My guess is that it has an analog-to-digital converter to measure the line voltage at high frequency and a microcontroller to analyze the data to look for trans

My guess is that it has an analog-to-digital converter to measure the line voltage at high frequency and a microcontroller to analyze the data to look for transients that indicate arcing. I found a datasheet for an arc-fault detector chip for solar panels which would be similar concepts: https://supp.iczoom.com/images/public/20181016/1539670869717085600.pdf https://supp.iczoom.com/images/public/20181016/1539670869717...