There are these:

60hz To 50hz Converter - Home Improvement - Compare Prices ...

You might get away with running your 50Hz epuipment directly on 60 Hz. Many motors are rated 50/60 Hz. Look at your specs. Remember if you do this your 50 Hz motors will run at 6/5 their "normal" speed. They may run hotter, too.

I suppose, one can get 2 phase 110 V supply which will provide 220 V. The frequency will require a solution. Don't they make motor-generator? The motor running on 220 V 60 Hz, (common shaft) driving the alternator, having rated out put 220 V 50Hz.

OOPS. Unless you can get 220V at the shore power outlet, you may need a transformer to boost the voltage to 220V. A motor/generator may be a better choice as Joshi said.

There is no direct fundamental problem, except for your fridge and AC if on board. Almost all the US Marinas have 120 N 120VAC 60 Hz.

They use Stainless steel 50 Amps Hubbell twist lock where 240 volts can be taken from. (L1 and L2)

Our Fairlane, an English Yacht has been used for 19 years like this. Run your fridge on DC or propane position and adjust the AC's a few degrees higher. Since most of the AC's in yachts are water cooled, the pump also runs faster and cools your condenser and compressor system more down too.

The opposite: US stuff in Europe calls for problems.

Loved most of your reply, it fits in well with my take on the subject, except for running the fridge on gas. Why do you recommend that?

Most camping and I would expect sailing (could be wrong!) fridges are absorption types....usually so that they can run on gas, 220volts and 12 volts when required. Also far quieter too. None of these care about the frequency, only about the voltage......they have a resistive heater.

Even AC, if the extra motor speed is a problem, could have custom made pulleys (maybe the manufacturer sells in the USA too! and you can simply purchase them...) fitted to slow the output down (assuming a belt and pulley are used!).

Thanks for any reply you care to give and have a great day.

thanks for all the comments.

Cruisair make a dual frequency model AC which I have now specified rather than the 50Hz model. Based on RAMConsult's suggestion I am following up on the Taylor Transformer solution as a permanent installation on the boat to get round the 220/110V issue in US.

Hi Andy, The Fridge has no extra cooling for the compressor and runs also faster and at higher speed. (@60Hz) On gas - I mean the propane gas if available, to not drain the batteries too much. It just depends on the circumstances. The (propane)gas tank drains also of course. A Fridge has a compressor on AC in most boats - hermetic type - no pulleys - direct drive. Since the OP gives no more details, I assume the boat is a yacht, but the little fridge in my 30 years old sailboat is also with compressor too. In yachts they put also house appliances. Take care. D

I really don't know what type of fridge is involved, nobody who really knows has spoken yet.

But, since when did a compressor fridge have a gas option? Please post a model/manufacturer which has such options and is a compressor fridge as well......

I only have ever heard of (but willing to learn more!) absorption fridges that are built to use either 12/24 volts DC, Mains AC or Gas....as I wrote previously......such fridges do not care about frequency as nothing turns...

Learn more here:-

http://en.wikipedia.org/wiki/Absorption_refrigerator

I have been unable myself to find a compressor fridge with a gas option with Google......

Thanks in advance.

Your statement is right. The unit in the sailboat is a Norcold fridge and has a double system: 2 evaporators and ditto circuits. Only one is to select. I have no more specs now and need to disassemble it to get to the model#. The compressor is a DC 12 Volts type that also runs on 120 Volts AC (power supply built in) It doesn't care too much even when it is powered by both. I guess the power supply even charges the batteries a little. The propane is with a typical pilot flame, piezzo ignited and fed from the same low pressure line as the hot water heater.(Geisher type)

I found their website here:-

Norcold Inc Refrigerators

I was not able to find the exact model as you didn't mention it, but that is an very unusual configuration to my mind.

As the manufacturer is in/from the USA, I am sure that you will be able to buy replacement pulleys for 60Hz easily, assuming for the moment that they are even needed.....I somehow doubt it!!!

PDF Manuals are available as downloads, to help you further from the same place, under customer support.

Most of the marinas I've been to in the Northeastern US usually have a 30A 110V and/or a 50 A 220V outlet, a quick call to the ones of interest and you'll know. They often have adapters for nonstandard plugs as well, but I would check what your plug is and make up an adapter pigtail just in case. The frequency is the potential problem, especially if your craft doesn't have 50/60 Hz gear everywhere, but that is easily solvable without checking every single device. Just use shore power to charge your batteries and run everything off them, this only requires a charger that will handle both frequencies so there's only one thing to check.

If you're going to be in a marina that only has 110V then check out this article for a marine ready 110/220 V transformer. I know the article is for US boaters going to Europe, but the ideas presented should help you:

http://www.libertysails.com/html/modifications_.html

Where is the 220 Volts? I thought 120 Neutral 120, which gives you 240 Volts?? In a 3 phase Marine, probably also 208 Volts.

Most items will run satisfactorily. The exception being clocks with synchronous motors and those that count the AC line and compute the time. Both of these will run the ratio faster.

Transformers will work OK, the higher frequency means less heating in the iron etc.

The lower voltage of 220 versus the UK 240 is about 10% low, but should not be a problem for most uses, since most equipment is made to tolerate 10% line variance or more.

If the marina you are in gives you 190 volts, might be a problem.

Take care with the grounding, to make sure you do not inadvertently have a problem. Often a 5 KW step up/down transformer with line variation taps will solve the problem with using shore power and by care with the loads you can stay within the 5000 watts of the cheaper transformers.

Avoid an autotransformer - it does not offer ground isolation, but it is cheaper..