An electric appliance (100) is disclosed. The electric appliance has an electric load (205), and a driving element (215) for selectively energizing/de-energizing the electric load (205). The driving element (215) has a first driving terminal (A.sub.1) coupled to a first load terminal (T.sub.1) of the electric load, a second driving terminal (A.sub.2) coupled to a first power supply terminal (T.sub.N), and a control terminal (G) for switching on/off the driving element (215) thereby allowing said selective energization/de-energization, respectively. The electric appliance also has a switching element (230) for selectively coupling a second power supply terminal (T.sub.L) to a second load terminal (T.sub.2) of the electric load (205). The electric appliance (100) further has a detection arrangement (210,220) configured for detecting a first electrical quantity (V.sub.A1) at the first driving terminal (A.sub.1), and at least one between a second electrical quantity (V.sub.T2,CL,V.sub.T2,OP) at the second load terminal (T.sub.2) and a power supply electrical quantity (V.sub.MAINS) at the second power supply terminal (T.sub.L). The detection arrangement (210,220) has a coupling element (220) coupling the first driving terminal (A.sub.1) to the second load terminal (T.sub.2), and a control unit (210) coupled to the first driving terminal (A.sub.1), and to at least one between the second load terminal (T.sub.2) and the second power supply terminal (T.sub.L). The control unit (210) is further configured for determining dispersion of electric power towards ground in the electric load (205) according to the detected electrical quantities.

The invention relates to a method for detecting a direct-current fault current in an electrical alternating-current circuit, wherein a rectifier unit (14) is connected to an alternating-current network (34) by means of a primary side (13) and provides a direct current on a secondary side (15) and wherein the alternating-current network (34) is protected by means of a fault-current circuit breaker (38), which interrupts the circuit if an alternating-current fault current greater than a specified alternating-current tripping threshold occurs. A direct-current fault current on the primary side (13) is measured and is compared with a specified direct-current tripping threshold. An alternating-current fault current is produced if the direct-current fault current lies above the tripping threshold. The invention further relates to a device (10) for detecting a direct-current fault current and to a charging apparatus (12) comprising such a device (10).

Systems and methods for electronics systems are provided herein. An electronics system may comprise a heating circuit and a fault detection system. The heating circuit may include a heating element. The fault detection system may include a current-to-voltage converter, a voltage level detector, and a controllable switch connected in series with the heating element, the controllable switch in electronic communication with the voltage level detector. A fault may be detected in response to a secondary voltage being greater than a threshold value.

Disclosed are a circuit with a timing function and a leakage protection plug. An output terminal of a timing chip U2 is connected to an isolating switch U3; the isolating switch U3 is connected to a rectifier module D3; the rectifier module D3 is connected to a circuit breaker X1; a switch tube Q4 and the switch tube Q3 are connected to a resistor R21, and a second switch terminal of the switch tube Q4 is grounded; an output terminal of a zero sequence current transformer is connected to a first input terminal of a microprocessor U1; and an output terminal of the microprocessor U1 is connected to a control terminal of the switch tube Q4. The leakage protection plug of this disclosure has both leakage protection and timing functions.

A wiring device including an interrupting device, a fault detection circuit, and a testing circuit. The interrupting device is electrically connecting one or more line terminals to one or more load terminals. The fault detection circuit is configured to detect a fault condition and generate a fault detection signal in response to detecting the fault condition. The fault detection signal being provided to the interrupting device to place the interrupting device in a tripped condition. The testing circuit is configured to determine a frequency of an input voltage at the one or more line terminals, filter the frequency of the input voltage, determine whether the filtered frequency is within a predetermined range, and when the filtered frequency is within the predetermined range, perform a test of the wiring device.

An apparatus includes a safety fault interrupter circuit. The safety fault interrupter circuit includes a safety fault monitor coupled to a first bias node and configured to selectively assert a fault interrupter signal based at least in part on a first bias voltage and a first power consumption. The safety fault interrupter circuit also includes a power fault monitor for the safety fault monitor, wherein the power fault monitor is coupled to a second bias node and is configured to selectively assert the fault interrupter signal based at least in part on a second bias voltage and a second power consumption that is less than the first power consumption.

The present disclosure relates to an inverter system capable of detecting an output ground fault and an output ground fault detection method using same and, particularly, to an inverter for detecting an output ground fault by detecting the current of a leg-shunt resistor, and an inverter output ground detection fault method using same. The present disclosure compares absolute peak values of 3-phase current AD raw values detected from a shunt resistor, and thus may reliably detect the output ground fault of an inverter.

A circuit interrupter device includes line hot, line neutral, load hot, and load neutral terminals, a solid-state switch, internal short-circuit switch circuitry, and control circuitry. The solid-state switch is connected in an electrical path between the line hot and load hot terminals. The internal short-circuit switch circuitry comprises an internal short-circuit switch and a shunt resistor serially connected between the line hot and line neutral terminals. The control circuitry is configured to detect for an occurrence of a fault condition and in response to detecting the occurrence of a fault condition, the control circuitry is configured to drive the solid-state switch into a switched-off state, and activate the internal short-circuit switch to generate an internal short-circuit path between the line hot and line neutral terminals and allow short-circuit current to flow through the shunt resistor between the line hot terminal and the line neutral terminal of the circuit interrupter device.

A wiring device including one or more line terminals and a controller. 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 mining machine including a motor, an adjustable speed drive providing a voltage to the motor, the voltage having an excitation component comprising a magnitude and a frequency for operating the motor at a desired speed and including an additional voltage component for use in detecting a ground fault condition, and a ground fault relay for detecting a ground fault current when the ground fault current exceeds a predetermined threshold.