Leo, Do you Know what the Gird is? Do you want to know the truth?
The answer, the number 60. As in 60 Hz.
The voltage is 120 or 230.
So, as I've said before, if you can
trick the GTI into thinking it's
connected to the grid, then it will work..
That's why the 12Vdc-to-120Vac inverter needs to have a pretty clean output.
I'm pretty sure that my little modified-sine-wave inverter would NOT work.
But I'll bet an old UPS (computer back-up Un-interruptable Power Supply) would work just fine.
And, it has it's own LA pack!