Different Shore Power Question

[Grinna 2]

While we're talking about shore power connections, here's a question that has been rattling about in my head for a while.

 

Let's say a hypothetical Kiwi boat goes travelling to other parts of the world. The 240V AC power distribution system on this hypothetical boat is of EWOF standard so connecting to marinas in Australia say is no problem. Places like Fiji use the same 240V system so that's OK, but what happens in places that run 110V power systems (like American Samoa, Hawaii, mainland USA, etc)? Will a 240V battery charger still work on 110V power supply? What about 240V appliances plugged into outlets being supplied by 110V? Will they work? Is it safe?

 

Presumably a 110V boat wouldn't be able to connect to 240V system without serious issues. Do travelling boats just avoid connecting to different power supply systems?

[Guest]

240V can be achieved in 110V countries by connecting between phases instead of phase & neutral. The main problem occurs with 110V boats in 240V countries. The best and most common option nowadays is duel voltage input charger and inverter for boat supply. A lot of modern appliance are duel voltage input anyway, PCs laptops etc.

[wheels 543]

The main issue you run into are the types of plugs in use around the world. India ain't so bad, you just throw a wire over the overhead lines above

Most all countries around the world generate using a 3 phase system. Knowing you are going to get three phases on the Marina could be a little more dicey. But as Pete said, the higher voltage comes from between two phases. Only problem is, that countries that use 110V, will only give you 200V ruffly. Many of those countries have ramped the volatge up a little now to 115 and 120V and that results in the 220V between phases. You will not get 240V anywhere that uses the lower voltage system. Lower voltage systems also tend to operate in the 60Hz mode. So for any 240V device that has a transformer, the tranny will buzz more and get hotter. One more reason why more and more devices are going switchmode now. Dual volatges, frequency doesn't worry them and no heavy transformer.

Some boats used to have step up and step down transformers. But they are heavy and bulky and expensive and mostly it is done with the phases and the plug types now. Most other countries, other than Oz and NZ are farmore relaxed about their electrical laws and it is easy to muck around with wiring your plug.Providing you know what you are doing of course.

[smithy09 50]

Ahhh beware the 220Vac, 2 phase trap grasshopper.

If you do this, you need 2 pole breakers, and you cannot earth your "neutral" in any way.

In NZ, if you grab hold of a neutral wire and dangle your feet in the water, you are reasonably safe. No shock.

Try it with the 2 phase system from a 3 phase supply in 110V countries...

One of the common faults we find offshore is that containers have been wired with single breakers and MEN (multiple earthed neutral) systems. If they have a linked earth and neutral bar, the container is immediately live!!

I have rewired a few container panels because of this...

Also 60hz makes motors run faster. If you just transform the voltage, the motors run 20% faster. Stuffs up aircon motors in about 3 months...