Confusion reigns.
I suggest you look in the mirror.
Note that while this auto-transformer has UL listing, that was not as part of a system with this inverter. Just stand-alone.
There is neither UL listing nor a licensed PE's stamp for the configuration shown.
(A design could be correct and safe without those, but this particular design I and others have found safety issues with.)
Consider again at the Inverter/Autotransformer schematic.
What happens if a fault from line to ground occurs at either of the two locations shown?
I say that chassis of inverter, and ever ground wire and component, is now driven to 120 Vrms relative to Earth.
You may have a ground rod driven where the ground symbol is shown. Service entrance also has one. There will be what, 25 ohms between those to ground rods? So 5A flows. The Earth near your ground rod is raise to 125Vrms, but elsewhere is lower.
If you touch anything grounded to your system, and you touch anything else grounded like a water pipe or gas stove, you get a shock.
Why do you think this use of an autotransformer is OK?
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