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 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 electric circuit breaker enclosure includes a pultruded glass-filled plastic inset for added strength to the line and load terminal straps. The line and load terminal straps are fastened to the inset on the side and receive the corresponding line and load terminal cables on an opposite side thereof. The inset allows connection within a high-rated electrical power distribution circuit without damage to the circuit breaker case upon short circuit interruption.

Abstract: A residential circuit breaker design provides heat sink facility to the current carrying members within a thermoset plastic base. A thermoplastic plastic cover is ribbed internally to minimize contact between the interior of the cover and current carrying components. The thermoplastic cover results in a substantial savings in material costs since the thermoplastic waste material is recoverable and re-useable.