Running a 120 volt american yacht off 240v

[Paul71]

Hi guys, I've recently bought an American trawler yacht which has a 50 amp external socket. 4 wire lead (2 x 120v live, 1 neutral and earth.) The boat is in the uk and need to know how to go about connecting to 240v off the pontoon. Do I need a transformer with 2 x 32amp sockets then plug in the marinco shore cable with the splitter into that? Help!

[goboatingnow]

Originally Posted by Paul71

Hi guys, I've recently bought an American trawler yacht which has a 50 amp external socket. 4 wire lead (2 x 120v live, 1 neutral and earth.) The boat is in the uk and need to know how to go about connecting to 240v off the pontoon. Do I need a transformer with 2 x 32amp sockets then plug in the marinco shore cable with the splitter into that? Help!

A 230VAC to 50A split phase transformer is pricey but available

https://www.ato.com/5kva-split-phase-transformer

However while 16A 230 vac is common in marinas , only the fancy ones will have 32A 230VAC and many marinas will struggle with 16A. You cant parallel two 230 VAC systems together.

You’ll also need to ensure your 120vac appliances will cope with the different frequency of the mains

[ItDepends]

The short answer, is there is no cheap and easy way do doing what you want to do.

In some places marinas will rent transformers. A single 32A line at 239V will supply all the power you need (equal to 64A at 120V) but not in a form you can use.

For more expensive approaches there are several, and each has it’s own pros and cons. Will this boat be staying in the 230V part of the world? Or are you looking for a temporary solution?

[Paul71]

Yes the boat will now be staying in the uk. Everything aboard her is 120v and I think to rewire the whole boat and change all appliances will be more expensive and hassle so looking for a straight forward solution. This boat 56ft and has air conditioning which also does the heating etc so don't really want to replace everything.

[AKA-None]

Wouldn’t the simplest but not the cheapest be a massive inverter?

[Paul71]

Yes the boat will now be staying in the uk. Everything aboard her is 120v and I think to rewire the whole boat and change all appliances will be more expensive and hassle so looking for a straight forward solution. This boat is 56ft and has air conditioning which also does the heating etc so don't really want to replace everything. Nothing is easy is it.

[Paul71]

Yes maybe that would be the easiest option.

[ItDepends]

A large inverter (or bank of them paralleled) with a battery bank to run, and a large, voltage agnostic, battery charger disconnects you front the grid, and lets you have voltage and frequency as you like no matter where you plug in.

It’s not a bad solution, it’s just a bulky expensive one to enable operation of air conditioners and heaters.

[goboatingnow]

The charger invertor solution is very expensive at this type of power levels but it does provide the ability to use two 16 A 230VAC power outlets ( by using two battery chargers ) rather then relying on finding 230 VAC 32A outlets.

Can you get split phase inverters for boats ?

[skipperpete]

I had the exact same problem with a US built boat and only partially solved it by buying an isolating transformer with 240 volt input, I got the transformer built in Perth Australia and then wired it in where the original transformers were installed. These things are very heavy, around 350kg for a 14kva size ( to match the genset output). I considered getting a phase converting transformer but finally ditched that idea and replaced all the US 240v stuff...... aircons, stove, refrigeration etc. so the system remained with the live neutral for 240v and the rest at 110 v but I never felt at ease with this arrangement and actually had little signs printed to warn unaware electrician contractors that the neutral was hot.
During this adventure I was told that in Australia the boat would need to be rewired and it was suggested that the insurance company might have issues with live neutrals if it was aware of the situation.

[Hobiehobie]

So I have a US powered sail boat that will be heading to UK and other EU countries for three to four years. I have efficient solar and a genset so was thinking I can manage without plugging in, but it would be nice to do so when I leave the boat in sunless places. Are my options only those rather cumbersome solutions described above?

[AZUS]

I had the same problem when we sailed to the Med 5 years ago. A French electrician in Stuart, FL gave us our solution. We added a 230v shore power inlet, wired it to a new big charger and then to the batteries. We run everything 120v off of the inverter or the genset. It’s not as convenient as plugging in directly, but we avoid the voltage and to 50 vs 60 hertz problem.

[PaulCrawhorn]

A world-compatible universal charger being the only shore power connection, plus inverters to power all the AC loads is the cleanest solution.

Aircon and electrically powered heat sources are what makes it hard.

[TheOffice]

Our Hylas has a step down transformer, but it won’t convert 50 hZ to 60 hZ

[kaz911]

I ran my US 110v boat on 240v in the Middle East without any issues.

I permanently installed a Victron isolation transformer and it did the job well.

AirCon - many air-condition systems runs on any frequency. But you will loose 20+% of the nominal capacity going from 60 to 50 hz as the compressor turns slower. I did not have any issues with my old Dometic Aircon (as in production year 2008)

There was talk about brushless DC motor compressors which would remove the issue but I don't know if any have made it into production. There was also talk about Inverter based compressors. There is a new Dometic Turbo range that is open to both 50/60 Hz from "factory" but I can't see if they solved by DC Brushless or Inverter based operation.

Some (not all) microwave ovens will work. Most resistive loads will work (oven/cookers) but check labels and talk to an electrician.