Converting A/C system to US from Singapore

If the boat is configured for Singapore are the a/c units not already 230VAC?

If they are, try them on 220/60Hz before trashing them. The volts/Hertz ratio is actually less so saturation and overheating is not an issue. The motors will run faster on 60Hz but that shouldn't bother the compressor or fans. It's worth trying before committing to a very expensive replacement program.

You definately do not want to run the compressors on 110v. They will draw too much power, requiring an upgrade to the supply, cables, breakers, etc. Also an upgrade to the shorepower requiring possibly two 50amp cords. I am not an expert on these compressors but i would feel safe in assuming that they are 50hz only. They are more then just a motor, it is possible that the compressor will overheat from running too fast, or the gas will freeze over. Somebody else can clarify this, but its not wise too deviate from the manufacture name plate.

Paneltronics can custom fabricate whatever you like, 240/120V, just provide dimensions and breaker poles and sizes. i can provide contact information for the factory in Miami.

As for the convertor look into A/Sea, they make compact frequency convertors. A 12 to 15 Kva unit would suit you well. Also provide the vessel the ability to get shorepower anywhere. charles makes a nice isolation + boost transformer but will not convert frequency, that I know of.

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I get you Marmot, the gas wont freeze, but the lines will. Point is to follow the manufactures label. If the name plate says 50Hz only dont run it on 60Hz, unless its yours on your workbench.

The only way the lines will "freeze" and by that I must assume you mean that ice will form externally or internally, is if in the latter case there is moisture in the refrigerant, and in the former, if there is evaporation taking place in the liquid (exceedingly unlikely) or vapor lines. In either event, increasing the rotational speed of a scroll type compressor compressor is irrelevant.

I stand by my suggestion that rather than trash a functional air conditioning plant just because the dataplate says 50 Hz (I doubt that it reads 50Hz ONLY), supplying it with 60 Hz at the proper voltage (230 in Singapore - 220 in the US) and monitoring the operation is a valid approach.

I am very very skeptical about that claim. If the unit uses a scroll compressor as is highly probable, the 20 percent speed increase is not going to destroy the unit very quickly if at all. Cruisair just finds it safer to say no than to have to fight your claim later if the unit fails for some reason.

They are your units and unless you have someone waiting to buy them as is, what are you going to do with them? What is a used 50Hz unit worth in your local market? What is it going to cost you to recycle them?

If they were mine I would run them on 60 Hz for as long as they last. If it's only a couple of seasons then so what? Who knows, you might get a long run out of them before you have to replace them, one at a time as they fail, if they ever do fail.

Yeah, I understand now. I thought it was your boat, poor reading on my part.

It's a shame because it is going to cost the customer big bucks. Nothing to cry about though, the profit is there for you, and the customer has warranty protection.

Every Searay I've ever run that had a 50amp 220 volt shorepower cable coming into the boat, had all 220 volt a/c's. It would be perfectly acceptable and the prefered way to go to put all 220 volt a/c's in the boat. It also would be the preferred way by ABYC standards as 4 a/c's at 110volts would overpower the shorepower coming in. I would not put 110 volt units in by any means.