[wang_li]

If one is not modifying the house wiring how does this prevent backflow into the grid? Does it shutdown completely on power loss from the mains?

[eleventen]

The standard governing this is UL 1741 in the US or VDE-AR-N 4105 in the EU. both require certified inverters to detect grid loss and immediately cut off.

[trial3]

yeah, it’s called anti-islanding. UL 3700 is the thing to look at if you want to read more about some of the safety precautions