A low-voltage circuit breaker device includes: at least one line conductor path from a line conductor supply connection of the low-voltage circuit breaker device to a line conductor load connection of the low-voltage circuit breaker device; a neutral conductor path from a neutral conductor connection of the low-voltage circuit breaker device to a neutral conductor load connection of the low-voltage circuit breaker device; a mechanical bypass switch arranged in the line conductor path; a first semiconductor circuit assembly of the low-voltage circuit breaker device being connected in parallel with the mechanical bypass switch; an electronic control unit for actuating the mechanical bypass switch and the first semiconductor circuit assembly; an ammeter assembly arranged in the line conductor path, which ammeter assembly is connected to the electronic control unit; and a second semiconductor circuit assembly arranged in the line conductor path.

Compliant electrical circuit protection devices are described for use in hazardous environments without presenting ignition risks for potentially explosive environmental conditions. Sensing features and systems may evaluate wiring limits and user selected settings for compatibility, detect loose connections and operating parameters to ensure safe operation of the device, and to intelligently diagnose and manage issues of concern for the circuit protection devices as well as the larger electrical power system.

A method of operating a Fault Current Limiter Circuit Breaker including a plurality of FLCB modules connected in series, including at least a first module and a second module. Each module has a plurality of parallel component legs including a mechanical switch leg having a mechanical switch, a semiconductor switch leg having a semiconductor switch, and a Metal Oxide Varistor leg having a MOV. The method includes, when the FLCB is in an open configuration, obtaining an indication that the FLCB should be closed; in response to the obtained indication, closing the semiconductor switch of each of the modules; and, after the closing of the semiconductor switches and while the mechanical switch of the second module remains open, closing the mechanical switch of the first module.

In one embodiment, a method includes, by a switch device, determining a position of an on/off input selector, the on/off input selector being located within a switch device, in response to determining the position of the on/off input selector is in an off position, operating one or more solid state switches to suspend current to one or more load-side terminals, determining whether the one or more load-side terminals of the switch device are electrically isolated, in response to determining the one or more load-side terminals of the switch device are electrically isolated, generating a prompt via a graphical user interface, and receiving, via the graphical user interface, one or more inputs, the one or more inputs including at least a request for safety lockout instructions.

Solid state and hybrid circuit protection devices include improved arc-less switching capability and overcurrent protection, improved terminal assemblies and improved thermal management features that reduce or eliminate ignition sources for hazardous environments. The solid state and hybrid circuit protection devices are ignition protected and avoid possible explosions and therefore obviate a need for conventional explosion-proof enclosures to ensure safe operation of an electrical power system in a hazardous location.

A current cut-off device for high-voltage DC current includes: between a primary point and an intermediate point, a primary diversion member and, in parallel, a primary surge protector; a secondary mechanical switch between the intermediate point and the secondary point; a main resonator whose terminal is linked to the secondary point; a main oscillation switch; a main surge protector, in parallel with a main capacitance of the main resonator; wherein the main oscillation switch includes three terminals linked respectively to the primary point, to the intermediate point and to the other terminal of the main resonator; the changeover switch can switch at least between three direct, inverting and isolated states.

This disclosure describes a hybrid circuit breaker for an industrial automation system. The hybrid circuit breaker may include a mechanical switch and solid-state switches. The hybrid circuit breaker may receive control signals to open and close a current path based on moving a spanner of the mechanical switch. In some cases, moving the spanner of the mechanical switch may generate electrical arcs when the hybrid circuit breaker is conducting electrical current. In such cases, the hybrid circuit breaker may remove the electrical arcs by drawing the electrical arcs to a conductive bar and away from the spanner. Moreover, the hybrid circuit breaker may dissipate the electrical arcs on the conductive bar by opening one or multiple solid-state switches disposed on the conductive bar. In some cases, one or multiple voltage suppressors may receive (e.g., suppress or ground) an electrical power of the electrical arcs when the solid-state switches are opened.

A low-voltage circuit breaker includes at least one current sensor for determining the magnitude of the electric current of a conductor of the low-voltage circuit breaker; and at least one electromechanical switching unit for connecting and disconnecting at least two electrical contact points. In a first switching position of the movable contact point, two contact points are connected and in a second switching position the contact points are not connected to one another. The circuit breaker further includes at least one electronic switching unit having a semiconductor switching element, electrically conductive in a first switching state and electrically blocking in a second switching state; an electronic tripping unit, connected to the current sensor, the electronic switching unit and the electromechanical switching unit. Further, when current and/or current/time-period limit values of the conductor are exceeded, first the electromechanical switching unit is opened and then the electronic switching unit is blocked.

Solid state and hybrid circuit protection devices include improved chemical, static discharge and impact resistant housing construction, arc-free switching operation, secure terminal assemblies and thermal management features. The solid state and hybrid circuit protection devices are ignition protected and avoid possible explosions and therefore obviate a need for conventional explosion-proof enclosures to ensure safe operation of an electrical power system in a potentially explosive environment.

A switching apparatus for electric power distribution grids including: a withdrawable first switching unit having one or more first electric poles; a withdrawable second switching unit having one or more second electric poles and electrically connected ins series with said first switching unit; and a controller implementing control strategies directed to increase the safety of the withdrawal manoeuvres of said first and second switching units.