By the way, I finished my testing and am back to the grid tied mode. There is an important reason:
When in off-grid mode, I took some measurements around the house and realized high voltages between neutral and ground. Also all the neutral wiring became live. The thing is SUN2000 probably does not do an automatic N-G bond in off-grid mode (apparently some inverters do) and since the main grid breaker (dual pole) was open, I basically lost my N-G bond from the utility (because neutral line gets broken when main breaker is open).
So if you're gonna run off-grid permanently, you should make sure you're grounded properly. Probably you'll need to create your own N-G bond in your house electrical panel.
When in off-grid mode, I took some measurements around the house and realized high voltages between neutral and ground. Also all the neutral wiring became live. The thing is SUN2000 probably does not do an automatic N-G bond in off-grid mode (apparently some inverters do) and since the main grid breaker (dual pole) was open, I basically lost my N-G bond from the utility (because neutral line gets broken when main breaker is open).
So if you're gonna run off-grid permanently, you should make sure you're grounded properly. Probably you'll need to create your own N-G bond in your house electrical panel.