Abstract: The outer surfaces of adjoining electrical busway side frames are shaped to define a protruding rail extending along the vertical axis thereof. A pair of recessed channels formed within the inner surfaces of the side frames of an intervening busway joint receive the busway rails at opposing ends thereof. Clearance arranged within the respective busway joint channels allows lateral movement of the busway side frames relative to the busway joint. Slots are provided on the busway joint side frames for visual indication of the position of the busway rails.

Abstract: A circuit breaker operating handle formed from a plastic composition includes a handle access post and a curvilinear handle skirt. A pair of opposedly positioned detent members are integrally-formed on the surface of the handle skirt opposite the handle access post. The detents correspondingly engage the top planar surface of a U-shaped handle yoke which interfaces with the circuit breaker operating mechanism. The circuit breaker operating handle is robotically down-loaded onto the handle operating yoke prior to attachment between the handle yoke and the circuit breaker operating mechanism.

Abstract: A thermally efficient joint for electrical power distribution busway electrically connects between adjacent busway sections. Each busway joint includes a modular assembly containing spaced metallic splice plates separated by corresponding insulating plates. The module is sandwiched between a pair of joint covers by means of an insulated thru-bolt. The spacing between the splice joint for receiving corresponding busway stabs is accurately set by an apertured depression stamped within each of the splice plates.

Abstract: A circuit breaker operating mechanism for automated assembly finds application within circuit breakers of different ampere ratings. The circuit breaker contacts are opened and closed by means of a roller connected to the circuit breaker operating handle through a cradle link and a cam arranged on the movable contact carrier. The operating springs, cradle and latch are first assembled to the operating mechanism prior to assembly of the operating mechanism within the breaker housing.

Abstract: An integrated protection unit is a circuit breaker which includes basic overcurrent protection facility along with selective electrical accessories. A molded plastic accessory access cover secured to the integrated protection unti cover protects the accessory components contained within the integrated protection unit cover from the environment. A combined overcurrent trip actuator and multiple accessory module is either field-installed or factory-installed within the integrated protection unit. A separate actuator-accessory module is selected for different combinations of accessory functions.

Abstract: An integrated protection unit is a circuit breaker 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 circuit breaker cover from the environment. An auxiliary switch unit is one such accessory component which can be field-installed without affecting the integrity of the circuit breaker overcurrent protection components.

Abstract: Molded case circuit breakers connected to two different sources of power within an industrial application are interlocked to prevent one circuit breaker from being turned on while the other circuit breaker is already on. The circuit breakers include a molded plastic crossbar arranged for rotation within the circuit breaker enclosure. The interlock arrangement consists of a pivoted bell crank assembly including a pair of pivotally mounted insulative posts on either end of the bell crank. A corresponding cam integrally formed on the circuit breaker crossbar is in interference with one of the upstanding posts when the circuit breaker is in the "OFF" position and is out of interference with the upstanding post when the circuit breaker is in its "ON" condition.

Abstract: Molded plastic outlet boxes are attached to an electric busway power distribution system at each location along the system where the bus bar conductors are provided with plug-in stabs. Slotted openings arranged through a top of the outlet box are centered with respect to the busway stabs to assist in connection therewith. A molded plastic access cover can be mounted optionally on either side of the box to electrically isolate the busway stabs.

Abstract: A test kit for a digital and analog electronic circuit breaker determines the calibration and overcurrent response of the circuit breaker when connected within an electric power circuit. The test kit simulates an overcurrent condition and provides verification of the circuit breaker response without de-energizing the circuit breaker or interfering with the circuit breaker's protection functions. The test kit connects with the digital communications circuit within the digital circuit breaker to obtain status information concerning pick-up conditions, trip conditions and fault currents which are viewed on the test kit liquid crystal display. A ground fault suppression circuit is included within the test kit for single-phase current-injection without causing ground fault tripping. The test kit circuit further includes means for optionally tripping the circuit breaker upon completion of any of the tests.

Abstract: Line and load lugs are fixedly attached to each pole of a multi-pole molded case circuit breaker without requiring screws. The lugs are positioned within the line and load lug compartments at opposing ends of the breaker by grooves formed along the sides of the lugs and rails formed within the internal surfaces of the compartments. A lug support cap fitted to the bottom of each line and load lug interacts with detents formed on the inner surfaces of the compartments to securely retain the line and load lugs within the compartments.

Abstract: An integrated protection unit is a circuit breaker 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.

Abstract: A two-piece extruded aluminum alloy housing is shaped to provide support and ground conduction facility to power busway conductors contained therein. The two-piece housing is attached together with snap-fit connectors along its top and bottom surfaces. The housing is attached to the busway power conductors by means of insulated bolts. The bolts may be hollow so that air can flow through the bolts to aid in cooling the conductors within the housing by convection.

Abstract: A molded case circuit breaker movable contact arm or carrier electrically connects with the circuit breaker trip unit or load terminal without requiring a flexible electrical conducting braid. The contact carrier is pivotally arranged within a contact carrier support to which the trip unit or load terminal lug is attached. The contact carrier pivot pin is supported on a pair of parallel posts extending from the contact carrier and a spring clip is positioned around the parallel posts and the pivoting end of the contact carrier to promote good electric transport without interfering with the rotational movement of the contact carrier.

Abstract: An undervoltage release accessory is attached to the interior of a circuit breaker enclosure proximate the operating handle assembly. A reset mechanism positioned between the handle operator and the undervoltage release plunger resets the undervoltage release plunger after an undervoltage condition. A flexible reset spring on the reset mechanism compensates for mechanical tolerances between the reset mechanism and the undervoltage release plunger.

Abstract: An integrated protection unit is a circuit breaker 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 circuit breaker cover from the environment. A trip signal indicator is one such accessory component which can be field-installed without affecting the integrity of the circuit breaker overcurrent protection components.

Abstract: An integrated protection unit is a circuit breaker 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 circuit breaker cover from the environment. An auxiliary switch unit is one such accessory component which can be field-installed without affecting the integrity of the circuit breaker overcurrent protection components.

Abstract: A fused disconnect switch is contained within a molded plastic cover pivotally attached to a molded plastic case. The switch contact blade is directly attached to the cover whereby movement of the cover in one direction slidingly connects the switch contact blade between the line and load stabs mounted within the case. Movement of the cover in an opposite direction slidingly disconnects the switch contact blade from the line and load stabs. Tabs integrally formed within the cover and slots integrally formed within the case cooperate to prevent access to the switch components when the switch blade is in its "ON" position. An opening is provided for locking the switch in either the "ON" or "OFF" position.

Abstract: An industrial rated molded case circuit breaker having an electronic trip circuit contained within the circuit breaker enclosure includes a reset spring in cooperation with the circuit breaker latch spring to insure manual reset of circuit breaker after an automatic trip function. The reset spring allows the circuit breaker latch assembly to be manually reset upon minimum travel of the circuit breaker operating handle due to internal circuit breaker component space restrictions. The circuit breaker latch assembly is robotically loaded to the operating mechanism which is then attached to the circuit breaker case by an automated fastening process.

Abstract: An integrated protection unit is a circuit breaker 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 circuit breaker cover from the environment. A combined overcurrent trip actuator and multiple accessory unit can be field-installed within the integrated protection unit.

Abstract: Electronic trip units employed within static trip circuit breakers are individually calibrated and automatically adjusted to ensure that the trip transfer characteristics are within specification requirements. A trimming network within the trip unit circuit contains a plurality of parallel resistors each separately connected within the circuit by means of a fusible link. Test input and output values are compard to idealized values that are binary-weighted within a look-up table in the test equipment computer. The percent correction required is determined and the appropriate links are interrupted to provide ideal trip response.