Generator Polarity

Robmoo wrote:
Had the same thing on my Ryobi inverter generator. I cut the 110 to the house and connected the generator and suddenly the polarity was correct. When I connected the generator to the house I connected it to the house ground. The generator detected this and adjusted. This is the floating neutral feature. Try running a ground stake connected to the ground screw and see if the generator doesn't adjust and correct the issue. Generally AC devices with run fine no matter the polarity. In a house it can generate safety issues so it does matter. In your RV it is probably fine.

It actually doesn't automatically detect anything; it's just that the neutral and the ground terminal are not connected together in any way in the generator. Neutral (and hot) are free to float to any voltage relative to the rest of the world.

It works when hooked up to your house because neutral and ground are bonded together in the main electric panel of the house as per code.

Note that bonding and grounding are actually two completely separate things. Bonding just means that the two prongs/wires are connected together at one point, basically the source for the system, so as to provide a low-impedance path for current to return in the event that something is improperly shorted to ground (and thereby cause the circuit breaker to trip and the current to shut off). Grounding, on the other hand, means tying the neutral voltage more or less to the voltage of the surrounding environment so that it doesn't tend to be way off comparatively and cause a greater shock hazard. This is more important the larger and more spread out the electrical system is. A portable generator powering a hand saw or whatever is not a very large electrical system.