Abstract: A residential load center includes an electronic trip unit as the main circuit breaker for overcurrent and arcing fault protection while connecting with thermal magnetic circuit breakers in each of the branch circuits for overcurrent protection within the individual branch circuits.

Abstract: A circuit interrupter of the type including an electronic trip unit for overcurrent determination includes a separate circuit to power the trip unit along with a Hall Effect or GMR Device to sense the current flow within the protected circuit. A removable option plug electrically interconnects with the trip unit to enable ground fault and arcing fault protection.

Abstract: Circuit breaker arc exhaust apertures in the line end of the circuit breaker case transfer arc gases from the circuit breaker interior during overcurrent circuit interruption. A flexible shield protects the circuit breaker terminal lug from arc gas contamination.

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. The reset mechanism allows the actuator-accessory unit to become reset without interferring with the operation of the integrated protection unit.

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: An interchangeable operating mechanism assembly for molded case circuit breakers having a detachable movable contact arm and trip unit assembly allows the same mechanism assembly to be employed across a wide range of breaker ratings. A snap-on common trip bar attachment further allows multiple-pole facility off the common interrupter mechanism assembly. The mechanism assembly is designed to maintain the operating handle in the "on" position upon the occurrence of a welded contact and prevents the mechanism from being reset.

Abstract: A circuit breaker design and process for high speed assembly utilizes a unique secondary latch arrangement to reduce frictional forces and increase the breaker calibration test yield. The design allows for interchangability of the trip unit by first pre-assembling the arc chute cavity and operating mechanism. Arrangement of the primary and secondary latch pivots reduces the trip force for further increase in the calibration yield.

Abstract: An interchangeable operating mechanism assembly for molded case circuit breakers having a detachable movable contact arm and trip unit assembly allows the same mechanism assembly to be employed across a wide range of breaker ratings. A snap-on common trip bar attachment further allows multiple-pole facility off the common interrupter mechanism assembly. The mechanism assembly is designed to maintain the operating handle in the "on" position upon the occurrence of a welded contact and prevents the mechanism from being reset.

Abstract: A composite line strap is used with molded case circuit breakers to support the circuit breaker stationary contact and to retain the circuit breaker line terminal screw. The fixed contact is welded to the line strap within the breaker at a first end and the line terminal screw is attached to the opposite end of the line strap by a through-hole in a spring-steel retainer which extends partially within the circuit breaker. The line terminal screw is tightly held within the through-hole of the retainer at the first end and the retainer itself is trapped between the bottom of the circuit breaker case and the line strap at the opposite end of the line strap.

Abstract: A circuit breaker design and process for high speed assembly utilizes a unique secondary latch arrangement to reduce frictional forces and increase the breaker calibration test yield. The design allows for interchangeability of the trip unit by first pre-assembling the arc chute cavity and operating mechanism. Arrangement of the primary and secondary latch pivots reduces the trip force for further increase in the calibration yield.

Abstract: A miniature current limiting circuit breaker incorporates double break circuit interrupting contacts capable of being abruptly separated by a high fault current responsive solenoid acting to first trip the breaker mechanism and then forcibly effect contact separation. The arc chamber is constructed to achieve enhanced blowout of the arc into the arc chute and to develop gas pressures acting to accelerate contact separation. The circuit breaker is trip-free and includes both thermal tripping and internal common tripping capabilities.

Abstract: A compact three-pole circuit breaker is modularly constructed utilizing two identical operating mechanisms in controllably articulating three movable contact arms. The operating mechanisms are ganged together for concerted manual operation by an external handle tie and internal means intercoupling the three movable contact arms and the operating mechanisms. Trip units, one in each breaker pole, independently act on an internal common trip bar to simultaneously trip the two operating mechanisms and thereby effect concerted opening movement of the contact arms in quick break fashion under the urgence of mechanism springs and assisting helper springs.

Abstract: A molded case circuit breaker having a raised escutcheon case portion through which its operating handle protrudes and a mounting shoulder at each end is accommodated in an enclosure having a removable frontal cover in which an opening is provided. An elongated sheet metal bracket is slideably mounted within the enclosure and has a hook for engaging one of the breaker mounting shoulders and resilient latch releaseably engaging the other breaker mounting shoulder. The breaker and bracket are slideably positioned as a unit to register the breaker escutcheon case portion with the cover opening for protrusion therethrough in close fitting relation.

Abstract: An arc chute for assisting in the extinction of an arc drawn between circuit interrupting contacts opening in air includes a stack of closely spaced metallic plates coated with a weld deterent material, such as silicone varnish. By virtue of this coating, the propensity of metal particles condensed from the metal vapor generated by the arc to weld to the arc plate surfaces is reduced. Consequently, material degradation of the arc chute dielectric strength is avoided, and arc reignition is discouraged.