Abstract: A digital solid-state trip unit of an electrical circuit breaker is equipped with an electrical contact wear indicator enabling the degree of wear of these contacts to be known. Each time the circuit breaker performs a break, the microprocessor determines a contact wear value, in terms of the maximum value of the current broken. The correspondence between the wear value and the current broken is stored in a ROM memory and the successive wear values are added in a NOVRAM memory whose contents are representative of the degree of contact wear. These contents can be displayed to indicate to the user that the condition of the contacts has to be checked.

Abstract: A metalclad substation having a busbar isolating switch including an operating mechanism housed in the busbar compartment. The movable contacts of the isolating switch are housed in a compartment separated by a tight insulating partition from the busbar compartment. Tight partitioning of the compartments enables operations to be carried out in the different compartments while maintaining at least one of the busbars switched on to supply the unaffected part of the installation.

Abstract: A converter comprises a plurality of modules each having a heat-sink unit with a base-plate made of a good heat-conducting metal material, acting as a support for the electronic components, a pair of parallel flanges laterally fixed to the opposite edges of the base-plate, and a rear plate for connection of the draw-in contacts capable of cooperating with the studs of a fixed connecting base. Error prevention means, formed by pins and orifices prevent any module connection error. The draw-in contacts are achieved by tulip-fingers or grips capable of being housed in six holes of the connection plate. The assembly forms a rack which can be actuated by a handle.

Abstract: The device comprises a solid-state switch and a pair of mechanical contacts electrically connected in series. The solid-state switch is housed in a compartment towards the rear of the moulded case of the device, in thermal contact with an external metal plate. The solid-state switch housing is separated by an insulating partition from the remaining part of the moulded case, which contains the contacts, their operating mechanism, the arc chute and the trip unit. The power terminals and control terminals of the solid-state switch are located on the small side faces of the case on either side of the movement plane of the movable contact, which extends parallel to these small side faces.

Abstract: The protective filter comprises an internal reference plane, electrically insulated from the converter housing and acting as ground plane for the internal elements of the static converter, and filtering capacitors respectively connecting the internal reference plane to the input and output cables of the converter.

Abstract: A sub-assembly comprising a contact finger support cage and a connection pad of each pole is securedly united to an intermediate insulating partition of the case by a bracket and screw fixing device. The cage is pivotally mounted on a spindle positioned in bearings of the pad, and is connected to a switching bar by a mechanical link cooperating with a disengageable coupling, capable of breaking the linking system with the bar at the level of each pole. One side wall of the insulating case includes an opening communicating with the compartment housing the separable contacts of each pole. The arc chute is fixedly secured to an insulating support capable of being moved in translation in the longitudinal direction of the pole to ensure either blanking-off of the opening in the inserted position of the arc chute inside the compartment, or removal of the arc chute via said opening allowing the condition of the contacts of each pole to be checked visually, without removing the main fixing screws of the case.

Abstract: A test circuit simulates the operation of a multipole electrical circuit breaker, and includes a pair of auxiliary terminals connected by a connection circuit to the input terminals of a bridge rectifier cell whose output is connected in parallel with the respective outputs to two other rectifier cells associated with current transformers. A first resistor delivers a first signal proportional to the maximum intensity of the mains currents. Diodes cooperate with a second measuring resistor of a residual earth leakage current discriminator. Reversing the direction of the test current flow in the test circuit is performed by simply changing the polarity of the test terminals, and enables overcurrent protection and earth leakage protection of the electronic trip device to be checked separately.

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: The present invention relates to a display device for a digital trip device associated with a current breaking device. The trip device comprises apparatus for entering operating parameters and apparatus for measuring the current in the breaking device, these two apparatuses being coupled with a first microprocessor comprising memory areas in which the parameters and measurement data are entered. The display device is of the portable type, able to be coupled temporarily with the trip device, and comprises: an alphanumerical display, a second microprocessor comprising memory areas, apparatus associable with complementary apparatus in the trip device to transfer the contents of the memory areas of the trip device to the memory areas of the display device, these contents then being able to be displayed selectively by the reader during or after the temporary coupling.

Abstract: A puffer-type electrical circuit breaker is insulated by an SF6 insulating gas contained in a casing of moulded insulating material. The circuit breaker comprises a system of contacts, a pair of connection terminals electrically connected to the contacts by means of bushings passing through the wall of the casing in a perpendicular direction to the longitudinal axis, and means of fixing the casing to a metal support at ground or earth potential. The external lateral surface of the insulating casing comprises a plurality of longitudinal flanges designed to increase the creepage distance between the terminals and the support. The creepage distance value is greater than the distance in the air between the same parts.

Abstract: An isolating switch of a metalclad installation having an earthed metal enclosure is filled with a high dielectric strength gas. The isolation gap "d" separating the stationary contact from the movable sliding pin is surrounded by an annular electrode fitted between this isolation gap "d" and the enclosure. The annular electrode extends over the whole length of the isolation gap "d" and is electrically connected to the stationary contact to prevent any migration of the arc drawn between the contacts towards the earthed enclosure. The metal enclosure is advantageously spherical in shape, the contacts being disposed appreciably in the center of the sphere.

Abstract: The invention relates to a draw-in mechanism for an extractible molded insulated case circuit breaker, equipped with main and auxiliary circuits with fixed and movable connectors. The fixed connectors are arranged on the upper horizontal wall of the case, and the interacting movable connectors plug into the fixed connectors when the circuit breaker is immobile. The reversible mechanism movement transmission system comprises a first mechanical link with the movable connectors drive device, and a second mechanical link with the movable circuit breaker support, the assembly being arranged so that the first mechanical link is active when the second mechanical link is broken, and vice-versa. The racking mechanism comprises an operating device with a handle, and a movable mechanical support having a pair of symmetrical rails sliding in slide plates of the chassis, and a rail locking system in the drawn-in and drawn-out positions.

Abstract: A mechanism for a circuit breaker includes a support lever insulated from a contact arm and a trip lever supported by a plate fitted with limited swivelling on a pivot. A mechanical link arranged between a toggle-joint and the contact arm includes a latching stop fixed on the plate. The stop is formed by a notch cooperating with a step of the trip lever to push the end of a toggle rod back to a retracted unlatched positon, as soon as the trip lever is actuated to the tripped position. The support lever is equipped with a locking arm having a sloping part cooperating with a pawl of the handle to form a high-speed contact closing device.

Abstract: A high voltage self-blowing circuit breaker with closing resistors is equipped with an auxiliary contact inserted in the trip control circuit of an electrical circuit breaker. The auxiliary contact is actuated by the mechanical control rod of the circuit breaker, in such a way as to prevent any operator closing error. A high-speed mechanism is inserted in the link system connecting the control rod and the auxiliary contact, with a dead travel mechanism to delay closing of the auxiliary contact when a closing operation takes place and to prevent a tripping order, liable to cause a flashover on the inserter contacts and damage to the circuit breaker, from being transmitted too early.

Abstract: The low voltage capacitor of a capacitive divider of a metalclad substation is located in a sealed compartment separated from the substation enclosure. In normal operation, the compartment is in direct communication with the enclosure via a communication orifice. The compartment can be isolated from the enclosure by closing the communication orifice valve to drain this compartment and thus have access to the low voltage capacitor or to other components of the capacitive divider housed in this compartment. Any pressure or temperature difference between the compartment and the enclosure, liable to affect the measurement, is thus avoided, while authorizing access to the low voltage capacitor without having to drain the installation.

Abstract: An electrical circuit breaker with self-expansion and rotating arc insulated with SF6 comprises a fixed arcing contact secured to the front face of a magnetic blow-out coil.An electrode is electrically insulated from the fixed arcing contact and covers the front face being connected to the opposite end of the coil by a branch circuit. The electrode is arranged to pick up a fraction of the arcing current, so that the magnetic field generated in the breaking zone by the coil remains appreciably constant when the value of the short-circuit current exceeds a predetermined threshold.

Abstract: The invention relates to improving the dielectric withstand of a puffer circuit breaker having a main circuit arranged side by side with an arcing circuit inside a sealed insulating casing filled with an insulating gas SF6.The disconnection area arranged between the main contacts when the main circuit opens is located facing the breaking gap between the arcing contacts. The fixed main contact and the fixed arcing contact are at the potential of the upper terminal, being located at appreciably the same level on either side of the longitudinal axis of the casing.

Abstract: An instantaneous solid-state trip device has two threshold values providing an upper and a lower tripping threshold. A current increase rate detector determines, when a short-circuit occurs, the prospective peak current value and, if the peak value corresponding to the electrodynamic withstand of the circuit breaker is liable to be exceeded, causes a change of threshold to bring about tripping, as soon as the lower threshold is exceeded. This high-speed tripping favours short-circuit current limiting. When a short-circuit of a lesser importance occurs, the current variation is lower and the instantaneous trip release only trips when the upper threshold is exceeded. In most cases, this upper threshold is not reached and tripping selectivity can be easily achieved in the usual way. A break in the circuit connecting the sensor to the trip unit also causes the circuit breaker to trip.

Abstract: The circuit breaker-contactor includes a circuit breaker part with mechanical contacts and a contactor part with mechanical contacts connected in series. A solid-state switch is connected in parallel to the contacts of the contactor part. A control unit controls the solid-state switch and the contactor part, in such a way as to close the circuit when the potential difference passes zero by conduction or interrupting the solid-state switch. The mechanical contacts perform only current conduction by shunting the switch in normal operation. The contacts of the circuit breaker part have associated with them an arcing electrode and a shunt circuit disposed to draw the arc, as soon as the contacts open, and to shunt the solid-state switch and contactor part mechanical contacts assembly.

Abstract: Microprocessor-based digital solid-state trip unit (48) generating an inverse time long delay and/or short delay trip by digital simulation of the heating and cooling of a bimetallic strip. A digital value (TETALR), stored in a RAM memory simulates the temperature of the bimetallic strip, this value being incremented when the current exceeds a preset pick-up (ILR) or on the contrary decremented if the current is lower than this pick-up (ILR). Tripping is caused when the stored value (TETALR) exceeds a maximum pick-up (TETAMAX). The microprocessor (48) computes the incrementation factor (DTETAE) in terms of the square of the current.