Zwy
Solar Wizard
OK.... Sorry. Is this the diagram?
View attachment 86057
That one is confusing because the 'highlighted' current does not go through a load.
It is correct to say that there would be no objectionable current with a single 240 V load (or any perfectly balanced load).
However, with any imbalanced load there will be an objectionable current. (Unbalanced loads is the typical case if you have 120V loads)
There will be an imbalance with a 120V load, current will return to the source (inverter providing the phase).
In the diagram above, it's all messed up. It appears the poster is has connected 2 neutrals to each inverter. Have no idea where they get this idea from. I believe it is the poster that wanted to tie input and output neutrals together which is not approved by MPP.
The primary differences between the drawing I showed and the one above is that there is no Grid on the AC input and no xfer switch.
Not what is being discussed.