IIRC the drill is to turn it OFF "at the inverter" not at the remote panel unplug the remote control cable aka phone line plug disconnect from batteries for 10 minutes then connect batteries turn on check operation..\ IF okay, turn off, plug in remote, turn on again
this helps to isolate problem to inverter or remote board, if there is a problem with one or the other
After the reboot and still gives overload fault I would remove the 120v connection and turn it on one more time. Then it would be needing replacement if the overload continues.