Arc fault detection system
AssigneeSquare D Company
InventorsAndy A. Haun, Alan G. Coats, Kon B. Wong, Robert F. Dvorak, Gary W. Scott
Life of this patent
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Abstract
An arc fault detector system detects arcing faults in an electrical distribution system by monitoring one or more conductors and producing an input signal representing one or more electrical signal conditions in the circuit to be monitored. This input signal is processed to develop signals representing the electrical current flow through the monitored circuit and broadband noise signal components. The system analyzes these signals to determine whether an arcing fault is present, and if so, outputs a trip signal which may be used directly or indirectly to trip a circuit breaker or other circuit interruption device.
Claims30
A method of determining whether arcing is present in an electrical circuit comprising:
- sensing current in said circuit and developing a corresponding first signal;
- analyzing said first signal to determine the presence of broadband noise in a predetermined range of frequencies, and producing a corresponding second signal;
- and
- processing said first signal and said second signal to determine current peaks, and to determine, using said current peaks and the presence of broadband noise, whether an arcing fault is present in said circuit by comparing data corresponding to said current peaks and broadband noise with preselected data indicative of an arcing fault.
A system for determining whether arcing is present in an electrical circuit comprising:
- a sensor for sensing current in said circuit and developing a corresponding sensor signal;
- a circuit for analyzing said sensor signal to determine the presence of broadband noise in a predetermined range of frequencies, and producing a corresponding output signal;
- and
- a controller for processing said sensor signal and said output signal to determine current peaks and to determine, using said current peaks and the presence of broadband noise, whether an arcing fault is present in said circuit, by comparing data corresponding to said current peaks and broadband noise with preselected data indicative of an arcing fault.
A controller for a system for determining whether arcing is present in an electrical circuit in response to input signals, said input signals corresponding to a changing current in said circuit and to the presence of broadband noise in at least one predetermined range of frequencies in said circuit, said controller comprising:
- a plurality of counters;
- means for incrementing said plurality of counters in response to said input signals corresponding to a changing current and to said input signals corresponding to the presence of broadband noise;
- and
- means for periodically determining whether an arcing fault is present by monitoring said plurality of counters and comparing counts in said counters with one or more preselected counts indicative of an arcing fault.
A method of determining whether arcing is present in an electrical circuit in response to input signals, said input signals corresponding to a changing current in said circuit and to the presence of broadband noise in at least one predetermined range of frequencies in said circuit, said method comprising the steps of:
- incrementing a plurality of counters in response to said input signals corresponding to a changing current and to said input signals corresponding to the presence of broadband noise;
- and
- periodically determining whether an arcing fault is present by monitoring said plurality of counters and comparing counts in said counters with one or more preselected counts indicative of an arcing fault.
Dependencies are inferred from the claim text.