Abstract: An electrical switching apparatus includes separable contacts, an operating mechanism structured to open and close the separable contacts, and an arc chamber. The arc chamber includes a slot motor having a core and a housing with an opening therein, an arc chute, and a number of gassing inserts disposed in the opening of the housing. The number of gassing inserts and the housing are structured to form a number of gas flow circulation paths. The number of gas flow circulation paths are structured to drive an arc into the arc chute.

Abstract: An electrical interface includes a nano-particle layer. The electrical interface also includes a first conductor and a second conductor. The nano-particle layer and the first and second conductors are electrically coupled together.

Abstract: A handle arm assembly is for a circuit interrupter including an undervoltage release mechanism having a reset mechanism. The handle arm assembly includes a body portion rotatable through an arc between an on position, an off position, and a reset position beyond the off position and an arm portion projecting laterally from the body portion out of the plane of the arc through which the body portion rotates. The body portion and the arm portion are formed from a single piece of material wherein the body portion and the arm portion are different portions of the single piece of material. The arm portion is structured to engage the reset mechanism in a manner such that arcuate movement of the arm portion as the body portion moves to the off position is translated into actuation of the reset mechanism.

Abstract: An electrical interface includes a nano-particle layer. The electrical interface also includes a first conductor and a second conductor. The nano-particle layer and the first and second conductors are electrically coupled together.

Abstract: A heater assembly is provided for an electrical switching apparatus. The heater assembly includes a heater element and an elongated bimetal. The heater element includes first and second ends, an intermediate portion disposed therebetween and an aperture disposed proximate the first end. The elongated bimetal includes opposing first and second ends, and is movable between first and second positions corresponding respectively to the separable contacts of the electrical switching apparatus being closeable, and to the first end of the elongated bimetal cooperating with a trip bar to cause an operating mechanism to open the separable contacts. The second end of the elongated bimetal is coupled to the intermediate portion of the heater element. When the elongated bimetal is disposed in the first position, the first end of the elongated bimetal extends beyond the upper surface of the first end of the heater element into the aperture of the heater element.

Abstract: A handle arm assembly is for a circuit interrupter including an undervoltage release mechanism having a reset mechanism. The handle arm assembly includes a body portion rotatable through an arc between an on position, an off position, and a reset position beyond the off position and an arm portion projecting laterally from the body portion out of the plane of the arc through which the body portion rotates. The body portion and the arm portion are formed from a single piece of material wherein the body portion and the arm portion are different portions of the single piece of material. The arm portion is structured to engage the reset mechanism in a manner such that arcuate movement of the arm portion as the body portion moves to the off position is translated into actuation of the reset mechanism.

Abstract: A heater assembly is provided for an electrical switching apparatus. The heater assembly includes a heater element and an elongated bimetal. The heater element includes first and second ends, an intermediate portion disposed therebetween and an aperture disposed proximate the first end. The elongated bimetal includes opposing first and second ends, and is movable between first and second positions corresponding respectively to the separable contacts of the electrical switching apparatus being closeable, and to the first end of the elongated bimetal cooperating with a trip bar to cause an operating mechanism to open the separable contacts. The second end of the elongated bimetal is coupled to the intermediate portion of the heater element. When the elongated bimetal is disposed in the first position, the first end of the elongated bimetal extends beyond the upper surface of the first end of the heater element into the aperture of the heater element.

Abstract: A cradle stop assembly is provided for a circuit breaker including an operating mechanism. The operating mechanism includes a pivotable movable contact arm and a cradle member which is movable between a latched position corresponding to separable contacts of the circuit breaker being closeable and an unlatched position corresponding to the separable contacts being tripped open. The cradle stop assembly includes a first member coupled to a portion of the operating mechanism, a second member disposed opposite the first member, and a generally planar stop plate extending between the first and second members. A first stop portion of the stop plate resists movement of the cradle member beyond a first predetermined position to avoid the cradle member undesirably interfering with the pivotable movable contact arm. A second stop portion resists the pivotable movable contact arm from undesirably pivoting beyond a second predetermined position.

Abstract: A circuit breaker includes separable contacts, an operating mechanism structured to open and close the separable contacts, a molded enclosure comprising a first molded portion and a second molded portion, a plurality of thread cutting screws fastening the first molded portion to the second molded portion, and a plurality of machine screws. The first molded portion and the second molded portion cooperate to form a plurality of exterior walls. The exterior walls define an interior volume, which encloses the separable contacts and at least a portion of the operating mechanism. The machine screws extend within and reinforce the exterior walls and restrict expansion of the exterior walls away from the interior volume.

Abstract: A circuit breaker includes fixed and movable contacts, an operating mechanism including a movable arm carrying the movable contact, an arc chute including a plurality of spaced apart first and second arc plates, and a slot motor. A slot motor structure is disposed about the contacts and a portion of the movable arm. An insulative housing at least substantially covers and insulates the slot motor structure from the movable arm and contacts. The insulative housing includes a base and a pair of arms disposed therefrom. Each of the arms includes a first portion disposed proximate the first arc plates and a second smaller portion disposed proximate the second arc plates. A space extending from the first portion, not occupied by the second portion, is generally occupied by a portion of the second arc plates. The second portion forms a debris shield between the second arc plates and the operating mechanism.

Abstract: A cradle stop assembly is provided for a circuit breaker including an operating mechanism. The operating mechanism includes a pivotable movable contact arm and a cradle member which is movable between a latched position corresponding to separable contacts of the circuit breaker being closeable and an unlatched position corresponding to the separable contacts being tripped open. The cradle stop assembly includes a first member coupled to a portion of the operating mechanism, a second member disposed opposite the first member, and a generally planar stop plate extending between the first and second members. A first stop portion of the stop plate resists movement of the cradle member beyond a first predetermined position to avoid the cradle member undesirably interfering with the pivotable movable contact arm. A second stop portion resists the pivotable movable contact arm from undesirably pivoting beyond a second predetermined position.

Abstract: A circuit breaker includes a circuit breaker frame and a trip unit. The circuit breaker frame includes a housing, a line terminal, a load terminal, separable contacts electrically connected between the line terminal and the load terminal, an operating mechanism structured to open and close the separable contacts, and a latch cooperating with the operating mechanism to open the separable contacts when actuated. The trip unit includes a housing, a line end terminal electrically connected to the load terminal of the circuit breaker frame, a load end terminal, and a fuse including a plunger. The fuse is housed by the housing of the trip unit and is electrically connected between the line end terminal and the load end terminal. An interface mechanism is structured to actuate the latch of the circuit breaker frame when the interface mechanism is engaged by the plunger of the fuse.

Abstract: A circuit breaker includes a molded base and cover, with at least one of the base and cover being a molded member including a pair of end walls, a pair of side walls, and an opening between the side walls. A strengthening member engages the base and cover between the side walls at the opening, engages at least one of the side walls and is an interior wall of the molded member. The base and cover are made of a first material, such as glass polyester or a suitably high strength plastic, and the strengthening member is made of a second dissimilar material, such as aluminum or steel, which has greater strength than the first material. An operating mechanism coupled to separable contacts is structured to move the contacts between open and closed positions. A trip mechanism coupled to the operating mechanism is structured to actuate the operating mechanism.

Abstract: A crossbar assist mechanism is for a circuit breaker including a housing, a movable contact, a stationary contact, and an operating mechanism. The operating mechanism includes a crossbar, a carrier coupled to the crossbar, and a movable contact arm which is pivotably cooperable with the carrier. The movable contact is disposed on the movable contact arm. The crossbar moves the carrier and the movable contact arm, thereby moving the movable contact into and out of electrical contact with the stationary contact. The crossbar assist mechanism includes an electrically conductive member electrically interconnecting the carrier and the movable contact arm to a load terminal. A spring disposed between the crossbar and the electrically conductive member biases the crossbar from a first position corresponding to the movable contact and the stationary contact being separated, toward a second position corresponding to the movable contact being in electrical contact with the stationary contact.

Abstract: A circuit breaker includes a housing having first and second openings, with stationary and movable separable contacts disposed therein. An operating mechanism is disposed in the housing, is coupled to the separable contacts and is structured to move those contacts between open and closed positions. A trip mechanism is disposed in the housing and cooperates with the operating mechanism to trip open the separable contacts. A slot motor assembly is disposed about the separable contacts and has upper and lower slot motor portions. The upper slot motor portion is disposed above the movable contact and the lower slot motor portion is disposed below the stationary contact. The upper slot motor portion includes a rigid, laminated steel member having a general U-shape, with a bight portion, and first and second legs. The first and second legs engage the housing at the respective first and second openings.

Abstract: This concerns a molded case circuit breaker having separable main contacts and an operating mechanism utilized to cause the separable main contacts to open and close. A trip unit is provided to actuate the operating mechanism in desirable circumstances. The trip unit has a magnetic trip level adjustment dial, which has an adjustment face with a series of detents therein. The dial has a cam service, which interacts with internal portions of the trip unit to set or calibrate the level at which a magnetic trip actuation occurs. The aforementioned detent interacts with a spring loaded L-shaped member which fits into the casing of the trip unit along with the dial as a single unit.

Abstract: This concerns a molded case circuit breaker having separable main contacts and an operating mechanism utilized to cause the separable main contacts to open and close. A trip unit is provided to actuate the operating mechanism in desirable circumstances. The aforementioned trip unit has disposed on an outside surface thereof, dials for adjustment of the thermal and magnetic tripping characteristics of the circuit breaker. The face of the trip unit also has a set of hinge regions disposed therein into which a plastic, transparent, hinged cover may be inserted. The top of the trip unit has a convenient ridge around the outside of the dial regions. The cover after insertion is rotated downward on to the face of the dial region and then moved transversely to abut one of the ridges. Both the cover and the surface of the dial region have bridged openings therein through which a single wire may be fed and locked in place with a solder lock at the ends of the wires.

Abstract: This concerns a molded case circuit breaker having separable main contacts and an operating mechanism utilized to cause the separable main contacts to open and close. A trip unit is provided to actuate the operating mechanism in desirable circumstances. The trip unit is removable. In this case the trip unit is insertable into a trip unit region in the case of the circuit breaker from the top or end thereof. The trip unit is then joined to an internal electrical conductor by way of a bolt and an internally fixed nut. The bolt can be driven into the nut through the trip unit conductor and the internal conductor from a position external to the circuit breaker case. The trip unit can be inserted into the trip unit conductor from a point above the circuit breaker case or vise versa. The trip unit has a securement nut built into its case.

Abstract: This concerns a molded case circuit breaker having separable main contacts and an operating mechanism structured to cause the separable main contacts to open and close. A trip unit is provided to actuate the operating mechanism in desirable circumstances. The circuit breaker housing has an auxiliary device compartment therein into which may be inserted a key lock arrangement. The trip unit has a plunger member which protrudes into the auxiliary device compartment and which, when actuated, causes the trip unit to actuate the operating mechanism to open the main contacts. When the key lock is actuated, a slideable member interacts with the plunger member in the trip unit and maintains the trip unit in a configuration that prevents the main contacts from engaging. Thus, as long as the lock member is maintained in the locked state, the circuit breaker may not be reset.

Abstract: This concerns a molded case circuit breaker having separable main contacts and an operating mechanism utilized to cause the separable main contacts to open and close. A trip unit is provided to actuate the operating mechanism in desirable circumstances. Disposed within the circuit breaker casing is a region for the installation of an auxiliary device, such as a bell alarm device, shunt trip device etc. The case of the auxiliary device has an opening disposed therein through which a movable auxiliary device lever protrude. The opening of the circuit breaker case has a region for interfacing with the operating mechanism of the circuit breaker. A separate lever is disposed between the operating mechanism and the auxiliary device lever member. This separate lever member is driven by the operating mechanism of the circuit breaker and actuates the lever of the auxiliary device. It is pivoted about a protrusion on the auxiliary device.