Power outlets adapted for installation within an enclosure are provided. Power outlets are provided having a safety interlock adapted to prevent the creation of a hazardous condition within the enclosure as a result of the continued operation of an electrical device within the enclosed space. The safety interlock may include current limiting circuitry and hardware, hazard sensing devices interconnected with such current limiting circuitry and hardware or other circuit breaker switches, and combinations of such safety interlocks.

The invention relates to an elevator comprising at least one elevator car moved by at least one elevator motor, which elevator motor is driven by a frequency converter controlled by a control device of the elevator, the frequency converter comprising a rectifier bridge, an inverter bridge and a DC link connected in-between, the inverter bridge being connected to the elevator motor and the rectifier bridge being connected to AC mains via three phase supply lines comprising an LCL-filter and a mains switch. The elevator further comprises a backup power supply and a safety device of the control device, which in case of a mains power failure is configured to switch off the mains switch and to connect the backup power supply to the DC link and/or to at least one phase supply line, whereby the rectifier bridge is a bidirectional rectifier bridge being configured to convert DC supplied to the DC link from the backup power supply to an AC voltage supplied to at least two of the phase supply lines connected with at least one load circuit. An earth fault protection circuit for the load circuit is connected between earth and a common terminal of the capacitors of the LCL filter for monitoring an earth fault indicating signal, and which earth fault protection circuit is configured to issue an earth fault signal and/or initiating earth fault safety measures, dependent on the earth fault indicating signal.

A metering and control subsystem for a photovoltaic solar system is configured for metering the photovoltaic solar system using current measurement devices and individually controlling relays to selectively energize photovoltaic branch circuits. In some examples, the metering and control subsystem includes photovoltaic branch connectors, a relay matrix, current measurement devices, and a metering and relay control circuit. The metering and control circuit is configured for metering the photovoltaic solar system using current measurement data from the current measurement devices and individually controlling the relays to selectively energize each photovoltaic branch circuit.

An arc detection device includes: a current detector that includes a magnetic core penetrated by first and second paths and each connecting a DC power source and a device, and detects a current flowing through each of the first and second paths and in accordance with a magnetic field generated at the magnetic core; a low impedance circuit having a lower impedance than the DC power source and the device, the low impedance circuit being connected to the first path and the second path to cause a high frequency component to bypass one of the first path or the second path; and an arc determiner that determines an occurrence of an arc based on a current detected by the current detector. In the magnetic core, a direct current flows through the first path in a direction opposite to a direction in which a direct current flows through the second path.

A power cord includes multiple current-carrying wires covered by an outer insulating layer, each wire including a current-carrying conductor covered by an insulating layer. At least one wire further includes a shield layer covering the insulating layer and a metal conductor between the insulating layer and the shield layer. The shield layer is formed of a band wound around the metal conductor and insulating layer. The outward-facing surface of the band is insulating; the inward-facing surface has one or more conductive regions and one or more insulating regions. One insulating region is located along a longitudinal trailing edge of the band. Consecutive turns of the band partially overlap each other; the trailing edge of a subsequent turn is disposed over part of a previous turn. The structure ensures effective insulation of the metal conductor from other components. The power cord is used in a leakage current detection and interruption device.

A system and method that identify a location and/or magnitude of a ground fault in a circuit having a bus that connects battery strings with loads and a ground reference between the loads are provided. Potential of the bus is shifted relative to a ground reference in a first direction. A first impedance in the bus between the battery strings and the ground reference is determined, and the bus is shifted relative to the ground reference in a second direction. A second impedance in the bus between the battery strings and the ground reference is determined. A location and/or severity of a ground fault is determined based on a relationship between the first impedance and the second impedance.

An ESD clamp circuit has an ESD detection circuit connected between a first terminal and a second terminal, with a first output node and a second output node. The ESD detection circuit is configured to output respective first and second control signals at the first and second output nodes in response to an ESD event. A discharge circuit includes a p-type transistor having a source, a drain and a gate, with the gate connected to the first output node. An n-type transistor has a source, a drain and a gate, with the gate connected to the second output node. The drain is connected to the drain of the p-type transistor. The discharge circuit is configured to establish a first ESD discharge path from the first terminal, through the p-type transistor and the n-type transistor, to the second terminal, and to further establish a second ESD discharge path in parallel with the first ESD discharge path. The second ESD discharge path includes a parasitic silicon controlled rectifier (SCR).

A series Z-source circuit breaker including a semiconductor switch that breaks source power being provided to a load in response to overcurrent. An electromechanical switch is electrically coupled in parallel with the semiconductor switch, a first capacitor is electrically coupled to an output side of the semiconductor switch, a second capacitor is electrically coupled in parallel with the semiconductor switch, and a delay circuit is electrically coupled in series with the first capacitor. The semiconductor switch is in an open position and the electromechanical switch is in a closed position when overcurrent is not present. Upon detection of overcurrent the semiconductor switch is closed, the electromechanical switch is opened and the delay circuit is controlled to delay when reverse bias current is provided from the first capacitor to the semiconductor switch to prevent source power from being provided to the load to give the electromechanical switch time to open.

In order both to accommodate instantaneous current as well as overcurrent protection in accordance with the load, an overcurrent protection circuit has: a threshold value generation unit that, in accordance with a threshold value control signal, switches between setting an overcurrent detection threshold value to a first set value (∝ Iref) and a second set value (∝ Iset) lower than the first set value; an overcurrent detection unit that compares a sense signal in accordance with the current being monitored and the overcurrent detection value and generates an overcurrent protection signal; a reference value generation unit that generates a reference value (∝ Iset) in accordance with the seconds set value; a comparison unit that compares the sense signal and the reference value, and generates a comparison signal; and a threshold value control unit that monitors the comparison signal, and generates a threshold value control signal.

A circuit interrupting device including a fault detection circuit and an auto-monitoring circuit. The fault detection circuit is configured to output a pre-trigger signal, wherein the pre-trigger signal is configured to not place the circuit interrupting device in a tripped condition. The auto-monitoring circuit is configured to monitor an auto-monitoring input signal, wherein the value of the auto-monitoring signal is at least partially determined by a value of a pre-trigger signal generated.