A device for monitoring a current in a primary conductor with respect to a predetermined current threshold, comprising: a magnetic circuit associable to the primary conductor and comprising a fixed part and an element which can rotate about a rotation axis; at least one spring operatively connected to the rotating element for keeping it in a first position, the spring being elastically deformable along a linear axis; and sensing means operatively associated to the magnetic circuit. The magnetic circuit is configured in such a way that the rotating element rotates from the first position to a second position when the current in the primary conductor exceeds the predetermined current threshold, so as to at least reduce one or more air gaps between the rotating element and the fixed part and to elongate the spring from a first length to a second length. The sensing means are configured for generating an output electrical signal caused by the rotation of the rotating element from the first position to the second position. The at least one spring is operatively connected to the rotating element in such a way to tilt towards the rotation axis moving above a surface of the rotating element which is transversal to the rotation axis, during the rotation of the rotating element from the first position to the second position.

An electromagnetic relay includes an electromagnet device, a contactor, and a trip device turning the contactor into an open state in which the contactor opens when an abnormal current flows. The electromagnet device includes a first excitation coil, a fixed element, first and second movable elements, and a permanent magnet. The contactor includes a fixed contact and a movable contact. In the electromagnetic relay, while the permanent magnet causes the first movable element to attractingly contact the second movable element, the fixed element attracts the first movable element due to a magnetic flux generated by the first excitation coil so as to move the second movable element together with the first movable element from a normal position to an attracted position. In the contactor, the movable contact moves, as the second movable element moves, so as to switch between a closed state in which the movable contact contacts the fixed contact and the open state in which the movable contact is removed from the fixed contact. The contactor is turned into the closed state when the second movable element is located at the attracted position. The trip device includes a second excitation coil connected in series to the contactor and a spring for acting a force on the second movable element in a direction away from the first movable element.

Fuse devices and electrical systems using the fuse devices are disclosed, with the fuse devices having internal components to cause a fuse blown event when the pre-determined current level is reached through the contacts. The internal components can comprise a levitation actuator that causes separation between one or more of the contacts as the current level approaches the predetermined level. This causes contact levitation and arcing, which increases the resistance at the contact being separated. This in turn causes the current through the contacts to seek another path that in the embodiments herein is a path to a pyro feature. The current activates the pyro feature, which causes the contacts to separate and puts the fuse device in fuse blown condition where currents can no longer flow through the contacts.

A device for monitoring a current in a primary conductor with respect to a predetermined current threshold, comprising: a magnetic circuit associable to the primary conductor and comprising a fixed part and an element which can rotate about a rotation axis; at least one spring operatively connected to the rotating element for keeping it in a first position, the spring being elastically deformable along a linear axis; and sensing means operatively associated to the magnetic circuit.

The magnetic circuit is configured in such a way that the rotating element rotates from the first position to a second position when the current in the primary conductor exceeds the predetermined current threshold, so as to at least reduce one or more air gaps between the rotating element and the fixed part and to elongate the spring from a first length to a second length. The sensing means are configured for generating an output electrical signal caused by the rotation of the rotating element from the first position to the second position.

The at least one spring is operatively connected to the rotating element in such a way to tilt towards the rotation axis moving above a surface of the rotating element which is transversal to the rotation axis, during the rotation of the rotating element from the first position to the second position.

A circuit breaker includes a trip mechanism having reduced trip movement and an integrated signal flag. The trip mechanism includes a spring-biased trip lever and a latching member for keeping the trip lever in an on or latched position. Upon occurrence of an abnormal current condition, the latching member is moved away from the trip lever to trip the trip mechanism. The latching member also has a catch mechanism designed to catch the trip lever after it is released, thereby halting further progress of both the trip lever and the latching member. As a result, less space is needed within the circuit breaker for trip movement compared to existing solutions. Moreover, the location of the catch mechanism on the latching member is selected such that the halting of the latching member places the integrated signal flag in an optimal viewing position within a viewing window.

A tripping mechanism includes a magnetic core with first, second and third yokes, the third yoke comprising a yoke through hole; an armature comprising an armature through hole, a leading rod, a spring and means for tensioning the spring, a tripping lever, means for transferring a movement of the armature, wherein the armature is movably placed between the first yoke and the second yoke, wherein the leading rod extends throughout the magnetic core and the armature and is fixed relative to the magnetic core, wherein the leading rod is placed inside the spring and the spring is placed between the armature and the means for tensioning, wherein the spring is configured to push the armature towards the first yoke.

An electromechanical rotary latch for use in current interruption devices disclosed. In a particular embodiment, a fuse device comprises a rotary latch; a rotatable armature configured to actuate the rotary latch; and a contact configured to change between a set position that allows current flow through the fuse device and a triggered position which interrupts current flow through the fuse device; wherein the fuse device is configured such that when a threshold current level passes through the fuse device, the rotatable armature changes configuration in response to a generated electromagnetic field, which actuates the rotary latch causing the contact to transition to the triggered position.

A trip device for a power circuit breaker has a trip element, a trip circuit with a trip coil, which, when energized, is configured to effect a movement of the trip element, and at least one electrical delay element, which can be connected to the trip circuit and reduces the rate of a rise in a current flowing in the trip coil once the trip circuit has been closed and/or delays a rise in a current flowing in the trip coil once the trip circuit has been closed.

A ground fault circuit interrupter device includes a switch unit for controlling a power connection between input and output ends; a leakage protection unit including a leakage detection module, for generating a leakage fault signal upon detecting a leakage current signal, and a leakage drive module including a first coil, for driving the switch unit to disconnect the power connection in response to the leakage fault signal; a timing unit including a timing control module, for performing timing in response to a time duration setting signal and generating a timed trip signal after a first preset time duration elapses, a time duration setting module for sending the time duration setting signal to the timing control module, and a timing drive module including a second coil separate from the first coil, for driving the switch unit to disconnect the power connection in response to the timed trip signal.

Disclosed is a switching device having an electromagnetic actuation device for driving a movable contact, which actuation device has an excitation coil for generating a magnetic field, a magnetic yoke for amplifying the flux density of the magnetic field, and a magnet armature which can be pulled from a starting position to a pulled position by the magnetic field and which is connected to the movable contact. The actuation device includes a locking element which at least partly consists of a ferromagnetic material and is arranged such that by virtue of the effect of the magnetic field, the locking element is brought from the unlocking position to the locking position. The magnetic yoke is designed to have a discontinuity when the locking element is in the locking position, and the discontinuity of the magnetic yoke is closed by the locking element when the locking element is in the unlocking position.