220v 2 wire 50hz to 220 3 wire usa transformer

A 120 to 240 v transformer is probably what you need, taking US 120v input and outputing euro 220v. I ve done this with a french appliance a few years ago. It was only 1500 watts but they come in bigger sizes

It depends on the appliance. He said that according to cruisair running his 50Hz system on 60Hz isn’t a problem.

back in 80a/90s I lived on St Barths where power was French 220v but 60hz. Everything worked fine except electric clocks which were 20% faster…

I'm not sure witch way your going, From Euro to NA or NA to Euro.

Most AC compressors will work on 50 AND 60 htz. Just the performance will be a lil low on the 50HZ.
I'm sure the later controller boards will work 50/60 htz also.
Later compressors can run on 208 to 240 Vac.

You typed for the A/C only.
Neutral or 115Vac is not needed. So you can stay just 2 wire to 2 wire.

From Euro to NA, using 115VAc options is going to be a task.

It is hard for me to wrap my head around this, Euro is neutral then 230Vac? Your fault current goes out on the bottom of the 230(220)v leg?
So for NA, You have to transform a 230Vac to 230Vac with tap, isolate your Euro fault current lead to NA neutral for fault current path?
Sorry to distract your thread with my questions.

Euro 220v is like our 120v, 1 hot and 1 neutral except that the hot is 220v not 120v.

so yes, connect 120v to the transformer and you will get 220v at the output which can be connected to the boat.

going back to my youth on st barths, to connect a US washer and dryer to French 220v took 3 heavy duty transformers. I think they were 5 KVA. One was used to power the washer by stepping down a 220 feed to 120v. Then the other two were used to step down two separate 220v feeds on opposite phases to two 120v still on opposite phases which resulted in US 240 for the washer…

Dockside GFI can’t trip when using an isolation transformer since neutral isn’t used.

that said, if you have this on the boat, then you should be all set as it is outputting the euro 230v you need

as much as we all try to help, missing details in questions make difficult.

I never thought about where the fault current (ground/neutral) path was.
Here in the swamps we don't think about this that often.
Thx

Inverters intake DC and output AC. You can’t hook up shore power AC to an inverter.

Pascal, actually not only you can, at least with Victron inverters (which are very popular in Europe), but you should.
In fact, they are designed to work also for topping up shore power in the event of peak loads, adding AC generated from the batteries.
To provide this functionality, shore power must be wired to the inverter(s) first, with AC passing through the inverter(s) before going to the onboard AC circuit.
This way, if for instance you have only 32A or whatever available from the dock, you can set that limit for dockside drawing, avoiding to trip the pedestal breaker.
And whenever more than 32 amps of AC is demanded (typically, upon airco compressors startup), the inverters add it to the dockside 32A by drawing currrent from the batteries.
At least, up to a limit - that can also be set, obviously.

That said, the thread subject is actually different, and involves something (voltage + frequency conversion) that I don't think the Victron inverters I have in mind can handle.
But they are very sophisticated units, with plenty of functionalities aside from the one I just explained, so I wouldn't be surprised if there's something they can do that I'm not aware of.