Disconnecting the neutral wire simply completely disconnects the house system from the power company system. The house system is still grounded via its own ground rod. As I mentioned in another post, I also have a ground rod that I attach the generator ground to. Disconnecting the neutral wire that comes into the house from the pole does not create an unsafe condition when the load wires are also disconnected. The house is a stand alone system with its own ground that is connected to the house neutral at the panel