Abstract: An electric protection apparatus is provided for protection against current faults of different intensities, including, in series in an internal circuit, a first switch with automatic opening, which is controlled by moderate current levels, and a second switch with automatic opening having short circuit current limiting properties; a zinc oxide voltage limiting component, which is placed in parallel across this latter, has a fairly low stabilization threshold so that diverted currents, flowing through it at the time of opening on a short circuit, extend as far as the resistive portion of the characteristic which follows the stabilization level portion.

Abstract: A static switch is provided for controlling the closing and opening of an AC electric circuit including an inductive load. This switch includes an inhibitable thyristor having an RCD network for protection against the voltage gradients on turn-off. The anode-cathode path of the inhibitable thyristor and its protection network are connected to the AC energy source through a full wave rectifier device, whereas a voltage clipping member is disposed at the terminals of the rectifying device.

Abstract: Each phase circuit comprises a static switch of the IGT or GTO type, between the anode and the cathode of which there is arranged in parallel a series mounting of a CTP resistance and of a normally open switch which is closed when a current detector detects a short abnormal intensity lower than six times the rated current; said static switch is locked either immediately when the rate is higher than six, or with a short delay on the contrary. Said device is particularly convenient to be used in industrial installations where it is desired to replace the associations of contactors, thermal relay and circuit breaker by static apparatuses.

Abstract: An electric switching unit for preventing oxidation of copper-base contacts in contactors comprises a body (2), comprises an electromagnet (11) having a stationary yoke (7) and a moving armature (15) in cooperating relation with a plurality of switches (36). A protective casing (42) is fixed on the body so as to contain the switches. The contact-studs (30, 31, 32, 33) of the switches (36) essentially have a base of cuprous materials while a non-oxidizing atmosphere is confined and maintained beneath the protective casing (42) by seals (55, 23, 47). The seals are placed on the one hand between the moving armature (15) and a first face (21) of the body (2) and on the other hand between the casing (42) and a second face (41) of the body which is opposite to the first face.

Abstract: A current limiting switch is provided comprising two mobile levers subjected to the action of springs which apply, one against the other, separable contact pieces placed at the respective ends thereof; a thin electrically insulating screen placed between the levers so that its edge is inserted between the contact pieces while maintaining complete insulation between the levers when these latter move away from each other, following short circuit currents flowing in the switch, wherein the ends of the levers, where the contact pieces are placed, are situated in the immediate vicinity of an insulating surface of the case, so that the path of the arc is essentially tangential with respect to the movement of the mobile contacts, the movement of said edge towards and against said insulating surface causing constriction of the arc and completely insulating from one another the two opposite and sealed chambers which the screen separates within the internal volume of the case.

Abstract: A contactor capable of having a very high breaking power comprises a movable contact carrier bridge (3) having a central part in the form of a blade (3c) and conducting J-shaped pieces (2a-2b) supporting fixed contacts. A non-magnetic blade bent in the form of a U is mounted slidable inside a hollow movable insulating contact holder (1) and guides and holds at its upper end a magnetic plate (8) cooperating with said blade (3c) and forming an air-gap with another U-shaped magnetic piece (6), disposed between the legs of the bent blade (5) and integral (at 7) with the contact holder (1). A contact pressure spring (4) bears on the basis of the U-shaped magnetic piece (6) and on the bottom of the bent blade (5).

Abstract: An a-c current sensor for measuring the current which flows in a conductor has an insulating frame having a central compartment open at its upper end and encompassed by a U-shaped receptacle for a bent portion of the conductor. A coil is housed in the central compartment. The frame is slidingly mounted within a sleeve made of a soft magnetic material and having two assembled half-shells. The voltage generated by the current across the coil is proportional to the intensity of current flow.

Abstract: A device is provided comprising a simple means for holding the contacts apart and insulated from each other after circuit breaking.A screen formed by an insulating plate of small thickness, is placed between two mobile contact levers and is urged by springs against flanges which are integral with the levers and which move apart when short circuit currents appear for allowing this screen to be rapidly projected between the contact inserts.This simple circuit-breaker device may be used such as it is or in association with a contactor for protecting lines which supply consumer apparatus.

Abstract: An apparatus comprising a plurality of circuit breakers with a rigid contact bridge 16 cooperating with fixed contacts 9, 10 carried respectively by conductors 11, 12, generating repellent forces; the median region 21 of the bridge cooperates with a magnetic structure 37 providing the bridge with compensation forces for the contact pressure when the latter is under a predetermined threshold, above which the bridge is ejected from the fixed contacts. This contactor is advantageously used for the control of power consuming apparatus and protection of their supply lines.

Abstract: An arc blowing element comprises two parallel arms and a stem disposed in the neighborhood of a support for a fixed contact, and a deflector coupled to an extremity of that arm which is remote from the contact and to which it is perpendicular, in order to extend up to the arc extinction chamber.