General Electric Company

Douglas B Tilghman

Raymond K Seymour

Henry Hall Mason, Jr

Frederic W Glabau

Joseph Criniti

Michael C Guerrette

Kevin J Fuhr

Zhiqun Brenda Zhang

Joseph L Desormeaux, Jr

An arc fault current interrupting (AFCI) circuit breaker includes a pair of electrical contacts for stopping the flow of electrical current in a protected portion of the distribution circuit. A low pass filter is configured to receive a signal indicative of a voltage across a resistance in the distribution circuit. The low pass filter amplifies the signal and provides the signal to an arc fault detection circuit. The low pass filter includes an input resistance and a feedback resistance. In one embodiment of the invention, the input resistance has a positive temperature coefficient. In another embodiment, the feedback resistance has a negative temperature coefficient. In yet another embodiment, the input resistance has a positive temperature coefficient and the feedback resistance has a negative temperature coefficient. In any of the embodiments, when temperature decreases, the gain provided by the temperature compensation circuit increases due to the temperature coefficients of the input and/or feedback resistors. As a result, the arc fault detection circuitry will maintain a constant sensitivity to arc faults throughout the entire operating temperature range of the AFCI circuit breaker.

Temperature compensation circuit for an arc fault current interrupting circuit breaker

An arc fault circuit breaker (,) conducting an electric current to a protected load is presented. The circuit breaker (,) has a first (mechanical) compartment (,) and a second (electrical) compartment (,). A bimetal resistor (,) is disposed within the first compartment (,) and conducts the current therethrough. The bimetal resistor (,) has a stud (,) extending into the second compartment (,). A single sense line (,) is electrically connected to the bimetal resistor (,) and routed into the second compartment (,). The sense line (,) and said stud (,) conduct a voltage signal indicative of arcing of the current. A circuit board (,) is disposed within the second compartment (,) and is connected to the sense line (,) and stud (,) within the second compartment (,) to process the voltage signal. The circuit board (,) has a first conductive path (,) electrically connected to the stud (,), and a second conductive path (,) electrically connected to the sense line (,). The first and second conductive paths (,) run substantially parallel and proximate to each other such that electromagnetic interference of the voltage signal is substantially reduced.

Arc fault circuit breaker

A visible trip indication arrangement for a circuit breaker. The visible trip indication arrangement comprises a viewing window forming a part of the breaker housing, the viewing window including indicia thereon that is readily or enhancedly visible when the circuit breaker has been tripped and essentially not visible when the circuit breaker is operating by way of a trip indicator that moves under and aligns with the viewing window when the circuit breaker is in the tripped condition. The trip indicator having a brightly colored surface, causes the indicia on the viewing window to be readily visible by way of the reflected light off a surface thereof.

Circuit breaker with trip indication arrangement

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Marlton, NJ, United States of America

Douglas B Tilghman