Abstract: A compact molded case circuit breaker with increased ampere rating employs a latch assembly for maintaining the circuit breaker operating mechanism in a closed condition against a pair of powerful operating springs. To increase the mechanical advantage required to move the operating handle against the springs, a retractable handle extender is attached to the handle. For higher-rated circuit applications, a lug cover extension is added to the line end of the breaker to assist in extinguishing the intense arc that occurs during circuit interruption and to protect the line lugs from inter-phasal circuit faults. A visual access slot is arranged next to the circuit breaker handle to ascertain and verify the condition of the circuit breaker contacts. The line and load terminal straps are slotted to receive protrusions on the bottom of the line and load terminal lugs and provide anti-turn facility to the line and load terminal lugs under short circuit overcurrent conditions.

Abstract: A compact molded case circuit breaker with increased ampere rating employs a latch assembly for maintaining the circuit breaker operating mechanism in a closed condition against a pair of powerful operating springs. To increase the mechanical advantage required to move the operating handle against the springs, a retractable handle extender is attached to the handle. For higher-rated circuit applications, a lug cover extension is added to the line end of the breaker to assist in extinguishing the intense arc that occurs during circuit interruption and to protect the line lugs from inter-phasal circuit faults. A visual access slot is arranged next to the circuit breaker handle to ascertain and verify the condition of the circuit breaker contacts. A rebound cushion is inserted on the interior surface of the circuit breaker cover to deter the return of the movable contact arm during contact separation under extreme overcurrent conditions.

Abstract: A compact molded case circuit breaker with increased ampere rating employs a latch assembly for maintaining the circuit breaker operating mechanism in a closed condition against a pair of powerful operating springs. To increase the mechanical advantage required to move the operating handle against the springs, a retractable handle extender is attached to the handle. For higher-rated circuit applications, a lug cover extension is added to the line end of the breaker to assist in extinguishing the intense arc that occurs during circuit interruption and to protect the line lugs from inter-phasal circuit faults. A visual access slot is arranged next to the circuit breaker handle to ascertain and verify the condition of the circuit breaker contacts.

Abstract: An electronic trip molded case circuit breaker includes components that are designed for high speed robotic assembly. A unitary trip-to-test button is down-loaded within the circuit breaker housing for automatic alignment with the circuit breaker operating mechanism during the circuit breaker assembly process. A unitary auxiliary switch interface unit is also down-loaded within the housing for automatic alignment with the operating mechanism during the assembly process.

Abstract: A combination panelboard-switchboard housing accepts plug-on connection with a plurality of electric switch-circuit breaker modules. Circuit breakers can also be directly connected into the bus bars in a plug-on connection with minor modification. The bus bars are "edge-mounted" such that the minor dimension of the bus bars is perpendicular to the bottom of the housing to receive the modules as well as the circuit breakers, per se. Plastic or fiber insulation shields are arranged over those bus bars that are not connected with the circuit breakers or modules to prevent inadvertent contact with the bus bars when energized.

Abstract: A molded case circuit breaker of the type containing an electronic trip unit and a combined acutator-accessory unit to articulate the circuit breaker operating mechanism employs an optimum cradle configuration within the circuit breaker operating mechanism. The optimized cradle interacts with the circuit breaker latch assembly to substantially reduce the tripping force required to articulate the operating mechanism.

Abstract: A molded case circuit breaker of the type using electrodynamic repulsion to separate the circuit breaker contacts under intense overcurrent conditions also includes an arc chute arrangement for cooling and quenching the arc that occurs during such contact separation. A plastic insert added to the interior of the circuit breaker cover multi-functionally retains the arc chute within the circuit breaker case while providing clearance for the circuit breaker operating handle shutter.

Abstract: A molded case circuit breaker with a visual access slot next to the circuit breaker operating handle allows the conditions of the circuit breaker contacts to be visually ascertained. To prevent inadvertent displacement of the circuit breaker operating handle when the circuit breaker is connected within an electrical distribution circuit, a handle guard is positioned over the circuit breaker operating handle. The handle guard is arranged such that the circuit breaker operating handle is free to reciprocate between the ON, OFF and TRIPPED positions while the operating handle guard is in position.

Abstract: Low voltage electric switchgear equipment includes a central programmer unit electrically interconnected with electronic main and branch circuit interrupters within the same enclosure and used with a multi-phase power distribution circuit. Indicating diodes are arranged on each of the circuit interrupters for signaling the occurrence of an overcurrent condition. The same indicating diodes are arranged for responding to address commands generated by the field programmer as to the exact location of each circuit interrupter within the enclosure.

Abstract: A compact molded case circuit breaker with increased ampere rating employs a latch assembly for maintaining the circuit breaker operating mechanism in a closed condition against a pair of powerful operating springs. To increase the mechanical advantage required to move the operating handle against the springs, a retractable handle extender is attached to the handle. For higher-rated circuit applications, a lug cover extension is added to the line end of the breaker to assist in extinguishing the intense arc that occurs during circuit interruption and to protect the line lugs from inter-phasal circuit faults. A visual access slot is arranged next to the circuit breaker handle to ascertain and verify the condition of the circuit breaker contacts.

Abstract: A compact single branch circuit breaker insulative support used within lighting panelboards is converted from an existing double branch support with minor alterations. The single branch circuit breaker arrangement allows the circuit breakers to be arranged in a closely-packed configuration within the lighting panelboard enclosure.

Abstract: An integrated protection unit is a circuit interrupter which includes basic overcurrent protection facility along with selective electrical accessories. A molded plastic accessory access cover secured to the integrated protection unit cover protects the accessory components contained within the integrated protection unit cover from the environment. A combined overcurrent trip actuator and multiple accessory unit can be field-installed within the integrated protection unit. The combined actuator-accessory unit includes electronic control circuitry for the accessories along with mechanical trip and reset interface components. An actuator-accessory unit arranged within the interrupter cover interacts between the actuator-accessory unit and the interrupter operating mechanism to separate the interrupter contacts and interrupt a protected circuit.

Abstract: An operating handle assembly for molded case circuit interrupters is robotically assembled to the circuit breaker operating mechanism without requiring any auxiliary fastening device. A visual access slot in the circuit breaker cover allows the condition of the circuit breaker contacts to be visually ascertained by use of colored indicia carried by the operating handle skirt. A slidably mounted handle shutter cooperates with the operating handle to prevent egress of arc exhaust gases in the event the circuit breaker contacts are closed or opened during overcurrent conditions when the circuit breaker is installed within an industrial power distribution circuit.

Abstract: An integrated protection unit is a circuit interrupter which includes basic overcurrent protection facility along with selective electrical accessories. A molded plastic accessory access cover secured to the integrated protection unit cover protects the accessory components contained within the integrated protection unit cover from the environment. A combined overcurrent trip actuator and multiple accessory unit can be field-installed within the integrated protection unit. The combined actuator-accessory unit includes electronic control circuitry for the accessories along with mechanical trip and reset interface components. One such accessory used with the integrated protection unit is a bell alarm for indicating the status of the circuit interrupter contacts.

Abstract: An electronic circuit interrupter includes an electronic trip circuit contained within a circuit interrupter enclosure along with an externally accessible rating plug for setting the ampere rating. The rating plug includes keying tabs that fit within corresponding keying slots formed on the top surface of the electronic circuit interrupter enclosure. Interlock is provided between the rating plug and the electric panelboard which includes a plurality of electronic circuit interrupters connected within an industrial power system. Tabs formed on the side walls of the rating plug are trapped under the panelboard face plate to prevent removal of the rating plug without first removing the panelboard face plate.

Abstract: A compact circuit breaker containing an electronic trip unit employs an actuator-accessory unit to articulate the circuit breaker operating mechanism and separate the circuit breaker contacts to interrupt current within a protected circuit. A tolerance compensating spring is attached to the actuator-accessory unit trip armature to precisely set the separation gap between the tip of the armature and the actuator-accessory trip actuator arm.