Abstract: A circuit interrupting device including a line terminal, a wideband current sensor configured to measure a current flowing through the line terminal, a zero cross detection circuit configured to measure a voltage and frequency of the line terminal, and a microcontroller including an electronic processor. The microcontroller is configured to apply a digital filter to a line current measurement signal received from the wideband current sensor and estimate spectral density of the filtered line current measurement signal. The microcontroller is further configured to calculate an arcing characteristic based on the spectral density, determine whether an arc fault is present within the circuit interrupting device based on a comparison of the arcing characteristic to one or more thresholds, and activate an interrupting device when an arc fault is present.

Abstract: A circuit interrupting device including a phase conductor, a neutral conductor, an interrupter configured to disconnect the phase conductor and the neutral conductor from a load, and a sensor configured to generate a signal indicative of current flowing through the phase conductor and the neutral conductor. The circuit interrupting device further includes a microcontroller that includes an electronic processor and is electrically connected to the first sensor and the interrupter. The microcontroller is configured to generate a reference signal, receive a first signal from the sensor, determine whether a difference between a voltage of the first signal and a voltage of the reference signal exceeds a threshold, determine whether the microcontroller has performed a ground fault self-test, and activate the interrupter when the difference exceeds the threshold and the microcontroller has not performed the ground fault self-test.