Please check wiring (inverter in UPS backup mode)


New Member
Mar 13, 2022
I am setting up inverter/batteries in UPS/Backup mode in a little house in Thailand, this is a temporary system.

I was hoping the forum could review my wiring, and also answer a couple of questions I have.

The house is 220-240V 2-wire single phase, pics:

Planned wiring diagram after adding the inverter:

Anything wrong with this design?

Most of the existing loads/outlets connected to the main switchboard do not have ground cables, pretty normal in Thailand and I don't plan to fix this. I am planning to add grounds to the inverter's AC loads.

Below is a video for the same switchboard box as used for my main switchboard, at the ~2:30 minute mark it shows how to connect grid wires to the box:
It clearly shows to wire grid neutral to the boxes ground bus, then to main breaker, that seems different to what my existing wiring is (and I understand is correct) to have the grid neutral go to main breaker, then bond the neutral bus to ground bus. Which is correct?

Is there any additional bond or ggrounding needed on the inverter or it's AC Out/inverter switchboard?

Is there any problem adding another main breaker (double-pole) in the inverter switchboard?