Abstract: A circuit breaker housing includes a base having a main portion and a separate subbase portion. The line contact arms for the breaker are mounted on the subbase portion and attached to the main portion which includes the load contact arms. The main portion of the base includes a bottom wall which insulates the load contact arms from the line contact arms along a portion of their lengths. In addition, the bottom wall forms a structural member which rigidly ties the two sidewalls of the main portion of the base. The bottom wall of the main portion of the base includes an opening through which line contacts coupled to the line contact arm make contact with load arm contacts coupled to the load contact arms. Adjacent to the opening, the main portion of the base includes vertical ribs directly tied to the bottom wall which strengthen internal and external side walls in the main portion of the base and reinforce the structural member formed by the bottom wall of the main portion of the base.

Abstract: A circuit breaker including a sliding connection between a trip unit and associated contact arm is disclosed herein. The sliding connection facilitates assembly of the circuit breaker and also permits a reduction of size for a circuit breaker of a given rating. An embodiment of the sliding connection includes a blade and jaw assembly connected between the trip unit and contact arm. Another embodiment of the sliding connection includes a blade or jaw assembly slidably connected directly to the contact arm.

Abstract: A circuit breaker including a sliding connection between a trip unit and associated contact arm is disclosed herein. The sliding connection facilitates assembly of the circuit breaker and also permits a reduction of size for a circuit breaker of a given rating. An embodiment of the sliding connection includes a blade and jaw assembly connected between the trip unit and contact arm. Another embodiment of the sliding connection includes a blade or jaw assembly slidably connected directly to the contact arm.

Abstract: The present invention provides a plug-in ground fault monitor module for a circuit breaker trip unit configured to operate with a plurality of different plug-in plug-in modules. The ground fault monitor module includes a memory which stores data representative of the its particular function. This memory is readable by the trip unit and enables the trip unit to automatically adapt to communicate monitored ground fault data to the ground fault module. The ground fault module also includes means for setting threshold levels for a ground fault alarm signal. The ground fault alarm signal is generated independently of ground fault alarms in the trip unit based on its internal thresholds. This signal can be used to control an external relay which operates a shunt trip mechanism or an external alarm. The trip unit includes a processor and programming which permits a bi-directional flow of data between the units, such as display data and control data.

Abstract: Apparatus for closing a circuit breaker of a circuit that carries a substantial current includes a terminals (W1, W2, W12, W13, W14) for connection to an available source of electric power. The electric power available is typically 24 VDC, 48 VDC, 125 VDC or 120 VAC. An actuator including an electric motor M and a solenoid S both designed to operate on 24 VDC first cocks charging springs and then releases the charging springs to close the circuit breaker. A controller including a microprocessor U3 is connected to and derives power from the connected terminals and produces a pulse width modulated control signal (RUN; CLOSE) for controlling the actuator. The duty cycle of the pulse width modulated signal is adjusted in relation to the electric power supplied by the selected source so that the power supplied to the motor and relay functions effectively as the required 24 VDC power. Sensors J1 sense the condition of the charging springs, a charging cam, the circuit breaker, etc.

Abstract: A stationary contact strap for a circuit breaker, with an electrically conductive body portion having a plurality of discrete apertures arrayed in a pattern which define at least two input portions for splitting transient current input into the contact strap into generally parallel pathways which are also in the same general direction as transient current flow in the circuit breaker movable contact arm; and an output portion electrically coupled to the input portions and the fixed stationary main contact, wherein the output portion is oriented so that transient current flow therethrough is in a direction generally opposite to transient current flow in the movable arm.

Abstract: The present invention provides a circuit breaker trip unit configured to operate with a plurality of different plug-in display units. The display unit includes a memory which stores data representative of the particular display unit, and which allows the trip unit to automatically adapt to communicate with the display modules. The trip unit includes a processor and programming which permits a bi-directional flow of data between the units, such as display data and control data.

Abstract: A circuit breaker including a trip unit interlock. The trip unit interlock provides a trip unit having a plug connectable with a mating plug which is slidable with respect to the circuit breaker. The trip unit engages a pair of pins mounted to the circuit breaker when the trip unit is in its operating position. The pins are oriented to prevent separation of the plug from the receptacle during circuit breaker tripping. Since it is undesirable to insert a trip unit into a circuit breaker where the trip unit is not compatible with the circuit breaker, the pins and openings in the trip unit are configured such that they will not mate if the trip unit is not appropriate for the circuit breaker. When the trip unit is in its operating position, the trip unit holds an interlock lever for the contact operating mechanism of the circuit breaker in a position where the contact operating mechanism may close the contacts and hold the contacts closed when the circuit breaker is in its ON state.

Abstract: A trip circuit for tripping a circuit breaker has a first coil having a relatively large number of turns and therefore a relatively slow reaction time and a second coil having a relatively small number of turns and therefore a relatively fast reaction time. The first coil is responsive to a relatively low current level through a circuit breaker for tripping the circuit breaker at the rated tripping current. The second coil is responsive to a higher current through the circuit breaker for tripping the circuit breaker with great rapidity in case the higher level is reached before the first coil has an opportunity to react.

Abstract: A circuit breaker including a trip unit interlock. The trip unit interlock provides a trip unit having a plug connectable with a mating plug which is slidable with respect to the circuit breaker. The trip unit engages a pair of pins mounted to the circuit breaker when the trip unit is in its operating position. The pins are oriented to prevent separation of the plug from the receptacle during circuit breaker tripping. Since it is undesirable to insert a trip unit into a circuit breaker where the trip unit is not compatible with the circuit breaker, the pins and openings in the trip unit are configured such that they will not mate if the trip unit is not appropriate for the circuit breaker. When the trip unit is in its operating position, the trip unit holds an interlock lever for the contact operating mechanism of the circuit breaker in a position where the contact operating mechanism may close the contacts and hold the contacts closed when the circuit breaker is in its ON state.

Abstract: A primary disconnect assembly for a circuit breaker. The assembly includes a plurality of contact fingers for engaging the terminals of a bus bar assembly. The terminals and fingers are configured such that the terminals each include depressions adapted to accept the contact portions of the contact fingers. This configuration provides at least two contact locations between each contact finger and terminal. Additionally, this configuration increases the force required to slide the fingers relative to the terminals.

Abstract: A mechanism for accumulating and storing mechanical energy, wherein the energy is used to close the primary contacts of a circuit breaker. The energy can be input to the mechanism manually or by means of a motor. The mechanism includes a series of linkages which function to utilize the energy to close the primary contacts. These linkages also function to maintain the closing force upon the primary contacts, while also functioning to allow rapid contact opening when desired.

Abstract: A primary disconnect assembly for a circuit breaker. The assembly includes a plurality of contact fingers for engaging the terminals of a bus bar assembly. The terminals and fingers are configured such that the terminals each include depressions adapted to accept the contact portions of the contact fingers. This configuration provides at least two contact locations between each contact finger and terminal. Additionally, this configuration increases the force required to slide the fingers relative to the terminals.

Abstract: A single piece contact barrier for separating and maintaining the spacing of the contact blades in a circuit breaker. The barrier is also adapted to form an insulating barrier between the contact blades and produce an arc quenching vapor. Under certain circumstances, when one contact and its associated contact are separated, an arc is formed between the contacts. The heat generated by the arc causes the barrier to vaporize in near the arc such that the vapor tends to quench the arc.

Abstract: A pivoting electrical connected useable in a molded case circuit breaker including a pair of contact plates for contacting the circular contact member of a contact carrying arm. The pivoting electrical connection provides at least three contact locations between the contact plates and the circular contact member. The contact locations provide current paths between a first terminal coupled to the contact plates and an electrical contact fixed to the contact carrying arm. The pivoting electrical connection allows the contact on the arm and an electrical contact coupled to a second terminal to be opened and closed.

Abstract: A contact blade for a circuit breaker configured such that the current path in the blade produces a magnetic field which affects an arc present at the contact of the blade. The configuration of the blade produces a substantially U-shaped current loop in the blade, wherein one leg of the current loop has its main component substantially parallel to, but in the direction opposite to, the main component of the current in the second leg of the loop. When an arc is formed at the contact, the current from the second leg flows through the contact and into an arc, while the current in the first leg of the loop produces a magnetic field which acts upon the arc and forces the arc off of and away from the contact.

Abstract: A mechanism for moving and supporting a circuit breaker relative to a bus bar arrangement such that the circuit breaker can be engaged and disengaged from the bus bar arrangement. The mechanism functions to engage and disengage the circuit breaker while also preventing engagement and disengagement of the circuit breaker from the bus bar arrangement while the circuit breaker is not tripped. The mechanism can also function to indicate whether or not the circuit breaker is engaged or disengaged with the bus bar arrangement.

Abstract: A charging handle assembly for charging the closing springs of a stored energy mechanism which closes the contacts of a circuit breaker. The charging handle has a generally U-shape and is pivotally attached to the circuit breaker cover. The handle is adapted to cooperate with the stored energy mechanism such that the cover and handle are easily removed from the circuit breaker. Additionally, the handle cooperates with the cover and the stored energy mechanism so that energy is transferred to the springs of the mechanism by pumpiing the handle.

Abstract: A barrier for isolating the electrical contacts of a circuit breaker from the operating mechanism for the contacts. The barrier includes openings to allow the operating mechanism to pass through the barrier, and venting channels for venting gas from within the circuit breaker to the exterior of the circuit breaker.

Abstract: An assembly adapted to commutate arcs from between the main contacts of a circuit breaker to an arcing contact such that a single arc at the arcing contact can be extinguished and dispersed within an arc chute. The assembly is adapted to be pivotally attached to the ends of the main contact carrying arms and includes arc channeling members joined to form a contact surface. An arcing contact can be fixed to the contact surface such that the arcs from the main contacts are channelled into one arc at the arcing contact.