A direct current circuit breaker comprises a mechanical relay in a first supply line configured to conduct electrical current during steady-state operation and an auxiliary relay assembly in parallel with the mechanical relay to define an auxiliary breaker path for conducting electrical current during transient operation of the circuit breaker. The auxiliary relay assembly comprises a power-semiconductor circuit configured for selective current conduction and for bidirectional current blocking when in a non-conductive state. There is also a controller configured to (i) activate the power-semiconductor circuit to conduct in response to a command signal to stop transfer of the electrical power, in order to provide a zero voltage condition under which the mechanical relay is to deactivate; (ii) deactivate the mechanical relay when current is being conducted through the auxiliary breaker path; and (iii) deactivate the power-semiconductor circuit after the mechanical relay is deactivated to stop the transfer of the power.

A solid-state circuit breaker (SSCB) comprises a breaker housing, line-in and line-out terminals and one or more solid state switching components. The SSCB further comprises an air gap disposed between the line-in and line-out terminals and coupled in series with the solid-state switching components to complete a current conducting path when closed. The air gap includes an air gap driving mechanism. The solid-state circuit breaker further comprises an air gap actuator to interact with the air gap driving mechanism. The SSCB further comprises a controller that controls the air gap actuator and is configured to: (a). send a tripping signal to the air gap actuator and the one or more solid state switching components at substantially the same time or (b). send a tripping signal to the air gap actuator a short amount of time earlier than sending the tripping signal to the one or more solid state switching components.

A switching device is for a low-voltage electric circuit having a plurality of conductors. In an embodiment, the switching device includes a housing having connection contacts arranged on the housing for connection of conductors of the low-voltage electric circuit; and a mechanical unit situated in the housing having an isolating function and an OFF or IN position, the mechanical unit including isolating contacts for galvanically interrupting the conductors of the low-voltage electric circuit. An electronic unit is provided which is connected to the mechanical unit in series on the current flow side; an auxiliary switch connected to the mechanical unit is provided and is connected in turn to the electronic unit; and the auxiliary switch and the electronic unit are designed in such a way that the electronic unit is highly resistive during an opening process of the mechanical unit.

A transformer arrangement is provided. The transformer arrangement includes a transformer with a primary and a secondary winding and a chain link of switching blocks connected in series between one of the windings and a load, where the switching blocks comprise a first set of voltage contribution blocks and a second set of circuit breaker blocks, where the first set of voltage contribution blocks is configured to adjust a voltage output by the transformer with an offset voltage and the second set of circuit breaker blocks is configured to interrupt a current running through the chain link.

Ground-fault circuit interrupter positioned between energy controlled supply circuit and load circuit which includes fault detection circuit that senses ground path current leakage to the load circuit, fault processing circuit that detects presence of fault and generates fault output signal when fault detected, and control circuit switch connected to fault processing signal output, wherein control circuit switch is opened by presence of fault output signal, thus isolating load circuit from supply circuit. Preferably fault processing circuit and control circuit are optically linked, such that when fault is detected, control circuit switch is opened by optical fault output signal, thus isolating load circuit from the supply circuit. Circuit interrupter may couple another circuit interrupter via power distribution control unit, optionally manageable remotely via automated control interface.

Provided is a touch sensing system that can make the life of a contact of an electromagnetic contactor longer. A touch sensing system includes a main operation circuit that connects a probe and a main operation power supply, and in which an electromagnetic contactor is provided; and a touch sensing circuit that is connected to the main operation circuit through the electromagnetic contactor in a branched manner, and connects the probe and a touch sensing power supply, is which a solid state relay switch is provided in the touch sensing circuit.

An apparatus (1) provided to connect at least one device (2) to a power distribution system (3), said apparatus (1) comprising a human machine interface, HMI, (4) having elements to interact with the apparatus (1), wherein the human machine interface elements (11,12) are adapted to display and/or to adjust setting values of operation parameters of the at least one connected device (2), wherein access to one or more human machine interface elements is restricted by at least one access restriction mechanism of said apparatus (1) to enhance the operation security of the at least one device (2) connected via said apparatus (1) to said power distribution system (3) and/or to enhance the operation security of the apparatus (1) and/or of the power distribution system (3).

A circuit breaker device or circuit breaker system may include a series connection of a semiconductor switch and an isolating contact system, for a low voltage electrical circuit, in which the magnitude of the current is determined.

An electrical protection device capable of operating without auxiliary electrical power supply includes a control module configured to detect an electrical fault and a switching module, a first circuit including at least two normally-on JFET transistors and a switching member including a first contact. The switching module is configured so that, upon a switchover of the first contact when the current circuits, an electric arc is formed and so that the appearance of the electric arc generates an electrical signal transmitted to at least one of the transistors, the electrical signal driving the switching of the transistor.

A circuit breaker comprises a solid-state bidirectional switch, a switch control circuit, current and voltage sensors, and a processor. The solid-state bidirectional switch is connected between a line input terminal and a load output terminal of the circuit breaker, and configured to be placed in a switched-on state and a switched-off state. The switch control circuit control operation of the bidirectional switch. The current sensor is configured to sense a magnitude of current flowing in an electrical path between the line input and load output terminals and generate a current sense signal. The voltage sensor is configured to sense a magnitude of voltage on the electrical path and generate a voltage sense signal. The processor is configured to process the current and voltage sense signals to determine operational status information of the circuit breaker, a fault event, and power usage information of a load connected to the load output terminal.