Abstract: A method of tripping a circuit breaker including sampling an AC line voltage at regular intervals during a first time period to generate a plurality of AC line voltage samples. Each sample of the set of AC line voltage samples is summed to generate a voltage area value. A controller determines whether the voltage area value exceeds a threshold. In response to the voltage area value exceeding the threshold, an amount determined as a function of the voltage area value is added to a count value. The circuit breaker is caused to trip in response to the count value equaling or exceeding a maximum count value. An improper line-to-neutral voltage can be detected by monitoring the line-to-neutral voltage and comparing it to a function such as a trip curve. Thus, components downstream from a circuit breaker, as well as the circuit breaker itself, can be protected from prolonged exposure to improper voltages, which can lead to component failure.

Abstract: A circuit breaker capable of microcontroller-based fault detection having a backup circuit for causing the circuit breaker to trip in response to a microcontroller fault, including a timing circuit powered by a power supply and a microcontroller. The timing circuit is electrically coupled to an SCR that causes the circuit breaker to trip. The timing circuit includes a BJT coupled to the gate of the SCR. The microcontroller has a first output coupled to the timing circuit and a second output coupled to the SCR. The first output is coupled to a node between a resistor and a grounded capacitor in the timing circuit, and the node is coupled to a gate of the SCR and to a base of the transistor. A voltage develops at the node sufficient to cause the gate of the SCR to turn on unless the microcontroller pulls the first high-impedance output to a logic low state.

Abstract: An apparatus for monitoring line voltage in a circuit breakor includes a controller configured to calculate a voltage difference between the neutral voltage and the AC line voltage of positive polarity based on a first signal and a second signal and assign, using a polarity signal, the voltage difference value to the AC line voltage of positive polarity and the second signal to the AC line voltage of negative polarity. Because the AC line voltage of positive polarity can be calculated based on the first signal and the second signal, the number of signals requiring A/D conversion is reduced, and the number of circuit components needed to measure the AC line voltage is reduced.

Abstract: A multiple pole arc-fault circuit breaker includes a first pole assembly, a second pole assembly, a microprocessor, and a single test button. At least one of the first pole assembly and the second pole assembly has a trip mechanism. The microprocessor is electrically coupled to the first pole assembly and to the second pole assembly, and, in response to receiving a single test signal, is operative to perform electrical tests for both the first pole assembly and the second pole assembly. In response to successful completion of the electrical tests, the microprocessor is further operative to actuate the trip mechanism. The single test button is mounted to the housing and includes a single test position which causes the sending of the single test signal for initiating the electrical tests.

Abstract: A method of tripping a circuit breaker including sampling an AC line voltage at regular intervals during a first time period to generate a plurality of AC line voltage samples. Each sample of the set of AC line voltage samples is summed to generate a voltage area value. A controller determines whether the voltage area value exceeds a threshold. In response to the voltage area value exceeding the threshold, an amount determined as a function of the voltage area value is added to a count value. The circuit breaker is caused to trip in response to the count value equaling or exceeding a maximum count value. An improper line-to-neutral voltage can be detected by monitoring the line-to-neutral voltage and comparing it to a function such as a trip curve. Thus, components downstream from a circuit breaker, as well as the circuit breaker itself, can be protected from prolonged exposure to improper voltages, which can lead to component failure.

Abstract: An apparatus for monitoring line voltage in a circuit breaker includes a controller, a neutral input for receiving a neutral voltage, a first input for receiving a first alternating current (AC) line voltage that periodically changes polarity with respect to the neutral voltage, and a second input for receiving a second AC line voltage that periodically changes polarity with respect to the neutral voltage and is 180 degrees out of phase from the first AC line voltage. The apparatus also includes a first circuit coupled to the first input, the second input, and the controller. The first circuit is configured to output to the controller a first signal representing the voltage difference between the first AC line voltage and the second AC line voltage. The apparatus also includes a second circuit coupled to the neutral input and the controller configured to output to the controller a second signal representing the difference between the neutral input voltage and the AC line voltage of negative polarity.

Abstract: A circuit breaker capable of microcontroller-based fault detection having a backup circuit for causing the circuit breaker to trip in response to a microcontroller fault, including a timing circuit powered by a power supply and a microcontroller. The timing circuit is electrically coupled to an SCR that causes the circuit breaker to trip. The timing circuit includes a BJT coupled to the gate of the SCR. The microcontroller has a first output coupled to the timing circuit and a second output coupled to the SCR. The first output is coupled to a node between a resistor and a grounded capacitor in the timing circuit, and the node is coupled to a gate of the SCR and to a base of the transistor. A voltage develops at the node sufficient to cause the gate of the SCR to turn on unless the microcontroller pulls the first high-impedance output to a logic low state.

Abstract: A multiple pole arc-fault circuit breaker includes a first pole assembly, a second pole assembly, a microprocessor, and a single test button. At least one of the first pole assembly and the second pole assembly has a trip mechanism. The microprocessor is electrically coupled to the first pole assembly and to the second pole assembly, and, in response to receiving a single test signal, is operative to perform electrical tests for both the first pole assembly and the second pole assembly. In response to successful completion of the electrical tests, the microprocessor is further operative to actuate the trip mechanism. The single test button is mounted to the housing and includes a single test position which causes the sending of the single test signal for initiating the electrical tests.