Abstract: An air circuit breaker ratcheting mechanism includes a ratchet and pawl whereby the closing springs charging gear is prevented from reverse rotation during the closing springs charging operation. Upon completion of the charging operation, the ratchet and pawl become disengaged from the charging gear when the charged closing springs are released in response to a manual closing button depression. An interlock arrangement prevents release of the holding prop to discharge the charged circuit breaker closing springs unless the circuit breaker operating handle is completely in the home position.

Abstract: A compact current limiting circuit breaker is equipped with a current limiting shunt for effective over-current circuit interruption. The circuit breaker trip unit responds to long time, short time and instantaneous over-current conditions by opening a set of contacts to isolate the protected circuit. Upon contact separation an arc is drawn, with the endpoints of the arc being initially rooted on the pair of open contacts. Further opening of the contacts commutates the arc into the current limiting shunt to redirect the current away from the trip unit and suppress the arcing current until the circuit breaker contacts are sufficiently open to isolate the protected circuit.

Abstract: An electronic circuit interrupter is protected against thermal damage upon loosening of the lug connectors that connect the circuit interrupter with the load circuit. Thermal sensing elements attached to the lugs connect with the circuit interrupter trip unit to initiate circuit interruption when the temperature sensed exceeds a predetermined value.

Abstract: An electric power busway system has multi-phase power bus bar conductors that are each housed within an individual duct. Individually housing the bus bar conductors provides short-circuit bending resistance as well as superior thermal heat dissipation characteristics because of the improved conductive heat transfer between the bus bar conductors to the individual housing, as well as convective heat transfer from the individual housing assemblies into the ambient air. Wedge-type support braces retain each housed bus bar in position and provide short circuit support.

Abstract: A circuit breaker contact position indicator is mounted on the same support platform as the circuit breaker electronic trip unit and contains a micro-switch to provide indication to the trip unit of the status of the circuit breaker contacts. The switch interacts with the circuit breaker operating mechanism crossbar cam by means of a spring-loaded paddle attached to the trip unit support platform.

Abstract: A circuit breaker trip unit enclosure is adapted to receive rotary knobs that are limited in rotation in proportion to the circuit breaker short circuit rating. The externally-accessible rotary knobs extend within the enclosure to contact with a potentiometer affixed to the circuit breaker trip unit printed circuit board. A stop member is inserted within the enclosure access opening to detent the rotary knob shank that extends through the access opening.

Abstract: An arcing fault detecting module is attached to a circuit breaker employing a thermal-magnetic trip unit to separate the circuit breaker contacts upon occurrence of an arcing fault. The arcing fault module contains a logic circuit and a current transformer for detecting the arcing fault and actuating a trip solenoid to articulate the circuit breaker operating mechanism and separate the circuit breaker contacts.

Abstract: A spring-loaded cam electrical connector is used to rapidly connect circuit breaker load terminal straps with the associated electric distribution system wire conductors. Rotation of the cam in one direction traps the end of the wire conductor between the bottom of the cam support and the circuit breaker load terminal strap to make the electrical connection while rotation of the cam in the opposite direction releases the end of the wire conductor to break the electrical connection.

Abstract: A gravity teaching aid in the form of a tennis ball which includes a magnet for retaining the tennis ball against a metal surface against the downward pull exerted by the earth's magnetic field.

Abstract: An integrated circuit breaker is provided with shunt trip capability along with automatic overcurrent protection through the circuit breaker trip unit and shunt trip module. The shunt trip module further provides auxiliary power to the trip unit and allows the trip unit microprocessor to report and record the shunt trip operation. The trip unit communicates with the circuit breaker operating mechanism to determine the ON-OFF status of the circuit breaker contacts.

Abstract: A field-installable circuit breaker trip actuator unit includes a flux shifter unit that interfaces with the circuit breaker operating mechanism and is installable without dismantling the circuit breaker components. The flux shifter unit responds to an electronic trip unit to articulate the circuit breaker operating mechanism and separate the circuit breaker contacts upon occurrence of an overcurrent condition. A reset arrangement allows the trip actuator unit to be automatically reset upon completion of the contact separation process.

Abstract: A circuit breaker operating mechanism interacts with the circuit breaker movable contact arm by means of an electrically-insulative linkage. Tolerance adjustments are made within the linkage without requiring an additional electrically-insulative shield.

Abstract: A high ampere-rated circuit breaker which meets the electrical code requirements of the world market. The charging of the powerful operating spring controlling the circuit breaker contacts is made automatically by means of an electric motor. The motor interlock arrangement prevents rotation of the closing shaft until and unless the circuit breaker contact closing spring has become completely charged.

Abstract: A lockout solenoid is connected with the circuit breaker accessory shunt trip in a high ampere rated circuit breaker and interacts with the circuit breaker accessory lever to prevent the closing of the circuit breaker contacts until the shunt trip activation voltage signal is turned off. The circuit breaker accessory lever interlocks the circuit breaker closing button to prevent closing the circuit breaker contacts until such shunt trip activation voltage signal is turned off.

Abstract: This invention relates to a high ampere-rated circuit breaker which meets the electrical code requirements of the world market. The circuit breaker electronic trip unit is contained within a recess in the circuit breaker cover and is interlocked with the circuit breaker operating mechanism to articulate the operating mechanism upon removal. A padlock assembly arranged within the circuit breaker case prevents the circuit breaker contacts from being closed and the cover from being removed. The padlock assembly is only functional when the circuit breaker contacts are in the OPEN condition.

Abstract: An arc isolation shield for molded case circuit breakers is inserted between the circuit breaker case and cover and attached to one leg of the operating cradle. The knee of the circuit breaker moveable contact arm contacts the bottom of the shield and moves the shield in unison with the contact arm to protect the contact arm, contact braid and operating spring upon contact separation under severe overcurrent conditions.

Abstract: A modular current transformer containing both air and metal cores on a common load strap provides sensing current to the electronic trip unit within the circuit interrupter along with supplying operating power to the trip unit components. The current sensing coil is arranged concentricity within the transformer core while the power generating coil is arranged concentricity outside the core.

Abstract: A single-sized circuit breaker electric isolation block provides both electric insulation between the circuit breaker operating mechanism as well as mechanical support to the circuit breaker contact arm assembly over a wide range of circuit breaker ampere ratings. The isolation block is formed from a plastic composition and is shaped to receive the circuit breaker operating mechanism connector link for each phase of a multi-phase circuit breaker assembly. The positional relationship on the block accommodates the connector links used with a wide range of circuit breaker ampere ratings.