a qualified electrician may ..
1- install a relay ... when ac is present ... no power on the inverter outlet ..
2- an automatic battery charger board.. to stop charging when the battery is full ..
3- install some lights ... to turn on when the city power went out ...
4- an overvoltage alarm ... when the voltage of the inverter goes up ..
5- a current protector ... to cut off the inverter when the load current is more than rating ..
technical notes ..
the waveform must be SINE with frequeny 50 or 60 hz .. other frequency changes the asynchronous motors speed
the waveform must be symmetric 0n half cycles .. if not there will be a little dc voltage that heats the motors and transformers ... ASK a tv repairman to check its waveform with the oscilloscope ...