The present disclosure discloses a self-check chip of a leakage protector. The self-check chip includes a power-on reset circuit, used for resetting the self-check chip after being powered-on; a reference voltage module, used for providing a reference voltage for a comparator module; a bias circuit, used for providing direct-current bias for the reference voltage module, the comparator module and a ring oscillator; the comparator module, used for monitoring an open-circuit condition of a trip coil and the change of a thyristor anode voltage and generating a power frequency clock; the ring oscillator, used for providing a clock for a counting module and a digital processing module; the counting module, used for generating a self-check signal, a leakage trigger signal, a PHASE pin detection signal and a reset signal of the counting module and the digital processing module; a trip enabling signal generation module; and the digital processing module.

Provided is an apparatus and method for protecting against unsafe electric current conditions. A protections circuit may be used in a device, as an electric grill, that has one or more electric loads, such as heating elements. The protection circuit may protect against various failure scenarios, including, without limitation, instances of ground fault, over current, driver failure, and failure of a microprocessor. In response to a failure, the protection circuit may trip a latch relay or disable a triac driver to stop current from flowing.

A safety switch input diagnosis device includes a circuit formed from a series connection of an emergency stop switch and a line having a resistor. A connection state of the emergency stop switch and failure modes of the lines are diagnosed on the basis of a voltage value at one end of the circuit. Consequently, an operation of the switch and failure modes of a circuit relating to the switch can be diagnosed.

A ground fault detection circuit can include a band-pass filter that can have a first node and a second node that can be coupled to an earth ground. The first node can be coupled to a local ground of an automatic test equipment (ATE) system for an electrical device that can be coupled via at least one wire to the ATE. The band-pass filter can be configured to pass and amplify a test current signal established at the first node in response to a coupling of one of a conductor of the at least one wire carrying the test current signal to the local ground, and a conductive element of the electrical device carrying the test current signal to the local ground. A fault alert signal can be provided to provide an indication of ground fault based on a comparison of the amplified test current signal.

A ground fault detection circuit can include a band-pass filter that can have a first node and a second node that can be coupled to an earth ground. The first node can be coupled to a local ground of an automatic test equipment (ATE) system for an electrical device that can be coupled via at least one wire to the ATE. The band-pass filter can be configured to pass and amplify a test current signal established at the first node in response to a coupling of one of a conductor of the at least one wire carrying the test current signal to the local ground, and a conductive element of the electrical device carrying the test current signal to the local ground. A fault alert signal can be provided to provide an indication of ground fault based on a comparison of the amplified test current signal.

Systems and methods of providing fault protection on direct current (DC) feeds to various engine or generator set components are provided. In some embodiments, generator set includes a ground fault device arranged between a DC power distribution circuit and a subsystem of the generator set. The ground fault device is configured to detect a fault condition based on a comparison of a first current in a first wire with a second current in a second wire between the DC power distribution circuit and the subsystem. In response to detecting the fault condition, the ground fault device is configured to disconnect the subsystem.

The present invention relates to a residual current circuit breaker, RCCB, (100) for an electrical circuit (300). The RCCB comprises a first switching device (106) and a second switching device (140) coupled in series with each other between the power supply (302) and the load (304). The first switching device (106) is configured to switch into an OFF mode, in which no current is fed to the load (304), upon detecting that a value of a current i fed to the load (304) is larger than a switching current is of the first switching device (106). The second switching device (140) is configured to switch into an ON mode, in which the load (304) is short cut, upon detecting a leakage of the current i fed to the load (304). Thereby, a novel RCCB architecture is provided. When a current leakage is detected a short cut is introduced which means that the voltage will be zero over the load and no person will be harmed by the current in the circuit. Flowever, when the load is short cut there will be a current rush in the circuit which will trigger the first switching device to break the circuit and no current will thereafter flow in the circuit. The invention also relates to a circuit comprising such a residual current circuit breaker and a corresponding method.

Ground-fault circuit interrupter positioned between energy controlled supply circuit and load circuit which includes fault detection circuit that senses ground path current leakage to the load circuit, fault processing circuit that detects presence of fault and generates fault output signal when fault detected, and control circuit switch connected to fault processing signal output, wherein control circuit switch is opened by presence of fault output signal, thus isolating load circuit from supply circuit. Preferably fault processing circuit and control circuit are optically linked, such that when fault is detected, control circuit switch is opened by optical fault output signal, thus isolating load circuit from the supply circuit. Circuit interrupter may couple another circuit interrupter via power distribution control unit, optionally manageable remotely via automated control interface.

A device, system, and method is disclosed for improving safety of a power system. For example, a differential current may be detected using at least one sensor by temporarily enabling sampling of current flowing through one or more conductors. Additionally, current flow may be temporarily altered in order to sample current in a system. The measurements may be handled locally and/or remotely and appropriate actions may be taken to enhance the overall safety of the system.

A circuit for a circuit interrupter is provided. The circuit may in include a first SCR configured to receive a first trigger signal at a gate of the first SCR, a second SCR configured to receive a second trigger signal at a gate of the second SCR, and a third SCR configured to receive a third trigger signal at a gate of the third SCR. A cathode of the first SCR may be connected to an anode of the third SCR. A cathode of the second SCR and a cathode of the third SCR may be connected to a ground. Methods of operating a circuit interrupter and a circuit are also provided.