arc contacts and associated with a gas blast assembly. The chamber also contains a carbon-based resistor having a resistance of approximately 500 ohms connected in parallel with the circuit-breaker contacts when the arc contacts are opened by an auxiliary switch. This resistor is connected in series with an arrangement of varistors, the resulting combination being disposed inside the casing and connected in series with the auxiliary switch. Opening of the auxiliary switch is effected by opening of the circuit-breaker. The volume of the resistor is greater than that of the arrangement of varistors by a factor of at least five.

Abstract: A high tension circuit breaker includes a gastight cylindrical insulating case filled with SF.sub.6 gas or the like and defining for each phase at least one current interrupting chamber. A fixed main contact and a fixed arcing contact are fixedly mounted within the chamber. Moving equipment of the circuit breaker includes moving main and arcing contacts and a member for moving the moving main and arcing contacts towards and away from the fixed main contact and the fixed arcing contact. A cylinder is fixedly mounted in said chamber and supports internally a movable blast piston and terminates in a blast nozzle facing the fixed contacts. A capacitor is disposed inside the circuit interrupting chamber optionally with a parallel connected varistor. A mechanism in the form of a switch including a fixed and a movable contact operates to insert the capacitor and the parallel connected varistor temporarily during both closing and opening of the circuit breaker contacts.

Abstract: A device for temporarily inserting an electrical component such as a varistor connected to a contact arm carrying a metal contact ring in parallel with the contact of a circuit-breaker comprises a small diameter metal tube mechanically joined and electrically connected to the exterior of the main mobile contact. A rod can slide inside the small diameter metal tube. The rod has at a first end, a metal contact sleeve which can come into electrical contact with the metal contact ring. The sleeve abuts a first end of the small diameter metal tube. The second end of the rod carries a conical abutment. The second end of the tube has a bore which terminates in a conical interior shape profile complementary to and sized to that of the abutment.

Abstract: A surge limiting circuit breaker has, for each phase, at least one interrupting chamber constituted by a gastight insulating enclosure filled with a gas having high dielectric strength. The enclosure contains fixed and moving main contacts and fixed and moving arcing contacts. Moving equipment effects movement of the moving contacts relative to the fixed contacts. The enclosure includes a varistor. The varistor is inserted in parallel with the circuit breaker contacts on separation of the main contacts when the circuit breaker is being opened, disconnecting the varistor before the end of the stroke of the moving arcing contact. The varistor is inserted in parallel with the circuit breaker contacts while closing the circuit breaker and prior to bringing the arcing contacts into contact with each other. The varistor is short-circuited when the arcing contacts come into contact.

Abstract: The invention relates to superconductor current-limiting apparatus of the type having a magnetic core around which firstly a superconductor component is disposed, followed by an electric coil made of non-superconducting material, the apparatus being designed to be inserted in a line to be protected (L), the assembly constituted by the magnetic core (6A, 6B), the superconductor component (3A, 3B) and the electric coil (2A, 2B) forming a current-limiting unit which is connected in the line to be protected in series with a circuit-breaker.

Abstract: A varistor and resistor device for incorporating in the interrupting chamber of a dielectric gas circuit breaker, the varistor and resistor components being connected in series and being housed in an insulating tube. The varistor components and the resistor components are firstly superposed with superposed components being separated from one another by insulating components, and are secondly juxtaposed with juxtaposed components being electrically interconnected by conductor components interposed between the ends of the superposed components and the insulating components.

Abstract: A high tension circuit-breaker has an insulating case filled with a dielectric gas such as SF.sub.6. A high capacitance capacitor and at least a varistor are electrically interconnected in parallel and are connected to a first terminal. The capacitor and varistor are associated with an insertion mechanism which momentarily inserts the capacitor and varistor in parallel with the arcing contacts during circuit-breaker disengagement or engagement. The insulating case is extended by at least one conductive case housing both the capacitor and at least part of the varistor.

Abstract: A circuit-breaker including at least one insulating interrupting chamber inside which there are contacts and a blast nozzle. The insulating interrupting chamber is placed on an insulating support containing a drive rod. The circuit-breaker further includes a first terminal and a second terminal. The circuit-breaker has at lest one fluorescent or scintillating optical fiber disposed inside the support and constituting a symmetrical loop around the drive rod. Each end of the fiber is connected to a photodiode equipped with an amplifier. Light propagated in the interrupting chamber, as a result of arcing, reaches the optical fiber loop via a light passage within a terminal of the interrupting chamber remote from the arcing zone within the interrupting chamber.

Abstract: A circuit breaker comprising, for each pole, at least one interrupting chamber having fixed contacts and moving equipment including a moving contacts, and in parallel with each interrupting chamber series circuit comprising a varistor and a switch, said switch being open when the circuit breaker is disengaged and being closed when the circuit breaker is engaged. The switch comprises a moving contact driven by the moving equipment when the circuit breaker is performing an engagement operation, with the moving contact being constrained to follow the movement of the moving equipment when the circuit breaker performs a disengagement operation, but with a certain delay.

Abstract: A superconductor protected against partial transition includes superconductor strands around at least one non-superconductor central strand or at least one non-superconductor central core electrically insulated from the superconductor strands. At least at both ends of the superconductor, the central strand or said central core is electrically connected to the superconductor strand. The central strand or the central core comprises at least one non-superconductor metal filament whose resistivity at 4.2.degree. K. is less than 10.sup.-9 .OMEGA..m embedded in a metal alloy matrix whose resistivity at that temperature is greater than 10.sup.-8 .OMEGA..m.

Abstract: An SF.sub.6 circuit breaker having a varistor incorporated in line with its interrupting chamber in which insertion of the varistor on opening and closing is performed by coaxial translation of two electrodes outside and around the main contacts.

Abstract: A hybrid current limiter comprising a first winding of non-superconducting conductive material having a large number of turns and electrically connected in series with a superconductoring coil of low self-inductance and placed in a cryostat, and a second winding of non-superconducting conductive material having a small number of turns, said second winding being closely coupled with said first winding in such a manner as to obtain low overall inductance, the second winding being connected in parallel with the series circuit constituted by the first winding and the superconducting coil.

Abstract: A high tension circuit breaker comprising at least one circuit-breaking chamber and, in parallel with the circuit-breaking chamber, firstly a varistor in series with an interrupter, and secondly a tension-distributing capacitor. The circuit breaker has a linear resistor having a resistance lying in the range range 30 ohms to 300 ohms inserted in series with the varistor. The invention is particularly suitable for reactance circuit breakers.

Abstract: The invention relates to a circuit breaker for limiting a direct current and comprising a combination of first means including superconducting windings for limiting the current and second means for interrupting the residual current. The invention is applicable to interrupting high tension direct currents.

Abstract: A circuit breaker/isolating switch device intended, in particular, to be associated with a generator in a power station for protection purposes. The device is disposed inside a metal sheath and comprises a gastight insulating casing filled with a gas having good dielectric properties and at a pressure of a few bars, the casing containing a fixed assembly comprising a fixed permanent contact and a fixed arcing contact, a moving assembly comprising a moving permanent contact and a moving arcing contact, a blast cylinder, a blast piston, and a blast nozzle. The moving assembly is connected to a drive rod passing in gastight manner through the casing and connected outside the casing to a drive mechanism. The casing carries a metal collar disposed level with the contact separation zone and connected to ground and the collar includes a radial channel provided with an optical device enabling the position of the contacts to be inspected.

Abstract: A braking resistance having at least one basic element (400) including a ceramic envelope (1) receiving at least one stack of conducting solid disks (11) made of a carbon-based ceramic and having a resistivity lying in the range 100.OMEGA..cm to 1000.OMEGA..cm. A tube (20) maintains the stack. A spring (14) exerts pressure on the stack of disks. Electrical contact is provided between each end of each stack and respective conducting plates located at the ends of the envelope and the envelope is filled with nitrogen at a pressure of 1 to 2 bars.

Abstract: A current limiter comprising a cryostat provided with a first insulating feedthrough for an inlet conductor and a second insulating feedthrough for an outlet conductor, and a conductor running from one feedthrough to the other inside the tank, said conductor being constituted at least in part by a superconducting material, the cryostat being filled with a fluid at a temperature which is low enough to maintain said material in the superconducting state, said portion made of superconducting material including at least one portion comprising superconducting wires (7, 8) wound in opposite direction windings on two coaxial insulating formers (14, 15). Respective the ends of each of the superconducting wires (7, 8) are connected firstly to the inlet conductor and secondly to the outlet conductor via identical elementary current feeds (21A, 22A).

Abstract: A sulphur hexafluoride circuit breaker usable at very low outside temperatures, the circuit breaker comprising:a sealed enclosure containing a fixed contact assembly and a moving contact assembly;a drive rod for driving the moving contact assembly, said rod being connected to a drive mechanism;a blast volume;a blast nozzle; anda condenser located outside the enclosure and disposed in the vicinity of said drive mechanism and connected to the same potential, with the inside of the condenser being put into communication with the inside of the circuit breaker via at least one duct;the circuit breaker including the improvement of first means (108B, 109, 109A) for permanently taking a portion of the liquefied gas in the condenser and for vaporizing it by heating, and second means (300) for conveying the resulting vapor into a thermally insulating enclosure, said enclosure being located in the vicinity of the arcing zone within the circuit breaker and communicating with the blast volume via an orifice.

Abstract: A high pressure circuit breaker comprising a sealed enclosure (1) having a fixed assembly (10) and a moving assembly (20) disposed therein, said fixed assembly and said moving assembly each including a respective main contact and a respective arcing contact, and said enclosure being filled with gas under pressure constituted, at least in part, by sulfur hexachloride, the circuit breaker including the improvement of a fluid condenser (30) disposed outside the circuit breaker with the inside of the condenser being in communication with the inside of the enclosure via at least one first channel (31) for transferring gas between the inside of the enclosure and the condenser, and via at least one second channel (32) for transferring liquified gas from inside the condenser to the inside of the enclosure.