A circuit breaker includes: at least one external conductor section from an external conductor supply connection in the circuit breaker to an external conductor load connection in the circuit breaker; and a neutral conductor section from a neutral conductor connection in the circuit breaker to a neutral conductor connection in the circuit breaker. The at least one external conductor section includes a mechanical bypass switch and a first mechanical isolating switch which are serially arranged. A second mechanical isolating switch is arranged in the neutral conductor section. A semiconductor circuit arrangement in the circuit breaker is connected in parallel to the bypass switch. A current measuring device is arranged in the at least one external conductor section that is linked to an electronic control unit in the circuit breaker. The electronic control unit operates the bypass switch, the first and second mechanical isolating switches, and the semiconductor circuit arrangement.

An electrical AC/DC converter arrangement includes: an AC circuit breaker; a rectifier; at least one smoothing capacitor; at least one first isolating relay for electrical isolation; at least one first current sensor; and a control and monitoring unit. An input of the AC circuit breaker forms an AC input of the arrangement. An output of the AC circuit breaker is connected, at least indirectly by a circuit, to an input of the rectifier. The at least one smoothing capacitor connects a first output of the rectifier to a second output of the rectifier. The first output of the rectifier is connected, at least indirectly by a circuit, to an input of the at least one first isolating relay. An output of the at least one first isolating relay forms a first DC output of the arrangement and connects a DC network to at least one first DC load.

A power supply including an input configured to receive input power, an output configured to provide output power to a load, at least one relay, a crowbar circuit configured to selectively divert the input power away from the load, and a controller configured to detect a high-voltage condition at the input, activate, in response to detecting the high-voltage condition at the input, the crowbar circuit to divert the input power away from the load, output, in response to detecting the high-voltage condition at the input, a signal to operate the at least one relay to transition from a first state to a second state, and deactivate the crowbar circuit in response to a determination that the at least one relay has transitioned to the second state.

A circuit breaker includes: at least one external conductor section from an external conductor supply terminal of the circuit breaker to an external conductor load terminal of the circuit breaker; and one neutral conductor section from a neutral conductor terminal of the circuit breaker to a neutral conductor load terminal of the circuit breaker. A mechanical bypass switch is arranged in the at least one external conductor section. A semiconductor circuit arrangement of the circuit breaker, which semiconductor circuit arrangement comprises a four-quadrant switch, is connected in parallel with the bypass switch. A current measuring arrangement is arranged in the at least one external conductor section and is connected to an electronic control unit of the circuit breaker. The electronic control unit is configured to operate the bypass switch and the semiconductor circuit arrangement in a prespecifiable manner. A voltage-dependent resistor is arranged in parallel with the bypass switch.

Provided is an arc protection system in which an arc remover does not operate in a case of a phase-to-phase short circuit fault or a ground/earth fault among arc faults in a distribution panel, the arc protection system including a sensor configured to sense an arc fault of a distribution panel, an arc removing unit configured to ground a fault current, and a control unit connected to the sensor and configured to measure a short circuit current value of the distribution panel, wherein when the arc fault is sensed and the short circuit current value corresponds to a three-phase short circuit current, the control unit drives the arc removing unit, and when the short circuit current value is smaller than the three-phase short circuit current, the control unit does not drive the arc removing unit.

A power management circuit has a power input terminal coupled to a power supply or a load, a power terminal configured to provide an output voltage, and a battery terminal coupled to a battery. The power management circuit further has a current limiting circuit, an over-current indication circuit and an over-current threshold selecting circuit. The current limiting circuit compares a current feedback signal indicative of an output current flowing out of the power terminal with a current threshold signal and generates a square wave signal. The over-current indication circuit generates an over-current indication signal based on the square wave signal. The over-current threshold selecting circuit selects a first over-current threshold voltage or a second over-current threshold voltage as an over-current threshold voltage based on the over-current indication signal, wherein the first over-current threshold voltage is higher than the second over-current threshold voltage.

An output module includes a first connection terminal, a second connection terminal, a power supply terminal, a controller, an output device, and a first cutoff switch. The first connection terminal is connected to a high potential side terminal of an external load. The second connection terminal is connected to a low potential side terminal of the external load. The power supply terminal is provided with an external power supply from an external power source. The output device is configured to operate by receiving a power supply generated by or based on the external power supply and to output an analog voltage or an analog current of a value instructed by the controller toward the first connection terminal. The first cutoff switch is configured to be controlled by the controller to open and close a first path between the second connection terminal and a ground.

A circuit breaker includes a circuit breaker housing, an air-gap switch disposed within the housing, and a first visual indicator configured to provide an indication of an open state and a closed state of the air-gap switch. The first visual indicator includes a first window that is formed as part of the circuit breaker housing, and first and second indicator elements disposed within the circuit breaker housing. The first indicator element is configured to move into position behind the first window as the air-gap switch is placed into the open state and thereby provide a visual indication of the open state of the air-gap switch. The second indicator element is configured to move into position behind the first window as the air-gap switch is placed into the closed state and thereby provide a visual indication of the closed state of the air-gap switch.

A hybrid circuit breaker for interrupting a current in an electrical circuit line, the hybrid circuit breaker includes an input terminal for connection to a power line and an output terminal for connection to a DC system, a first solid state switching device connected to the input terminal, and a mechanical isolator relay arranged in series with the first solid state switching device and connected to the output terminal. The hybrid circuit breaker further includes a crowbar circuit electrically connected between the output terminal and ground or mid-pole, and a controller for controlling the first solid state switching device, the mechanical isolator relay and the crowbar circuit.

An electrical system forming part of a solar power plant is described. The electrical system includes a plurality of photovoltaic (PV) panels, a power converter, and a controller. In response to a detected electric arc on the DC side of the power converter, the controller is configured to enable a short circuit state of the power converter by controlling semiconductor switches of the power converter (e.g., turning on some or all of the semiconductor switches) to create a short circuit between DC input terminals of the power converter. The short circuit path though the power converter will extinguish the detected electric arc in the connected DC circuit.