A remote load switching circuit breaker includes a primary contact; a secondary contact in series with the primary contact and coupled to a secondary contact driving circuit, where the secondary contact is switched on and off remotely by a user using a user device communicatively coupled to the remote load switching circuit breaker via wireless communications technologies; a shunt element structured to measure a shunt voltage drop and to tap power from a line side of the primary contact; a control circuit comprising a controller and a communication module, the controller including a firmware; and a power supply and sensing circuit structured to supply power to the control circuit and to sense various voltages, where the secondary contact is fully powered by the power supply and sensing circuit.

A method and system are provided to control circuit breaker operations. In the method and system, near-field RF signal is monitored at or around electrical contacts of the circuit breaker using at least one near-field radio frequency (RF) sensor, and far-field RF signal away from the contacts of the circuit breaker are monitored using at least one far-field RF sensor. A rate of change of current over time is also monitored on the circuit using at least one sensor. An arc fault on the circuit is detected based on the monitored near-field RF signal, the monitored far-field RF signal, and the monitored rate of change of current. A tripping operation is implemented on the circuit breaker to disconnect the power supply from the circuit, in response to the detection of the arc fault.

A method and system are provided to control circuit breaker operations. In the method and system, near-field RF signal is monitored at or around electrical contacts of the circuit breaker using at least one near-field radio frequency (RF) sensor, and far-field RF signal away from the contacts of the circuit breaker are monitored using at least one far-field RF sensor. A rate of change of current over time is also monitored on the circuit using at least one sensor. An arc fault on the circuit is detected based on the monitored near-field RF signal, the monitored far-field RF signal, and the monitored rate of change of current. A tripping operation is implemented on the circuit breaker to disconnect the power supply from the circuit, in response to the detection of the arc fault.

A circuit breaker includes a set of separable contacts moveable between a closed position and an open position, an operating mechanism configured to open the set of contacts, a conductor coupled to the set of contacts, a current transformer coupled to the conductor, and a trip circuit coupled to the operating mechanism and to the current transformer and configured to cause the operating mechanism to open the set of contacts when a current through the conductor exceeds a current threshold that is greater than a saturation threshold of the current transformer. The trip circuit is further configured to vary the current threshold during an interval following a closure of the set of the contacts and to provide a fixed current threshold thereafter.

A circuit breaker includes a set of separable contacts moveable between a closed position and an open position, an operating mechanism configured to open the set of contacts, a conductor coupled to the set of contacts, a current transformer coupled to the conductor, and a trip circuit coupled to the operating mechanism and to the current transformer and configured to cause the operating mechanism to open the set of contacts when a current through the conductor exceeds a current threshold that is greater than a saturation threshold of the current transformer. The trip circuit is further configured to vary the current threshold during an interval following a closure of the set of the contacts and to provide a fixed current threshold thereafter.

A protection device comprises a resin base, PTC component, bimetal component, arm and upper plate which are housed in a resin housing wherein the base includes a terminal integrated with the base by insert molding. A resin cover is formed by insert molding to cover the PTC component, bimetal component, arm and upper plate which are superposed in this order over the terminal within a space in the base. The space in the resin base is substantially closed by the upper plate, the base and the cover are integrally bonded to define the resin housing, the terminal and the arm are electrically connected in series in a normal state, and in an abnormal state where the bimetal component is activated, the terminal and the arm are electrically cut off, while the terminal, PTC component, bimetal component, and arm are electrically connected in series in this order.

A protection device comprises a resin base, PTC component, bimetal component, arm and upper plate which are housed in a resin housing wherein the base includes a terminal integrated with the base by insert molding. A resin cover is formed by insert molding to cover the PTC component, bimetal component, arm and upper plate which are superposed in this order over the terminal within a space in the base. The space in the resin base is substantially closed by the upper plate, the base and the cover are integrally bonded to define the resin housing, the terminal and the arm are electrically connected in series in a normal state, and in an abnormal state where the bimetal component is activated, the terminal and the arm are electrically cut off, while the terminal, PTC component, bimetal component, and arm are electrically connected in series in this order.

A reverse fault current interruptor (RFCI) may be employed in one or more locations in an electrical power system. In one example, an RFCI may be installed in a combiner box of a solar power system. The RFCI may include a reverse current detector and a circuit protector such as a circuit breaker, operable in combination to clear a line-line fault in the combiner box. The RFCI enables a reduction of incident energy levels through detection of a reversal in a fault current characteristic of some DC power systems, where a traditional overcurrent protection device (OCPD) (e.g., fuse, breaker) may not trip in the same period of time.

A circuit breaker is for protecting a low-voltage circuit when current or current-time limits are exceeded in the low-voltage circuit. The circuit breaker includes an electronic trip unit which initiates an interruption or reduction of the current flow in the low-voltage circuit when first current or current-time limits are exceeded, and second current or current-time limits stored in the electronic trip unit, which are characterized by lower current limits or lower current-time limits, the second limits being activatable by an initiated switchover. A communication unit connected to the electronic trip unit is provided, which enables wireless communication, and the circuit breaker is designed such that when a wireless communication signal is received that exceeds a field strength value, the second limits are activated.

A circuit breaker arrangement includes a housing, a contact seated in the housing, and a lead in electrical communication with the at least one contact and disposed outside the housing. The circuit breaker arrangement includes a heat sink in thermal communication with the lead to transfer heat between the contact and the lead.