Abstract: A circuit interrupting device having an auto-monitoring circuit for automatically testing various functions and structures of the device. The auto-monitoring circuit initiates an auto-monitoring routine which, among other things, establishes a self-test fault during either the positive or negative half-wave, or both, of an AC power cycle and determines whether the detection mechanisms within the device properly detect the self-test fault. An early detection signal indicates that the self-test fault was properly detected without interfering with the normal operation of the detection circuitry and without causing a false trip within the device. Additional functionality of the auto-monitoring circuit permits automatic verification that the device is properly wired, that is, not miswired, and determines whether the device has reached the end of its useful life.

Abstract: A circuit interrupting device having a dual-coil solenoid for delivering an increased magnetic field to the solenoid plunger when a fault is detected and it is desired to place the device into a tripped condition. Independent switching devices control the flow of current through the respective coils of the solenoid and a third switching device controls the operation of the two coil driving switch devices. A detection circuit detects faults and controls the third switching device to activate the coil driving switching devices when a fault is detected. A programmable device runs a self-test program to determine whether the device is operating properly and faults can be detected. The programmable device can also independently control the operation of the two coil driving switching devices.

Abstract: A circuit interrupting device having an auto-monitoring circuit for periodically testing various functions and structures of the device. The auto-monitoring circuit initiates an auto-monitoring routine which, among other things, generates a self-test fault condition and determines whether the detection mechanisms within the device properly detect the self-test fault. Processing an early detection signal determines whether the self-test fault was properly detected without interfering with the normal operation of the detection circuitry and without causing a false trip within the device. Additional functionality of the auto-monitoring circuit permits automatic verification that the device is properly wired, that is, not miswired, and determines whether the device has reached the end of its useful life.

Abstract: A circuit interrupting device having an auto-monitoring circuit for automatically testing various functions and structures of the device. The auto-monitoring circuit initiates an auto-monitoring routine which, among other things, establishes a self-test fault during either the positive or negative half-wave, or both, of an AC power cycle and determines whether the detection mechanisms within the device properly detect the self-test fault. An early detection signal indicates that the self-test fault was properly detected without interfering with the normal operation of the detection circuitry and without causing a false trip within the device. Additional functionality of the auto-monitoring circuit permits automatic verification that the device is properly wired, that is, not miswired, and determines whether the device has reached the end of its useful life.