With Differential Sensing In A Single Phase System Patents (Class 361/45)
  • Publication number: 20080234879
    Abstract: A ground fault interruption (GFI) system is incorporated onto a DSP based LRM of an aerospace vehicle. The GFI system operates with digital controls and, unlike the prior art, the system does not employ current transformers. Synchronization pulses are employed to coordinate instantaneous current measurement samplings in each phase of a multi-phase power system. Coordinated sampling may reduce phase angle current differential errors and improve operational precision of the GFI system.
    Type: Application
    Filed: November 9, 2007
    Publication date: September 25, 2008
    Inventors: Randy J. Fuller, Zhenning Z. Liu, Milind Ghanekar
  • Publication number: 20080232007
    Abstract: A leakage current protection device with a single laminated magnetic core transformer that is formed by punch pressing an amorphous metal material, or a nanocrystalline soft metal material, in a high punch velocity press to form the ring laminations for the magnetic core. In a ground fault circuit interrupter, the single laminated magnetic core transformer serves as the input sensor for both the current imbalance detection circuitry and the low impedance ground fault protection circuitry.
    Type: Application
    Filed: March 20, 2008
    Publication date: September 25, 2008
    Inventors: Rodica Musat, Frank A. Raneiro, Thomas H. Rooney
  • Publication number: 20080225448
    Abstract: A method of preventing an overload current from a power supply to a load through a ground fault circuit interrupter includes the steps of: obtaining an interrupted fault current from a hot wire to a ground wire via a first zero-phase current inductor and a fault current from a neutral wire to the ground wire via a second zero-phase current inductor; amplifying a signal of the fault current by an Op-Amp; and determining the fault current by a programmable control module, wherein when the fault current is larger than a preset threshold, the programmable control module sends a control signal to a control switch such that the control switch electrifies a second coil of a trip breaker to drive an armature at an unlocked position, so as to separate a movable terminal with a fixed terminal for electrically disconnecting the load with the power supply.
    Type: Application
    Filed: September 18, 2007
    Publication date: September 18, 2008
    Inventors: Xuguang Li, Xiaobing Dong, Yi Yin
  • Patent number: 7423854
    Abstract: An interrupter circuit is disclosed for interrupting power in a power cable from a power source. The power cable comprises an insulated line wire and an insulated neutral wire with a conductive shield surrounding the line wire and the neutral wire. A non-insulated drain wire contacts the conductive shield. An outer insulating layer is molded about the conductive shield. A disconnect switch is interposed between the power source and the power cable with a disconnect switch driver controlling the disconnect switch. A sensing circuit is connected between the drain wire and the disconnect switch driver for sensing a leakage current between the conductive shield and one of the insulated line wire and the insulated neutral wire for opening the disconnect switch for disconnecting the power cable from the power source.
    Type: Grant
    Filed: July 7, 2006
    Date of Patent: September 9, 2008
    Assignee: Technology Research Corporation
    Inventors: Paul R. Gandolfi, Frank S. Brugner, Jr.
  • Publication number: 20080192393
    Abstract: The present invention provides a circuit interrupting device which comprises a novel reset mechanism to allow a user to test whether the device is wired properly. The novel reset mechanism includes a reset conducting apparatus which contains a reset start switch (KR-4). The KR-4 contains a first conducting pin, a second conducting pin, and a conducting bridge. When the reset button is depressed and the device is wired properly, the KR-4 is closed to allow the conducting bridge to be in contact with both the first and the second conducting pins so as to reset the device. The present invention also provides a circuit interrupting device which is capable of automatically checking the components of the circuit interrupting device (i.e., the end of life test) through a novel status test switch (KR-1). The KR-1 comprises a flexible metal piece and a simulated leakage current controlling resistor, which is located underneath of the flexible metal piece.
    Type: Application
    Filed: July 6, 2007
    Publication date: August 14, 2008
    Inventors: Huadao Huang, Lu Huayang
  • Publication number: 20080180866
    Abstract: 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.
    Type: Application
    Filed: January 29, 2007
    Publication date: July 31, 2008
    Applicant: HONOR TONE, LTD.
    Inventor: Chi Wing Wong
  • Patent number: 7400481
    Abstract: Low cost apparatus and methods of detecting arc faults for better discriminating electrical events. The arc fault detection apparatus includes a current sensor, a di/dt input sense circuit, a dv/dt input sense circuit, and a processing unit. The current sensor monitors a power line current, and provides high frequency components of the power line current to the di/dt input sense circuit. The dv/dt input sense circuit monitors a power line voltage. The di/dt and dv/dt input sense circuits generate signals carrying information relating to changes in the power line current and the power line voltage, respectively. The processing unit analyzes these changes in the power line current and the power line voltage to discriminate detected electrical arcing events from nuisance loads with increased accuracy.
    Type: Grant
    Filed: December 29, 2005
    Date of Patent: July 15, 2008
    Assignee: Sensata Technologies, Inc.
    Inventors: Christian V. Pellon, Christopher A. Nicolls, Michael T. Parker
  • Patent number: 7375939
    Abstract: A relocatable power tap having a plug configured to connect to a source of AC power and at least one receptacle. The relocatable power tap also includes a power supply connected to the plug and configured to convert an AC signal to a DC signal, and a detector connected to the plug and configured to determine the existence of ground and polarity faults. The detector includes a first current-controlled switch configured to turn on if an open ground or polarity fault exists. A power switch is controlled by the detector. The power switch is connected to the power supply, and configured to communicate AC power from the source of AC power to the at least one receptacle based on whether a ground or polarity fault exists.
    Type: Grant
    Filed: August 21, 2006
    Date of Patent: May 20, 2008
    Assignee: Trippe Manufacturing Co.
    Inventor: Eugene A. Weil
  • Publication number: 20080112100
    Abstract: A digital electric leakage detecting and monitoring device includes a leakage current detection element connected to an AC power supply loop. When an outgoing current supplied from an AC line source to a load is not equal to a backflow current flowed from the load back to the AC line source, a leakage signal is generated by the leakage current detection element and sent to a microprocessor via a leakage signal processing circuit, so that the microprocessor generates a switch control signal to switch a switch unit from a close-circuit position to an open-circuit position and thereby cuts off the power supplied from the AC line source to the load. A switch status monitoring circuit is parallelly connected to the load for monitoring the switch status of the switch unit, and timely generating and sending a switch status signal to the microprocessor.
    Type: Application
    Filed: November 7, 2007
    Publication date: May 15, 2008
    Inventor: Daniel Liu
  • Publication number: 20080049364
    Abstract: A leakage current monitor device suitable for use in or with a Relocatable Power Tap. The device includes a leakage current detector circuit and an alarm circuit coupled thereto. The leakage current detector circuit is configured to detect leakage current from one or more loads connected to the RPT. The alarm circuit activates an alarm device when a detected leakage current exceeds a defined threshold.
    Type: Application
    Filed: December 8, 2006
    Publication date: February 28, 2008
    Inventors: Steve Campolo, Kenneth J. Brown, Carlos G. Ramirez
  • Patent number: 7298598
    Abstract: The present invention is directed to a protective wiring device that includes a plurality of line terminals coupled to a plurality of load terminals by way of at least one conductive path. A miswire detection circuit is coupled to the at least one conductive path. The miswire detection circuit is configured to monitor signal propagation characteristics on the at least one conductive path and generate a miswire detection signal based on the signal propagation characteristics commencing each time source power is applied to either the plurality of line terminals or the plurality of load terminals. A fault detection circuit is coupled to the at least one conductive path. The fault detection circuit is configured to detect a fault condition propagating on the at least one conductive path. The fault detection circuit is configured to generate a trip signal in response to either the fault condition or the miswire detection signal. A circuit interrupter is coupled to the fault detection circuit.
    Type: Grant
    Filed: September 28, 2005
    Date of Patent: November 20, 2007
    Assignee: Pass & Seymour, Inc
    Inventors: Kent Morgan, Jeffrey C. Richards, Thomas N. Packard
  • Patent number: 7283340
    Abstract: The present invention is directed to a protective device that includes a plurality of line terminals and a plurality of load terminals. A wiring state detection circuit is configured to detect a wiring state associated with the plurality of line terminals and the plurality of load terminals. A fault detection circuit is coupled to the plurality of line terminals and configured to generate a fault detection signal in response to detecting at least one fault condition. A circuit interrupter is coupled to the fault detection circuit. The circuit interrupter includes four sets of interrupting contacts configured to provide electrical continuity at least between the hot line terminal and the hot load terminal and the neutral line terminal and the neutral load terminal in a reset state. The four sets of interrupting contacts are open in a tripped state.
    Type: Grant
    Filed: September 1, 2006
    Date of Patent: October 16, 2007
    Assignee: Pass & Seymour, Inc.
    Inventors: David A. Finlay, Sr., Thomas N. Packard
  • Patent number: 7268559
    Abstract: An apparatus for testing the life of a leakage current protection device having a leakage current detection circuit. In one embodiment, the apparatus a trip mechanism state generator, a fault alarm generator, a ground fault simulation unit. In operation, the ground fault simulation unit generates a simulated ground fault signal during every positive half-wave of an AC power, the simulated ground fault signal is detected by the leakage current detection circuit, the leakage current detection circuit responsively generates a signal to turn a switching device into its conductive state so as to allow a current to pass therethrough, the passed current is converted into a DC voltage in accordance with a trip mechanism state generated by the trip mechanism state generator, the fault alarm circuit receives and analyzes the DC voltage and indicates whether a fault exists in the leakage current protection device.
    Type: Grant
    Filed: October 26, 2006
    Date of Patent: September 11, 2007
    Assignee: General Protecht Group, Inc.
    Inventors: Wusheng Chen, Fu Wang, Lianyun Wang
  • Patent number: 7233464
    Abstract: A ground fault detection system is provided where one current sensor is used to calibrate a second sensor in order to provide automatic zeroing of the difference measurement. The calibration is done gradually in order to differentiate between sensor drift and a transition in current due to a differential fault.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: June 19, 2007
    Assignee: Goodrich Corporation
    Inventor: Kevin Edward Rice
  • Patent number: 7224559
    Abstract: A detection circuit detects a difference between a source current and a return current. The detection circuit includes a constantly biased magnetic core through which conductors of the source and return currents extend, and a sense winding around the core. The sense winding carries an AC signal. A sensing circuit connected with the sense winding senses a change in small signal impedance of the sense winding relative to the core. This detection circuit can be used to protect people and equipment against accidental contact with high-voltage DC systems.
    Type: Grant
    Filed: May 21, 2004
    Date of Patent: May 29, 2007
    Assignee: General Motors Corporation
    Inventors: Christopher P. Henze, Rohit K. Tirumala
  • Patent number: 7196886
    Abstract: A resettable circuit interrupting device having a switch and timer circuit connected to the line side of the interrupting device to cause a leakage current to flow for a defined interval of time when power is applied. The timer and switch circuit comprises a timer powered by current from the phase leg of the device which is designed to operate for a defined interval of time. The timer starts operating when power is applied to the circuit interrupting device and normally continues to operate for the defined interval to time. Upon completion of the timed interval, the timer turns itself off and stays off until power is again applied to the device after an interruption. When power is first applied to the interrupting device, the timer is energized from the phase leg and causes the switch to close which connects the neutral leg on the line side of the interrupting device to a ground terminal.
    Type: Grant
    Filed: August 29, 2005
    Date of Patent: March 27, 2007
    Assignee: Leviton Manufacturing Co., Ltd.
    Inventors: David Chan, Steve Campolo
  • Patent number: 7161780
    Abstract: A typical duplex GFCI receptacles has two buttons, a test button that, when pressed, shuts off power to the receptacle and down stream devices, and a reset button that, when pressed, restores power to the GFCI and down stream devices. Generally, the test button is pressed to verify that the GFCI will interrupt power to the conductive paths and the reset button is pressed to reset the GFCI. In operation, the test portion of the GFCI will automatically break electrical continuity in one or more conductive paths (i.e., open the conductive path) between line and load sides upon the detection of a fault such as a reverse wiring condition, a ground fault, an open neutral and/or a defective GFCI device. When this happens the reset button in the typical GFCI receptacle is then pressed in an to attempt to restore power. The GFCI here disclosed has only one button which is used for both the test and reset operation.
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: January 9, 2007
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: Frantz Germain, Stephen Stewart
  • Patent number: 7113075
    Abstract: A detection circuit includes a first power line, a first signal conditioning module operationally coupled to the first power line, a neutral line (N) operationally coupled to the first signal conditioning module, a second signal conditioning module operationally coupled to the first power line, a second power line operationally coupled to the second signal conditioning module, and an analog to digital (A/D) converter operationally coupled to the first and the second signal conditioning modules.
    Type: Grant
    Filed: December 23, 2003
    Date of Patent: September 26, 2006
    Assignee: General Electric Company
    Inventors: Kresimir Odorcic, Scott Horning, Timothy Ray Jackson, Timothy Francis Powell, Cecilia Maria Blanchard, Meher Prasadu Kollipara, Mark Dilip Shah, Gregory Michael Thomas
  • Patent number: 7079365
    Abstract: A microcontroller-based system to detect ground-fault and grounded-neutral conditions in a monitored circuit of an electrical distribution system having line and neutral conductors. The system includes a single sensor producing an output signal responsive to current flow in both the line and neutral conductors of the monitored circuit, and a microcontroller receiving the sensor output signal and initiating the generation of a circuit status signal indicating one of a normal operating condition, a ground-fault condition or a grounded-neutral condition in the monitored circuit. The microcontroller is programmed to continuously test for ground-fault conditions by evaluating the sensor output signal and, at selected intervals, test for grounded-neutral conditions by evaluating the sensor's output signal response to a microcontroller initiated ping in the sensor circuit.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: July 18, 2006
    Assignee: Square D Company
    Inventors: Scott R. Brown, Kyle P. Hunter, Roy S. Colby
  • Patent number: 7064941
    Abstract: The aircraft applicable current imbalance detection and circuit interrupter interrupts an electrical circuit when a current imbalance is sensed. The current imbalance detection and circuit interrupter includes a housing, power supplies, a sensor for sensing a current imbalance at the line side of the electrical circuit, a logic controller and a power controller. In a preferred embodiment, the invention can also include a fault indicator, a press to test switch and a reset switch. The power supplies provide power to the sensor, logic controller, and the power controller. The logic controller receives input from the sensor and the relay control signal, and the power controller receives input from the logic controller, and interrupts power to the load side of the electrical circuit when the sensor senses a current imbalance. Power interruption due to a sensed current imbalance is maintained until the line side power source is cycled.
    Type: Grant
    Filed: October 18, 2004
    Date of Patent: June 20, 2006
    Assignee: Hydro-Aire, Inc.
    Inventor: Ronald A. Bax
  • Patent number: 7042688
    Abstract: Resettable circuit interrupting devices, such as GFCI devices, that include neutral fault test simulation.
    Type: Grant
    Filed: July 3, 2003
    Date of Patent: May 9, 2006
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: David Y. Chan, James Richter, Gerald N. King
  • Patent number: 7031126
    Abstract: A method and apparatus for a protection device for indicating when ground fault protection is not being provided by the protection device. The protection device includes source and load terminals between a conductive path and face terminals. The protection device further includes a latching mechanism, adapted to be operable between a first state in which the latching mechanism permits electrical contact between the source terminals and the load terminals and a second state in which the contact is broken; an alarm indicator, adapted to provide an indication that the protection device is not providing ground fault protection; and a fuse, adapted to blow when the latching mechanism fails to open during a manual test of the protection device.
    Type: Grant
    Filed: July 21, 2003
    Date of Patent: April 18, 2006
    Assignee: Hubbell Incorporated
    Inventors: Nelson Bonilla, Joseph V. DeBartolo
  • Patent number: 7016171
    Abstract: A power controller is positioned within a current path between the line side and the load side of an electrical circuit. The power controller closes the current path in the presence of a control supply and opens the current path in the absence of the control supply. A power supply electrically connected to the current path provides the control supply. A sensor system receives power from the power supply, monitors the current in the current path and outputs a sensor signal indicative of a current condition within the current path. A logic controller also receives power from the power supply, receives the sensor signal and removes the control supply from the power controller when the sensor signal does not satisfy an established criteria. The sensor system may include one or both of an imbalance sensor for monitoring the current balance among two or more electrical lines and over-current sensors for monitoring current in individual lines.
    Type: Grant
    Filed: July 19, 2002
    Date of Patent: March 21, 2006
    Assignee: Hydro-Aire, Inc.
    Inventors: Ronald A. Bax, Rudy H. Rusali, Timothy E. King
  • Patent number: 6937452
    Abstract: A resettable circuit interrupting device having a switch and timer circuit connected to the line side of the interrupting device to cause a leakage current to flow for a defined interval of time when power is applied. The timer and switch circuit comprises a timer powered by current from the phase leg of the device which is designed to operate for a defined interval of time. The timer starts operating when power is applied to the circuit interrupting device and normally continues to operate for the defined interval to time. Upon completion of the timed interval, the timer turns itself off and stays off until power is again applied to the device after an interruption. When power is first applied to the interrupting device, the timer is energized from the phase leg and causes the switch to close which connects the neutral leg on the line side of the interrupting device to a ground terminal.
    Type: Grant
    Filed: January 23, 2004
    Date of Patent: August 30, 2005
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: David Chan, Steve Campolo
  • Patent number: 6873158
    Abstract: 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.
    Type: Grant
    Filed: September 23, 2003
    Date of Patent: March 29, 2005
    Assignee: Pass & Seymour, Inc.
    Inventor: Bruce F. Macbeth
  • Patent number: 6856498
    Abstract: An AC power line protection device which includes a protection circuit which guards against miswiring also has an indicator lamp which lights when the device is in the tripped condition and turns off when the device is reset. If the device is miswired after having been wired properly, the indicator lamp does not light when the device is tripped, and so provides a supplemental indication of miswiring. The protection circuit is powered from the hot line bus bar. The indicator lamp is also powered via the hot line bus bar of the interrupting contacts to meet safety standards.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: February 15, 2005
    Assignee: Pass & Seymour, Inc.
    Inventor: David A. Finlay, Sr.
  • Patent number: 6839208
    Abstract: 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.
    Type: Grant
    Filed: February 16, 2001
    Date of Patent: January 4, 2005
    Assignee: Pass & Seymour, Inc
    Inventors: Bruce F. Macbeth, Thomas N. Packard, Jeffrey C. Richards, James P. Romano
  • Patent number: 6828915
    Abstract: A fault warning system controls light sources and a warning signal to provide an indication of fatal and non-fatal faults in a communication system. The circuitry uses a pull-down circuit in electrical communication with light and signal control circuits. The circuit can be operated to activate a first light emitting diode (LED) if an operational status of a monitored circuit is either fatal or non-fatal fault. The circuit can be operated to deactivate a second LED if an operational status of a monitored circuit is fatal, and the second LED remains active if the operational status of the circuit is a non-fatal fault.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: December 7, 2004
    Assignee: ADC DSL Systems, Inc.
    Inventor: Gary Gottlieb
  • Patent number: 6807037
    Abstract: An electronic earth leakage current device, comprising: a moving contact and a fixed contact which can be mutually coupled/uncoupled; and first sensor means for detecting an earth leakage current and for generating an electric signal which is indicative of the value of the earth leakage current; and first electronic means which are electrically connected to the first sensor means in order to generate, on the basis of the electric signal which is indicative of the value of the earth leakage current, an electric tripping signal; and actuation means, operatively connected to the moving contact, in order to perform, in response to an electric tripping signal, the separation of the moving contact from the fixed contact; Its particularity consists of the fact that it comprises: second sensor means for detecting one or more physical values which are indicative of the operating condition of the electronic device for protection against earth leakage current; and second electronic means, electrically connected t
    Type: Grant
    Filed: October 3, 2002
    Date of Patent: October 19, 2004
    Assignee: ABB Service S.r.l.
    Inventors: Walter Patruno, Salvatore Brandonisio, Paolo Antonello, John Samuel Beniston, Willy Schwarz
  • Patent number: 6807035
    Abstract: A fault interrupter having a microcontroller is provided to detect actual faults. The fault interrupter initiates a periodic self-test and provides external notification to the user upon successful or unsuccessful completion of the test. The fault interrupter generates the test signal at a selected time to substantially coincide with the zero-crossing of the AC power source. A manual test can also be performed using a manual test switch provided as a direct input to the microcontroller.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: October 19, 2004
    Assignee: Hubbell Incorporated
    Inventors: John Richard Baldwin, Thomas James Batko, David Francis Ellison, Thomas Michael McDonald
  • Patent number: 6804093
    Abstract: A safe method and apparatus for interrupting electric utility ground and open neutral fault currents and isolating customer's grounding system from utility's neutral utilizing thermal-magnetic circuit breaker pole(s) (18) electrically connected between the neutral bus/lug(s) (38) and the equipment ground bus/lug(s) (32). In addition the grounding electrode conductor (26) is connected directly to the equipment ground bus/lug(s) (32). The method of overcurrent protection for grounding electrode conductors is applicable to electrical installations where from one to six main circuit breakers are used. Circuit breaker enclosure(s) (10) are bonded to the equipment ground bus/lug(s) (32). This method is applicable to load centers, panelboards, and switchboards rated 600 volts or less, single phase or three phase. Ampere ratings vary from 20 amperes to 4,000 amperes. Short circuit ratings vary from 10,000 to 200,000 RMS symmetrical amperes.
    Type: Grant
    Filed: January 10, 2002
    Date of Patent: October 12, 2004
    Inventor: Lonnie L. Buie, Jr.
  • Patent number: 6795285
    Abstract: An appliance is protected against ground faults by a ground fault interrupter (GFI) that sends a signal to an AND gate between the GFI and a controlling microprocessor on one side and a load relay for operating a load device in the appliance on the other side. The GFI signals a ground fault directly to the load relay causing it to deactivate the load device. The appliance is also protected against reverse polarity by a flow detector circuit that signals the load relay to deactivate the load device in a reverse polarity condition.
    Type: Grant
    Filed: February 19, 2003
    Date of Patent: September 21, 2004
    Assignee: Whirlpool Corporation
    Inventors: Todd Michael Jozwiak, David Wayne Mundy
  • Patent number: 6788504
    Abstract: A mobile system for use in supplying AC power to different types of electrical loads including those having grounded neutrals as well as those having neutrals that are electrically isolated from ground. The system includes a GFCI circuit and can be switched between a first mode, in which the circuit provides AC power with ground fault protection for those loads having ungrounded (isolated) neutrals, and a second mode, in which the GFCI is deactivated so that it will not experience false tripping due to the intentional grounding of the neutral at the load. Both single and multi-phase systems are disclosed which can be incorporated into a vehicle, towed trailer, or portable generator. The system is useful for providing AC power to various types of electrical loads at locations where public utility power is not readily available.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: September 7, 2004
    Assignee: General Motors Corporation
    Inventor: Richard John Vanderkolk
  • Patent number: 6782329
    Abstract: A zone arc fault detection system for detecting arcing faults in a defined zone of an electrical circuit, such as an aircraft circuit, includes a pair of substantially identical parallel insulated conductors for each zone in which arcing is to be detected. A detection zone is defined by the parallel conductors between end points where the two conductors are coupled together. A current sensor is operatively associated with each pair of parallel conductors. The current sensor and conductors are respectively configured and arranged such that the current sensor produces a signal representative of a difference in current between the two conductors.
    Type: Grant
    Filed: January 17, 2001
    Date of Patent: August 24, 2004
    Assignee: Square D Company
    Inventor: Gary W. Scott
  • Patent number: 6760202
    Abstract: An electrical coil module of planar type manufactured by printed circuit techniques on a generally flat substrate (21) has a first layout (20) of conducing material constituting a first electrical conductor having an input terminal (23), arranged on one side of the substrate (21). A second layout (20′) of conducting material constituting a second electrical conductor having an output terminal (24), is arranged on the opposite side of the substrate. The first and second conductors are connected by an electrical connection (22) through the substrate (21), so that an electrical voltage connected between the input and output terminals of the coil module will drive a current from one terminal through the conductor on one side of the substrate via connection (22) through the substrate and the conductor on the other side of the substrate to the other terminal.
    Type: Grant
    Filed: December 26, 2001
    Date of Patent: July 6, 2004
    Inventors: Jean-Marc Meyer, Henri Duffour, Serge Martin
  • Patent number: 6747856
    Abstract: A device is for protecting against fault currents, even with frequencies of fault currents higher than 1 kHz. Additionally, it is for protecting against fires to dependably protect people. The converting core of a total current converter mounted upstream of a triggering arrangement, in a releasing circuit, is designed for detecting fault currents of different types. Further, an RC circuit is mounted parallel to the triggering arrangement, on the input side.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: June 8, 2004
    Assignee: Siemens Aktiengesellschaft
    Inventors: Markus Huber, Gerald Lehner
  • Patent number: 6738241
    Abstract: A fireguard circuit for a power cable, which comprises a power line, a neutral line and a metal sheath surrounding the power line and the neutral line, includes a switch located in one of the lines. A solenoid sets the switch in either an open position or a closed position. A first silicon controlled rectifier (SCR) causes the solenoid to open the switch upon detecting the presence of an arcing condition between the power line and the metal sheath. A second silicon controlled rectifier (SCR) causes the solenoid to open the switch upon detecting the presence of an arcing condition between the neutral line and the metal sheath. The second SCR is connected in parallel with the first SCR, the anode of the first SCR being connected to the cathode of the second SCR and the cathode of the first SCR being connected to the anode of the second SCR.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: May 18, 2004
    Assignee: Tower Manufacturing Corporation
    Inventor: Victor V. Aromin
  • Patent number: 6731482
    Abstract: A sensing configuration for a ground fault circuit interrupter for devices having an internal or floating ground electrically isolated from an external ground. The sensor includes a conductor connected to the internal or floating ground so that EMF and leakage current are detected, thus preventing the ground fault circuit interrupter from tripping due to signals caused only by EMF and leakage current in the load circuit.
    Type: Grant
    Filed: January 9, 2001
    Date of Patent: May 4, 2004
    Inventor: Gheorghe Jack Juncu
  • Patent number: 6724589
    Abstract: A method and apparatus including indicators and a Ground Fault Current Interrupter (GFCI) are provided to test the marina's power and the boats electrical system load to make sure that both are proper and safe to be inter-connected. A low voltage high impedance ground current path including an oppositely connected pair of typically four silicon diodes in series in each of the pairs, sufficient to raise the voltage to a safe level encompassing the typical combined AC ground fault and DC galvanic currents in a Marina is incorporated. This protects against low level AC ground faults present in the marina, as well as DC current due to the harbor safety ground interconnect between boats in the harbor.
    Type: Grant
    Filed: September 13, 1999
    Date of Patent: April 20, 2004
    Inventor: Donald G. Funderburk
  • Patent number: 6674289
    Abstract: 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.
    Type: Grant
    Filed: November 29, 2000
    Date of Patent: January 6, 2004
    Assignee: Pass & Seymour, Inc.
    Inventor: Bruce F. Macbeth
  • Patent number: 6671145
    Abstract: Resettable circuit interrupting devices, such as GFCI devices, that include a reset lockout mechanism, an independent trip mechanism and reverse wiring protection. A conical reset plunger is notched to force a successful test before reset.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: December 30, 2003
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: Frantz Germain, Stephen Stewart, Roger M. Bradley, David Y. Chan, Nichalas L. Disalvo, William R. Ziegler
  • Patent number: 6650517
    Abstract: A ballast safety circuit is disclosed. The ballast safety circuit includes a sensor in the form a toroid that includes a pair of coil windings for coupling to a pair of input lines on an input side of a ballast. The toroid further includes a third coil winding for detecting a leakage current flowing through one of the input lines when a person is attempting to mount a lamp on the ballast. Upon detection of the leakage current, the ballast safety circuit impeded an operation of the lamp to thereby dissipate the leakage current whereby the person can safely complete the mounting of the lamp on the ballast.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: November 18, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Zhengguo Zhou, Shihua Shen, Hui Jiang
  • Patent number: 6646839
    Abstract: An improved surge suppressor which combines a ground fault circuit interrupter with overvoltage protection for AC power lines. The surge suppressor includes a switchable device for disconnecting power from the ground fault circuit interrupter in the event the AC neutral is lost.
    Type: Grant
    Filed: November 7, 2001
    Date of Patent: November 11, 2003
    Assignee: TII Industries, Inc.
    Inventors: Nisar A. Chaudhry, Alfred J. Roach
  • Patent number: 6646837
    Abstract: A device inserted between a grounded poly-phase external voltage source and a load providing low insertion loss for differential mode currents and high insertion loss for ground currents. The device receives voltages from the grounded poly-phase external voltage source over atone or more voltage lines. The voltages contain common mode voltages. A filter connected to each of the voltage lines reduces the ground current from the load. A summing block adds the voltages from each of the voltage lines to generate a total common mode voltage. A ground referenced controlled voltage source generates a cancellation voltage equal to the total common mode voltage in response to the generation of total common mode voltage. The total common mode voltage is injected into the filter and substantially reduces the common mode voltage on each voltage line thereby substantially reducing the ground currents associated with each common mode voltage on each voltage line.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: November 11, 2003
    Assignee: Ballard Power Systems Corporation
    Inventor: Orrin B. West
  • Patent number: 6643108
    Abstract: A control system for a pool and spa. Main line voltage is provided through a single line voltage service and a single ground fault circuit interrupter circuit, facilitating a ground fault test and simplifying installation. The control system acts as a power distribution system for controlling the pool and spa equipment, with a circuit board assembly including individual fuse protection devices and switching circuits. A test algorithm is included, wherein the control system is disabled from normal operation if the GFCI test fails. The pool operator manually enters a water fill command, and the controller system automatically opens the fill valve for a predetermined time interval, and then automatically closes the valve. An emergency disconnect switch is mounted near the bathing area, connected by low voltage wiring to the controller system cabinet. The controller system senses the emergency switch closure and disconnects line voltage to the line voltage loads.
    Type: Grant
    Filed: February 4, 2002
    Date of Patent: November 4, 2003
    Assignee: Balboa Instruments, Inc.
    Inventors: David J. Cline, Cindy Otto
  • Patent number: 6639770
    Abstract: A current transformer for a ground fault circuit breaker used on a circuit having at least one line conductor and a neutral conductor includes a toroidal core having a circular opening defining a center point and a multi-turn winding wound on the core. A first guide member is disposed on one side of the core, and a second guide member is disposed on another side of the core. The first and second guide members each have a hole for receiving the line conductor and a hole for receiving the neutral conductor formed therein. The guide members thus position the conductors with respect to the core. The present invention also includes a method of correcting asymmetries in the current transformer. The method includes measuring the magnitude and orientation of any asymmetries, and then altering the current transformer based on the measured magnitude and orientation of the asymmetries so as to eliminate the asymmetries.
    Type: Grant
    Filed: November 14, 2001
    Date of Patent: October 28, 2003
    Assignee: General Electric Company
    Inventors: Jerome Johnson Tiemann, Richard Dudley Baertsch
  • Patent number: 6639768
    Abstract: Tripping of a circuit breaker by an arc fault detector is blocked by a disable circuit upon detection of a transient associated with cold turn-on of an incandescent bulb powered by a dimmer. The peak value of pulses generated by the bandpass filter of the arc detector in response to step increases in the ac current is decayed approximately exponentially. The amplitude of each pulse is compared with upper and lower percentage limits of the decaying peak value. If the amplitudes of the pulses remain below the upper threshold for about 3 to 4 half cycles and exceed the lower threshold each half cycle, a dimmer transient is identified and logic is set to block generation of a false arc signal.
    Type: Grant
    Filed: December 20, 2001
    Date of Patent: October 28, 2003
    Assignee: Eaton Corporation
    Inventors: Joseph C. Zuercher, Steven Christopher Schmalz
  • Patent number: 6633472
    Abstract: A remote control and power protection circuit installed in an electric outlet and adapted to control the operation of each electric socket of the electric outlet by means of a remote controller and to automatically trip off the circuit upon an overcurrent or overvoltage. The remote control and power protection circuit includes a CPU having voltage/current detector and amplifier circuit means and voltage/current judging circuit means adapted to detect the voltage/current value of inputted power supply, and to drive a red LCD to flash and a buzzer to buzz when inputted current value approaches the rated value, and to drive an overload switch element to trip off power supply upon an overcurrent or overvoltage.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: October 14, 2003
    Inventor: Jung-Hua Lai
  • Patent number: 6628486
    Abstract: A protection device connected between hot and neutral conductors of an AC power line includes a fault detection circuit which controls a breaker coil operatively associated with a set of interrupting contacts. A capacitance circuit connected between the hot conductor and the neutral conductor stores a charge of a polarity indicative of a line-load miswire. This stored charge independently activates the set of interrupting contacts when the interrupting contacts are closed and the device is miswired, thus preventing the miswired device from providing power.
    Type: Grant
    Filed: March 5, 2001
    Date of Patent: September 30, 2003
    Assignee: Pass & Seymour, Inc.
    Inventor: Bruce F. Macbeth
  • Patent number: 6618229
    Abstract: The aircraft applicable current imbalance detection and circuit interrupter interrupts an electrical circuit when a current imbalance is sensed. The current imbalance detection and circuit interrupter includes a housing, power supplies, a sensor for sensing a current imbalance at the line side of the electrical circuit, a logic controller and a power controller. In a preferred embodiment, the invention can also include a fault indicator, a press to test switch and a reset switch. The power supplies provide power to the sensor, logic controller, and the power controller. The logic controller receives input from the sensor and the relay control signal, and the power controller receives input from the logic controller, and interrupts power to the load side of the electrical circuit when the sensor senses a current imbalance. Power interruption due to a sensed current imbalance is maintained until the line side power source is cycled.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: September 9, 2003
    Assignee: Hydro-Aire, Inc.
    Inventor: Ronald A. Bax