Abstract: The present invention is directed to a protective wiring device for use in an electrical distribution system. The device includes a test facility includes a testing circuit configured to periodically generate at least one first test signal without execution of software instructions. A test monitoring circuit operates without execution of software instructions and is configured to effect an end-of-life detection state if the circuit interrupter fails to effect the tripped state in response to the electronics test failure state or in response to detecting a failure in the actuator assembly. An end-of-life circuit assembly is coupled to the test monitoring circuit, the end-of-life circuit assembly being configured to permanently decouple the plurality of line terminals from the plurality of load terminals in response to the end-of-life detection state.

Abstract: Disclosed herein is an abnormal current detection circuit for circuit breaker, comprising a full-wave amplifier, a positive wave-period comparator for comparing a positive wave-period amplification voltage signal with a positive wave-period reference voltage signal to output a pulse signal, a negative wave-period comparator for comparing a negative wave-period amplification voltage signal with a negative wave-period reference voltage signal to output a pulse signal, a combining circuit for combining pulse signals outputted from the positive wave-period comparator and the negative wave-period comparator to output a full-wave combining signal, a reference voltage generator for generating a reference voltage signal, and a comparative driving circuit section for comparing the combining signal with the reference voltage signal to output a signal for controlling a circuit breaker to be driven to a circuit breaking position when the combining signal is greater or equal to the reference voltage signal.

Abstract: A semiconductor component includes a semiconductor substrate, and a doped well having a well terminal and a transistor structure having at least one potential terminal formed in the semiconductor substrate. The transistor structure has a parasitic thyristor, and is at least partly arranged in the doped well. The potential terminal and the well terminal are connected via a resistor.

Abstract: A power plug, including: a shell, the shell having two sides, a reset button and a test button protruding from the first side, and a live wire pin and a neutral wire pin protruding from the second side; a circuit board; a stationary contact; a movable contact; a tripping device; a cross arm; and a push block. The stationary contact is connected with the live wire pin and the neutral wire pin; the movable contact can be connected to or disconnected from the stationary contact. The tripping device includes a sliding pedestal and a sliding part and controls the connection between the movable contact and the stationary contact. An elastic member is disposed on the push block. An ejector spring is disposed on one end of the movable armature. A reset spring is disposed between the sliding part and the sliding pedestal.

Abstract: A circuit, system and method for detecting the presence of a leakage path in a multi-cell voltage source is described. The system includes a detection circuit, the detection circuit having a first amplifier and a second amplifier, a first input of the first amplifier connected to a first terminal of the voltage source and the first input of the second amplifier connected to a second terminal of the voltage source, a second input of each of the first and second amplifiers connected to a reference voltage point, and an output of each of the first and second amplifiers connected to a respective first and second output of the detection circuit; and a processor having inputs connected to the first and second outputs of the detection circuit.

Abstract: An SCR module tester facilitates rapid testing of SCR modules by a series of tests that are tailored to detect faults without applying full power to the modules. The SCR tester includes a quick clamp connector that is able to securely and easily clamp SCR modules for both the F/A-18 A/D GCU and F/A-18-E/F GCU facilitating the rapid testing of SCR modules.

Abstract: A multi-pole circuit breaker having the same number of sensors and controllers as poles. One pole is monitored by a first sensor and a first controller, which are disposed on a first circuit board. Another pole is monitored by a second sensor and a second controller, which are disposed on a second circuit board that is cable-connected to the first circuit board. A ground-fault sensor monitors the sum of current flowing through the line conductors and a neutral conductor, and the output of the ground-fault sensor is provided to one or both of the controllers. Each controller is operable to detect arc faults on the respective line that it is monitoring, and at least one is operable to detect ground faults. A push-to-test algorithm is executed in relay fashion, with one controller executing the test before passing the result of the test onto the next controller, which in turns executes the test.

Abstract: A photovoltaic installation includes a photovoltaic generator, electrical connector lines, an enabling signal source, and an arc discharge detector. The generator is configured to generate a DC voltage when an enable signal is applied to the generator. The electrical connector lines connect the generator to a voltage converter for the voltage converter to receive the DC voltage from the generator. The enabling signal source is configured to apply the enable signal to the generator. The arc discharge detector is configured to detect for an arc discharge by detecting for the presence on the connector lines of an AC voltage signal having characteristics indicative of an arc discharge. The arc discharge detector is further configured to cause the enabling signal source to stop applying the enable signal to the generator when an arc discharge is detected.

Abstract: A testing apparatus for testing a welding apparatus is disclosed. The testing apparatus includes a receptacle, a fault indicator, and a power supply. The receptacle includes a grounding socket and a plurality of power sockets. The power supply is electrically coupled to the grounding socket, the fault indicator, and at least one of the plurality of power sockets. When a plug of the welding apparatus is matingly coupled to the receptacle, the fault indicator indicates whether an electrical resistance between a grounding prong of the plug and at least one of a plurality of power prongs of the plug is below a predetermined threshold.

Abstract: An apparatus is for a power circuit providing an alternating current to a load. The apparatus includes a high frequency current sensor structured to cooperate with the power circuit to provide a high frequency current signal. A voltage zero crossing detector is structured to cooperate with the power circuit to provide a voltage zero crossing signal. A high pass filter is structured to provide a filtered current signal from the high frequency current signal. A threshold comparator is structured to provide an output when the filtered current signal exceeds a predetermined value. A processor is structured to receive the voltage zero crossing signal and the output of the threshold comparator and output a trip signal in response to undesired series arcing by detecting an unsymmetrical high frequency signal for a predetermined number of cycles.

Abstract: A device for controlling a transistor, the device comprising an amplifying device (15) for controlling the transistor gate via an output control signal, the device including a first input connected to the transistor drain, the whole assembly forming a first connection, a second input connected to the transistor source, the whole assembly forming a second connection. The control device also comprises: at least one protecting device including at least one switching element (T1) which is inserted in series in the first connection of the amplifying device (15) to prevent a leakage current from passing through the first connection, and a device generating a regulating voltage to control the transistor, the generating device being configured such that there exists the same number of semiconductor junctions between the first and second connections. The invention is in particular applicable on battery charging devices.

Abstract: Disclosed is an electronic device capable of controlling a power supply interrupt according to the state of water leakage. A portable telephone (1) is equipped with a water leakage detection unit (60) that detects a physical quantity which changes according to the state of water leakage and a CPU (49) that interrupts a power supply in response to the detection result from the water leakage detection unit (60). When the electrostatic capacity detected by the water leakage detection unit (60) is greater than or equal to a threshold value A and less than a threshold value B, the CPU (49) continues to interrupt the power supply until a time T1 elapses, and when the electrostatic capacity detected by the water leakage detection unit (60) is equal to or greater than the threshold value B, said CPU continues to interrupt the power supply until a time T2 which is longer than the time T1 elapses.

Abstract: Solid state power controllers are described that include a switch controlled by a microcontroller and communication contacts. In one aspect of the invention, the microcontroller is galvanically isolated from the communication contacts using magnetoresistive isolation. In another aspect of the invention a number of solid state power controllers are connected to an external microcontroller to form a power distribution array. In addition, messages exchanged between the external microcontroller and the solid state power controllers can be used to configure the solid state power controllers and provide a user interface.

Abstract: An electrical system responsive to overheating and/or electric arcing of an electrically conductive member, e.g. a heating member of an aircraft windshield, includes a first switch in a first current path, and a second switch in a second current path. The first current path is from an electrical power supply through the first switch, through an arc sensor to the heating member to the power supply. The second current path is from a temperature sensor monitoring the temperature of the heating member through the second switch to a temperature controller. When the temperature of the heating member is at or above a predetermined value, the temperature controller causes the first switch to open. When there is arcing, the second switch is moved to the open position. The temperature controller senses that the second switch is open and causes the first switch to open.

Abstract: A generator winding-to-ground fault detection system is disclosed that includes a signal injection source in electrical communication with a winding of an electric power generator via an injection transformer. The winding may be coupled to ground via a winding-to-ground path and the signal generation source may generate an injection signal capable of being injected to the winding using the injection transformer. The disclosed system may further include a protection module in communication with the signal injection source and the electric power generator configured to receive the injection signal and a signal relating to the current through the winding-to-ground path, and to determine the occurrence of a winding-to-ground fault condition based at least in part on the injection signal and the signal relating to the current through the winding-to-ground path.

Abstract: The present invention is directed to an electrical device configured to be disposed in an electrical distribution system between a source of electrical power and an electrical load. The electrical distribution system includes at least one line hot conductor, a line neutral conductor, and a line ground conductor. The line neutral conductor is connected to the line ground conductor at a termination point in the electrical distribution system. The electrical load includes at least one load hot conductor, a load neutral conductor, and a load ground conductor. The device includes a grounding confirmation circuit that includes at least one signal generator that directs at least one test signal into a current path that includes at least the line ground conductor. The grounding confirmation circuit is configured to determine a ground continuity status of the current path based on at least one ground continuity measurement.

Abstract: A monitoring device and a method safeguards the function of a type A residual current device (RCD) in a power supply system. The monitoring device includes a measuring current transformer circuit for detecting a DC fault current (IF), an evaluation unit for processing the current detected by the measuring current transformer circuit, and a communication interface connected to the output of evaluation unit. In one embodiment, the monitoring device forms part of an electrical protection device with a type A residual current device (RCD) for ensuring the function of the type A residual current device (RCD).

Abstract: A leakage detector is provided with the addition of an output control circuit that monitors a circuit wire-to-ground voltage, which is at the root of a suffered operation and produced between a transformer B-class grounding phase of a monitored circuit and a D or C-class grounding electrode or a ground structure etc. of an electrical equipment connected to the grounding electrode, execute a phase judgment of a leakage current detected by a zero-phase current transformer on the basis of the monitored voltage, and stop an output operation of the leakage detector when the leakage current is a suffered current flowing from a load side L of the detecting zero-phase current transformer toward the power side K, i.e. the transformer and when the circuit wire-to-ground voltage exceeds an appropriately-established dynamic sensitivity voltage value.

Abstract: A protection system configured to couple between a generator that has a number of partial strings and an inverter includes a control device, and a series-connection switching device configured to selectively connect the partial strings together in series. The system also includes a parallel-connection switching device configured to selectively connect the partial strings together in parallel, wherein the series-connection switching device is actuated by the control device such that it interrupts the series connection of the partial strings in case of a hazard, and the parallel-connection switching device is actuated by the control device such that it connects the partial strings together in parallel in case of a hazard.

Abstract: An apparatus for detecting a leakage current flowing between at least one supply conductor of a multi-conductor electricity supply to load and non load currents carrying electrical conductor nominally insulated from the supply conductor. The apparatus includes a current transformer having a primary winding and a secondary winding. The primary winding is connected between the non load current carrying conductor and at least one other supply conductor so that leakage current flowing between the at least one supply conductor and the non load current carrying conductor flows through the primary winding to the other supply conductor. An electromechanical relay has a set of normally-closed contacts in series with the electricity supply. Circuitry connecting the secondary winding of the current transformer and the relay is provided so the relay is actuated by a current induced in the secondary winding by a leakage current meeting certain criteria as to magnitude and/or duration.

Abstract: A wiring device includes a leakage control unit for detecting a leakage current flowing through an electrical path connecting a commercial power supply and a load to perform a leakage determination and a switching unit for interrupting the electrical path in accordance with the leakage determination of the leakage control unit The leakage control unit has a filter for filtering the detected leakage, a square operation unit for calculating the square operation value of a signal which relates to the leakage current passing through the filter, and a threshold determination unit for performing the leakage determination in accordance with the square operation value obtained by the square operation unit. Consequently, the leakage determination is performed in accordance with the square operation value, so that the leakage can be detected with high accuracy even when the leakage current has a distorted waveform, and the electrical leakage can be reliably interrupted.

Abstract: The present invention discloses a power plug providing leakage protection comprising a casing, reset button and test button provided to the surface of the top of the casing; wherein movable springs respectively connected to power supply live wire and neutral wire pins are fixedly provided to the bottom part of a circuit board, movable contact points have separate electrical connections with free ends of the movable springs, stationary contact points corresponding to the movable contact points are provided to the circuit board and connected to a loading power supply cable; and a tripping device capable of contacting or disconnecting the movable and stationary contact points is provided inside the casing. The present invention is safe; has strong protective performance, simple structure, and reasonable design, and is safe, suited for mass production, and able to detect a power cable leakage failure and promptly sever the loaded connection with the power supply.

Abstract: A residual-current circuit breaker includes at least one summation current transformer through which at least one first lead and one second lead of a network to be protected are guided. At least one secondary winding is arranged on the summation current transformer and operatively connected at least indirectly with at least one energy storage element. At least one discharging resistor is switched in parallel with the energy storage element. The residual-current circuit breaker has a trip element which is operatively connected with break contacts in the at least one first lead and the at least one second lead. In order to reduce unexpected cut-offs of a network to be protected, the at least one discharging resistor includes a first partial resistor, and a second partial resistor switched in series with respect to the first partial resistor, with a least one electric signaling device operatively connected, at least indirectly, with the first partial resistor.

Abstract: A power switch disposed in a housing includes a contact breaker configured to connect and disconnect a low-voltage switchgear from a power source supplying the low-voltage switchgear, a triggering device configured to disconnect the low-voltage switchgear in an overload event, a current detection device, a control device, a first evaluation device configured to evaluate an accidental arc overcurrent, and a second evaluation device configured to evaluate the accidental arc overcurrent. The power switch is configured to be activated via an overcurrent signal generated by an arc monitoring system in response to the accidental arc overcurrent. The overcurrent signal is linked to the at least one triggering signal. The second evaluation has a threshold above a threshold of the first evaluation device. The triggering device is configured to be activated via a turn-off pulse when a signal from the current detection device is above the threshold of the second evaluation device.

Abstract: A circuit breaker, may comprise a circuit board, a resetting button, a tripping button, a lock pin and an elevator. The resetting button may comprise a locking device with a resetting drawbar having a resetting spring on an upper portion, a tripping spring on a middle portion, and a hook at a lower end. A lock pin below the resetting drawbar, may comprise a lock pin slope for selectively contacting the hook. The tripping button may comprise a tripping device configured to selectively contact the locking device. The tripping device may comprise a tripping block, a loosening block slope configured to selectively contact the lock pin slope, and a moveable spring between the tripping block and the circuit board. The elevator may house the portion of the resetting drawbar covered by the tripping spring, and the hook may align with the bottom of the elevator.

Abstract: A controller-based detection system configured to adaptively learn to distinguish between detected light that is indicative of an arc fault event and detected light that is not related to an arc fault event. In particular, the detection system is configured to observe the electrical power system as it is operated under various conditions to induce light events that are unrelated to arc fault events. Using the observed information about the light events that are unrelated to arc fault events, the detection system determines one or more detection algorithms. During normal operation of the electrical power system, the adaptively determined one or more detection algorithms are utilized to identify arc fault events in the electrical power system.

Abstract: The present invention relates to a method for determining the existence of an earth-fault on-the-fly and thereby protecting a motor controller having a high- and a low-side DC-link, and having high- and low-side switching elements, the high- and low-side switching elements being operatively connected to the high- and low-side DC-link buses, respectively, the method comprising the steps of generating a fault signal, generating at least one test vector in response to the fault signal by switching at least one of the switching elements on, and measuring, while the at least one switching element is on, the magnitude of a current flowing in that DC-link operatively connected to the conducting switching element in order to detect an earth-fault. The present invention further relates to additional methods for on-the-fly determination of earth-faults.

Abstract: The present invention is directed to an electrical wiring device that includes a circuit coupled to the line terminals and configured to conduct a predetermined current flow when the line terminals are connected to a source of AC power, the predetermined current flow does not simulate a fault condition. An interrupting contact assembly includes four sets of interrupting contacts that are configured to provide electrical continuity between the line terminals, the load terminals and the at least one receptacle in a reset state and configured to interrupt the electrical continuity in tripped state. The interrupting contact assembly is energized to effect the tripped stated and substantially deenergized otherwise, the interrupting contact assembly being substantially prevented from effecting the reset state absent the predetermined current flow.

Abstract: A ground fault circuit interrupter comprises a reset key, a reset locking mechanism, a reset mechanism, a reset bracket, a bracket reset mechanism, a bracket homing mechanism, a reset linkage mechanism, and a reset linkage clutching mechanism. A conductive assembly is configured to selectively connect or disconnect electrical continuity between the power input side and the load side. The conductive assembly comprises pairs of short-circuit conductive strips with conductive movable contacts, power input connection assemblies with input conductive stationary contacts, wiring output assemblies, receptacle output assemblies with output stationary contacts, and a first short-circuit conductor and a second short-circuit conductor.

Abstract: When a malfunction of an ungrounded drive electric system including first and second ungrounded power supplies, an inverter, and a motor which is energized by the first and second ungrounded power supplies through the inverter, i.e., an erroneous opening of switches of a battery, is detected, switches of an insulation resistance detector are opened to insolate the insulation resistance detector from the ungrounded drive electric system.

Abstract: Load current from an electrical AC supply circuit is monitored so that both high frequency (10-100 kHz), and low frequency (60 Hz) signal current components are measured over certain time periods. A high frequency energy component is measured in an integral fashion, e.g., summing a plurality of samples taken. A certain amount of high frequency energy during a half-cycle is required to indicate an arc event. A certain number of these arc events per half-cycle must occur within a specific time period to indicate the presence of an arc. The root-mean-square (RMS) value of the low frequency energy component is used to determine the severity of the arc. The higher the amperage of the load current arc, the faster the arc fault circuit interrupter (AFCI) will respond by disconnecting the arcing load from the AC supply circuit, e.g., fewer number of arc events necessary for tripping of the AFCI.

Abstract: A universal serial bus (USB) protection circuit. The circuit includes a V+ line, a ground line, a D+ line, a D? line, a first resettable device, a second resettable device, a windowing comparator, a first switch, and a second switch. The V+ line is configured to be connected to a V+ connection of a USB cable. The ground line is configured to be connected to a ground connection of the USB cable. The D+ line is configured to be connected to a D+ connection of the USB cable. The D? line is configured to be connected to a D? connection of the USB cable. The first resettable device is coupled to the V+ line and links the V+ line to a V+ of a local device. The second resettable device is coupled to the ground line and links the ground line to a common node of the local device. The windowing comparator has a negative input coupled to the common node and a positive input coupled to the ground line.

Abstract: A method and system for remotely monitoring the status of a standby generator. The system includes a PLC transmitter in communication with the control unit for the generator. The PLC transmitter receives error codes from the control unit of the generator and transmits encoded error codes over the power distribution network in a home using a PLC frequency. A remote status display device can be connected to the power distribution network in the home at any convenient location. The remote status display device includes a PLC receiver that decodes the error codes. The decoded error codes are displayed on a display of the remote status display device for viewing by the home occupant at a location remote from the standby generator.

Abstract: Embodiments of the invention are directed to systems and methods using an interruption device for automatically re-routing power upon the occurrence of an event. The interruption device may interrupt the flow of power to an external device upon the detection of an event, such as a circuit overload or short circuit. Interrupting the flow of power may cause power to be cut off to a receiving connector, which supplies power to the external device, by re-routing the flow of power away from the receiving connector by the use of relay switches. By interrupting and re-routing the flow of power, an electrical fire, damage to the external device or other hazard may be prevented. Once the source of the problem, such as a defective external device, has been removed or fixed, the flow of power may be re-routed back to the receiving connector.

Abstract: The present invention relates generally to a circuit breaker. More particularly, the invention encompasses a modular circuit breaker. The present invention is also directed to a novel a modular circuit breaker with a trip bar. The inventive two pole residential circuit breaker includes an Arc Fault and Ground Fault electronic detection system. The modular breaker design includes an electronic system used for tripping a designated mechanism pole which in turn trips the secondary mechanism pole. Electronic components are included that sense the continuous current flow through each mechanism pole simultaneously to determine when a trip event is needed. The electronic system of this invention includes a self diagnostic system with electronic visual indicators that display the method of which trip condition occurred.

Abstract: A ground tether circuit is provided for a power circuit that includes a power source, at least one load and at least one rectifier. The ground tether circuit includes an adjustable voltage converter connected to the rectifier. The adjustable voltage converter includes a positive power switch, a negative power switch, an inductor, a current sensing device and a controller.

Abstract: A circuit interrupter, such as a GFCI or AFCI product, is provided having a suppression and protection circuit and circuit interrupter circuitry. In one configuration, a semiconductor device and a voltage clamping device or surge protector, such as a metal oxide varistor (MOV), are utilized in the circuit interrupter for handling transient surges and overvoltage conditions. The semiconductor device, such as a SIDCA and a TVS diode, is connected to a solenoid or trip coil of the circuit interrupter circuitry to limit the amount of current through the semiconductor device. The MOV is placed between phase and neutral conductors of the circuit interrupter circuitry.

Abstract: A power saving circuit for a computer. When the computer is powered on, an LED is lit. When the computer if off but power is still being supplied from the commercial power source to the power supply of the computer, the LED blinks. A counter chip determines the time to start blinking or the frequency of blinking.

Abstract: A branch wire L5 from the voltage detection circuit 14 is inserted in the zero-phase-sequence current transformer ZCT in the direction from the load side to the external power supply side. For this configuration, the zero-phase-sequence current transformer ZCT is to detect unbalance of the sum of current flowing in the first and second conductive wires L1, L2 and the current flowing in the branch wire L5. Therefore, the present invention can accurately detect occurrence of electrical leakage.

Abstract: A ground fault sensing device for a drive system that converts direct current electrical power from a direct current power supply into alternating current electrical power and drives an electric motor with that alternating current electrical power, comprises: an extraction circuit that is connected to a power supply line of the direct current power supply via a coupling capacitor, that detects an amplitude wave that is generated when an alternating current side including the electric motor is suffering a ground fault, and that extracts the envelope of the amplitude wave; a measurement circuit that measures the voltage level of the envelope; and a determination circuit that makes a decision as to whether or not a ground fault has occurred on the alternating current side by comparing together the voltage level measured by the measurement circuit and a ground fault decision value.

Abstract: According to the features discussed herein, through a single generalized arc-fault detection algorithm, various types of series and/or parallel arc faults can be detected without any nuisance trip for either AC or DC Electric Power Systems. Running Discrete Fourier Series (RDFS) formulation for nuisance-free operation and cost-effective implementation is developed. Unlike other methods which require numerous source and load-side current and voltage measurements, only source side current is required. An arc detector may include a first detector to monitor variations of a magnitude of a fundamental component of a current, and a second detector to monitor an overload condition based in an i2t calculation.

Abstract: An arc fault protection circuit and method, provides arc fault protection in a multiphase power system by actuating a plurality of disconnect switches to disconnect the source from the load in response to detecting arcing proximate said load. As well, in response to detecting the arc, a plurality of impedances are introduced into the current path between said source and said load, with each of the impedances increasing the impedance between the source and the load along one phase, prior to the plurality of disconnect switches disconnecting the source from said load.

Abstract: A method for preventing fake charging of an electronic apparatus is provided. The method includes: providing a power management table for setting function units for each power range; activating a fake charging preventing function according to a predetermined condition or an activating operation of users; detecting power of the electronic apparatus every a first predetermined time interval; determining a current power range the detected power falls into; determining whether the current power range is changed; beginning to time when the current power range is changed; activating function units which are disabled and whose power range is the current power range when the timing reaches a second predetermined time interval and the detected power is still in the current power range.

Abstract: An apparatus and method for protecting against electrocution hazards that arise when an appliance is electrically connected to a miswired single-phase AC electrical source which includes an energized ground lead are described. The apparatus includes one or more sensors that detect electrical energy in the ground lead combined with a miswiring condition in the hot and common leads. A tester embodiment is also illustrated. The method includes the steps of detecting if the putative ground of the electrical source is energized and whether the hot and common leads are reversed.

Abstract: Electrical fault restricting system for an electrical equipment and/or electrical system has a monitoring unit placed at location of interest to sense or measure electrical fault occurred with the help of sensing or measuring device which is further connected to signal processing and controlling unit which receives data collected by the monitoring unit that provides output for fault identification, alarming and controlling actions to alarming. An indication unit and command for trip signal to circuit breaking device where processed data of data collecting and processing unit are stored at data history storage. A display unit for back reference monitoring unit provides images to image receiver. A processor and controlling unit further provides processed images to an additional data history storage and display unit for future analysis of conditions where plurality of signal processing and controlling unit is inter connected with additional remote central controlling and data handling unit.

Abstract: A method of making an electrical power supply of an electrically controllable system having variable optical properties, when fitted near water, electrically safe, the electrically controllable system comprising a carrier substrate that bears an electroactive element placed between first and second electrodes supplied with a periodic voltage U(t) having a given maximum RMS value U0 at a given low supply frequency, the method including limiting the touch potential at an input or output terminal of the electrically controllable system to a maximum value of 50 V or less, the touch potential being defined as the potential experienced by the human body in case of contact with the input or output terminal.

Abstract: This invention relates to a method and apparatus of detecting and compensating for DC residual fault currents on electrical systems. In particular, the present invention relates to a method and apparatus which is capable of accurately detecting one or more parameters of the fault current waveform and generating a compensation factor which compensates for specific pulsed DC fault components present. In this way, trip sensitivity is optimized for all types of fault current waveforms. In a preferred embodiment, the present invention operates by detecting one or more parameters of the encoded fault current waveform and generating a measure of symmetry comparing the mean squared values of negative and positive sections of said encoded fault current waveform. In use, various bands of the ratio of the mean squared sum of the positive and negative sections of said encoded fault current waveform are obtained, and a compensation factor is determined from a look-up table stored in a processing means.

Abstract: A hub for use with a circuit protection system includes a first input port configured to communicatively couple to at least one sensor device, wherein the at least one sensor device includes a light source and at least one light sensor. The hub also includes a first output port configured to communicatively couple to at least one controller, and a processor communicatively coupled to the first input port and to the first output port. The processor is configured to receive a sensor status signal from the at least one light sensor via the first input port in response to a test pulse emitted by the light source, and transmit a hub status signal to the at least one controller via the first output port based at least in part on the sensor status signal.

Abstract: The present invention is directed to an electrical device configured to be disposed in an electrical distribution system between a source of electrical power and an electrical load. The electrical distribution system includes at least one line hot conductor, a line neutral conductor, and a line ground conductor. The line neutral conductor and the line ground conductor are connected to earth ground at a termination point in the electrical distribution system. The electrical load includes at least one load hot conductor, a load neutral conductor, and a load ground conductor. The device comprises a power supply coupled to the power input mechanism. The power supply comprises at least one DC voltage output terminal and a reference terminal coupled to the line ground termination element.

Abstract: In an information processing apparatus having a service mode for a service person to carry out maintenance of the apparatus enters for carrying out the maintenance, a registration page is provided for registering the service person as a service person in charge of the maintenance of the apparatus, and an input page is provided for inputting authentication information required for the service person that is registered in the registration page as a person in charge of the maintenance of the apparatus to enter the service mode.