An overload relay is disclosed in which a single operator coil is controlled for both tripping and resetting. A permanent magnet and a spring make the device bi-stable, so the coil may be unpowered when in the trip and reset states. Energization of the coil overcomes the magnet to allow tripping, while energization in an opposite direction adds to the magnet force to reset the device. An electromagnetic activation path overrides a mechanical activation path for electromagnetic tripping despite attempted manual resetting. The device may be pulse width modulated to reduce power consumption

An overload relay is disclosed in which a single operator coil is controlled for both tripping and resetting. A permanent magnet and a spring make the device bi-stable, so the coil may be unpowered when in the trip and reset states. Energization of the coil overcomes the magnet to allow tripping, while energization in an opposite direction adds to the magnet force to reset the device. An electromagnetic activation path overrides a mechanical activation path for electromagnetic tripping despite attempted manual resetting. The device may be pulse width modulated to reduce power consumption

A controllable trip device includes a magnetic actuator, including a coupling member intended to be coupled to a switching mechanism of an electrical circuit breaker to cause the switching thereof and a coil configured to displace the coupling member towards a tripped position when it is supplied with a pulse of a current of intensity greater than a first predefined threshold for a duration greater than or equal to a predefined duration, a control device, configured to supply the coil, immediately on receipt of a control signal, with a series of pulses of duration equal to the predefined duration and of intensity greater than or equal to the first threshold and less than or equal to a second threshold equal at most to 120% of the first threshold.

A controllable trip device includes a magnetic actuator, including a coupling member intended to be coupled to a switching mechanism of an electrical circuit breaker to cause the switching thereof and a coil configured to displace the coupling member towards a tripped position when it is supplied with a pulse of a current of intensity greater than a first predefined threshold for a duration greater than or equal to a predefined duration, a control device, configured to supply the coil, immediately on receipt of a control signal, with a series of pulses of duration equal to the predefined duration and of intensity greater than or equal to the first threshold and less than or equal to a second threshold equal at most to 120% of the first threshold.

A self-powered recloser includes a circuit breaker, an electrical actuator, an electrical generator, a capacitor, and a lever. When in an on state, the circuit breaker harvests power from a medium voltage line required to actuate its movable contact to interrupt current flow in the medium voltage line, and when in an off state, it does not harvest power from the medium voltage line. The electrical actuator is configured to transition the circuit breaker from the off state to the on state. The capacitor when charged is configured to provide the electrical actuator with the electrical power required to transition the circuit breaker from the off state to the on state. The lever is configured to be moved by an operative. Movement of the lever is configured to charge the capacitor via the electrical generator.

A self-powered recloser includes a circuit breaker, an electrical actuator, an electrical generator, a capacitor, and a lever. When in an on state, the circuit breaker harvests power from a medium voltage line required to actuate its movable contact to interrupt current flow in the medium voltage line, and when in an off state, it does not harvest power from the medium voltage line. The electrical actuator is configured to transition the circuit breaker from the off state to the on state. The capacitor when charged is configured to provide the electrical actuator with the electrical power required to transition the circuit breaker from the off state to the on state. The lever is configured to be moved by an operative. Movement of the lever is configured to charge the capacitor via the electrical generator.

A reset mechanism includes: a reset button, electromagnet, and reset mounting bracket, where a rotary lifting block is movably on the bracket; lifting parts are separately at two sides of one end of the block, and a clamping hook is the other end; a lifting block spring is on one side of the lifting part of the block; a position-limiting block matched with the block is on the bracket, which has a slide rocker in a movable manner; a rocker bending part is at a tail of the slide rocker; an end part of the rocker bending part has a rocker bayonet; an iron core of the electromagnet has an iron core card slot matched with the bayonet, which is clamped to the iron core card slot; and a bottom of the reset button has a reset lever matched with one side of the clamping hook of the block.

A reset mechanism includes: a reset button, electromagnet, and reset mounting bracket, where a rotary lifting block is movably on the bracket; lifting parts are separately at two sides of one end of the block, and a clamping hook is the other end; a lifting block spring is on one side of the lifting part of the block; a position-limiting block matched with the block is on the bracket, which has a slide rocker in a movable manner; a rocker bending part is at a tail of the slide rocker; an end part of the rocker bending part has a rocker bayonet; an iron core of the electromagnet has an iron core card slot matched with the bayonet, which is clamped to the iron core card slot; and a bottom of the reset button has a reset lever matched with one side of the clamping hook of the block.

An example device in accordance with an aspect of the present disclosure includes a housing, mountable to a power distribution unit (PDU) associated with at least one circuit breaker. The device also includes a mechanism coupled to the housing, movable between a first position and a second position to reset the at least one circuit breaker, in response to receiving a reset signal.

A controllable trip device includes a magnetic actuator, including a coupling member intended to be coupled to a switching mechanism of an electrical circuit breaker to cause the switching thereof and a coil configured to displace the coupling member towards a tripped position when it is supplied with a pulse of a current of intensity greater than a first predefined threshold for a duration greater than or equal to a predefined duration, a control device, configured to supply the coil, immediately on receipt of a control signal, with a series of pulses of duration equal to the predefined duration and of intensity greater than or equal to the first threshold and less than or equal to a second threshold equal at most to 120% of the first threshold.