How to Build a 240 / 220 / 110vac Boat

[Sabbatical II]

I am a total ignoramus on electrical issues and am currently building a yacht in Australia where the standard AC voltage is 240v. However, I want to be able to hook up to AC shorepower wherever I might be, including US & Europe. I do not want to carry an independent generator and the Yanmar 75hp has come with the standard 80amp & optional factory supplied 130 amp alternators. How do I need to build the boats electrical system to accommodate this and is it possible to buy appliances that can do it? Does the shorepower usually hook to the inverter and then AC stuff is powered off that? Is the AC on totally separte circuts to the DC system? Is it simply a matter of having the wiring large enough to handle the different voltages and then purchasing appliances to suit?

[Dockhead]

The Victron isolation transformers, and probably other makes, will convert 110v power up to 220v. As a bonus you get protection from ground leakage corrosion. That would solve your problem pretty neatly.

[djmarchand]

In addition to Dockhead's comment which is valid, get a copy of a good marine electrical manual, read it cover to cover and then ask your questions. There is more that you don't know than could be answered in thousands of words. Charlie Wing and Nigel Calder are two good authors.

David

[Dockhead]

Originally Posted by djmarchand

In addition to Dockhead's comment which is valid, get a copy of a good marine electrical manual, read it cover to cover and then ask your questions. There is more that you don't know than could be answered in thousands of words. Charlie Wing and Nigel Calder are two good authors.

David

A good idea.

Indeed your DC power and AC power are completely separate systems which interact with each other only through your ground system, and through your battery charger(s), and inverter if you have one.

You will need to understand these systems quite a bit if you are going to use your boat successfully. Read, read, read.

[billyehh]

A problem. Be sure that the electronics, motors and transformers will work with both 50hz and 60hz. Here in Grenada you can get 110 volts but it is at 50 hz. Most of the electronics seem to work, but motors run slower and tend to heat up fast

[Sabbatical II]

Thanks for the help guys. I have just ordered Nigel Calder's book online as I couldn't see any of those yellow "Dummies" books that seemed appropriate.

[SvenG]

Assuming no separate generator to worry about ...

I'm wondering if the easiest solution isn't to install one 110v/60hz inverter-charger and one 220-240v/50hz inverter charger, hooked up in parallel at the batteries.

You run two sets of AC plugs, each set dedicated to their inverter. You hook up the shore power to the appropriate charger as needed.

It is a real pain to have to run redundant systems but unless there is an off the shelf inverter/charger that has the combined functionality I'm not sure how else to do it ?



-Sven

[capn_billl]

Not a bad plan to use either the isolation/steup transformer or seperate systems. One decision you have to make is what do you want to power from what? My boat had a mix of both AC and DC systems. I have changed most things to AC and power from an inverter. That only leaves the charger that has to be compatible with shore power. Since you have the high output alternater already, changing everything to DC is a viable option. Some chargers are available that work on multiple power types. That would leave only your stove, fridge, and Air conditioner to worry about. Consult a marine electrician, now is the time to do it right.

[capt_douglas]

Depending on your power requirements a multi-tap transformer should solve your problem. The one's I've seen have connections for 240, 220, 200 input and 120, 115, 110 out. Most transformers will work with 50 hz although they can get a bit warm.

Some transformers are autosensing and will change imput connections depending on input voltage but they're expensive.

Here's a link: Guaranteed Low Prices on Step Down Transformer, Step Down Converter - UK Step Down Transformer, Step Down Voltage Converter, Step Down Voltage Converter Transformer

[Dockhead]

Originally Posted by SvenG

Assuming no separate generator to worry about ...

I'm wondering if the easiest solution isn't to install one 110v/60hz inverter-charger and one 220-240v/50hz inverter charger, hooked up in parallel at the batteries.

You run two sets of AC plugs, each set dedicated to their inverter. You hook up the shore power to the appropriate charger as needed.

It is a real pain to have to run redundant systems but unless there is an off the shelf inverter/charger that has the combined functionality I'm not sure how else to do it ?


Sven

Most good chargers will run on either 110v or 220v (mine has jumpers to change it over), so this idea -- to run all your AC loads off your inverter when you're connected to shore power at a strange voltage -- can usually be implemented without any special or redundant equipment.

The big advantage of Sven's idea is that the inverter will give you the right frequency for all your equipment on board.

On the other hand you do lose a lot of power converting it to DC and then back up to AC, so you will have heat and noise and the final output through your inverter will be less than what the shore power is able to provide. That problem can be fatal if you are running air conditioning and need every amp your shore power connection can provide.

If you transform the AC power to our own voltage just as it enters the boat, however, you will be able to use that power directly through your boat's AC power system, for equipment that doesn't care about the frequency. The transformer, obviously, does not change the frequency.

[SvenG]

Originally Posted by Dockhead

Most good chargers will run on either 110v or 220v (mine has jumpers to change it over)

Very true for many chargers. I am planning for small power tools or appliances (vacuum packer, mixer ...) that don't run on chargers. These are all things that we might also want to replace in a place with different voltage.

Power loss, heat, noise, interference (?) are all issues that have to be accepted or somehow dealt with. Certainly not an ideal solution, just one that seems relatively KISS under the circumstances.


-Sven

[CharlieJ]

This is a relatively complex undertaking. I would suggest hiring a qualified electrical designer to develop the systems and a marine electrician to assist you in the installation of the systems. You will have a much better vessel in the end.

Charlie

[goboatingnow]

The best solution in my mind is to go the AC->Batt Charger-> DC->Battery->Inverter route. This allows you to use any shore power system as long as the battery charger is multi-system. ( the good ones are). Decide on the main AC system on board ( ie 230 VAC or 110) but cable for 110VAC. If you want both voltages aboard. then use two invertors one for each voltage. If you want to bullet proof the system , then use N+1 invertors, and make the system out of 1Kw units , giving you redundancy ( since you depend on these).

If you want belt an braces put a isolating transformer before the battery charger, but in my view there no need as this is the only Main AC device directly connected. Note wherever possible get an isolated ground battery charger. In my opinion nothing good comes from tying AC neutral to DC ground.

Secondly ensure you have a 30ma RCD immediately after the shore power entry into the boat. Only take the shore power earth wire to the battery charger. Follow thw invertor wiring for boat side earth wiring , usually the neutral and earth and joined at the invertor. Again use RCD's on the output of the invertor.

Both the 110VAC, 230VAC( if you have two onboard voltage systems) and DC system should be isolated from each other. ( which is not ABYC practice but is current EU practice as RCB are required and these provide sufficient protection .

All three system need independant panels etc. It can get quite complex

Note that in practice for these system to work , you will need big battery banks 1000amp/h or greater and a good big charger ( 100amps+) and engine driven alternator ( with a smart regulator) and a good battery monitor, but its a very flexible system. The charger should have a controllable limit to avoid tripping shore power systems

It will however in pratice be limited to 3-4Kw AC on board, fine for power tools, microwaves etc, but will rule out on-board Air Conditioners.

The next stepis to add a AC Generator and use it to power heavy AC devices and run the charger , but in my mind its not needed. ( buy a little Honda 2000i for backup). A DC generator would be useful if you have a big batteyr bank, but they are expensive and fault prone ( I built my own).

Dave

Dave