Abstract: A support for anchoring a trip unit of a circuit breaker to a base thereof to prevent separation of the trip unit from the base during a short circuit fault. The support has top-facing two locking tabs that snap into place behind a wall in a lug-receiving area of the base. The support also has an opening through which a terminal of the trip unit is received snugly. The locking tabs keep the support in place and prevent forces produced by gasses during a fault from forcing the trip unit away from the base. The terminal, attached to the trip unit, is retained by the opening, which transfers upward forces to the top of the support, which is positioned against a top section of the base. The snug fit by the terminal through the opening and retention of the support in the lug-receiving area during a fault increases post-fault dielectric performance.

Abstract: A support for anchoring a trip unit of a circuit breaker to a base thereof to prevent separation of the trip unit from the base during a short circuit fault. The support has top-facing two locking tabs that snap into place behind a wall in a lug-receiving area of the base. The support also has an opening through which a terminal of the trip unit is received snugly. The locking tabs keep the support in place and prevent forces produced by gasses during a fault from forcing the trip unit away from the base. The terminal, attached to the trip unit, is retained by the opening, which transfers upward forces to the top of the support, which is positioned against a top section of the base. The snug fit by the terminal through the opening and retention of the support in the lug-receiving area during a fault increases post-fault dielectric performance.

Abstract: A terminal assembly for use in a circuit breaker. The terminal assembly includes a first member and a second member abutting the first member. The second member includes a pair of protruding arms to be inserted into a corresponding pair of recesses in a circuit breaker housing. Because the pair of protruding arms are inserted into the housing, the first member is protected against rotational force.

Abstract: An electrical device, such as a circuit breaker, for interrupting the flow of current, which includes a stationary contact, a blade having a movable contact, a releasably latchable trip lever, a bimetal, and a magnetic armature. The movable contact is movable into and out of engagement with the stationary contact. The trip lever is releasable from a latched position for movement to a tripped position to cause separation of the stationary and movable contacts. The bimetal causes the release of the trip lever from the latched position by having the armature drawn a predetermined distance in response to a predetermined short circuit current. The trip lever is held in the latched positioned by a hardened latch having a minimal surface area, which is positioned near an opening located in the armature. When the predetermined short circuit current flows through the bimetal, the trip lever moves to the tripped position.

Abstract: An electrical device, such as a circuit breaker, for interrupting the flow of current, which includes a stationary contact, a blade having a movable contact, a releasably latchable trip lever, a bimetal, and a magnetic armature. The movable contact is movable into and out of engagement with the stationary contact. The trip lever is releasable from a latched position for movement to a tripped position to cause separation of the stationary and movable contacts. The bimetal causes the release of the trip lever from the latched position by having the armature drawn a predetermined distance in response to a predetermined short circuit current. The trip lever is held in the latched positioned by a hardened latch having a minimal surface area, which is positioned near an opening located in the armature. When the predetermined short circuit current flows through the bimetal, the trip lever moves to the tripped position.

Abstract: An apparatus and method for interrupting the flow of electrical current in a line is disclosed. The invention provides for better limitation of current than can be achieved in the prior art. With effective current limitation, the magnetic force generated by the circuit breaker coil will not be excessive thereby reducing potential damage to the circuit breaker armature, increasing the interruption rating of the circuit breaker and end-use equipment and decreasing the interruption pressure within the circuit breaker.

Abstract: A reverse deflection prevention arrangement is provided for use in a circuit breaker for preventing a bimetal from bending in a direction opposite its normal thermal deflection. The reverse deflection prevention arrangement includes a tab portion extending from a yoke and a corresponding block member disposed on the inside surface of a circuit breaker cover. The tab portion engages the block member when the bimetal is forced to deflect in the direction opposite its normal deflection. An alternate embodiment of the reverse deflection prevention arrangement includes a reinforcement member secured to one end of the bimetal. The reinforcement member strengthens and supports the bimetal so that it is prevented from bending in the direction opposite its normal thermal deflection.

Abstract: A circuit breaker includes a first section and a second section with independently operating pairs of contact assemblies in each respective section. In the first section, at least one of the contact assemblies is constructed and arranged to interrupt the current by moving from a normally closed position to a blown-open position and latching with the contact assemblies separated. The second section has a biasing extension spring for biasing the contact assemblies of the second section so as to permit interruption of the current in response to a blow-open force, which causes the contacts to separate only momentarily and then return to a normally closed position. The first and second pairs of contact assemblies separate substantially simultaneously in response to the blow-open force, and only the first section reacts to lower-level over-current conditions. In addition to the contact assemblies, the second section of the circuit breaker is designed to operate using only a spring which is "Z-axis" mountable.

Abstract: An arc stack for receiving a circuit breaker blade moveable between a closed position and an open position, includes a plurality of arc plates positioned substantially parallel to one another and arranged in a plurality of adjacent groups. Each of the groups includes one or more arc plates having substantially similar respective arc throats formed therein. The respective arc throats progressively decrease in size from group to group along the length of the arc stack in a direction extending away from the closed position of the blade. A connecting support maintains the plurality of arc plates substantially parallel to one another.

Abstract: An arc stack for receiving a circuit breaker blade moveable between a closed position and an open position, includes a plurality of generally rectangular are plates having substantially similar length and width dimensions and positioned substantially parallel to one another. The straight edges of the arc plates are in line with one another so that the are stack is generally rectangular in shape. The arc plates have respective arc throats formed therein having a plurality of sizes so as to form a longitudinal passageway extending through the arc throats following the arc generated by the blade moving between the closed and open positions. The arc plates include sets of arc plates with the arc plates in each set having identical arc throats. The sets of arc plates are arranged in order of decreasing arc throat size with the set having the largest arc throats being positioned adjacent the circuit breaker blade in the closed position.

Abstract: A circuit breaker includes a first section and a second section with substantially independently operating pairs of contact assemblies in each respective section. In the first section, at least one of the contact assemblies is constructed and arranged to interrupt the current by moving from a normally closed position to a blown-open position and latching with the contact assemblies separated. The second section has a biasing extension spring for biasing the contact assemblies of the second section so as to permit interruption of the current in response to a blow-open force, which causes the contacts to separate only momentarily and then return to a normally closed position. The first and second pairs of contact assemblies separate substantially simultaneously in response to the blow-open force, and only the first section reacts to lower-level over-current conditions.

Abstract: A mid terminal for a double break circuit breaker comprises first and second elongated conductive plates, where each of the plates have first and second ends. The second end of the first plate is longitudinally spaced from the first end of the second plate and the first end of the first plate is connected to the second end of the second plate by a lateral conductive plate. A first are runner is electron beam welded to the second end of the first plate, and a second are runner is electron beam welded to the first end of the second plate. The first and second arc runners are preferably made of steel. A first stationary contact is mounted on the first plate adjacent the first arc runner, and a second stationary contact is mounted on the second plate adjacent the second arc runner.

Abstract: A high current capacity blade for a circuit breaker, comprises a conductive blade body having front and rear sections connected to one another, where the rear section includes a surface attachment area for fastening a flexible connector of the circuit breaker thereto. A strain relief tang extending from the rear section of the blade body is used to engage the flexible connector so as to stabilize the fastening of the flexible connector to the surface attachment area. A broad conductive lateral section is connected to and extends laterally from the front section, and includes a blade tab for engaging a toggle spring of the circuit breaker. A broad moveable contact is mounted on the broad lateral section and is adapted to interface with a stationary contact of the circuit breaker. A pair of substantially parallel L-shaped blade legs are spaced from one another to permit the toggle spring to pass therebetween.