Abstract: An apparatus monitors and controls application of three phases of alternating voltage to a load by detecting the sequence of the three phases. A switch module is operated, in response to the detected sequence, to ensure that the three phases are properly applied to the load, even if the utility lines are improperly connected. The monitoring also senses loss of a phase in which case the switch module disconnects the application of electricity to the load. The apparatus is capable of being used with different loads that operate at different peak to peak levels of alternating voltage.

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 includes a test circuit having one or two indicators, an arc fault signal generator, and first and second test switches. A first indicator is electrically connected in series with the first test switch. This series combination provides a first alternating current signal to the arc fault signal generator, which provides an arc fault signal to an arc fault trip circuit, in order to trip open separable contacts in response to closure of the first test switch. The series combination of the second test switch and the second indicator provides a second alternating current signal to a ground fault trip circuit, in order to trip in response to closure of the second test switch. The indicators provide a visual indication of failure of the arc fault or ground fault trip circuits to trip in response to closure of the first or second test switches, respectively.

Abstract: An LED driver circuit that includes first and second switching mechanisms. The first mechanism is in a first switching condition when a source voltage is at or below a first threshold and moves to a second switching condition when the source exceeds the first threshold. The second mechanism is in a third switching condition when the source voltage is applied thereto and is at or below a second threshold less than the first threshold and moves to a fourth switching condition when the source voltage is applied thereto and is between the first and second thresholds. The third and fourth switching conditions each cause a safe current to flow through the LED. The second switching condition causes a safe current, preferably none, to flow through the LED, and the first switching condition causes the source voltage to be applied to the second mechanism. Also, a switching assembly including the circuit.

Abstract: A compact power circuit breaker has a molded insulative casing providing the structural support and electrical isolation for the pole mechanisms mounted in cavities in the casing and the operating mechanism mounted to the front of the casing. A grounded barrier between the pole mechanisms and the operating mechanism protects the operator actuating push buttons controlling the operating mechanism and accessible through a molded insulative cover. Preferably, the grounded barrier is sandwiched between a rear section of the molded casing containing the pole cavities and a forward section to which the operating mechanism is secured. The grounded barrier is connected to an electrically conductive pan extending under the molded insulative casing which also houses electrically grounded linkages coupling the operating mechanism to the vacuum interrupters of the pole mechanisms.