DrewZA

Sorry, if its directly bonded this measurement is not necessary.

I don't think the generator in question is V-0-V. I think it was unbonded, but it had some kind of filter on it that causes the voltage to settle in the usual manner about halfway on either side.
The lamp was a way to test. If it was an actual V-0-V generator, it would be able to push significant current on one of the "115V legs" and the lamp should light up dimly. Instead the voltage pulled right down, indicating that it is not a V-0-V generator.

I am confused? That is not what he is doing. He has an inverter generator, he is not moving the center tap, there is none. He just used the bulb for testing, and bonded neutral to earth after testing - direct connection. I believe it only seemed to be a V0V generator due to the output filter, a floating ground and the measurements he took.

With the neutral bonded to earth at the inverter output, it is no longer V-0-V...
N-E=0V
L-E=230V
L-N=230V
Please advise how it will differ from a standby genny @phil.g00?

Also just keep in mind, if you do bond neutral end earth on the genny and take it to your earthing point, make sure your neutrals are also switched through your change over.

Well, here is an idea. Wire a 230V incandescent lamp, or something around that wattage, between neutral and earth. If the lamp actually glows dimly, and you can measure 115V across it, then you have V-0-V setup and you can't bond it. If the lamp fails to glow and you read zero volts across it, then the floating you see is a result of a filter or something else that creates a voltage divider.
Basically, the trick is to bond neutral and earth through something with a bit of resistance, that can also dissipate the power should there be any. That way, if it is indeed a V-0-V setup, you're not shorting out half of it.
Edit: Oh wait... I see it's already been suggested above 🙂