50amp - 120vac on Neutral

[Ultimarv]

We have finally installed our Victron Autotransformer 32-amp (240v) to connect a USA 50-amp when in Europe.

Our tests directly after the stepdown transformer shows:
Leg1 + Neutral = 120v
Leg2 + Neutral = 120v
Leg1 + Leg2 = 240v
Neutral + Ground = 120v (normal USA shore should show 0v)

The 120v on the Neutral concern us since this would be an open neutral situation on stateside shore power. We have been told this may be normal with the Victron since it produces it's own floating neutral. We have also been told to ignore the reverse polarity light on our onboard status display.

Any reassurance or contrary knowledge concerning a floating neutral produced by the Victron?

[S&S]

120V to ground is still 120V. I'd bond it to ground. A floating neutral will kill you just like a hot would.

[DeepFrz]

Get in touch with Victron support and get the answer from them.

[djmarchand]

I discovered that on a Charles Industries isolation transformer on my Mainship 34T that the ships ground was open. Looking inside the tranformer I saw that the ships ground was terminated to a case connector but the case connector was never connected to neutral.

The NEC and maybe ABYC require that the ground and neutral be tied together at one point- the source, in this case the secondary of the tranformer. I talked to Charles and they said that they never deliver the transformer with the neutral/ground tied; it is up to the installer. In this case Mainship didn't do it. I tied the neutral and ground together and my open ground problem was solved.

Why you are getting 120V between the neutral and ground (obviously they aren't tied) is that you have a bit of leakage into the neutral. A little is ok unless it trips the GFCI protecting the galley outlets.

So tie the neutral and ground and see what happens.

David