OCC Forums

Ship to Shore Adapters for US vessels in Europe


By Gianluca - 28 Mar 2013

In my planning to cross the Atlantic to Europe, I was thinking how to deal with plugging my cable to shore. I use a 50A 230V cable and, I have not been able to find an adapter for European docks. Do you know if the marinas have adapters to lend? or, do you know if there is a place to purchase them?
Your help is appreciated,
By dcaukill - 15 Apr 2013

Sockets in most marinas are standard blue three pin 16 amp or 32 amp connections. 50 amp in super yacht berths. In case mine dont fit (e.g in some places inDenmark) I carry a pig tail to connect to the end of my cable with bare wires to wire into a local plug that you will be able to get at a chandler locally.

You need to keep an eye on frequency. And ask before connecting. As you probably know the USA is 60hz. And most of Europe 50hz. It if you plug (as I have) a 50Hz item into a 60hzsupply you risk trashing It. Applies to motors and microwaves esp.
By alshaheen - 29 Apr 2013

Hi Gianluca
As David has said you will need a European blue male 3-pin plug, either 16 or 32 amp. If you like I can buy one for you here in the UK and deliver it to you in the Azores when we meet. You can then fit it to your power cable in place of your US 50 amp plug. Alternatively, you may be able to buy in the US an adaptor with female fitting to mate with your 50 A plug and having a male European 16 or 32 A to fit marina sockets. Bear in mind that with a 230 volt supply the current will be half that of a 125 volt supply. If you have the wrong size plug most marinas will loan you an appropriate adaptor 16A/32A or vice versa.
By ka4wja - 1 Jul 2013

I assume you 've already left the US for Europe, as your question was posted 3 months ago, but just in case you haven 't departed or even more likely that others facing your dilemma will find this helpful, please read over this brief posting....
Do NOT try to plug in a boat with a US (North American) "220" (or 230, etc.) system, cord, plug, etc, into a UK/EU 230 volt shore power!!!
It will NOT work!!
[quote="Gianluca" post=870] In my planning to cross the Atlantic to Europe, I was thinking how to deal with plugging my cable to shore. I use a 50A 230V cable and, I have not been able to find an adapter for European docks. Do you know if the marinas have adapters to lend? or, do you know if there is a place to purchase them?[/quote]

1) First off, you can buy the 16-amp and 32-amp UK/EU marina plugs in almost every chandlery, marine store, and marina office....(as well as in hardware, electrical, and RV / Caravan stores.)
And, you 'll fall in love with the smaller, lighter, and easier-to-handle UK/EU 230vac shore power cord...(I made mine while still in Florida, and just added the appropriate plugs when arriving in Horta, and then again in Gibraltar....)
But, this does NOT solve your problem...

2) US, Canada, Mexico, etc. and most of the Caribbean, use the US standard "110 volt" / "220 volt" system....
(the actual voltages have been almost universally 120-125 and 240-250 volts for the past 40-50 years, but the old "110" and "220" nomenclature is still used....although in various countries in Europe, there ARE various voltages from 220vac to 240vac, but you can just use 230 volts as the norm)

This US / North American[b] standard, is a single-phase 110/120/125 system...and a dual-phase 220/240/250 system...
The US "220" (or 230, or 240, or 250, whatever you wish to call it) is a DUAL-PHASE system, with two "hot" wires, with each "hot" wire carrying about 115-125 volts AC (referenced to the neutral/ground) in opposite phase to each other....and giving you 230-250 volts AC across the two "hot" wires...

This VERY different than the UK/EU standard, which is a 230 volt AC single-phase system, with ONE "hot" wire, carrying 230 volts AC (referenced to neutral/ground)

You CANNOT plug he UK/EU 230 volt system into a US standard "220" boat, it does NOT work, and will trip breakers, burn out equipment, and cause many to become instantly angry with you!!
Do NOT even attempt this!!!

You MUST use a transformer to convert the UK/EU 230vac single-phase down to approx. 115-120vac single-phase, and feed your boat with this power...
You can use the transformer output (115-120vac) to feed both sides of your boats AC electrical system (assuming that you do NOT have any actual "220 volt" appliances on-board (such as a big SCUBA compressor or LARGE Air Conditioning Units), as most "220" boats have basic "110" appliances, including Air Cond, etc....

3) You can do little about the AC frequency difference, 50hz in UK/EU and 60hz in US/N. America....but luckily most appliances work on both...
Although some motors will run slower and a bit hotter on 50hz, they usually work fine....

Ironically some (very few these days) small electronic devices will not like the 50hz frequency...

4) There are various way to use UK/EU power on board....
a) I chose a 5000 watt (4000 watt continuous duty) transformer for my boat...and it worked perfectly...(even ran my Air Cond units at the dock in August in Gibraltar!)
See photos here...

b) Fellow OCC member Jack Tyler wrote a great synopsis of what US/N. American boats need to do in order to be prepared for UK/EU live-aboard life....
Have a look here at his site...


c) The smaller, lighter UK/EU 230vac shore power cords are a dream to use....
I made mine in Florida, before I sailed for Europe, and simply bought the appropriate plugs when I arrived in Horta (16-amp)and then later in Gibraltar (32-amp)....

I do hope someone finds this information useful...

Fair winds.

s/v Annie Laurie
By HARALDSAMMER - 18 Jan 2014

I must admit that until today I hadn 't noticed that the OCC has a forum and to my surprise it is quite lively and I read a lot of interesting contributions. Now, when I came across this shore power question I realised that I hadn 't seen another quite comprehensive solution to the world wide shore power problem. It is probably too late for Gianluca who posted the question 9 moths ago, but as it is a reoccurring topic, let me propose another approach:

High power, almost loss free semiconductors have revolutionised the power supply world in the last ten years. It brought us hi-power inverters, that give you perfect sine wave, exact frequency and stable AC voltage at affordable prices. Some are even able to synchronise with other AC sources and help out with additional power in peak demand situations. 3.5kW per inverter is common today and if you need more you can run more than one in parallel.

What I 'm trying to say, that inverters can meet the AC power demand on most boats, even if you are cooking electrically or run a few air conditioners. What this also means is, that you don 't need to take in shore power to your AC appliances directly. All you may need to care about while docked, is that get the equivalent electrical energy that your are using in average, into your boat via the shore power connection. Your peak demand may be quite a bit higher, than what the shore supply can deliver.

Now all you need is something that 'eats ' about anything that the shore supply brings to you, and that could be quite ugly in some places.

Here are some different ways to achieve it:

(1) Combine a hi-power battery charger that provides for a wide input rage with a powerful inverter. Besides the above mentioned benefits you also get a perfect galvanic isolator from shore.

Chargers that take a wide range of input voltage and frequency are available fro several good sources. An example would be a Mastervolt ChargeMaster. It takes input from 90V to 265V and Frequencies from 45Hz to 70Hz. Note though that the actual input ranges are 90V to 135V and 180V to 265V with a gap in between. That is because the range in which the switching power supply can transfer the proper amount of energy is limited and it needs to internally switch its windings to cover the full range. It also means that for example 160V would not work. But that is only a small deficiency that shouldn 't bother any of us too much. Whatever is in the two voltage ranges will be rectified and then converted to an AC of a much higher frequency to keep the transformer small.

These type of chargers have just to AC input wires that are equal and isolated from anything else (ground and output). They do have a ground wire connector, but I would connect that one to ships ground and leave the shore side ground wire alone. When you connect to shore power, all you need to do, is to connect these two wires to whatever you find on shore power, regardless of 'polarity '. You may run these through an RCD and breakers if you don 't trust your charger. The RCD would notice current diverted to your ships ground by a faulty charger. Galvanically you will be completely isolated from the shore power and fancy chargers will tell you what they see on their input, less fancy ones will just quietly eat what you feed them.

While your Inverter will give you perfect AC at your required voltage and frequency, the charger will bring in the DC required for the inverter, up to the limit of the charger or shore power, eventual peaks would be supplied by the batteries, which would quickly recharge afterwards.

All you need then is a bucket full of adapter plugs for around the world.

(2) Using an Inverter Charger Combo device. These have become quite popular as they use less space and are usually somewhat cheaper then two discrete units. But they have a live of their own and it might be hard to find a unit that does everything the way we would like. Most of these sense if there is shore power present and then switch that through to your AC system. In addition they can power assist when there is not enough shore power. Luckily on many units you can configure them to keep things separate and then you have the same as in version (1). One other issue with combos might be, that they are hard to get for such a wide input range and that you have to specify either 120V or 230V. This may work worldwide if your bout AC system is for 230V, since you can just connect to phase wires to the input while you are in the 120V world. But it would be hard to find a solution for 120V boats. Obviously the boat electrics companies have not seen that marked and use yet, or they think it is too small to bother.

(3) The, same is true for all the electronic isolation transformers that I had looked at. Let me first explain what that is: A line frequency isolation transformer consists of a lot of copper and iron and is very heavy. The size or weight of a transformer is roughly invers proportional to the frequency. So 60Hz transformers of the same wattage are a bit lighter than those for 50Hz, and that is why 60Hz transformers may have some trouble with 50Hz, the other way round usually works.

Electronic isolation transformers use frequencies 10 to 20 times higher and are hence rather small and light. But it needs additional electronics, much like in an inverter charger unit, to first rectify the incoming AC convert it to higher frequency AC, run it over the transformer, rectify it again and then switch off from the DC the desired AC. The difference to an inverter charger is that they just have one transformer step and hence a somewhat better efficiency.

While they certainly could convert voltage and frequency to your desire, most units on the market are built to just fake a real transformer. This means they sense the input voltage and frequency, (if it is a bit off, they will make a guess on what it is supposed to be), and then copy this on the output. It would merely be a change of the internal program (firmware) to provide your choice of voltage and frequency on the output. So this may be reality soon and would also be a quite attractive solution.

On the other hand, since you need a charger and inverter anyway, (1) or (2) might be more pragmatic.

A last word on efficiency: Certainly, going direct from shore power to the appliances has the least losses and even a real massive copper/iron isolation transformer delivers an efficiency in the upper 90% range. Looking at modern chargers and inverters, both are around 93% effective and coupling the two would get you some 86%. 14% would heat your engine room. I personally think that is a relatively small problem.
By simoncurrin - 18 Jan 2014

Thank you for a comprehensive post and welcome to the OCC Forum.