We have an off-grid UK home on occasion powered by a generator (MOSA GE 6000).

Due to the design of the generator, it has two modes: centre-tapped-earth 110 V, and 230 V.  When running in 230 V mode, the two windings in the generator are connected in series; in 110 V mode, the windings are operated in parallel.

The result is that when the house is powered (generator operating in 230 V mode) there is 50 volts between the neutral and earth, and 180 volts between the live and earth.

I am told by an electrician that the neutral should be 0V (tied to earth) while the manufacturers of the generator unsurprisingly say that 50 volts on the neutral is fine.

**Which is correct?**


System Diagram 
[![generator diagram][1]][1]
Note: Generator is connected to earth by an earth stake connected to the case.

Portion of internal circuit diagram of generator:
[![enter image description here][2]][2]

Note 1: BL=Neutral (230V), BR=Live (230V).
Note 2: The manufacturer added that the two windings are: connected in series when the generator is in 230 V mode, and connected in parallel when in 110 V mode.


  [1]: https://i.sstatic.net/svf0t.png
  [2]: https://i.sstatic.net/opw1s.png