Abstract: A test apparatus tests an arc fault circuit breaker with an arc fault generator having an input and an output. The test apparatus includes a first electrical connector electrically connected to the load side of an arc fault circuit interrupter. A second electrical connector is electrically connected to the input of the arc fault generator. A third electrical connector is electrically connected to the output of the arc fault generator. A plurality of fourth electrical connectors are electrically connected to one or more of a plurality of masking loads. A fifth electrical connector is electrically connected to another load. A two pole, plural position rotary selector switch provides a plurality of different configurations of at least the arc fault generator and the one or more masking loads downstream of the load side of the arc fault circuit breaker.

Abstract: An arc fault circuit interrupter includes separable contacts electrically connected between line and load terminals, and a current sensor adapted to sense current flowing between the terminals and through the contacts. An arc fault detection circuit is adapted to collect a plurality of samples of the sensed current for a line cycle, determine a first slope of the sensed current at about a zero crossing of a line voltage, determine a magnitude of one of the samples at about the zero crossing, determine a second slope of the sensed current at another one of the samples having about the magnitude, with the first slope being opposite in polarity with respect to the second slope. The arc fault detection circuit calculates a difference between the slopes, and generates a trip signal as a function of the difference. An operating mechanism is adapted to open the contacts responsive to the trip signal.

Abstract: A circuit breaker for locating an arc fault for a protected circuit includes separable contacts interrupting the protected circuit and an arc fault detector determining an arc fault in the protected circuit. An analog to digital converter circuit measures a value of peak arc current at the arc fault detector. Another analog to digital converter circuit provides a peak line-to-neutral voltage. A memory provides an arc voltage operatively associated with the value of peak current. A microprocessor determines a distance from the arc fault detector to the arc fault from the value of peak arc current, a wire resistance per unit length or a wire conductance per unit length, the peak line-to-neutral voltage and the arc voltage.

Abstract: An arc fault detection circuit collects samples of sensed current, determines a peak current value from the samples for each line cycle, determines a hysteresis value for a compressor load as a function of differences between the peak current values, and generates a trip signal responsive to the sensed current and the hysteresis value. The circuit determines a difference value for each line cycle from the present peak current value less the previous peak current value, low pass filters the difference value to provide a low pass filtered value, determines a peak value from the low pass filtered value, determines that the absolute value of the low pass filtered value is less than a portion of the peak value and responsively saves the peak value, and determines the hysteresis value as a function of the saved peak value. An operating mechanism opens separable contacts responsive to the trip signal.

Abstract: A trip unit for a circuit interrupter includes a power supply, a plurality of input terminals and a plurality of output terminals. A heater conductor is electrically connected between each pair of the input and output terminals. The heater conductor is adapted to generate heat responsive to current flowing through the conductor. A diode is disposed proximate each of the conductors for heating thereby. The diodes are electrically interconnected with the power supply and are adapted to provide a forward voltage representative of the temperature of the corresponding conductor. Another diode is electrically interconnected with the power supply and is adapted to provide a forward voltage representative of ambient temperature. A thermal trip circuit generates a trip signal for the circuit interrupter responsive to the forward voltage of the diodes.

Abstract: A circuit analyzer tests a power circuit including an earth leakage ground fault circuit interrupter, a receptacle, and a line, a neutral and a ground electrically connected between the circuit interrupter and the receptacle. The circuit analyzer includes a plurality of pushbuttons for inputting a plurality of test requests. A microprocessor outputs a plurality of test signals responsive to the test requests. A plurality of load circuits selectively provide a load between the line and the neutral responsive to one of the test signals. A display confirms tripping of the ground fault circuit interrupter responsive to the load, in order to determine if the neutral is electrically connected to the ground between the circuit interrupter and the receptacle.

Abstract: A circuit analyzer tests a power circuit including an earth leakage ground fault circuit interrupter, a receptacle, and a line, a neutral and a ground electrically connected between the circuit interrupter and the receptacle. The circuit analyzer includes a plurality of pushbuttons for inputting a plurality of test requests. A microprocessor outputs a plurality of test signals responsive to the test requests. A plurality of load circuits selectively provide a load between the line and the neutral responsive to one of the test signals. A display confirms tripping of the ground fault circuit interrupter responsive to the load, in order to determine if the neutral is electrically connected to the ground between the circuit interrupter and the receptacle.

Abstract: A circuit breaker for locating an arc fault for a protected circuit includes separable contacts interrupting the protected circuit and an arc fault detector determining an arc fault in the protected circuit. An analog to digital converter circuit measures a value of peak arc current at the arc fault detector. Another analog to digital converter circuit provides a peak line-to-neutral voltage. A memory provides an arc voltage operatively associated with the value of peak current. A microprocessor determines a distance from the arc fault detector to the arc fault from the value of peak arc current, a wire resistance per unit length or a wire conductance per unit length, the peak line-to-neutral voltage and the arc voltage.

Abstract: A trip unit for a circuit interrupter includes a power supply, a plurality of input terminals and a plurality of output terminals. A heater conductor is electrically connected between each pair of the input and output terminals. The heater conductor is adapted to generate heat responsive to current flowing through the conductor. A diode is disposed proximate each of the conductors for heating thereby. The diodes are electrically interconnected with the power supply and are adapted to provide a forward voltage representative of the temperature of the corresponding conductor. Another diode is electrically interconnected with the power supply and is adapted to provide a forward voltage representative of ambient temperature. A thermal trip circuit generates a trip signal for the circuit interrupter responsive to the forward voltage of the diodes.

Abstract: An active power conditioner for mitigating zero-sequence currents in electrical distribution by items wherein a multi-phase, neutral-forming structure employs a controllable voltage source, which source is controlled by a current-responsive voltage controller, to cancel an equivalent impedance of the multi-phase, neutral-forming structure so that zero-sequence currents are shunted to ground, thereby effectively nullifying the zero-sequence current respective to the source. The multi-phase neutral-forming structure may include multi-phase, neutral-forming autotransformers, zig-zag autotransformers, grounded-wye/unloaded-delta transformers and the like. While zero-sequence fundamental harmonic currents may be selectively shunted to ground, positive- and negative-sequence currents may remain essentially unaffected. The compensating action employed herein may be purely reactive in nature and thus consume little real power.