Abstract: A charging device includes: a plurality of main relays forming a connection between an electric vehicle (EV)-side connector and an outlet-side connector; a relay welding sensing unit connected to the plurality of relays to sense the presence or absence of welding of the plurality of relays; a welding monitoring relay opening and closing between the relay welding sensing unit side node and a main relay side node; and a control unit controlling the open and close of the welding monitoring relay.

Abstract: A system and method includes a circuit for protecting a photovoltaic string. A bypass switch connects in parallel to the photovoltaic string and a hot spot protection switch connects in series with the photovoltaic string. A first control signal controls opening and closing of the bypass switch and a second control signal controls opening and closing of the hot spot protection switch. Upon detection of a hot spot condition the first control signal closes the bypass switch and after the bypass switch is closed the second control signal opens the hot spot protection switch.

Abstract: An overheat-protection device with a cord that includes a transmission wire to transmit electrical power and a sensor wire to transmit a signal, a plug attached to an end of the cord, and a thermistor includable in the plug and connected to the sensor wire. The signal may be received and/or analyzed by a sensing device, which may control a switching device to open and/or close a power circuit. The thermistor may detect a level of heat, which may be communicated as a signal via the sensor wires. The signal may be definable by the thermistor varying a level of resistance to the signal responsive to the level of detected heat. The thermistor may be a NTC thermistor and may be constructed from a thermal plastic or a ceramic.

Abstract: A differential protection device is designed for an electric disconnecting apparatus, the disconnecting apparatus comprising at least one fixed contact suitable for being connected to a corresponding electrical conductor, at least one movable contact, between a closed position, the movable contact being electrically connected to the corresponding fixed contact in the closed position and electrically isolated from the corresponding fixed contact in an open position, and an actuator for activating opening of the movable contacts when a differential fault is detected. The differential protection device comprises a controller for controlling the actuator. The differential protection device further comprises measuring circuitry for measuring an electrical variable associated with the controller and inhibiting circuitry for inhibiting the controller when the measured electrical variable satisfies a predetermined criterion.

Abstract: A method and program for minimizing objectionable currents while still providing neutral-to-ground voltage measurements by controlling a switch to determine when the neutral-to-ground impedance is placed in an electrical circuit.

Abstract: This document discusses, among other things, a self-test (ST) ground fault circuit interrupter (GFCI) monitor configured to generate a simulated ground fault starting in a first half-cycle of a first cycle of AC power and extending into a second half-cycle of the first cycle of AC power, wherein the first half-cycle of the first cycle of AC power precedes the second half-cycle of the first cycle of AC power. Further, the ST GFCI monitor can detect a response to the simulated ground fault.

Abstract: A system and method for detecting faults within an electrosurgical instrument having a shield and an active electrode uses multiple possible fault conditions. In one embodiment the monitoring system comprises an electrosurgical generator coupled to the electrosurgical instrument and adapted to deliver power to the active electrode of the electrosurgical instrument, monitoring circuitry coupled to the electrosurgical generator and the electrosurgical instrument.

Abstract: A device for detecting a fault in an AC supply comprising a detection circuit for detecting a fault in an AC supply to a load and providing a corresponding output. A disconnect circuit disconnects the load from the supply in response to an output from the detection circuit. The device also includes a generator of intermittent test pulses, and a test circuit coupled to the detection circuit and containing a first solid state switch. Each test pulse turns on the solid state switch for the duration of the test pulse so that a current simulating the fault flows intermittently in the test circuit and a corresponding output is provided by the detection circuit. The device further comprising means to disable the disconnect circuit in response to each test pulse.

Abstract: A switching device has a current transformer for measuring in a potential-free manner a current to be switched by the switching device, a current sense amplifier, to which the unrectified measurement current of the current transfer is fed on the input side, and a controller, to which the output current of the current sense amplifier is fed on the input side and which is configured so as to digitalize the fed output current and to perform one or more performance-related measurements and to output the measurement results.

Abstract: A software code operates with a circuit interrupting device having an auto-monitoring circuit including a controller for automatically testing various functions and structures of the device. The auto-monitoring circuit initiates the software code which includes an auto-monitoring routine which, among other things, establishes a self-test fault during the positive or negative half-wave of an AC power cycle and determines whether the detection mechanisms within the device properly detect the self-test fault. Moreover, the software code executed by the controller compares sensed voltages from test signals with a determined or set maximum voltage value and compares the sensed voltages with a set or determined minimum voltage value. The sensed voltages must be greater than the maximum voltage value or lower than the minimum voltage value for a predetermined number of counts before an end-of-life state is determined for the circuit interrupting device.

Abstract: Embodiments of the present disclosure include a method of operating an arc fault detection system, an arc fault detection system, and a system. An embodiment is a method of operating an arc fault detection system coupled to a power line, the method including determining one or more arc fault detection windows in power line signals on the power line, the power line signals comprising a communication signal and an alternating current (AC) power signal. The method further includes receiving the power line signals from the power line during the one or more arc fault detection windows, and performing arc fault detection processing on the received power line signals.

Abstract: A circuit interrupter includes a first terminal structured to electrically connect to a power source, a second terminal structured to electrically connect to a load, separable contacts electrically connected between the first terminal and the second terminal and being moveable between a closed position and an open position, an operating mechanism structured to trip open the separable contacts, an electronic trip unit structured to detect a fault condition based on power flowing between the first and second terminals and to retrieve diagnostic or setting information associated with the circuit interrupter, and a wireless unit structured to provide the setting or diagnostic information associated with the circuit interrupter to an external device via a wireless communication protocol.

Abstract: A method for reconstituting a diagram of an electrical installation including a plurality of electrical elements connected to a power source via protective elements arranged in an electrical panel. The wired electrical elements of the installation are identified using the electrical panel. The tree structure of the electrical connections of the elements identified and the position of each element in the arborescence are automatically determined. An electrical diagram of the installation is deduced using the tree structure of the electrical connections and the position of each element in the arborescence.

Abstract: Power conversion systems and methods are presented for detecting input filter capacitor degradation or approach of end of operational life based on filter capacitor current measurements using single and/or dual threshold comparisons for computed instantaneous sum of squares of filter currents or power values.

Abstract: The present invention discloses a leakage current detecting circuit-breaker with a flexible shield cord, which comprises a detection circuit, a trigger circuit and a tripping mechanism. The detection circuit comprises a flexible shield cord, a zero sequence current transformer and diodes connected in series. The flexible shield cord comprises a foil wrapped around outer insulating layers of a live line and a neutral line and a tinned copper wire between the outer insulating layers and the foil. The flexible shield cord senses an abnormal or fault signal of a power line, and the zero sequence current transformer amplifies the abnormal or fault signal to such an extent as to trigger the trigger circuit. The diodes comprise a fifth diode and a sixth diode; anodes of the fifth diode and the sixth diode are connected to each other, and cathodes of the fifth diode and the sixth diode are respectively connected to the live line and the neutral line.

Abstract: An arc fault detection circuit for an arc fault circuit interrupter (AFCI). The arc fault detection circuit includes an arc detecting circuit for detecting an arc fault in one or more power supply lines and outputting a detected signal, an arc filtering circuit electrically coupled to an output terminal of the arc detecting circuit for removing signal parts unrelated to the arc fault from the detected signal and outputting a filtered half-cycle signal, and an arc processing circuit electrically coupled to an output terminal of the arc filtering circuit for generating, based on the filtered half-cycle signal received, a processed half-cycle signal characterizing the arc fault. The arc fault detection circuit also includes simulated arc testing circuit that has a user-touchable test switch, and an arc oscillator to generate a simulated arc fault signal for testing the arc fault detection circuit or its respective components.

Abstract: A circuit interrupter includes phase and neutral conductive paths between a line side and a load side of the circuit interrupter. Differential and ground/neutral transformers are coupled to the phase and neutral paths. A circuit interrupter chip is coupled to the phase and neutral conductive paths, and to respective fault inputs from the transformers. A calibration circuit including a calibration resistor is coupled to a circuit interrupter controller. An interrupter circuit is configured to open the phase and neutral paths when a predetermined ground fault current condition is sensed. The circuit interrupter controller is configured to perform a self-calibration function to adjust a ground fault current trip-time response to maintain the ground fault current trip-time response within a predetermined range. Methods for using the self-calibrating circuit interrupter are also disclosed.

Abstract: A power control device includes a multiple socket-outlet, a power plug and a power supply control circuit. The control circuit includes a power output unit, a first relay and a second relay, a first capacitor, a mechanical switch, an electronic switch and a connector connected to the host of a computer to receive a first voltage. The mechanical switch is turned on to supply power to the multiple socket-outlet, the first relay is closed, the power output unit outputs a working voltage for charging the first capacitor, the electronic switch is turned on, the second relay is closed. If the connector is turned off, the electronic switch is turned off, and the second relay is turned off so that the the multiple socket-outlet is closed.

Abstract: An AC arc fault detection module includes a current detecting section having at least one output and being structured to determine whether at least one signal based on a current measured from an AC phase line exceeds at least one corresponding predetermined threshold level and cause the at least one output to indicate that the threshold has been exceeded. The module also includes a processing device structured to: (i) receive the at least one output, (ii) determine whether an arc fault in the AC electrical system has occurred based on at least the at least one output, (iii) determine an estimation of background noise based on at least one signal indicative of a current on the AC phase line, and (iv) adjust the at least one corresponding predetermined threshold level based on the estimation of background noise.

Abstract: A method for detecting fault conditions in a motor drive at power up is disclosed. During the power up sequence, input power is applied to the motor drive and the DC bus begins to charge to its normal operating level. Once the DC bus has reached a suitable level and prior to commanding motion of the attached motor, the shunt resistor is connected across the DC bus for a short duration. The amplitude of voltage and current present on the DC bus are measured while the shunt resistor is connected across the DC bus. The measurements are then used to detect fault conditions in the motor drive. The presence of the fault conditions are relayed to an operator. Thus, the motor drive may detect certain fault conditions prior to commanding motion from the drive.

Abstract: An electric leakage determination circuit for an electric leakage circuit breaker according to the invention comprises a zero current transformer on an alternating-current circuit to provide an electric leakage detection signal upon occurrence of electric leakage, a filter circuit unit connected to an output terminal of the zero current transformer to remove noise, and an electric leakage determination circuit unit comparing a voltage value of the electric leakage detection signal with a first reference voltage value, to be charged with electric charges when the voltage value is not smaller than the first reference voltage value and discharge electric charges when being smaller than the first reference voltage value, and comparing a charged voltage value with a second reference voltage value to determine occurrence of electric leakage when the charged voltage value is not smaller than the second reference voltage value.

Abstract: A circuit interrupting device having an auto-monitoring circuit for periodically testing various functions and structures of the device. The auto-monitoring circuit initiates an auto-monitoring routine which, among other things, generates a self-test fault condition and determines whether the detection mechanisms within the device properly detect the self-test fault. Processing an early detection signal determines whether the self-test fault was properly detected without interfering with the normal operation of the detection circuitry and without causing a false trip within the device. Additional functionality of the auto-monitoring circuit permits automatic verification that the device is properly wired, that is, not miswired, and determines whether the device has reached the end of its useful life.

Abstract: A fault current detection circuit comprises a primary current transformer that detects a current; a pair of secondary current transformers that convert a current detection signal into secondary conversion signals with a small current; a fault detection circuit section that determines whether or not a fault current occurs by comparing a current value according to a secondary conversion signal with a predetermined reference current value; a surge detection circuit section that determines whether or not a surge current occurs on the electric power circuit; and a trip determination unit that receives a fault detection signal and a surge detection signal, and generates a trip control signal when at least either one of the fault detection signal and the surge detection signal is received.

Abstract: Systems and methods of detecting ground faults in energy storage and/or generation systems that can detect ground faults on the DC and/or AC side of an energy storage/generation system, and generate warning signals and/or shutdown at least part of the system upon detection of such ground faults. The systems and methods can monitor levels of DC voltages and amplitudes of AC voltages occurring on the positive and negative side of a DC bus with respect to ground on the DC side of the energy storage and/or generation system, and process the monitored DC voltage levels and AC voltage amplitudes to detect a ground fault. Having detected such a ground fault, the systems and methods can generate a warning signal and/or shutdown at least part of the system, for example, by disconnecting a DC energy system from the DC bus, and/or by disabling a DC-to-AC bidirectional inverter included in the system.

Abstract: For monitoring an inverter that includes separate input-side connectors for multiple direct-current generators with regard to the occurrence of a critical fault current, differential currents in at last two pairs of input lines are measured separately in the inverter. The at last two pairs of input lines conduct the currents that are fed in at different input-side connectors, and all pairs of input lines in their entirety transmit all currents that are fed in at the connectors. The differential currents are compared with a limit value separately for each pair of input lines. A case of the limit value being exceeded is recognized as a fault. In addition, a sum of simultaneously occurring differential currents in all pairs of input lines is determined and the sum is compared with a further limit value, wherein a case of the further limit value being exceeded is also recognized as a fault.

Abstract: A circuit breaker baying a switch housing and at least one contact for tapping a voltage on a primary conductor.

Abstract: The present invention is an in-vehicle charger for detecting ground faults originating in sections in which alternating current is flowing. This device is an in-vehicle charger (100) for charging a vehicle-mounted battery, wherein the device is provided with: a bridge rectifier (14) for converting alternating current supplied from a power source to direct current; a ground fault detecting circuit (21) for outputting a test voltage when a test current flows in a circuit in the in-vehicle charger (100) and, based on changes in the test current in response to the presence or absence of a ground fault resistor, for detecting a ground fault in the circuit of the in-vehicle charger (100); and a controller (23) for controlling the ground fault sensing circuit (21) so as to output a test voltage exceeding the forward voltage of a diode provided by the bridge rectifier (14).

Abstract: A device includes an integrated circuit programmed with an operating surface equation. The operating surface equation may define an operating point as a function of operating voltage, operating frequency, leakage current, and one or more additional operating factors. The additional operating factors may be, for example, an operating temperature of the integrated circuit, a number of active execution units in the integrated circuit, and/or an age of the integrated circuit. The operating surface equation may be adjusted based on changes in one or more of the additional operating factors. Changes in the operating surface equation may change the operating surface of the integrated circuit. Thus, operating points (e.g., operating voltage) of the integrated circuit may be adjusted in response to changes in the additional operating factors.

Abstract: Systems and methods for protecting an electrical component in an alternating current system that includes a transformer are disclosed. In one aspect, a circuit includes a switch assembly connected between a transformer neutral of a transformer and a ground and having an open position and a closed position. In normal operation, the switch remains in a closed position.

Abstract: Circuit configuration for error reporting, having a signal transmitter (1) for issuing error signals, having an error reporting line (46) that is connected with an error report evaluation device (6), having a coupler (2) for galvanic separation of the error reporting line (46) from the signal transmitter (1), and having a power supply (5) for making available an operating voltage for the coupler (2). A connection circuit (3) is provided between coupler (2) and error reporting line (46), which places the error reporting line (46) at a predetermined potential, the error report potential, if the operating voltage of the coupler (2) is insufficient. The connection circuit (3) can furthermore be controlled by the coupler (2), in such a manner that if the signal transmitter (1) issues an error signal, the connection circuit (3) places the error signal onto the error reporting line (46).

Abstract: A motor driving device includes a failure detector detecting the failure of switching elements and diodes of an inverter circuit. When the failure detection unit detects a failure according to which a switching element of a phase C upper stage is not conducting, but does not detect a failure according to which the diode connected is not conducting, a motor is driven using the switching element paired with the faulty switching element and the switching elements of the other phase. When the failure detection unit detects the failure according to which the switching element of the phase C upper stage is not conducting, and detect the failure according to which the diode connected is not conducting, the switching element paired with the faulty switching element is maintained in an off state, and each of the switching elements of the other phase is on/off controlled.

Abstract: There is provided a water leakage detection device including a water leakage detection unit which is configured to detect water leakage, a water leakage detection circuit unit which is configured to be driven by a DC voltage from a DC power source and apply an AC voltage for detecting water leakage to the water leakage detection unit, and is configured to determine whether water is leaking based on a detection signal of the water leakage detection unit. The water leakage detection unit includes an insulating transformer having a primary side and a secondary side, the second side being connected to the water leakage detection unit, and a water leakage detection determining unit which is connected to the primary side of the insulating transformer.

Abstract: A protection system configured to protect plural DC voltage sources configured to be connected in parallel between first and second input terminals of a voltage inverter. The voltage inverter can convert a DC input voltage into an AC output voltage. Each DC voltage source is connected by a first electrical conductor to the first input terminal and by a second electrical conductor to the second input terminal. The protection system includes: for each DC voltage source, a first cut-off member and first detector of a defect of isolation of the first conductor with respect to an electrical ground, the first detector and associated first cut-off member connected in series between the corresponding DC voltage source and the first input terminal of the inverter; and a mechanism triggering, in event of detection of the isolation defect, the associated first cut-off member to open the electrical link corresponding to the first conductor.

Abstract: The protecting relay may include: an input conversion unit configured to receive the analog signal and sample the analog signal according to a pre-set sampling period; a multiplexer configured to selectively output any one of a plurality of signals output from the input conversion unit; a programmable gain amplifier (PGA) configured to set different gain values according to signals output from the multiplexer, and amplify a signal output from the multiplexer with a pre-set gain value; an analog-to-digital converter (ADC) configured to convert an analog signal output from the PGA into a digital signal; and a controller configured to determine whether the analog signal received through the input conversion unit includes a surge signal based on the plurality of sampled data which have been converted into the digital signal, and determine whether to perform a relay function based on the determination results.

Abstract: A power conversion device 300 includes: an AC/DC converter section 10 which has an initial charging circuit 36 that initially charges a smoothing capacitor 22 provided at an output portion, and converts alternating current power into direct current power; a DC/DC converter section 11 which performs voltage conversion of direct current power supplied from the smoothing capacitor 22; and a control unit 5 which controls output of the AC/DC converter section 10 and output supplied from the DC/DC converter section 11. The control unit 5 performs a predetermined charging from the initial charging circuit 36 to the smoothing capacitor 22 at start-up of the AC/DC converter section 10, and starts the operation of the DC/DC converter section 11 after completion of charging, whereby the circuit can be protected from an inrush current at start-up.

Abstract: A method for analyzing appliances in a power line network, comprises obtaining an electrical characteristic of the power line network, using a sensor that is connected to the power line network, and detecting an appliance connected to the power line network on the basis of the electrical characteristic of the power line network and a model profile. The model profile is based on electrical characteristics of one or more candidate appliances and on a configuration of the power line network.

Abstract: A power supply system includes: a switching power supply; a control device; an auxiliary power supply circuit, which is connected in parallel with the switching power supply with respect to an AC power supply, which includes an electricity storage unit for storing electricity by charging current fed from the alternating current power supply, and which feeds power to the control device; and a first switching unit for switching a connection state of the auxiliary power supply circuit to the alternating current power supply. The control device is configured to, upon starting up the switching power supply, switch the first switching unit into a state where the auxiliary power supply circuit is separated from the alternating current power supply.

Abstract: An appliance leakage current interrupter (ALCI) for interrupting the flow of current through a pair of lines extending between a source of power and a load. The appliance leakage current interrupter having a housing integrating components that would normally be positioned on an ALCI circuit board. The ALCI having a prong assembly for supplying power from a source of power to the remainder of the ALCI, the prong assembly having first and second contact prongs which are in a first embodiment integrated into an ALCI circuit and in a second embodiment integrated into the housing assembly.

Abstract: A method for analyzing appliances in a power line network comprises obtaining an electrical characteristic of the power line network, using a sensor that is connected to the power line network, extracting a line-neglecting feature from the electrical characteristic of the power line network, and detecting an appliance connected to the power line network based on the extracted line-neglecting feature.

Abstract: An AC motor controller is provided that utilizes a direct torque controller and primary and secondary control loops. The primary control loop operates in a relatively conventional manner, determining a voltage vector that sets the inverter switching variables for the motor's power inverter, where the voltage vector is based on the motor's torque and flux as estimated from the measured voltage and current of the motor. The voltage vector determined by the primary loop is selected and applied immediately upon completion of the corresponding primary control loop computational cycle. The secondary loop, utilizing a faster sampling rate than that of the primary loop, compares the measured phase current to a preset current limit. If the secondary loop determines that the measured phase current has exceeded the preset current limit, it sets a null voltage vector, thereby limiting transient over currents.

Abstract: The disclosure relates to a method for detecting an arc in a DC circuit. The method includes measuring and analyzing an AC component (IAC) of a current (I) flowing in the circuit and determining at least one parameter of the AC component (IAC). The level of a DC component (IDC) of the current (I) is varied and a degree of correlation between the level of the DC component (IDC) of the current (I) flowing in the DC circuit and the at least one parameter of the AC component (IAC) is determined. An arc is detected and selectively signaled based on the degree of the determined correlation. The disclosure also relates to an apparatus for carrying out the method and to an inverter comprising such an apparatus.

Abstract: An AC motor controller is provided that utilizes a direct torque controller and primary and secondary control loops. The primary control loop operates in a relatively conventional manner, determining a voltage vector that sets the inverter switching variables for the motor's power inverter, where the voltage vector is based on the motor's torque and flux as estimated from the measured voltage and current of the motor. Application of the voltage vector determined by the primary loop is delayed until initiation of the next primary control loop cycle. The secondary loop, utilizing a faster sampling rate than that of the primary loop, compares the measured phase current to a preset current limit. If the secondary loop determines that the measured phase current has exceeded the preset current limit, it sets a null voltage vector, thereby limiting transient over currents.

Abstract: A system for identifying a fault in a light source is presented. The system includes at least one luminaire that includes the light source configured to emit light. Also, the at least one luminaire includes a monitoring device disposed proximate to the light source. The monitoring device includes a sensing unit configured to measure an amount of light emitted by the light source, and a squawk unit configured to generate a squawk signal based on the amount of light emitted from the light source, where the squawk signal is indicative of the fault in the light source. Further, the system includes a diagnostic unit communicatively coupled to the at least one luminaire and configured to determine the fault in the light source based on the squawk signal, and transmit a termination signal to the squawk unit to decouple an electrical power supply from the light source.

Abstract: A system for autonomous protection from fires and electrical shock of components used in construction of photovoltaic arrays is disclosed. The system detects conditions that left unattended will result in conflagration of combustible materials and unwanted electrification. The disclosed system provides an active control mechanism that operates to take defective components off line and thus provide protection from fire and electrification hazards that otherwise could arise. The system also provides means for annunciation and notification when actions are taken. The system can be used, for example, to determine that a photovoltaic (PV) module is at risk of conflagration of its flammable structural elements due to intense heat of plasma produced by a direct current (DC) arc at a point in the grid of conductors that collect and carry current from photovoltaic cells exposed to solar irradiation.

Abstract: A method for protecting a bipolar power distribution network supplied with power by an electric power source isolated from an electrical ground of an aircraft. The network includes a resistive protection device configured to be connected to the electrical ground and to the two phases of the network. The method includes the steps of receiving at least one voltage value on at least one of the two phases and/or at least one current value in the electrical ground, comparing the at least one voltage value with a first predetermined threshold value and/or the at least one current value with a second predetermined threshold value and controlling the protection device by changing its resistivity according to the comparison.

Abstract: Embodiments of the invention provide systems and methods for detecting a sustained arc in an electrical system containing polymer-based, semi-conducting components which derive their conductivity from carbon black, carbon nanotubes or other conductive materials. Over a time period, current and voltage data for a cable signal are collected, from which spectral information is extracted. The spectral information has a frequency component and an amplitude component. The cable signal is processed to remove a line frequency signature that includes the electrical system's line current frequency and its harmonics. One or more off-harmonic frequency bands are extracted from the cable signal and analyzed to determine the presence of an arc signature therein. Analysis of the off-harmonic frequency bands can include applying a matched filter to the off-harmonic frequency bands to obtain an indicator signal and determining if the indicator signal exceeds a threshold that indicates the presence of the sustained arc.

Abstract: An engine control unit for driving an electric circuit, e.g., a starter in a vehicle, includes at least a first element for making a first signal, particularly an ignition signal, available, a second element for making a voltage available for the electric circuit, a third element for connecting the electric circuit, a first switch which is disposed between the second and third elements to control the electric circuit, and a fourth elements for generating a second signal, the first signal cooperating with the second signal to form a virtual second switch for turning the electric circuit on or off with the aid of the first switch.

Abstract: A circuit for indicating a broken or missing neutral in a split phase electrical distribution configuration having an unbalanced load includes: a voltage divider configured to divide the voltage difference between a first line and a second line and to output the divided voltage difference as a virtual neutral; a rectifier including an input of the virtual neutral, the neutral, and an output, the rectifier configured to rectify a voltage difference between the virtual neutral and the neutral; a determination circuit including an input of the rectified voltage difference, a reference voltage and an output, the determination circuit configured to determine if the neutral is missing or broken based on the rectified voltage difference and the reference voltage; and an indicator circuit configured to indicate when the neutral is missing or broken based on the output of the determination circuit.

Abstract: A method and circuit for determining a circuit element parameter in a ground fault circuit interrupter circuit. An electrical signal provided to a first node is used to generate another electrical signal at a second node. The electrical signal at the second node is multiplexed with a modulation signal to generate a modulated signal that is then filtered and converted into a digital representation of a portion of the circuit element parameter. The electrical signal at the second node is multiplexed with the modulation signal after it has been phase shifted to produce a modulated signal that is filter and converted into a digital representation of another portion of the circuit element parameter. In another aspect, a slope based solenoid self-test method is used for self-testing in a GFCI circuit. Alternatively, a method for determining a wiring fault is provided using a digital filter.

Abstract: A line-side circuit interrupter protection system monitors the current flowing in a circuit in order to determine whether any current is flowing outside of the circuit upstream of the point at which a power supply is connected to a plurality of circuits. The system is located between the power supply and the main circuit panel, which is advantageous in certain applications in which an auxiliary power supply is used when a utility power supply is unavailable. In the event that the system detects current flowing outside of the circuit, the circuit will be broken to eliminate any potentially unsafe conditions.