Abstract:
A system for determining whether arcing is present in an electrical circuit in response to a sensor signal corresponding to current in the circuit includes a circuit for analyzing the sensor signal to determine the presence of broadband noise in a predetermined range of frequencies, and producing a corresponding output signal. A controller processes the sensor signal and the output signal to determine current peaks and rise times and to determine, using the current peaks and rise times and the presence of broadband noise, whether an arcing fault is present in the circuit, by comparing data corresponding to the current peaks and rise times and broadband noise with preselected data indicative of an arcing fault. The circuit for analyzing and the controller are integrated onto a single application specific integrated circuit chip.
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.
Abstract:
An arcing fault protection assembly and a corresponding method determine whether arcing is present in electrical circuits. The assembly powers-up quickly without dissipating excessive heat while power is being supplied to the assembly. The assembly comprises a sensor, a broadband noise circuit, a controller, and a dual-mode power supply. The sensor detects a current flowing in an electrical circuit and develops a corresponding sensor signal. The broadband noise circuit determines the presence of broadband noise in the sensor signal and produces a corresponding output signal. The controller processes the sensor signal and the output signal in a predetermined fashion to determine whether an arcing fault is present in the circuit. The dual-mode power supply supplies power to the sensor, broadband noise circuit and controller using a first mode and later switching to a second mode. The first mode reaches steady state faster than the second mode.
Abstract:
An electrical fault detector system detects electrical 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 a first signal representing the electrical current flow through the monitored circuit and a second signal representing signal components in a selected frequency range typical of arcing faults, and which exceed a predetermined threshold. The system also detects ground faults in the circuit being monitored.
Abstract:
A method of determining whether arcing is present in an electrical circuit includes sensing a change in current in the circuit and developing a corresponding input signal, analyzing the input signal to determine the presence of broadband noise in a predetermined range of frequencies, and producing a corresponding output signal, and processing the input signal and the output signal in a predetermined fashion to determine whether an arcing fault is present in the circuit. The processing includes determining a type of load connected to the electrical circuit, based at least in part upon the input signal and the output signal.
Abstract:
An arc fault circuit interrupter system for use with an electrical circuit includes an arcing fault detector which monitors the electrical circuit and a controller which generates a trip signal in response to the detection of arcing faults. The controller may also generate one or more communication signals corresponding to information relating to the operation of the arcing fault circuit interrupter. The system may also include one or more of the following: a communication port which communicates to a user the information relating to operation of the arc fault circuit interrupter in response to the communication signals; a memory for retaining predetermined information related to the condition and operation of the arcing fault circuit interrupter, with or without a backup memory; and a combined self-test/reset switch.
Abstract:
An arcing fault protection assembly in an electrical outlet, and a corresponding method determine whether arcing is present in an electrical device connected to the outlet. The assembly comprises a sensor, a broadband noise circuit, a controller and s an electrical device. The sensor detects a current and develops a corresponding sensor signal. The broadband noise circuit determines the presence of broadband noise in the sensor signal and produces a corresponding output signal. The controller processes the sensor signal and the output signal in a predetermined fashion to determine whether an arcing fault is present. The sensor, the broadband noise circuit and the controller are mounted to the outlet receptacle or to an outlet box which houses the receptacle. The electrical device is connected in parallel to the first electrical outlet on the load side of the sensor.
Abstract:
A system for producing a simulated ground fault when arcing is present in an electrical circuit includes a sensor which monitors the electrical circuit. An arcing fault detection circuit determines whether an arcing fault is present in response to the sensor and produces a trip signal in response to a determination that an arcing fault is present in the electrical circuit. A ground fault simulator circuit produces a simulated ground fault in response to the trip signal.
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.
Abstract:
A system for detecting arcing faults in a line conductor carrying an electrical current between a power source and a load, the electrical current defining an AC waveform comprising a series of alternating positive half cycles and negative half cycles. In one embodiment, the method comprises the steps of obtaining current samples in a series of half cycles of the waveform, determining the peak current of each of the half cycles, and comparing the peak currents to determine changes in slope between half cycles. The number of changes in slope occurring within a selected time interval are counted and an arc indicative signal is produced when the number of reversals in polarity in slope occurring within the selected time interval equals or exceeds a predetermined threshold number. In another embodiment, the method comprises, in addition to the steps above, the steps of normalizing each of the current samples and autocorrelating the normalized current samples to obtain a measure of significant waveform shape changes between consecutive half cycles. Both the number of changes in slope and the number of significant waveform shape changes occurring within a selected time interval are counted and an arc indicative signal is produced when the number of reversals in polarity or the number of waveform changes equal or exceed predetermined threshold values.