Xantrex Pro XM1000 is an 'INVERTER' used to inverter DC (from batteries) to AC for that residential fridge
'CONVERTER' used to converter AC from AC Source (shore/gen) to DC for the 12V System and maintaining/charging batteries
You could have BOTH...Inverter and Converter
If you unplug shore power then Converter will stop operating --- Converter Fan
Should stop as it is AC Powered
If you turn off Inverter....then it will stop
Inverter ManualDetermine which one is making the noise.
Humming could be 'Normal' or an indication of component failing