Abstract: An electrical apparatus for magnetothermal and differential protection, of the type comprising a device for sensing differential currents associated with a magnetothermal protection switch, comprises a differential current sensor connected to an input of a controlled gain signal amplifier, in turn connected to a plurality of light indicators arranged to go on progressively in dependence on the sensor. The apparatus provides a quantitative and qualitative measurement of the stray current.

Abstract: An electrical apparatus for magnetothermal and differential protection, of the type comprising a device for sensing differential currents associated with a magnetothermal protection switch, comprises a differential current sensor connected to an input of a controlled gain signal amplifier, in turn connected to a plurality of light indicators arranged to go on progressively in dependence on the sensor. The apparatus provides a quantitative and qualitative measurement of the stray current.

Abstract: An apparatus with remote control features for tripping off magnetothermal switches comprises at least one switch having a central core supporting trip-off linkages wherein a voltmeter coil is housed with each switch being connected to a respective one, e.g. a lamp, of user electric appliances.The apparatus also comprises a pushbutton control connected to each voltmeter coil in each magnetothermal switch for remotely and simultaneously operating the trip-off linkages to thus turn off simultaneously each electric appliance, while enabling function regaining by operating the corresponding switch locally.

Abstract: An electrical contactor comprises a rectangular base carrying at least one pair of spaced fixed contacts. A movable support element carrying movable contacts is disposed on the base. A prismatic casing open at both ends is disposed on the base. A solenoid disposed within and supported by the casing comprises a movable armature having two parallel legs directed towards the base with their free ends resting on the movable support element. Two arms are hinged to the base near diagonally opposed corners of the base and have inwardly-directed projections arranged to engage diagonally opposed corners of the end of the casing remote from the base when the arms are pivoted against the casing. The inwardly-directed projections are provided with threaded holes.

Abstract: An electrical device, in particular a fuse, circuit breaker or the like, comprises a housing having extending therefrom a projection, together with two conductive pins for connecting the device to an external circuit. A receptacle for accommodating the device has a wall provided with a seat and also with two holes through which the device pins pass when the device is inserted in the receptacle. A fitting is releasably accommodated in the seat and is able to accommodate the entrance therein of the projection to enable the device to be fully inserted. If an attempt is made to insert in the receptacle a different device provided with a projection that cannot enter the recess in the seat, the device cannot be fully inserted. However, the receptacle can be conditioned to accept the different device by inserting in the seat a different fitting having a different recess which will accommodate entrance of the projection of the different fitting.

Abstract: A fuse cartridge has a hollow casing of insulated material having an internal chamber filled with quartz sand and being of a parallelepiped form having two transverse walls and two pairs of longitudinal walls. One of the transverse walls is integral with the housing, and the other transverse wall is removable therefrom and has holes, through which electrically conducting pins extend into the chamber. A partition wall is located in the chamber parallel to a plane of symmetry of a first pair of the longitudinal walls. At least one substantially flat fuse strip is located in the chamber and has two opposite ends, each electrically connected to a respective pin. The fuse strip is U-shaped and has two portions parallel to the second pair of the longitudinal walls and a third portion connecting the two portions of the fuse strip to one another and parallel to the transverse walls.

Abstract: A fuse strip used in protecting electrical circuits comprises an elongated strip-shaped body on which a plurality of polygonally-shaped apertures are spaced in the transverse direction. A current-carrying neck portion of uniform width is formed by respective longitudinal parallel sides of each adjacent pair of apertures, and a transverse band of uniform width is formed by two rows of apertures which are spaced in the longitudinal direction, each row of apertures having transverse sides which respectively lie on a common line extending in the transverse direction.