A wiring device including an interrupting device and a controller. The interrupting device electrically connects one or more line terminals to one or more load terminals when the interrupting device is in a reset condition and disconnects the line terminals from the load terminals when the interrupting device is in a tripped condition. The controller is configured to, determine a frequency of an input voltage at the one or more line terminals, determine whether the frequency is within a predetermined range, and when the frequency is within the predetermined range, perform a test of the wiring device.

A GFCI includes a current sensor system providing a current sensor signal indicating a leakage current of the AC power system. At least one signal conditioning channel conditions the current sensor signal to provide a conditioned current sensor signal. An integrated circuit-based controller is configured to receive the conditioned current sensor signal. The integrated circuit-based controller is configured to execute instructions stored in at least one nontransitory memory medium to determine at least one frequency value and at least one magnitude value of the conditioned current sensor signal, evaluate a trip condition in response to the at least one frequency value and the at least one magnitude value, and provide a fault trip signal in response to evaluation of the trip condition. A circuit breaker mechanism is configured to open a circuit of the AC power system in response to the fault trip signal.

Various embodiments disclosed herein provide techniques for detecting electrical arcing in an electrical system. The techniques include a network device receiving first voltage or current readings associated with a first power cycle, receiving second voltage or current readings associated with a second power cycle, determining that an electrical arcing condition is present by comparing the first voltage or current readings with the second voltage or current readings, and performing a remedial operation in response to determining that the electrical arcing condition is present.

Various embodiments disclosed herein provide techniques for detecting electrical arcing in an electrical system. The techniques include a network device receiving first voltage or current readings associated with a first power cycle, receiving second voltage or current readings associated with a second power cycle, determining that an electrical arcing condition is present by comparing the first voltage or current readings with the second voltage or current readings, and performing a remedial operation in response to determining that the electrical arcing condition is present.

A modular load management system comprises one or more compact modules designed to fit in the wiring troughs of a standard AC distribution panel of a building. The modules include one or more input terminals to receive electrical power from one or more circuit breakers in the panel and deliver power to load circuits of the building via one or more output terminals. The modules contain at least one disconnect switch for disconnecting circuits from breakers in response to a remote or locally-generated control signal. The modules may also include current sensors on some or all terminals, such that power and energy flow may be monitored on a per-circuit basis.

A first switch for connection in a first circuit path between a PV panel string and an inverter in a power system, and a second switch for connection in a second circuit path across an output of the PV panel string, are normally closed and open, respectively, during non-fault operation of the power system. Both series and parallel arc faults in the power system can be extinguished by further control of the switches. Arc fault detection could be based on probabilistic frequency analysis of current or power flow measurements in the PV panel string, current or power imbalance, interruption in communications with the PV panels, or combinations of these techniques.

A first switch for connection in a first circuit path between a PV panel string and an inverter in a power system, and a second switch for connection in a second circuit path across an output of the PV panel string, are normally closed and open, respectively, during non-fault operation of the power system. Both series and parallel arc faults in the power system can be extinguished by further control of the switches. Arc fault detection could be based on probabilistic frequency analysis of current or power flow measurements in the PV panel string, current or power imbalance, interruption in communications with the PV panels, or combinations of these techniques.

A GFCI includes a current sensor system providing a current sensor signal indicating a leakage current of the AC power system. At least one signal conditioning channel conditions the current sensor signal to provide a conditioned current sensor signal. An integrated circuit-based controller is configured to receive the conditioned current sensor signal. The integrated circuit-based controller is configured to execute instructions stored in at least one nontransitory memory medium to determine at least one frequency value and at least one magnitude value of the conditioned current sensor signal, evaluate a trip condition in response to the at least one frequency value and the at least one magnitude value, and provide a fault trip signal in response to evaluation of the trip condition. A circuit breaker mechanism is configured to open a circuit of the AC power system in response to the fault trip signal.

A charging apparatus for use with an electric vehicle includes a power transmission path, a switch, a first controller, a communication unit, and a second controller. The switch is disposed on the power transmission path. The communication unit is coupled to a second connection port. The first controller is coupled to the power transmission path, the switch, the second controller, and the communication unit. When the second controller receives a first request from a power management system and correspondingly notifies the first controller, the first controller switches from a first signal to a second signal to communicate with the electric vehicle and turns off the switch, and when the first controller receives a first EV notification provided from the electric vehicle, the controller turns on the switch.

An uninterruptible power supply device provided between a commercial power system and an essential load and supplying AC power to the essential load includes: a power supply part that has an energy storage device and is connected to a power line for supplying power from the commercial power system to the essential load; an open switch for opening/closing the power supply line, the open switch being provided on the power line on the commercial-power-system side of the power supply part; a system abnormality detection part for detecting a system abnormality occurring on the commercial-power-system side of the open switch; and a control part that, when the detected system abnormality is equal to or greater than the tolerance of the essential load or the power supply part against system abnormalities, opens the open switch and supplies AC power from the power supply part to the essential load.