European - US shore power

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zeta

zeta

Member
Joined
Apr 26, 2012
Messages
11
Location
US
Vessel Name
Zeta
Vessel Make
Diesel Duck 41-Plus
We have a vessel that was built to European standards. We are wanting to use US (4 wire) 240v shore power on the vessel that is European (3 wire).
There is nothing on board that is voltage or frequency sensitive.

The other item that we are trying to accomplish is a step up transformer to increase the 120v shore power (it powers a battery charger, then the batteries run a 240v inverter) to 240v.
 
Here is a link to step up-step down transformers. Step Up Voltage Transformer Converter - Step Up/Down Voltage Transformer, Step Down Transformer, Step up Transformer, Step up Voltage Transformer, Step UP/Down voltage converter/Regulator, step up and down voltage converters

USA 240v 4 wire power has two hot wires with 240volts between them, a neutral, and a ground. Using the two hot wires you get 240 volts, using either of the hots and the neutral gets 120volts. The ground is a safety ground.

You can try google search on the terms 'step up transformer 120volt to 240 volt'
Another google search would be 'convert usa marine electricity to european marine electricity'

Hope this gets you started in the right direction.
 
zeta said:
We have a vessel that was built to European standards. We are wanting to use US (4 wire) 240v shore power on the vessel that is European (3 wire).
There is nothing on board that is voltage or frequency sensitive.

The other item that we are trying to accomplish is a step up transformer to increase the 120v shore power (it powers a battery charger, then the batteries run a 240v inverter) to 240v.
Click to expand...
The circuit breakers are frequency sensitive. and maybe the plugs look different?
 
I understand the differences between the two methods of supplying shore power (US vrs European). At this time there are no CB's until the system gets to a component (this was one of the "dings" that showed up in the purchase servey, no CB for either the 120v or 230/240v shore power connections within 10 feet).

There is already a 120v shore power connection that supplies power to a battery charger (that is all it does). The battery charger then supplies 24v DC to the batteries and an inverter that supplies 230V, 50hz to the vessel.

As stated, there is nothing on the vessel that is not able to operate on a 230-240v, 50-60hz range.

Ideally, the step up transformer would be able to supply 30 Amps (this is what the vessel is set up for) when going from 120v to 240v.
 
A circuit breaker should not be sensitive to frequency. It's not even sensitive to the difference between AC and DC. It measures current flow, that's all.

Two thoughts:
1) This is probably a job for a qualified marine electrician. Electricity and water do not play well together so everything needs to be "by the book"

2) If you're going to keep and use the boat in the USA, I suggest converting everything to use the power that's commonly available in the USA. Running everything from batteries and an inverter is pretty inefficient and a battery or inverter failure leaves you without power.
 
zeta said:
We have a vessel that was built to European standards. We are wanting to use US (4 wire) 240v shore power on the vessel that is European (3 wire).
There is nothing on board that is voltage or frequency sensitive.

The other item that we are trying to accomplish is a step up transformer to increase the 120v shore power (it powers a battery charger, then the batteries run a 240v inverter) to 240v.
Click to expand...

The concern is the sizing of the wire. If the wire was truly sized for 24 volt DC it maybe to small to handle 12 volt DC. Watts= Amps X volts, so if the volts go down that amps go up. So make sure the wire is sized for 12 volts DC. :confused:

Also, I don’t think you can combine the two lets of 120 volts AC to make One leg of 240 volts AC. In all application I have done/see the two legs are kept separate. However, again the wire sized for 240 volts may not be able to handle 120 volts AC. watts=amps X volts. :confused:

Before you start changing things contact a Marine Electrician. When buying a boat out side of the US make sure it the elecrrical can hand the US electrical. We sell machinery world wide so the electrical is has to be clarified so we buy the correct motors and controlls.
 
Volts and amps

We are getting a bit lost here. We are not trying to change any voltage in the vessel.. It will stay 24v dc and 230/240v AC.

We are trying to step up the 120v AC when that shore power is used to the vessels 230/240v AC needs.

Then with a separate shore power source supply directly 240v AC.
 
zeta said:
We are getting a bit lost here. We are not trying to change any voltage in the vessel.. It will stay 24v dc and 230/240v AC.

We are trying to step up the 120v AC when that shore power is used to the vessels 230/240v AC needs.

Then with a separate shore power source supply directly 240v AC.
Click to expand...


You can buy a converter or a transformer that will step up 120 volts to 240. http://www.220-electronics.com/Transformers/trans/prod.html Keep in mind the converted amps/volts ,the wire size and fuse size required.

It would best to know if the wire is sized for 12 volt DC and/or 120 volt AC?
 
Let me see if I can make this clear;

All the AC appliances on your boat run on 240 volt AC. All the DC appliances on your boat run on 24 volts DC.

The boat is wired for 140 volts AC and 24 volts DC.

That's fine if you're at a marina that offeres 240 volts AC after you have an electrician change your shorepower inlet and possibly the wiring to the main panel.

You want to install a transformer so you can use your 240 volt appliances at marinas that only offer 120 volts AC shorepower connections.

Am I close?

You need a transformer that will input 60 amps AC at 120 volts and output 30 amps AC at 240 volts. I've never seen a marina with 60 amps at 120 volts, the most I'm aware of is 50 amps so you're only going to get 25 amps at 240 volts.

If you're satisfied with pluggung things in, you can find the transformer and cables. If you want something automatic or switched, you better call in an electrician. I would be looking for something industrial or marine, something that will stand up to the salt air and vibration in a marine environment.

I don't think it will be lightweight or inexpensive.
 
Just about right...

The vessel is wired for 24V dc and 230V ac. There are two shore power connections.. one 120V ac (3 wire) and one 230V ac (European 3 wire).

The 120V shore power supplies power to a 24v dc battery charger, and that is all it does.

The batteries supply power to an inverter that produces 230V ac, 50hz power to the vessel.

The 230v shore power was used in Europe to supply power directly to the vessel.
 
You might consider simply purchasing a modern batt charger.]

Some will accept most any input 120v US or 230V euro and still work fine.
Matervolt , and Charles should be looked at.

FF
 
rwidman said:
A circuit breaker should not be sensitive to frequency. It's not even sensitive to the difference between AC and DC. It measures current flow, that's all.
Click to expand...

rwidman, what is the difference between the 50 and 60 hz circuit breaker panels? The only reason I ask is that I found one for sale that was cheep but it was 50hz euro design. They said it wouldn't work.
 
There are breakers that are specific to 50 Hz or to 60 Hz and cannot be interchanged safely. There are breakers that can be interchanged. The new BlueSea breakers that I just purchased can be interchanged.
There are breakers that are specific to DC or AC and breakers that can be interchanged. DC breakers need beefier contacts and larger air gaps for the same current and voltage. Especially true at the higher ratings and should not be interchanged unless clearly marked.
Carefully reading the ratings labeled on the breakers and using the appropriate ones is your only safe option.
 
There are speciality circuit breakers of course, but when you go to the marine store to but a circuit breaker for your boat, it will be fine for AC or DC, and aany normal frequency.

BLS7210_detail.jpg
 
It is not the battery charger that we are concerned with. There are two battery chargers on the vessel. One for the 120v and another that is a charger/inverter that is 240v (accepts the 200+V range).

What we need is a method of connecting the US 240v four wire system to the European three wire system.

Blue Sea Systems carry's CB panels that are specified as European for 50hz. These can be seen on their web site: bluesea.com
 
Zeta, you have received enough conflicting advice, that if followed, will insure your boat will burn. Dependent upon where the vessel is located there should be a good marine electrician who works for a reputable firm and is experienced at how your problem best be solved. It cannot be done over the internet unless you have drawn up an accurate line diagram, and even then you have no idea whether the advice you are receiving is accurate.

This is not a new question or a unique set of circumstances. Boats travel from NA to Europe, Latin and South America and the South Seas every day. As R Widman suggested, get a good marine electrican/firm engaged. Where is the vessel located?
 
I do not "follow" any advise without verification. In part, that is what we are doing. The situation has already been looked at by a firm in Ft. Lauderdale. They provided a wiring diagram. But even "experts" can be wrong, thus the verification.

Some good, some bad advise is found on the internet. It is always a place to start when doing research.

The vessel is working it's way to San Diego.
 
You will have no problem finding reliable and experienced dual voltage marine electrical people in San Diego and vicinity. Nice to see you using your boat, that is what DDs are intended.
 
zeta said:
It is not the battery charger that we are concerned with. There are two battery chargers on the vessel. One for the 120v and another that is a charger/inverter that is 240v (accepts the 200+V range).

What we need is a method of connecting the US 240v four wire system to the European three wire system.

Blue Sea Systems carry's CB panels that are specified as European for 50hz. These can be seen on their web site: bluesea.com
Click to expand...

The first response (by Larry H) explains the USA standard electrical system pretty well.

Once your electrician has converted the boats input connections to the USA standard, you will have 120 volts AC available for your charger and 240 volts AC for your other appliances..
 
"What we need is a method of connecting the US 240v four wire system to the European three wire system"

To operate??

If your US loads are modest a good inverter , Trace 4024 (4KW at 24V input) will power many needs from a good sized batt set.

What US gear are you trying to power? For how long?

A dockside US power input and wiring for a few gadgets might be the simplest and safest .

With US 120 and 240 internal plugs and sockets very different from the euro style there should be little chance of a problem.

FF
 
zeta said:
We have a vessel that was built to European standards. We are wanting to use US (4 wire) 240v shore power on the vessel that is European (3 wire).
There is nothing on board that is voltage or frequency sensitive.

The other item that we are trying to accomplish is a step up transformer to increase the 120v shore power (it powers a battery charger, then the batteries run a 240v inverter) to 240v.
Click to expand...

In your same situation, with a European sailboat. Ours came set up for 230volt/16amp AC power and 12 Volt DC. So I am not sure if I can provide any relevant advice on the DC side if you are set up for 24 Volt DC.

If you talk to a marine electrician you will probably get the safe but expensive advice to tear everything from the shore power inlet to the breaker panel and convenience sockets (and the wiring in between) out and replace it all.

If you talk to the guy on the dock you will get the unsafe but inexpensive advice to do a little wire surgery.

I wasn't happy with either extreme.

Since we ended up already having a 12 volt DC system, I left that alone.

Decided to go with the 240V/50A US standard instead of the 120V/30A standard. Put in the right US shore power inlet, and within ten feet a new 240/50 main breaker. Immediately downstream of that a Victron Isolation Transformer capable of accepting 110V-250V and outputting 230V. Hooked the output from that to the existing AC system.

Got a couple of 230-110 step-down transformes for $150 to use US standard stuff at the existing convenience sockets.

End result is the boat still thinks it is in Europe, I can run it as is for however long I want, and I have the initial setup for a very safe ABYC compatible US 240V/50A installation already in place if I decide to replace the original AC breaker panel, convenience sockets, water heater, battery charger and wiring in the future.

Hope that helps.
 
The OP posted 5.5 years ago so I doubt it has helped him much!

Your solution does not address frequency. You can get 230 VAC, but it will be at 60 Hz whereas the Euro appliances are designed for 50 Hz. For resistive loads, no problem. For inductive loads there may well be issues such as premature failure.

A much better solution is to just use US shorepower to run a voltage AND frequency compatible battery charger. Victron make them for example. Then run all onboard AC appliances off a 230V / 50 Hz inverter. In this scenario the battery charger and inverter are separate - combined inverter/chargers don't handle both 50 & 60 Hz, just one or the other. Then your boat might well believe its still in Europe. The way you have done it, not so much.
 
Last edited:
True.

However

Neither the OP and I had no frequency sensitive devices on board.

I did give your solution some thought but in the end didn't want the AC system to be DC dependent based on a series of inverters.

This also results in leaving the door open to a complete AC replacement in the future without changing the DC system.
 
Insequent said:
The OP posted 5.5 years ago so I doubt it has helped him much!

Your solution does not address frequency. You can get 230 VAC, but it will be at 60 Hz whereas the Euro appliances are designed for 50 Hz. For resistive loads, no problem. For inductive loads there may well be issues such as premature failure.

A much better solution is to just use US shorepower to run a voltage AND frequency compatible battery charger. Victron make them for example. Then run all onboard AC appliances off a 230V / 50 Hz inverter. In this scenario the battery charger and inverter are separate - combined inverter/chargers don't handle both 50 & 60 Hz, just one or the other. Then your boat might well believe its still in Europe. The way you have done it, not so much.
Click to expand...

This is the route I took with Libra. Kept the Euro shore power cord and put a new plug in for that, added a US shore power cord and plug in for that. Routed both to a Victron charger that recognizes both voltages and frequencies to charge 12 and 24 volt banks of 2 volt industrial cells that total about 1500 amp hour equivalents at 12 volts. This is inverted to 230/50 by a Mastervolt inverter. The generators can also produce 380/50 for the windlass.

For US 110 we added a few of those little devices that plug into the Euro outlets to run those small devices.

Thus, for all practical purposes, the boat still thinks it is Euro with 12, 24, 230, and 380 volt power available to the equipment. WE scratched our heads about this for a bit but this seems to work nicely for us and is handy in terms of being able to hook up to about any power supply we may encounter at any port.
 
The problem to consider when going from European 240 v system to the North American system is that one of the benefits of the European higher voltage is the smaller wire gauge which is needed because of the higher voltage. If you leave the wiring in place for a 240 v coffee pot from Europe but substitute a 120 v coffee pot you may be using wire which is too small for the North American 120 v system.
 
Last edited:
Bay Pelican said:
The problem to consider when going from European 240 v system to the North American system is that one of the benefits of the European higher voltage is the smaller wire gauge which is needed because of the higher voltage. If you leave the wiring in place for a 240 v coffee pot from Europe but substitute a 120 v coffee pot you may be using wire which is too small for the North American 120 v system.
Click to expand...

For sure Marty. Anything with a decent amp draw or even moderate draw but long duration, we keep Euro 230/50. This includes things like coffee maker, toaster, microwave, crockpot, hair dryer etc. These things are readily available on Amazon.
 
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