1068results about "Arrangements resposive to fault current" patented technology

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. The circuit interrupter is prevented from entering the reset state if the at least one ground continuity measurement does not meet a predefined quality threshold. The at least one ground continuity measurement being a function of the at least one electrical load parameter after the circuit interrupter is in the reset state.

A circuit protection device connected between two lines of an AC power source self checks for an introduced simulated ground fault every half cycle during a period when a trip SCR cannot conduct. If the self check fails, the device is tripped on the next half cycle of different phase. Possible responses to the self check failure include lighting an indicator lamp and locking out the device reset mechanism.

A circuit breaker (such as a miniature circuit breaker) that wirelessly communicates state and fault information to a main energy monitoring module. The wireless circuit breaker includes a transceiver and a power supply that harvests energy inductively from the line current conductor without the need for a connection to a neutral conductor. The wireless circuit breaker can be implemented in the same package as existing circuit breakers, eliminating the need to replace the panel when upgrading to a system that employs a main energy monitoring module. The wireless circuit breaker can also include an energy storage device for supplying power to the circuit breaker after it has tripped, allowing the circuit breaker to transmit information after a trip. The main energy monitoring module includes a processor and a gateway for evaluating and transmitting information received from the circuit breaker to other applications, such as webpages and smartphones.

Circuits integrated or integrable with a photovoltaic panel to provide built-in functionality to the photovoltaic panel including safety features such as arc detection and elimination, ground fault detection and elimination, reverse current protection, monitoring of the performance of the photovoltaic panel, transmission of the monitored parameters and theft prevention of the photovoltaic panel. The circuits may avoid power conversion, for instance DC/DC power conversion, may avoid performing maximum power tracking to include a minimum number of components and thereby increase overall reliability.

An arc fault circuit interrupter (AFCI) detects arc faults by identifying the various signature patterns of arc fault noise while rejecting arc mimicking noise from normal load phenomena.

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. A voltage parameter detection circuit is configured to take a first voltage reading from a first termination element of the plurality of line termination elements and a second voltage reading from a second termination element of the plurality of line termination elements to derive at least one voltage parameter therefrom. The first voltage reading and the second voltage reading are referenced to the reference terminal. The circuit interrupter is driven into the tripped state if the at least one voltage parameter does not meet a predetermined condition, the voltage parameter detection circuit being operational when the reference terminal is not at an earth ground potential.

The present invention is directed to a protection device that includes line terminals coupled to a power source disposed in an electric power distribution system. The protection device is configured to protect a portion of the power distribution system from at least one fault condition. The device includes a receptacle member that has includes a housing and a cover. The cover includes receptacle openings configured to accommodate plug contact blades. Receptacle contacts are disposed in the housing. The receptacle contacts are also coupled to the line terminals to thereby establish an electrical connection between the receptacle contacts and the line terminals. Each receptacle contact is in communication with a corresponding receptacle opening. A protective shutter mechanism is integrated into the housing. The protective shutter mechanism is movable from a closed position to an open position upon insertion of the plug contact blades. The protective shutter mechanism is substantially hermetically sealed in the closed position. The protective shutter mechanism is also not movable from the closed position to the open position upon insertion of an object into only one receptacle opening, such that the object is prevented from making contact with the corresponding receptacle contact.

The present invention is directed to a protective device configured to be coupled between an AC power source and an electrical load. A ground continuity monitor is coupled to the ground conductor, the ground continuity monitor being configured to detect a ground discontinuity condition in the ground conductor. A circuit interrupter mechanism is configured to interrupt electrical continuity in a tripped state and establish electrical continuity in a reset state. A self-test circuit is coupled to the ground continuity monitor and configured to perform a simulated ground continuity test that simulates the ground discontinuity condition. The self-test circuit provides a test failure signal when the ground continuity monitor fails to provide an output signal in response to the simulated ground continuity test. The test failure signal is configured to trip the circuit interrupter mechanism.

An electrical power system for a cold cathode tube includes a high-voltage transformer with a primary side connected to a power supply and a secondary side connected to a cold cathode tube and includes a ground fault detector. The ground fault detector includes a resistive path, a detection circuit, an isolation circuit, and a stop latch. The resistive path is connected to the secondary side of the high-voltage transformer and is arranged to provide a ground fault path to ground fault current. The detection circuit is connected to the resistive path and is constructed and arranged to provide an output representing a fault detection signal. The isolation circuit is connected to the detection circuit and is constructed and arranged to isolate the fault detection signal from the primary side of the high voltage transformer. The stop latch has an input connected to the isolation circuit and an output connected to the power supply and is constructed and arranged to generate an inhibition signal for inhibiting operation of the power supply.

A method of detecting arcing conditions includes sensing current and HF signals therefrom; bandpass filtering the HF signals and providing filtered signals; detecting peak signals and envelopes from the filtered signals; counting occurrences of the envelopes exceeding a first value; maintaining temporary values corresponding to the peak signals; determining a trip time as a function of the current; determining if any peak signal is greater than a second value, and responsively increasing a temporary value and, otherwise, decreasing the temporary value; determining if a predetermined function of the temporary values is greater than a fifth value, and adding the temporary values to an accumulator, and otherwise, decreasing the accumulator; and tripping open the power circuit if: a difference between the occurrences of current and immediately previous half cycle having the same polarity is at least two, the accumulator is greater than a seventh value, and the trip time is reached.

The present invention discloses a ground fault detection system and method for an inverter. The ground fault detection method for the inverter includes a reference value setting step for setting a reference value for estimating a ground fault current and a reference value for deciding a ground fault, a ground fault current estimation step for comparing a current value obtained by adding up current values flowing through each phase of an output terminal of the inverter with the reference value for estimating the ground fault current, and estimating generation of the ground fault current when the calculated current value is larger than the reference value, and a ground fault phase decision step for deciding the phase in which the ground fault has been generated on the basis of a current difference value between start and end points of 0 vector sections of each phase or between start and end points of 7 vector sections of each phase. Therefore, even if the ground fault occurs in an output line during the load operation or a power frequency of the inverter is similar to an output frequency, the ground fault detection system and method for the inverter detect the ground fault to improve operational reliability of the inverter.

The current invention is an automatic AC power interruption system built into a portable power strip or a portable casing or integrated into an appliances control circuitry. The invention monitors the environment for hazard alarms, for example, a T3 signal smoke detector alarm, and responds by tripping open the power supply circuit to the power strip's receptacles and thus interrupts AC power to the protected appliances the user has chosen to plug into them. One alternate form of the invention uses a portable casing that can be plugged into a power receptacle and, when a hazard alarm is detected, trip off the nearest GFCI. Other alternate forms of the invention are integrated within an individual appliance's control circuitry and may interrupt power using a built-in switch or by tripping off the nearest GFCI device. The invention's purpose is to help prevent death, injury, and property damage by preventing fires or facilitating fire suppression; more particularly, by interrupting electrical power to problematic appliances, such as toasters, space heaters, battery chargers, stoves, and motors, when a hazardous condition alarm is emitted. It further interrupts power to the problematic appliances when a detector emits an alarm indicating toxic fumes, natural gas, radon, carbon monoxide, or whatever other detector-alarm the consumer installs in the area to be protected.

A test circuit first detects whether or not a relay unit is normal, and then examines an operation of leakage detecting circuit. This allows relay unit to interrupt an electric power supply path including power lines more securely if electrical leakage occurs in the electric power supply path. If welding in the contact of the relay unit is detected before starting charging of a power storage device included in an electrical device, a control device does not allow the charging of the power storage device, which can prevent a problem from occurring in the electrical device.

A combined arc fault circuit interrupter and leakage current detector interrupter. A current sensor, amplifier, and comparator are employed to detect the presence of leakage current in alternating current power conductors. Upon the detection of an amount of current leakage beyond a threshold level, a relay is opened, disconnecting a source of AC power from a power conductor being monitored, such as an appliance line cord. An arc sensor, envelope detector, amplifier, and microcontroller are employed to detect the presence of an arc fault in the alternating current power conductors. The arc fault detection algorithm implemented by the microcontroller is capable of discriminating between high frequency noise which is not caused by a parallel or series arc fault, with high frequency anomalies which are the result of arcing.

A transformer interface prevents a false ground fault interrupt in a power supply arrangement. The power supply arrangement has a line wire and a neutral wire connected by way of a ground fault interrupt circuit to an electrically powered device, to which a ground wire is also coupled. The interface has current imbalance sensor transformer windings coupled to the line and neutral wires. A ground wire current sensor transformer winding is coupled to the ground wire. A detector transformer winding produces a signal that triggers operation of the ground fault interrupt circuit, in response to the difference between currents produced by the current imbalance sensor transformer windings exceeding detected ground wire current by a prescribed value.

A circuit interrupter includes separable contacts, a neutral conductor, an operating mechanism structured to open and close the separable contacts, and a plurality of current sensors structured to sense at least current flowing through the separable contacts. Each of the current sensors includes a primary winding and a secondary winding, the primary winding being electrically connected in series with the separable contacts. A trip mechanism is structured to cooperate with the secondary winding of the current sensors and the operating mechanism to trip open the separable contacts. A test circuit tests the current sensors and the trip mechanism. The test circuit is structured to apply a test signal directly to the secondary winding of each of the current sensors.

There is disclosed a self-testing circuit interrupting device which provides uninterrupted power to a load during a complete electronic and electromechanical components self test to allow autonomous periodic automated self testing without damaging or resetting connected load equipment.

A ground fault detector for use in resistance grounded electrical systems. In one embodiment, the system includes a digital processor to monitor an electrical parameter of the resistance to determine and indicate whether a ground fault has occurred. Data regarding the ground fault occurrence can then be digitally stored transmitted, or processed, such as by an external computer. In another embodiment, the ground fault detector includes a filter to remove the harmonic components of the monitored electrical parameter, to avoid false alarms. In addition, in another embodiment, the ground fault detector can also determine whether a high harmonic condition is present in the monitored electrical system. The phase of the electrical system can be grounded by pressing a test switch, thereby causing a ground fault and allowing the harmonic components of the signal in the electrical system to be monitored.

A GFCI device includes a latch assembly provided with a rigid electrically conducting bar connected thereto such that when a user presses a reset button the latch assembly is moved toward a pair of contacts provided as part of a reset circuit to initiate a reset operation. When the electrically conducting bar on the latch assembly connects the pair of contacts, the reset circuit is closed and an actuator is activated to place the GFCI device in the latched, reset, condition. If the GFCI device is correctly wired, the latch assembly enters the latched state. If the device is not properly wired no power is provided to the actuator and the device remains in the tripped, or open, state.

A system and method for detecting ground faults in an AC motor drive is disclosed. A fault detection and protection system for an AC motor drive includes current sensors to measure first and second phase output currents, a voltage sensor to measure a DC link voltage, and a desaturation control circuit to determine a voltage and associated current across PWM inverter switches for a third phase of the output. A controller compares the first and second phase currents, the measured DC link voltage, and the voltage across the PWM inverter switches on the third phase, to a plurality of thresholds. The controller detects a ground fault on one of the first, second, and third phases of the three phase output to the AC motor based on the comparisons of the first and the second phase currents, the DC link voltage, and the voltage across the switches to the thresholds.

An apparatus and method for preventing the misfiring of a protection device. The protection device includes line terminals and load terminals. The protection device further includes a latching mechanism, adapted to move between a closed state which establishes electrical contact between said line and load terminals, and an open state which prevents electrical contact between said line and load terminals; and an initial reset prevention mechanism, adapted to prevent said latching mechanism from being set in said closed state until power is applied to said line terminals.

A ground-fault circuit-interrupter method and system for three-phase electrical power systems including a plurality of GFCI units and a processor forming a ground-fault circuit interrupting system for use in a three-phase power distribution network including a three-phase source of electrical power, a three- or four-wire main circuit, and a plurality of three- or four-wire feeder circuits connected across the main circuit. A GFCI unit is provided in the main circuit and in each of the feeder circuits. The processor is programmed to continuously monitor the main GFCI unit and each feeder GFCI unit to determine when and where a fault has occurred and, in response thereto, to interrupt the faulted circuit and to inhibit tripping of the non-faulted circuits. The novel GFCI system is applicable for solidly-grounded, resistance-grounded, or ungrounded as well as other three-phase systems.

Circuit interrupting devices are provided. One circuit interrupting device includes a fault sensor configured to output a sensor signal; a voltage sensor configured to sense a reference voltage; and a controller configured to determine an occurrence of an actual fault based on the sensor signal and the reference voltage. The circuit interrupting device further includes an amplifier configured to receive the sensor signal and the reference voltage and output an amplified signal; an analog-to-digital converter configured to receive the reference voltage and the amplified signal and output respective digital signals corresponding to the reference voltage and the amplified signal; and a line interrupt assembly configured to interrupt current flow through a conductive path when a characteristic of the sensor signal exceeds an actual fault threshold.