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US 6,477,021 B1Granted
Blocking/inhibiting operation in an arc fault detection system
AssigneeSquare D Company
InventorsAndy A. Haun, Brian G. Grattan, Kon B. Wong, Robert F. Dvorak, Gary W. Scott
Life of this patent
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Abstract
A system for determining whether arcing is present in an electrical circuit includes a sensor for monitoring a current waveform in the electrical circuit, and an arc fault detection circuit which determines whether an arc fault is present in response to the sensor. The arc fault detection circuit includes a controller which produces a trip signal in response to a determination that an arcing fault is present in the electrical circuit, and an inhibit/blocking function for preventing the production of the trip signal under one or more predetermined conditions.
Claims36
A system for determining whether arcing is present in an electrical circuit comprising:
- a sensor which monitors a current waveform in said electrical circuit;
- an arc fault detection circuit which determines whether an arc fault is present in response to said sensor by recognizing a signature of the waveform, said arc fault detection circuit including a controller which stores signature recognition data and produces a trip signal in response to a determination, based upon said signature recognition data, that an arcing fault is present in said electrical circuit;
- and
- a trip inhibitor which prevents production of said trip signal by the controller under one or more predetermined conditions;
- wherein said sensor detects current in said circuit and develops a corresponding sensor signal, and wherein said arc fault detection circuit comprises a circuit which determines the presence of broadband noise in said sensor signal and produces a corresponding output signal, and a controller which processes said sensor signal and said output signal in a predetermined fashion to determine whether an arcing fault is present in said electrical circuit;
- and
- wherein the controller implements a plurality of counters and increments said plurality of counters in a predetermined fashion in accordance with said sensor signal and said output signal, and periodically determines whether an arcing fault is present based at least in part on the state of said plurality of counters.
4 more elements
A system for determining whether arcing is present in an electrical circuit comprising:
- a sensor which monitors a current waveform in said electrical circuit;
- an arc fault detection circuit which determines whether an arc fault is present in response to said sensor by recognizing a signature of the waveform, said arc fault detection circuit including a controller which stores signature recognition data and produces a trip signal in response to a determination, based upon said signature recognition data that an arcing fault is present in said electrical circuit;
- and
- a trip inhibitor which prevents production of said trip signal by the controller under one or more predetermined conditions;
- wherein said trip inhibitor comprises a device for modifying said current waveform so as to appear to said are fault detection circuit to be a non-arc fault waveform.
2 more elements
A system for determining whether arcing is present in an electrical circuit comprising:
- a sensor which monitors a current waveform in said electrical circuit;
- an arc fault detection circuit which determines whether an arc fault is present in response to said sensor by recognizing a signature of the waveform, said arc fault detection circuit including a controller which stores signature recognition data and produces a trip signal in response to a determination, based upon said signature recognition data, that an arcing fault is present in said electrical circuit;
- and
- a trip inhibitor which prevents production of said trip signal by the controller under one or more predetermined conditions;
- wherein said trip inhibitor comprises a communication device which communicates information corresponding to at least one of said predetermined conditions to said controller.
2 more elements
A system for determining whether arcing is present in an electrical circuit comprising:
- a sensor which monitors a current waveform in said electrical circuit;
- an arc fault detection circuit which determines whether an arc fault is present in response to said sensor by recognizing a signature of the waveform, said are fault detection circuit including a controller which stores signature recognition data and produces a trip signal in response to a determination, based upon said signature recognition data, that an arcing fault is present in said electrical circuit;
- and
- a trip inhibitor which prevents production of said trip signal by the controller under one or more predetermined conditions;
- wherein said trip inhibitor is a plug-in module.
2 more elements
A method for determining whether arcing is present in an electrical circuit comprising:
- monitoring a current waveform in said electrical circuit;
- determining whether an arc fault is present in response to the monitored current waveform by recognizing a signature of the waveform;
- producing a trip signal in response to a determinations based upon said signature recognition, that an arcing fault is present in said electrical circuit;
- and
- preventing production of said trip signal under one or more predetermined conditions;
- wherein said monitoring includes detecting current in said circuit and developing a corresponding current signal, and wherein said determining comprises determining the presence of broadband noise in said current waveform and producing a corresponding broadband noise signal, and processing said current signal and said broadband noise signal in a predetermined fashion To determine whether an arcing fault is present in said electrical circuit, and
- wherein said determining includes implementing a plurality of counters and incrementing said plurality of counters in a predetermined fashion in accordance with said current signal and said broadband noise signal, and periodically determining whether an arcing fault is present based at least in part on the state of said plurality of counters.
4 more elements
A method for determining whether arcing is present in an electrical circuit comprising;
- monitoring a current waveform in said electrical circuit;
- determining whether an arc fault is present in response to the monitored current waveform by recognizing a signature of the waveform;
- producing a trip signal in response to a determination, based upon said signature recognition, that an arcing fault is present in said electrical circuit;
- and
- preventing production of said trip signal under one or more predetermined conditions;
- wherein said preventing comprises modifying said current waveform so as to appear to be a non-arc fault waveform.
3 more elements
A method for determining whether arcing is present in an electrical circuit comprising:
- monitoring a current waveform in said electrical circuit;
- determining whether an arc fault is present in response to the motored rent waveform by recognizing a signature of the waveform;
- producing a trip signal in response to a determination, based upon said signature recognition, that an arcing fault is present in said electrical circuit;
- and
- preventing production of said trip signal under one or more predetermined conditions performing said monitoring and determining in an electrical receptacle;
- wherein said preventing comprises an operator activatable control mounted to said electrical receptacle by prongs producing an inhibit signal.
3 more elements
A method for determining whether arcing is present in an electrical circuit comprising:
- monitoring a current waveform in said electrical circuit;
- determining whether an arc fault is present in response to the monitored current waveform by recognizing a signature of the waveform;
- producing a trip signal in response to a determination, based upon said signature recognition, that an arcing fault is present in said electrical circuit;
- and
- preventing production of said trip signal under one or more predetermined conditions performing said monitoring and determining in an electrical receptacle;
- wherein said preventing comprises inserting a plug-in module into said electrical receptacle.
3 more elements
A method for determining whether arcing is present in an electrical circuit comprising:
- monitoring a current waveform in said electrical circuit;
- determining whether an arc fault is present in response to the monitored current waveform by recognizing a signature of the waveform;
- producing a trip signal in response to a determination, based upon said signature recognition, that an arcing fault is present in said electrical circuit;
- and
- preventing production of said trip signal under one or more predetermined conditions performing said monitoring and determining in an electrical receptacle;
- wherein said preventing comprises an operator activatable control communicating information corresponding to at least one of said predetermined conditions with means in said electrical receptacle for performing said monitoring and determining.
3 more elements
A system for determining whether arcing is present in an electrical circuit comprising:
- a sensor which monitors a current waveform in said electoral circuit;
- an arc fault detection circuit which determines whether an arc fault is present in response to said sensor by recognizing a signature of the waveform, said arc fault detection circuit including a controller which stores signature recognition data and produces a trip signal in response to a determination, based upon said signature recognition data, that an arcing fault is present in said electrical circuit;
- And
- a trip inhibitor which prevents production of said trip signal by the controller under one or more predetermined conditions;
- wherein said sensor detects current in said circuit and develops a corresponding sensor signal, and wherein said arc fault detection circuit comprises a circuit which determines the presence of broadband noise in said sensor signal and produces a corresponding output signal, and a controller which processes said sensor signal and said output signal in a predetermined fashion to determine whether an arcing fault is present in said electrical circuit;
- wherein the controller implements a plurality of counters and increments said plurality of counters in a predetermined fashion in accordance with said sensor signal and said output signal, and periodically determines whether an arcing fault is present based at least in part on the state of said plurality of counters.
3 more elements
A method for determining whether arcing is present m an electrical circuit comprising:
- monitoring a current waveform in said electrical circuit;
- determining whether an arc fault is present in response to the monitored current waveform by recognizing a signature of the waveform;
- producing a trip sign in response to a determination, based upon said recognizing, that an arcing fault is present it said electrical circuit;
- and
- preventing production of said trip signal under one or more predetermined conditions;
- wherein said monitoring includes detecting current in said circuit and developing a corresponding current signal, and wherein said determining comprises determining the presence of broadband noise in said current waveform and producing a corresponding broadband noise signal, and processing said current signal and said broadband noise signal in a predetermined fashion to determine whether an arcing fault is present in said electrical circuit;
- wherein said determining includes implementing a plurality of counters and incrementing said plurality of counters in a predetermined fashion in accordance with said current signal and said broadband noise signal, and periodically determining whether an arcing fault is present based at least in part on the state of said plurality of counters.
4 more elements
Dependencies are inferred from the claim text.