Abstract: A miniature circuit breaker comprising a non-conductive housing assembly; a pair of separable contacts including a first, fixed contact coupled to said housing assembly and having a terminal extending outside said housing assembly, and a second, movable contact having a terminal extending outside said housing assembly; an operating mechanism coupled to, and structured to move, said movable contact between a first position, wherein said movable contact engages said fixed contact, and a second position, wherein said movable contact is spaced from said fixed contact; a trip device coupled to said operating mechanism and structured to actuate said operating mechanism to separate said separable contacts upon the occurrence of a trip condition; an arc fault trip mechanism having an arc fault detector and a shape memory alloy element; said arc fault detector structured to detect an arc fault on the load side of said separable contacts and to provide an electrical pulse; said shape memory alloy element structured to

Abstract: The continuity of the coil of the actuating solenoid of an electric power switch is detected through utilization of a signaling device, such as a light emitting diode (LED) that monitors energization of a dc power supply fed from the source side of the coil. A circuit energized from the other side of the coil generates a dc voltage V2 that is applied to the gate electrode of an electronic switch shunting the LED. The voltage V2 is greater than the dc supply voltage to bias the electronic switch off so that the LED is illuminated when there is continuity through the coil. If the coil fails, V2 will be zero and the electronic switch is turned on to short circuit the LED to signal the failure of the coil.

Abstract: A subminiature circuit breaker is equipped with an arc fault auxiliary switch actuated by the arc fault trip motor through an indicator actuator that also deploys a pop-up arc fault indicator. An additional auxiliary switch actuated by the drive link on the toggle mechanism provides an indication of the open/closed state of the circuit breaker separable contacts. Both the arc fault auxiliary switch and the contact state auxiliary switch are mounted on the outside of the subminiature circuit breaker housing and are operated by an operating member and a pivoted member, respectively, extending through openings in the housing.

Abstract: The continuity of the coil of the actuating solenoid of an electric power switch is detected through utilization of a signaling device, such as a light emitting diode (LED) that monitors energization of a dc power supply fed from the source side of the coil. A circuit energized from the other side of the coil generates a dc voltage V2 that is applied to the gate electrode of an electronic switch shunting the LED. The voltage V2 is greater than the dc supply voltage to bias the electronic switch off so that the LED is illuminated when there is continuity through the coil. If the coil fails, V2 will be zero and the electronic switch is turned on to short circuit the LED to signal the failure of the coil.

Abstract: A tester for in situ testing of a plurality of circuit breakers having a range of rated currents and multiple trip functions, includes a plurality of power resistors of known impedance, an electronic switch associated with each power resistor connecting the resistor in series with the load terminal of the circuit breaker under test, and a controller that turns on a number of the switches selected to collectively draw through the associated power resistors a test current that is a function of the rated current and sufficient to trip the circuit breaker within a selected time window. Turn on of the electronic switches is also controlled to generate a current waveform appropriate for the trip function being tested. In a self test mode, the value of each of the power resistors is verified as being within limits.

Abstract: A subminiature circuit breaker is equipped with an arc fault auxiliary switch actuated by the arc fault trip motor through an indicator actuator that also deploys a pop-up arc fault indicator. An additional auxiliary switch actuated by the drive link on the toggle mechanism provides an indication of the open/closed state of the circuit breaker separable contacts. Both the arc fault auxiliary switch and the contact state auxiliary switch are mounted on the outside of the subminiature circuit breaker housing and are operated by an operating member and a pivoted member, respectively, extending through openings in the housing.

Abstract: A tester for in situ testing of a plurality of circuit breakers having a range of rated currents and multiple trip functions, includes a plurality of power resistors of known impedance, an electronic switch associated with each power resistor connecting the resistor in series with the load terminal of the circuit breaker under test, and a controller that turns on a number of the switches selected to collectively draw through the associated power resistors a test current that is a function of the rated current and sufficient to trip the circuit breaker within a selected time window. Turn on of the electronic switches is also controlled to generate a current waveform appropriate for the trip function being tested. In a self test mode, the value of each of the power resistors is verified as being within limits.

Abstract: An indicator reset tool is for a movable arc fault indicator of a circuit breaker. The circuit breaker further includes a housing enclosing separable contacts, an operating mechanism for opening and closing the separable contacts, and an operating handle protruding through an opening in the housing. An actuator actuates the movable indicator arc fault indicator and actuates the operating mechanism to trip the separable contacts open. The indicator reset tool includes a reset member having a first end with an indicator engaging portion structured to depress and reset the movable arc fault indicator. The second end of the reset member includes a handle portion for gripping by a user.