Point of use protective wiring device

Patent metadata

Field	Value
Publication number	US-11095108-B2
Application number	US-201916439212-A
Country	US
Kind code	B2
Filing date	Jun 12, 2019
Priority date	Jun 13, 2018
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

The present invention is directed to protective wiring devices, and more particularly, to a protective wiring device that meets the prevailing electrical codes and is convenient for a homeowner to reset after it has tripped.

First claim

What is claimed is:

1. An electrical wiring device for installation in a branch circuit of an electrical distribution system for delivering power from a power source to a load, and a circuit breaker being disposed at the origin of the branch circuit comprising:
a housing including a front cover and a back body;
a plurality of line terminals at least partially disposed in the housing and configured to be coupled to upstream portions of the plurality of conductors extending between a circuit breaker at the origin of the branch circuit and the plurality of line terminals;
a plurality of load terminals at least partially disposed in the housing including user load terminals or feed-through load terminals and configured to be coupled to downstream portions of the plurality of conductors extending between the plurality of load terminals to the load;
a protective circuit disposed inside the housing including:
a directional arc fault sensor assembly comprising a sensor element and a filter element, the sensor element being configured to sense at least one fault condition when propagating on the downstream portion of one of the conductors, the filter element being configured to divert the at least one fault signal when propagating on the line portion of the conductor to another of the plurality of conductors, the filter element substantially preventing the sensor element from being able to sense the at least one fault condition when propagating on the upstream portion of the conductor;
an arc fault detector configured to generate an arc fault detection signal when the sensor element generates a sensor signal that exceeding a predetermined threshold;
a switching element configured to generate a trip signal in response to the arc fault detection signal; and
a circuit interrupter coupled to the switching element, the circuit interrupter being configured to disconnect the plurality of load terminals from the plurality of line terminals in a tripped state in response to the trip signal, the circuit interrupter being configured to connect the plurality of line terminals and the plurality of load terminals in a reset state,
wherein the circuit interrupter remains in the reset state when the fault condition at the predetermined threshold is propagating on the upstream portion of the conductor but enters the tripped state when the fault condition at the predetermined threshold is propagating in the downstream portion of the conductor.

2. The device of claim 1 , wherein the filter element includes a capacitor connected across the plurality of line terminals.

3. The device of claim 2 , wherein the filter element includes a capacitor connected across the plurality of line terminals in the tripped state.

4. The device of claim 3 , wherein a metal oxide varistor (MOV) is connected across the capacitor.

5. The device of claim 1 , wherein the filter element includes a capacitor in series with an inductor connected across the plurality of line terminals.

6. The device of claim 1 , wherein the sensor element includes a shunt sensor or a toroidal sensor.

7. The device of claim 1 , wherein the arc fault sensing assembly includes a toroidal sensor comprising the sensor element and a portion of the filter element.

8. The device of claim 7 , wherein the filter element includes a capacitor connected across the plurality of line terminals.

9. The device of claim 8 , wherein the filter element includes a MOV connected across the capacitor.

10. The device of claim 1 wherein the plurality of conductors includes a phase conductor, a neutral conductor, and a ground conductor, the device further comprising a cancellation circuit configured to propagate a supplemental current on an upstream portion of the neutral conductor such that the currents flowing on an upstream portion of the phase conductor and the upstream portion of the neutral conductor substantially null.

11. The device of claim 10 , wherein the neutral conductor is connected to a line neutral terminal, and the ground conductor is connected to a ground terminal, the cancellation circuit being coupled across the line neutral terminal and the ground terminal.

12. The device of claim 10 , further comprising a saturation transformer and a magnitude detector, wherein the saturation transformer is coupled to the phase conductor and the neutral conductor and generates a saturation signal in response to a difference in currents flowing on the phase conductor and the neutral conductor, the magnitude detector signaling the switching element to trip the circuit interrupter when the saturation signal exceeds a predetermined level.

13. The device of claim 1 wherein the plurality of conductors includes a phase conductor and a neutral conductor, the device further comprising a saturation transformer and a magnitude detector, the saturation transformer being coupled to the phase conductor and the neutral conductor and generating a saturation signal in response to a difference in currents flowing on the phase conductor and the neutral conductor, the magnitude detector signaling the switching element to trip the circuit interrupter when the saturation signal exceeds a predetermined level.

14. The device of claim 1 , further comprising a differential transformer coupled to the plurality of conductors, the differential transformer providing signal to a differential fault detector, the differential fault detector being configured to generate a differential fault detection signal when the difference in current between a pair of downstream conductors is greater than a predetermined level, the arc fault detector and the differential fault detector being coupled to the switching element by way of an OR gate, the switching element generating the trip signal in response to the arc detection signal or the differential fault detection signal.

15. The device of claim 14 , further comprising a saturating transformer coupled to the plurality of conductors, the saturating transformer being coupled to the OR gate via a bypass element that bypasses the differential fault detector, the switching element generating the trip signal in response to a saturating transformer signal having predefined characteristics.

16. The device of claim 15 , wherein the bypass element includes a pulse stretching circuit.

17. The device of claim 14 , further comprising a saturating transformer coupled to the plurality of conductors, the saturating transformer being coupled to the switching element by way of bypass element that bypasses the differential fault detector, the switching element generating the trip signal in response to a saturating transformer signal greater than a predetermined threshold.

18. The device of claim 1 , further including a remote control box having a manually operable reset button and a manually operable trip button capable of driving the circuit interrupter respectively between the reset state and the tripped state using wireless communication.

19. The device of claim 18 , wherein the circuit interrupter includes a trip solenoid and a reset solenoid.

20. The device of claim 1 wherein the plurality of conductors includes a phase conductor, a neutral conductor, and a ground conductor, the device further comprising a cancellation circuit configured to propagate a supplemental current on an upstream portion of the neutral conductor such that the currents flowing on an upstream portion of the phase conductor and the upstream portion of the neutral conductor substantially null.

21. The device of claim 20 , wherein

Assignees

• Pass & Seymour Inc

Inventors

• Packard Thomas N

Classifications

• H02H3/08

  responsive to excess current (responsive to abnormal temperature caused by excess current H02H5/04) · CPC title

• H02H1/0015 Primary

  Using arc detectors · CPC title

• H01H71/128

  Manual release or trip mechanisms, e.g. for test purposes (two similar push buttons for closing or resetting and opening or tripping H01H71/58; test switches for earth fault circuit breakers H01H83/04) · CPC title

• H02H3/044

  Checking correct functioning of protective arrangements, e.g. by simulating a fault (for differential current circuit breakers H02H3/335) · CPC title

• H01H2300/03

  Application domotique, e.g. for house automation, bus connected switches, sensors, loads or intelligent wiring · CPC title