Abstract: The earth leakage protection device comprises an input designed to be connected to a measuring toroid, a comparator to compare a signal representative of an earth leakage current with a reference threshold, and a processing circuit to command a trip relay for opening main contacts when an earth leakage fault is detected. The device also comprises a signal rectifier receiving at least one signal representative of an earth leakage current, and a filter connected to the rectifier to supply a filtered rectified signal to said comparison means. The electrical switchgear unit comprises main conductors and contacts connected in series, the measuring toroid of the earth leakage current, the relay, and an earth leakage protection device with a matching filter connected to the toroid and to the trip relay.

Abstract: The present invention relates to a vacuum cartridge for an electrical protection apparatus such as a switch or a circuit breaker, said cartridge comprising an enclosure of substantially cylindrical shape closed by two end plates, two contacts extending axially inside the enclosure, at least one whereof, called the movable contact, is connected to an operating mechanism and is mounted sliding between a closed position of the contacts enabling the current to flow and a position wherein the contacts are separated and form an electric arc between them, and a means for producing an axial magnetic field in the arc formation zone. This cartridge comprises at least one conducting shield fitted around the periphery of at least one of the contacts, said shield being shaped and arranged in such a way as to withstand the electric field arising from the recovery voltage imposed by the power system after breaking and to thus considerably reduce the electric field at the edge of said contact.

Abstract: The electrical short-circuit detection device comprises first signal processing means receiving a signal representative of an electrical current and supplying a first signal representative of the value of said electrical current and a second signal representative of the differential of said electrical current, and second processing means receiving said signals and comprising short-circuit detection means supplying a detection signal according to a curve overshoot. The second processing means monitor a limit curve overshoot and a ratio between variations of said signals. A short-circuit detection signal is supplied if said ratio exceeds a preset threshold. The circuit breaker incorporates such a device. The process comprises monitoring steps of limit curve overshoot and of the ratio between variations of the signals.

Abstract: Position switch whose box houses a switch assembly that can be manoeuvred by an activation head using a push button.