Abstract: A shunt assembly is provided for an electrical switching apparatus including a conductor assembly having a load conductor and a movable contact assembly with a number of movable contact arms. The movable contact assembly is movable in response to a fault current. The shunt assembly includes a number of flexible conductive elements each having a first end electrically connected to the load conductor, a second end electrically connected to a corresponding one of the movable contact arms, and a number of bends disposed between the first and second ends. At least one constraint element is disposed proximate a corresponding one of the bends and constrains movement of the flexible conductive element in response to the fault current, thereby translating the magnetic repulsion force associated with the fault current into a corresponding torque of the movable contact arms of the movable contact assembly.

Abstract: A circuit interrupter includes band pass filters cooperating with a current sensor to output bands having different, non-overlapping ranges of frequencies, peak detectors cooperating with the filters to detect corresponding peak current values, envelope detectors cooperating with the filters to detect corresponding occurrences from the bands being within corresponding predetermined magnitude ranges, a counter counting the occurrences, and a processor providing and disabling series arc detection when sensed current is greater than a first predetermined value. The processor determines tallies responsive to peak current values exceeding corresponding thresholds, determines series arcing from sensed current being less than the first predetermined value for a predetermined time, the tally for a current half-cycle being nonzero, and a count for the current half-cycle being different than the count for an immediately previous half-cycle of like polarity by at least a second predetermined value.

Abstract: An arc fault circuit interrupter includes separable contacts, a neutral conductor, an operating mechanism structured to open and close the separable contacts, at least one current sensor structured to sense current flowing through the separable contacts and output a sensed current value; and a processor. The processor includes a first routine structured to provide parallel arc fault detection, a second routine structured to provide series arc fault detection, and a third routine structured to enable the first routine and disable the second routine for a predetermined time when the sensed current value is greater than a predetermined value and to enable the second routine and disable the first routine for the predetermined time when the sensed current value is less than the predetermined value.

Abstract: An electrical distribution device that includes a terminal for providing a connection to a first conductor, a spring mechanism having a first end that is electrically connected to the terminal, and a second conductor electrically connected to one or more internal components of the device. The spring mechanism has a first condition and a second condition. In the first condition, the second end is electrically connected to the second conductor by solder. When the solder melts, the spring mechanism moves from to the second condition in which the second end is no longer electrically connected to the second conductor, thereby protecting the internal components from the fault condition that lead to the overheating. A condition indicator may also be provided for indicating a fault condition.

Abstract: A contact spring assembly is provided for an electrical switching apparatus including a movable contact assembly and a stationary contact assembly having stationary electrical contacts. The movable contact assembly includes a carrier assembly, and movable contact arms pivotably coupled to the carrier assembly and carrying movable electrical contacts. The contact spring assembly includes a first contact spring housing member, a second contact spring housing member coupled to and disposed opposite from the first contact spring housing member, a spring guide disposed between and coupled to at least one of the first and second contact spring housing members and including spring holes, springs received in the spring holes, and sliders coupled to the springs. The springs and sliders individually bias the movable contact arms and movable electrical contacts toward engagement with corresponding stationary electrical contacts. A movable contact assembly and an electrical switching apparatus are also disclosed.

Abstract: A circuit breaker includes a housing, separable contacts, an operating mechanism structured to open and close the separable contacts, a power conductor comprising a first conductor and a second reverse loop conductor, the second reverse loop conductor carrying one of the separable contacts; and a split core slot motor. The split core slot motor comprises a first slot motor portion having a number of coupling points, and a second slot motor portion having a number of corresponding coupling points. The coupling points of the first slot motor portion engage the corresponding coupling points of the second slot motor portion to form the split core slot motor. Both of the slot motor portions cooperate to form a base of the split core slot motor. The base is disposed between the first conductor and the second reverse loop conductor.

Abstract: A circuit breaker includes a housing, separable contacts, an operating mechanism structured to open and close the separable contacts, a power conductor comprising a first conductor and a second reverse loop conductor, the second reverse loop conductor carrying one of the separable contacts; and a split core slot motor. The split core slot motor comprises a first slot motor portion having a number of coupling points, and a second slot motor portion having a number of corresponding coupling points. The coupling points of the first slot motor portion engage the corresponding coupling points of the second slot motor portion to form the split core slot motor. Both of the slot motor portions cooperate to form a base of the split core slot motor. The base is disposed between the first conductor and the second reverse loop conductor.

Abstract: A gassing insulator for the arc chute assembly of a circuit breaker includes a number of insulating members. The arc chute assembly includes first and second opposing sidewalls, and arc plates having first and second ends and first and second legs. Each insulating member includes a first side coupled to one of the first and second opposing sidewalls of the arc chute assembly, a second side disposed generally opposite the first side, a first end disposed at or about the first ends of the arc plates, and a second end disposed distal from the first end of the insulating member and extending toward the second ends of the arc plates. The first side of the insulating member overlays at least one of the first and second legs of the arc plates, in order to electrically insulate them. An arc chute assembly and an electrical switching apparatus are also disclosed.

Abstract: An arc plate for a circuit breaker arc chute assembly includes first and second portions coupled to opposing sidewalls of the arc chute assembly, first and second ends, and a throat portion between the first and second portions and including an aperture. The aperture extends from the first end toward the second end and includes an end section, an intermediate neck section adjacent the end section, and an interior section adjacent the intermediate neck section and distal from the end section. The end section has a first width and attracts and directs an arc toward the intermediate neck section. The intermediate neck section tapers from the first width of the end section to a second width, further attracting the arc and directing it into the interior section. The interior section includes a taper and turns with respect to the intermediate neck section, in order to attract and retain the arc.

Abstract: An arc baffle for an arc chute assembly of a circuit breaker includes a first baffle member disposed at or about the second end of the arc chute assembly and including a plurality of first venting holes, a second baffle member including a plurality of second venting holes and being coupled to and disposed opposite from the first baffle member, and a filter assembly disposed at or about the second baffle member and including a number of filter elements. The first and second venting holes of the first and second baffle members are offset to induce turbulent flow of ionized gases being discharged from the arc chute assembly. The filter elements of the filter assembly filter the turbulent flow. An arc chute assembly and an electrical switching apparatus are also disclosed.

Abstract: A contact assembly for a circuit breaker includes a fixed contact, a movable contact, and a movable contact arm. The movable contact arm includes a first end carrying the movable contact, a second end, and a pivot portion proximate the second end. A moving arm portion extends from the first end toward the pivot portion. The moving arm portion has a width, an upper edge, a lower edge, and a height defined by the distance between the upper edge and the lower edge. In response to a trip condition, the movable contact separates from the fixed contact and the movable contact arm pivots open at an angular opening velocity. The height of the moving arm portion of the movable contact arm is at least four times the width of the moving arm portion, thus minimizing the moment-of-inertia of the movable contact arm, and increasing the angular opening velocity.

Abstract: A circuit breaker contact assembly includes a line conductor having a folded back fixed contact end, a fixed contact mounted on the contact end, and a movable contact arm having an inner edge and first and second ends. A movable contact is mounted on the first end. The movable contact arm is pivotable about the second end between a closed position in which the inner edge extends adjacent the contact end with the movable contact in contact with the fixed contact to form a reverse current loop, and an open position in which the movable contact is pivoted away from the fixed contact. The contact arm includes a first inner longitudinal member extending along the inner edge and a second outer longitudinal member. The first inner longitudinal member has a higher electrical conductivity than the second outer longitudinal member, which has a higher shear strength and a lower specific density.

Abstract: A shorting system, which eliminates persistent arcing faults in power distribution equipment, includes a first shorting switch having separable contacts, an actuation input and a fuse electrically connected in series with those contacts. A second shorting switch includes an actuation input and separable contacts, which are electrically connected in parallel with the series combination of the fuse and the first shorting switch contacts. A detection circuit includes one or more arcing light sensors and an actuation circuit. The light sensors detect arcing fault light and the actuation circuit responsively outputs a first trigger signal to the first shorting switch actuation input to close its contacts. For a persistent arcing fault, which is not eliminated by the first shorting switch, a predetermined time after the first trigger signal, the actuation circuit responsively outputs a second trigger signal to the second shorting switch actuation input to close its contacts.

Abstract: The support for the moving contact of a circuit breaker has a piston that is driven by arc gases generated by initial separation of the contacts through magnetic repulsion to rapidly open the contacts. A pair of telescoping shield sleeves that have aligned openings through which the moving contact is extended to close with the fixed contact are oppositely driven transversely to piston movement by the arc gases to cut off the arc.

Abstract: A current limiting power switch has a monolithic stationary conductor with a conductor section that mounts fixed contacts that engage moving contacts on moving contact fingers to form a reverse current loop with the contacts closed. A terminal section projects transversely from one end of the conductor section and an arc runner section extends from the other end. The tapered arc runner has a generally laterally centered tapered area that gathers the arcs and urges them along a raised rib on the arc runner to an arc chute. A reinforcing rib running from the back of the conductor and arc runner sections to the terminal section resists distortion of the monolithic stationary conductor by the high temperatures and closing and electromagnetic forces during interruption.

Abstract: The arc plates of an arc chute assembly for a circuit breaker are supported in spaced, stacked relation by a structural shell molded of a gas evolving resin. Generation of arc gases, that cool the arc thereby increasing the current interruption capability of the breaker, can be further enhanced by gas evolving additives included in the resin. Arc gas flow is increased to further cool the arc by molding the interior walls of the structural shell to form venturies between the arc plates. One or more elongated fibers wrapped around the stack of arc plates in an oval strengthen the structural shell to withstand the increased pressure generated by the high arc gas volume.

Abstract: An apparatus detects arcing faults at a first wavelength. A light source provides modulated light at a second different wavelength and a first frequency. An optical fiber receives the modulated light and gathers ambient light at both wavelengths. A splitter receives and splits the received light into first and second beams. A first filter extracts from the first beam a first filtered beam including the first wavelength. A first photodetector generates a first electrical signal from the first filtered beam. A second filter extracts from the second beam a second filtered beam excluding the first wavelength. A second photodetector generates a second electrical signal from the second filtered beam. A low pass filter extracts from the second electrical signal a third electrical signal representative of light at the second wavelength excluding the modulated light. A comparator generates an arcing signal when the first electrical signal exceeds the third electrical signal.

Abstract: A circuit interrupter arc chute includes first and second support portions, an exit portion supported by the support portions, and a plurality of arc plates supported by the support portions. The exit portion has one or more vent openings. The arc plates have a first edge offset from the exit portion and an opposite second edge distal from the exit portion. A plurality of insulating dividing members are disposed between the arc plates. The members have a first edge proximate the exit portion and an opposite second edge distal from the exit portion. The second edge of the members extends beyond the arc plate first edges and toward the arc plate second edges. The first edge of the dividing members extends beyond the arc plate first edge and away from the arc plate second edge.

Abstract: A moving contact assembly for a high-current interruption electric power switching apparatus has an inner carrier for the contact fingers that is rigidly held in a withstand position in an outer carrier by a spring biased cam follower pin engaging a cam profile on the inner carrier and configured to positively seat an inner carrier stop against an outer carrier stop on the outer carrier and to rapidly drive the inner carrier to a blow open position in response to a fault. The cam profile has an extended width divided between spaced apart cam profile sections to absorb the high closing and withstand forces. An abutment on the outer carrier resists bowing of the cam follower pin between the cam profile sections. Complementary convex and concave partial cylindrical surfaces on the inner carrier and a gas shield on the moving assembly carrier body maintain an arc gas seal during blow open.

Abstract: A circuit breaker vents at least some of the arc gases generated during current interruption from an internal cavity containing separable contacts through a terminal recess vent in a wall in the housing into an external terminal recess. The line side main conductor extends through the same wall into the external terminal recess adjacent the vent and into the collar of a terminal assembly. An electrically conductive stand seated on the main conductor electrically connects to the main conductor an external conductor clamped against the stand by a terminal screw threaded through the collar. The stand has a through opening aligned with the terminal recess vent to pass the arc gases through the external terminal recess to atmosphere.