Abstract: An alternator disconnector circuit-breaker of the invention includes a cylindrical cam (40) for optimizing the sequence for opening/closing the switch-over first switch (10), the circuit-breaker second switch (20), and the disconnector third switch (30). The cam (40) has a cylindrical wall in which three slots (42), and preferably three pairs of slots, of different shapes, are defined; an end element of an element driving a respective one of the switch contacts is mounted to slide in each slot.

Abstract: A first switch (10) has a first pair of contacts (12, 14) that are mounted to move relative to each other in translation. A circuit-breaker second switch (20) has a second pair of contacts (21, 24) that are mounted to move relative to each other in translation, the second switch (20) being put in parallel with the first switch (10). A disconnector third switch (30) has a third pair of contacts (32, 34) that are mounted to move relative to each other. Synchronization means (50, 50?) make it possible, while breaking is taking place, for the contacts of the first switch (10) to separate before the contacts of the second switch (20) separate, the contacts of the second switch themselves separating before the third contacts (32, 34) separate fully. The synchronization means are actuated by a servomotor (40).

Abstract: An alternator disconnector circuit-breaker of the invention includes a cylindrical cam (40) for optimizing the sequence for opening/closing the switch-over first switch (10), the circuit-breaker second switch (20), and the disconnector third switch (30). The cam (40) has a cylindrical wall in which three slots (42), and preferably three pairs of slots, of different shapes, are defined; an end element of an element driving a respective one of the switch contacts is mounted to slide in each slot.

Abstract: A first switch (10) has a first pair of contacts (12, 14) that are mounted to move relative to each other in translation. A circuit-breaker second switch (20) has a second pair of contacts (21, 24) that are mounted to move relative to each other in translation, the second switch (20) being put in parallel with the first switch (10). A disconnector third switch (30) has a third pair of contacts (32, 34) that are mounted to move relative to each other. Synchronization means (50, 50?) make it possible, while breaking is taking place, for the contacts of the first switch (10) to separate before the contacts of the second switch (20) separate, the contacts of the second switch themselves separating before the third contacts (32, 34) separate fully. The synchronization means are actuated by a servomotor (40).

Abstract: The drive rod for high-voltage switchgear that is insulated with a dielectric gas comprises a segment made of an electrically-insulating material and two metal end pieces fixed to respective ends of the segment, as well as a thermal shield that is made of an electrically-insulating material, that is disposed between the end pieces, and that surrounds the insulating segment while being spaced apart therefrom to define an annular gap serving to be filled with the dielectric gas. In this way, the insulating segment of the rod is protected against thermal attack from electric arcs.

Abstract: A power station switch having high nominal current, the switch comprising a break chamber containing a dielectric gas under pressure and mounted inside a protective sheath which may optionally carry a general flow of cooling air, and a radiator/heat-exchanger situated outside said sheath and connected to said break chamber in which said gas under pressure is put into continuous circulation. Said gas under pressure as cooled in the radiator/heat-exchanger is returned to the break chamber via a metal case of the break chamber that is designed to be grounded.

Abstract: The drive rod for high-voltage switchgear that is insulated with a dielectric gas comprises a segment made of an electrically-insulating material and two metal endpieces fixed to respective ends of the segment, as well as a thermal shield that is made of an electrically-insulating material, that is disposed between the endpieces, and that surrounds the insulating segment while being spaced apart therefrom to define an annular gap serving to be filled with the dielectric gas. In this way, the insulating segment of the rod is protected against thermal attack from electric arcs.

Abstract: The switchgear comprises a circuit breaker connected between a generator and a transformer, together with a disconnector connected between the circuit breaker and the transformer, the disconnector having a fixed pole common to three positions: a first position and a second position respectively for connecting together or isolating the transformer and the circuit breaker when the circuit breaker is respectively closed or open; and a third position for grounding the fixed pole when the circuit breaker is open. The fixed pole of the disconnector is electrically connected to the transformer, thereby making it possible to interconnect or to isolate or to ground the tranformer while using only one disconnector included in the switchgear.

Abstract: The switchgear comprises a circuit breaker having an open position for isolating a generator from the network, and a closed position for connecting the generator to the network, together with a disconnector having a fixed pole connected to the generator and a contact connected to the fixed pole and movable relative thereto to occupy, when the circuit breaker is open, a first position connecting the generator to a starter circuit and a second position connecting the generator to ground. The moving contact of the disconnector also possesses a third position in which it forms an equipotential appendix for the fixed pole when the circuit breaker is closed. The moving contact does not carry the steady electric current of the generator, thus making it possible advantageously to reduce its dimensions so that they are capable merely of withstanding transient electrical conditions when in the first and third positions.

Abstract: A switching system having a plurality of positions for separating or interconnecting a generator, a network transformer, and a starter device, the system including a circuit breaker for the generator and a busbar disconnector for separating or interconnecting the generator and the network transformer, and a starter disconnector for separating or interconnecting the generator and the starter device. The busbar disconnector includes a first fixed contact and a first moving contact that co-operates by sliding with the first fixed contact, the first fixed contact and the first moving contact being integrated with the circuit breaker of the generator. The starter disconnector includes a second fixed contact and a second moving contact that co-operates with the second fixed contact by rotation. This organization remains economical to implement even for applications in which the generator is an alternator in a combined cycle or a gas turbine power station.

Abstract: The interlock control for a circuit breaker and a disconnector comprises a moving bar for opening or closing the circuit breaker and a displacement rod for displacing a disconnector rod to open or close the disconnector. The moving bar is driven by an arm which is secured to an outlet shaft and which is rotatable in a plane perpendicular to the outlet shaft, and the displacement rod is driven via an L-shaped piece which is movable about an axis that is substantially parallel to the outlet shaft, the arm driving the L-shaped piece during a second opening or closing stage of the circuit breaker via a wheel which is fixed to the arm and which slides in a notch of the L-shaped piece. The outlet shaft makes it possible to achieve interlocking by means of a single control, thereby providing a high level of reliability and of safety.

Abstract: The generator circuit breaker includes synchronization means for separating its main contacts before its arcing contacts are separated. It has a lever which is hinged at one of its ends to a fixed contact piece and which is constrained to move firstly with the moving main contact and secondly with the moving arcing contact by means of a spring, and with a ramp having two horizontal levels interconnected by a sloping intermediate portion, the ramp serving as a sliding support for a trigger member which prevents or authorizes movement of the moving arcing contact. This organization makes it possible for the moving contacts to be synchronized mechanically in simple and single manner.

Abstract: An electric switch for use in a five-pole isolating switch used as a phase inverter has a fixed contact and a mobile contact cooperating with the fixed contact to open or close an electrical line. The mobile contact is moved in a longitudinal direction by an articulated pair of levers. An isolating switch used as a phase inverter having five switches comprises a single three-position actuator for maneuvering the mobile contacts through a linkage.

Abstract: A circuit-breaker including main contacts and arcing contacts includes a shaft carrying a first lever connected to the moving main contact. A hub is mounted inside the shaft and carries a second lever connected to the moving arcing contact; the shaft and the hub being shaped over a certain portion into two sectors between which a spring is disposed. A single control causes the shaft to rotate so that the shaft firstly causes the hub to rotate via the spring, the shaft and the hub rotating respectively causing the moving main contact and the moving arcing contact to move, and the shaft secondly rotates to a further extent, with the hub being prevented from rotating by action from an abutment. This arrangement makes it possible to implement a simple synchronization of the main contacts opening before the arcing contacts.

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: A gas blast circuit breaker comprises a cylindrical metal or insulative enclosure filled with pressurized insulative gas, a fixed arc contact and a mobile assembly coupled to an operating member comprising a gas blast cylinder associated with a gas blast nozzle and cooperating with a piston, and a mobile arc contact carried by a tubular member inside the gas blast cylinder. The inside wall of the tubular member comprises a bottleneck whose cross-section is less than the inside cross-section of the tubular member and coaxial therewith. The minimum cross-section of the bottleneck has a diameter less than or equal to the diameter of the inside cross-section of the mobile arc contact and equal to at least 0.75 times the diameter of the inside cross-section of the mobile arc contact. The operation of the circuit breaker is improved by increasing the gas pressure near the mobile arc contact by virtue of a particularly simple and low-cost arrangement.

Abstract: A safety device for an electrical apparatus comprising an enclosure filled with gas under pressure, the safety device comprising first means for detecting the appearance of an arc inside the enclosure, and second means controlled by the first means to establish a path for the gas through the enclosure when the first means has detected an arc for a given length of time.