Abstract: Systems and methods of detecting arcing in a DC power system that can provide improved noise propagation immunity. The system includes at least two current sensors for monitoring at least two current outputs, respectively. The current sensors have reverse polarities, and are configured and arranged in parallel to provide a combined current output signal. The current sensors monitor the respective current outputs, which are provided for monitoring by the current sensors over at least two adjacent conductors. If arcing occurs at a location on a first conductor, then arcing (adjacent conductor crosstalk), having an arc current signature like that of the arcing on the first conductor, can occur at a location on the other adjacent conductor. The system can effectively cancel out such adjacent conductor crosstalk within a photovoltaic (PV) system, thereby improving the capability of an arc fault detection device for detecting arcing at the PV string level.

Abstract: Systems and methods of detecting arcing in DC power systems that can differentiate between DC arcs and load-switching noise. The systems and methods can determine, within a plurality of predetermined time intervals, at least the pulse count (PC) per predetermined time interval, and the pulse duration (PD) per predetermined time interval, in which the PC and the PD can correspond to the number and the intensity of potential arcing events in a DC power system, respectively. The systems and methods can process the PC and PD using one or more arc fault detection algorithms, thereby differentiating between DC arcs and load-switching noise with increased reliability.

Abstract: Techniques disclosed herein include systems and methods for assembly of electric motor starter connecting packages that enable increased automation and reduced assembly via top-down assembly of circuit components, thereby allowing robotic placement, connection, and securing of circuit components. The connecting package can include an electric motor starter, with optional overload protector, packaged as one unit. The motor starter can include an electrical circuit containing a triac, current transformer, Positive Temperature Coefficient (PTC) element, resistor, and a capacitor. A cover and base of the connecting package enclose and firmly secure connected circuit elements without needing a circuit board or filler material. The device design enables quick testing of the motor starter circuit and circuit elements after being enclosed by the housing.

Abstract: Systems and methods of detecting arcing in a DC power system that can provide improved noise propagation immunity. The system includes at least two current sensors for monitoring at least two current outputs, respectively. The current sensors have reverse polarities, and are configured and arranged in parallel to provide a combined current output signal. The current sensors monitor the respective current outputs, which are provided for monitoring by the current sensors over at least two adjacent conductors. If arcing occurs at a location on a first conductor, then arcing (adjacent conductor crosstalk), having an arc current signature like that of the arcing on the first conductor, can occur at a location on the other adjacent conductor. The system can effectively cancel out such adjacent conductor crosstalk within a photovoltaic (PV) system, thereby improving the capability of an arc fault detection device for detecting arcing at the PV string level.

Abstract: Systems and methods of detecting arcing in DC power systems that can differentiate between DC arcs and load-switching noise. The systems and methods can determine, within a plurality of predetermined time intervals, at least the pulse count (PC) per predetermined time interval, and the pulse duration (PD) per predetermined time interval, in which the PC and the PD can correspond to the number and the intensity of potential arcing events in a DC power system, respectively. The systems and methods can process the PC and PD using one or more arc fault detection algorithms, thereby differentiating between DC arcs and load-switching noise with increased reliability.

Abstract: Techniques disclosed herein include systems and methods for assembly of electric motor starter connecting packages that enable increased automation and reduced assembly via top-down assembly of circuit components, thereby allowing robotic placement, connection, and securing of circuit components. The connecting package can include an electric motor starter, with optional overload protector, packaged as one unit. The motor starter can include an electrical circuit containing a triac, current transformer, Positive Temperature Coefficient (PTC) element, resistor, and a capacitor. A cover and base of the connecting package enclose and firmly secure connected circuit elements without needing a circuit board or filler material. The device design enables quick testing of the motor starter circuit and circuit elements after being enclosed by the housing.

Abstract: A thermistor device includes include supports, contacts and offset posts configured to assist the fracturing of failed thermistor “pills” and to distribute the fragments of the fractured pills into compartment away from electrically conductive contacts in order to minimize arcing and overheating.

Abstract: A thermistor device includes include supports, contacts and offset posts configured to assist the fracturing of failed thermistor “pills” and to distribute the fragments of the fractured pills into compartment away from electrically conductive contacts in order to minimize arcing and overheating.

Abstract: An apparatus and method for detecting electrical arc faults that has reduced susceptibility to nuisance tripping. The apparatus includes a current sensor, an input sense circuit, an arcing sense circuit, a power supply, a tripping circuit, a processing unit, and an electromechanical interface. The processing unit measures multiple voltage levels provided by the arcing sense circuit during a specified number of consecutive time periods. Next, the processing unit determines the number of consecutive time periods during which the voltage levels exceeded a specified minimum value, take on successively lower or higher values, or fall outside a predetermined normal range of values. Based upon the results of this determination, the processing unit either trips the electromechanical interface to interrupt power to a load, or inhibits tripping of the electromechanical interface, thereby reducing the occurrence of nuisance tripping.

Abstract: Low cost apparatus and methods of detecting arc faults for better discriminating electrical events. The arc fault detection apparatus includes a current sensor, a di/dt input sense circuit, a dv/dt input sense circuit, and a processing unit. The current sensor monitors a power line current, and provides high frequency components of the power line current to the di/dt input sense circuit. The dv/dt input sense circuit monitors a power line voltage. The di/dt and dv/dt input sense circuits generate signals carrying information relating to changes in the power line current and the power line voltage, respectively. The processing unit analyzes these changes in the power line current and the power line voltage to discriminate detected electrical arcing events from nuisance loads with increased accuracy.

Abstract: An apparatus and a method of detecting arc faults that have reduced susceptibility to nuisance tripping. The apparatus includes a current sensor, a differential current input sense circuit, a differential current (di/dt) characteristics sense circuit, an absolute current input sense circuit, an absolute current characteristics sense circuit, a power supply, a tripping circuit, a processing unit, and an electromechanical interface. The di/dt characteristics sense circuit provides information relating to the characteristic di/dt signature of a power line current. The absolute current characteristics sense circuit provides information relating to the absolute current waveform characteristics of the power line current. The processing unit correlates the di/dt characteristics to the absolute current characteristics to distinguish between electrical arc faults and nuisance loads, thereby reducing the susceptibility of the apparatus to nuisance tripping.

Abstract: A shouldered connector pin socket (14) is shown having an open channel (14a) formed in the face surface of a wall member of a circuit breaker housing. An electrically conductive spring member (16, 16?) is received over the channel and is formed with a first set of spring fingers (16d) that are adapted to engage a connector pin along a first axial length (14c) of the channel making electrical engagement with the pin and urging the pin against the channel surface as the pin is slidingly inserted into the channel. The spring fingers urge the flange of the connector pin into a recess formed by a stepped shoulder defining the entrance to a second axial length (14d) with the stepped shoulder and the spring fingers cooperating to retain the connector pin in the channel. A second set of spring contact fingers (16e) can also be used to engage the connector pin along a third axial length (14e) and thereby provide a redundant contact system.

Abstract: An apparatus and method for detecting arc faults that have reduced susceptibility to nuisance tripping. The apparatus includes a current sensor, an input sense circuit, an arcing sense circuit, a power supply, a tripping (firing) circuit, a processor, and an electromechanical interface. The current sensor monitors a power input comprising an AC current, and provides high frequency components of the. AC current to the input sense circuit. The input sense circuit filters and rectifies the AC signal, and provides the rectified signal to the arcing sense circuit. The arcing sense circuit provides a voltage level accumulated over a predetermined time period, and digital signals indicative of possible electrical arcing occurring during the sampling period, to the processor.

Abstract: An apparatus and method for detecting arc faults that have reduced susceptibility to nuisance tripping. The apparatus includes a current sensor, an input sense circuit, an arcing sense circuit, a power supply, a tripping (firing) circuit, a processor, and an electromechanical interface. The current sensor monitors a power input comprising an AC current, and provides high frequency components of the. AC current to the input sense circuit. The input sense circuit filters and rectifies the AC signal, and provides the rectified signal to the arcing sense circuit. The arcing sense circuit provides a voltage level accumulated over a predetermined time period, and digital signals indicative of possible electrical arcing occurring during the sampling period, to the processor.

Abstract: Current flowing through a load is monitored by a transformer (Tr1) having a small mutual inductance. The secondary coil is shorted through a rectifier circuit to deliver a charge which, in a first preferred embodiment, is connected to a log charge translator circuit comprising matching diodes (D9, D7 and D10, D8) and a capacitor (C2) to provide a capacitor voltage proportional to the log of the charge delivered through the rectifier circuit. The capacitor is reset after each measurement. In a modified embodiment, the log translator circuit comprises a pair of transistors (T1, T2) and a capacitor (C2). According to the preferred embodiments, two measurements of the capacitor voltage are taken each half cycle at a time determined by the absolute value of the line voltage.

Abstract: Current flowing through a load is monitored by a transformer (Tr1) having a small mutual inductance. The secondary coil is shorted through a rectifier circuit to deliver a charge which, in a first preferred embodiment, is connected to a log charge translator circuit comprising matching diodes (D9, D7 and D10, D8) and a capacitor (C2) to provide a capacitor voltage proportional to the log of the charge delivered through the rectifier circuit. The capacitor is reset after each measurement. In a modified embodiment, the log translator circuit comprises a pair of transistors (T1, T2) and a capacitor (C2). According to the preferred embodiments, two measurements of the capacitor voltage are taken each half cycle at a time determined by the absolute value of the line voltage.

Abstract: A thermally compensated circuit breaker has a movable contact assembly (24) which mounts a movable electrical contact (24m) for movement between open and closed contacts positions with a stationary electrical contact (26). The contacts are maintained in the closed circuits position by a latching mechanism (24b, 28g) which prevents opening of the contacts through an opening contacts force provided by a spring (24e). A current carrying trip arm (40a, 44a) deflects upon sufficient I2R heating to transfer motion to the latch to separate the latch (24b) from the latch receiving catch (28g) to trip the circuit breaker. The trip arm (40a, 44a) is part of a pivotably mounted actuator assembly (40, 44) having a movable end portion spaced from the pivot disposed adjacent a motion transfer member (28c). A calibration screw (42a) is located so that the longitudinal axis is in line with a movable end portion of the actuator assembly and the motion transfer member.

Abstract: A pushbutton resettable circuit breaker is shown having features to prevent manual opening by simply pulling outwardly on the pushbutton. In one embodiment, the pushbutton (16) is formed with slots (16b) which are configured to provide a reaction surface essentially inaccessible without a special purpose contact opening tool (30). The tool is provided with portions that are insertable into the slots and into engagement with the reaction surfaces for pulling the pushbutton out and manually opening the contacts. In a second embodiment, a small aperture 16k is formed through the rating tab and top and wall of the button and in alignment with a movable plunger (28). A special purpose contact opening tool (32, 34) can be inserted through the aperture to apply a force to the plunger and mechanically trip the circuit breaker.

Abstract: A circuit breaker (10) has a current carrying bimetallic element (18) which bends upon self-heating and upon being subjected to a selected overload current transfers motion to a connecting plate (32) which displaces a latch surface (42b) from a catch (34a) of a bell crank mechanism (34) allowing a spring biased operating member (28) to move movable contact means (12) out of contact engagement with stationary contact means (14) thereby tripping the circuit breaker. An arc sensing circuit (52) is coupled to the load circuit and upon sensing selected arcs causes an arc responsive actuator (56, 62) to be energized to transfer motion to the latch (42) to trip the circuit breaker.

Abstract: An electric circuit breaker (10) has a toggle mechanism (18) having two movable over center joints (3, 4) connected between a push-button (16) and a movable contact mechanism (30). When the push-button is depressed a first link rotates bringing the first movable over center joint (3) across a center position represented by a first imaginary straight line (1) to a stop surface (28). A spring member (36) provides a bias which acts on the second movable over center joint (4) normally maintaining the second movable joint against the stop surface so that with the two movable over center joints biased against the stop surface the movable contact mechanism is moved to a closed contact position when the push-button is depressed.