763results about "Switch operated by earth fault currents" patented technology

A ground fault detector and interrupter for a photovoltaic (PV) energy conversion system, method and apparatus are disclosed. In an exemplary embodiment, the system includes first and second inputs adapted to couple to a first and second rails of a PV array. An inverter is configured to convert DC power generated from the PV array to AC power. A ground fault detector and interrupter, which is coupled to the first and second rails and to the inverter, is configured to detect ground fault conditions in the PV array and to decouple the PV array from the remaining portion of the PV energy conversion system upon such detection. A known signal is coupled to the input of the ground fault detector and interrupter, and then sensed at the output of the ground fault detector and interrupter to determine whether components of the ground fault detector and interrupter are operating properly.

The present invention is directed to a circuit and method for self-testing a protection device for use in an AC power distribution system. The device is configured to be coupled between an AC power distribution system and at least one load. The method includes the step of introducing a simulated ground neutral fault during a first predetermined half cycle half cycle of the AC power. An attempt is made to detect the introduced simulated grounded neutral fault during the first predetermined half cycle half cycle. A fault condition is signaled if the introduced simulated grounded neutral fault is not detected within a predetermined period of time.

The present invention is directed to an electrical wiring protection device including a housing assembly including at least one receptacle, the at least one receptacle being configured to receive plug contact blades inserted therein. The housing assembly includes a hot line terminal, a neutral line terminal, a hot load terminal, a neutral load terminal, a hot user-accessible receptacle contact, and a neutral user accessible receptacle contact. A fault detection circuit is coupled to the hot line terminal and the neutral line terminal. The fault detection circuit is configured to detect at least one fault condition and provide a fault detect signal in response thereto. An interrupting contact assembly is coupled to the fault detection circuit. A weld breaker mechanism is coupled to the interrupting contact assembly. The weld breaker mechanism is configured to strike the first pair of contacts and/or the second pair of contacts in response to the tripping stimulus.

A GFCI device which has reverse wiring protection is provided where no power is present at the face terminals even when the device is reverse wired. The device has a pair of movable bridges connected to its terminals. The terminal bridge pair makes contact with the load and face terminals providing power to these terminals when the device is reset. The device also has a reset lockout feature that prevents it from being reset after having been tripped if the circuit interrupting portion of the device is non-operational.

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.

The present invention is directed to an electrical wiring protection device that includes a housing assembly having at least one receptacle. The receptacle is configured to receive plug contact blades inserted therein. The housing assembly includes a hot line terminal, a neutral line terminal, a hot load terminal, and a neutral load terminal. A set of receptacle contacts is disposed in the housing assembly and in communication with the receptacle. The receptacle contacts includes a hot user-accessible load contact and a neutral user accessible load contact. A fault detection circuit is coupled to the test assembly. The fault detection circuit is configured to detect at least one fault condition and provide a fault detect signal in response thereto. A four-pole interrupting contact assembly is coupled to the fault detection circuit and includes a set of four-pole interrupting contacts. A reset mechanism is coupled to the four-pole interrupting contact assembly. The reset mechanism includes a reset button and a reset actuator configured to reestablish electrical continuity between the first pair of hot contacts, the second pair of hot contacts, the first pair of neutral contacts, and the second pair of neutral contacts in response to a reset stimulus.

Located within a GFCI device having a receptacle is a movable contact bearing arm which is held in either a closed or open position with a fixed contact by a latching member that is connected to the spring loaded reset button. The reset button assumes a first or a second position which is determined by the conductive state of the GFCI. When the GFC is in a conducting state, the reset button is substantially fully depressed within the housing of the GFCI. When the GFCI is in a non-conductive state, the reset button projects outward beyond the top surface of the housing of the GCFI. Thus, the movable contact bearing arm, acting through a latching member, determines the position of the reset button. A blocking member located within the body of the GFCI is positioned by the reset button to allow free access of the prongs of a plug into the openings of the receptacle when the reset button is depressed or to block at least one opening of the receptacle to prevent a plug from entering the openings of the receptacle when the reset button projects out beyond the surface of the housing. Thus, when the GFCI is in a conducting state, the reset button is recessed within the GFCI housing and positions the blocking member to the first position to allow the prongs of a plug to be inserted into the receptacle openings. When the GFCI is in a non-conducting state, the reset button protrudes outward from the housing of the GFCI to position the blocking member to the second position to block at least one opening of the receptacle to prevent the prongs of a plug from entering the receptacle. GFCI's normally have two separate sets of internally located contacts known as bridge contacts where one set is used to connect a load to the source of electricity and the second set is used to connect a user accessible load to the source of electricity. The bridge contacts provide isolation between the conductors to the load and the conductors to the contacts of the GFCI receptacle when the GFCI is in a fault state. In the GFCI here disclosed, the blocking member prevents the prongs of a plug from entering the receptacle when the GFCI is in a fault state and, therefore, can eliminate the need for the bridge contacts.

A new type of switching mechanism for a ground fault circuit interrupter (GFCI) with reverse wiring protection preferably includes two pairs of fixed contact holders, each member of each pair having at least one fixed contact at one end; a pair of movable contact holders, each having an end having one or more of movable contacts, each movable contact being arranged for contacting one of the fixed contacts; and a movable assembly that moves between first and second positions, wherein the first position is a position in which each of the contacts of the fixed contact holders makes contact with one of the contacts of the movable end of one of the movable contact holders, and wherein the second position is a position in which the contacts of the fixed contact holders are separated from the contacts of the movable contact holders.

The present invention is directed to an electrical wiring protection device that includes a housing assembly having at least one line terminal and at least one load terminal partially disposed therein. A first conductive path is electrically coupled to the at least one line terminal. A second conductive path is electrically coupled to the at least one load terminal, the second conductive path being connected to the first conductive path in a reset state. A fault detection circuit is coupled to the first conductive path. The fault detection circuit is configured to generate a fault detection signal in response to detecting at least one fault condition. A wiring state detection circuit is coupled to the first conductive path. The wiring state detection circuit selectively provides a wiring state detection signal when the at least one line terminal is coupled to a source of AC power, and not providing the wiring state detection signal otherwise. An actuator assembly is configured to provide an actuation stimulus in response to the fault detection signal or the wiring state detection signal. A circuit interrupter is coupled to the actuator assembly. The circuit interrupter is configured to disconnect the first conductive path and the second conductive path in response to the actuation stimulus.

Located within a GFCI is a movable contact bearing arm which cooperates with at least one fixed contact. When the movable arm is moved up to allow the at least one contact on the arm to close with at least one fixed contact, the GFCI is in a conducting state and current flows from a source of electricity through the closed contacts to a load and to the contacts of a receptacle. When the movable arm is moved down to open the contacts, the GFCI is in a non-conducting state and current cannot flow from the source of electricity to either the load or the receptacle contacts. In this invention, the up and down movement of the movable contact bearing arm is harnessed to move a blocking member located within the housing of the GFCI to a first position to block at least one opening of the receptacle as the movable arm is moved down or to a second position to allow the prongs of a plug to enter the openings of the receptacle as the movable arm is moved up. The downward movement of the movable contact bearing arm occurs when the GFCI goes into a non-conducting state. Resetting the GFCI by pressing in and then releasing a reset button causes the movable contact bearing arm to move up to make contact with the at least one fixed contact. As the movable arm moves up, the blocking member moves to the first or non-blocking position to allow the prongs of a plug to freely enter the openings in the face of the receptacle. GFCI's normally have two separate sets of internally located contacts known as bridge contacts where one set is used to connect a load to the source of electricity and the second set is used to connect a user accessible load to the source of electricity. The bridge contacts provide isolation between the conductors to the load and the conductors to the contacts of the GFCI receptacle when the GFCI is in a non-conducting state. In the GFCI here disclosed, the blocking member prevents the prongs of a plug from entering the receptacle when the GFCI is in a non-conducting state and, therefore, the need for the bridge contacts is diminished.

The present invention is directed to a protective device that includes a plurality of line terminals configured to be connected to an electrical distribution system, and a plurality of load terminals configured to be connected to a load. The device includes a fault detection circuit coupled to the plurality of line terminals and the plurality of load terminals. The fault detection circuit is configured to detect at least one fault in the electrical distribution system. A power interruption circuit couples the plurality of line terminals to the plurality of load terminals to thereby provide power to the load under normal operating conditions. The power interruption circuit also is coupled to the fault detection circuit, and configured to decouple the plurality of line terminals from the plurality of load terminals in response to the fault detection circuit detecting the at least one fault. A test circuit is coupled to the fault detection circuit and the power interruption circuit. The test circuit is configured to provide a simulated fault signal to the fault detection circuit in response to a user stimulus. An end-of-life indication circuit is coupled to the test circuit and the power interruption circuit. The end-of-life indication circuit provides the user with an end-of-life alarm indicator if the fault detection circuit fails to respond to the simulated fault signal within a predetermined period of time.

A self testing fault detector having a line side and a load side and a conductive path there between. The apparatus includes a solenoid, which is adapted to move a plurality of contacts disposed in the conductive path from a first position to a second position when the self testing device is powered from the line side; and a processor, which is adapted to energize the solenoid using a first switch and maintain said solenoid in the energized state using a second switch.