Monitoring the presence of mains voltage in phase A. Monitoring the presence of voltage of the three phases of the generator, in the absence of mains voltage. Symmetry control of phase current distribution. ZMPT101B voltage transformer A 4x1 multiplex
Using an ESP8266 ESP-01 module and an Arduino Pro Mini 3.3V I wirelessly update all outputs from my thermostat to here for data analysis and because it's cool. This requires a voltage divided rectifier since thermostats run at least 24 VAC RMS.