Newby requesting advice about 120/ 240 volt wiring

[Menby]

I'm in the process of buying a new (old) boat. The owner sent me a 2005 survey which I would like to quote. "... Ensure that all AC voltage wiring throughout the vessel is sized for 120- volt AC voltage/30-amp service- vessel was wired for 240-volt service and as such wiring is smaller and must be upgraded..."

The owner hasn't "upgraded" the wiring. Some of you have European built boats. Did you upgrade yours? How serious is this as a fire hazard? Should I walk away from the deal if he refuses to rewrite the boat?
TIA
Bob

[mikefossl]

It really depends on how extensive the AC wiring is and the expected loads. In our case we have 4 AC outlets. Re-wiring the AC would not be a huge job.

[jeremiason]

If you get serious about this boat... DO NOT trust a survey from 2005. Pardon the pun, but a lot of water has passed under the keel in seven years and their maybe more problems...

I am no electrician, but higher voltage means lighter wire... So converting lighter wire to lower voltage means more resistance and higher heat or in other words FIRE!

Yes, it is easy to replace AC wiring, if you know what you are doing. If not depending on wher eyou live it will cost $60-$100 per hours to pay an electrician to do it. Depending on your wiring, you can figure the hours involved, not to mention the cost of materials.

[Wotname]

Originally Posted by Menby

I'm in the process of buying a new (old) boat. The owner sent me a 2005 survey which I would like to quote. "... Ensure that all AC voltage wiring throughout the vessel is sized for 120- volt AC voltage/30-amp service- vessel was wired for 240-volt service and as such wiring is smaller and must be upgraded..."

The owner hasn't "upgraded" the wiring. Some of you have European built boats. Did you upgrade yours? How serious is this as a fire hazard? Should I walk away from the deal if he refuses to rewrite the boat?
TIA
Bob

Welcome aboard Menby.

Bit difficult to give detailed advice as not enough data has been supplied but as a generalisation, this is a potential fire hazard. The degree of risk is in the detail!

Should you walk away? Well that is even more difficult. Is this the only sticking point, how much do you want this particular boat? Is it just a matter of dollars?

Previous posts are spot on IMO.

[RUSTYNAIL]

If the surveyor said it needs to be changed, factor that into the reduction of the price. Most European boats are well built, but the AC loads are half the current we use in the U.S. The circuit breakers may protect what ever load current is expected for the wire, but that may be half what you need for 120 Volt outlets, like an electrical cooking device that needs over 10 amps. Like previously said, if you can't do the work yourself, expect a big bill. Most older boats are overdue for new wiring and an updated 120 volt AC panel that shows reverse polarity, new breakers, and meters. If you only have 5 or 6 outlets this may be easier than you thought. Calculte from the shore power outlet to the panel, new AC panel, and marine boat cable all the way to the outlets. Even the European outlet boxes will not fit U.S. outlets, GFCI, and covers. If you plan on getting insurance, most good surveyors will require wiring that meets ABYC electrical standards. Good luck.

[DotDun]

Normal household voltage has nothing to due with the size of the wire required, it's the size of the current draw through a wire that dictates it's size. If the original wiring for the branch circuits are protected with properly size circuit breakers, it doesn't matter if you run 120v or 230v through the wire.

If the boat was wired for 230v 16a shore power, shore power to circuit breaker box wiring will need to be upgraded for 30a or 50a to be used at most US marinas.

[Wotname]

Originally Posted by DotDun

Normal household voltage has nothing to due with the size of the wire required, it's the size of the current draw through a wire that dictates it's size. If the original wiring for the branch circuits are protected with properly size circuit breakers, it doesn't matter if you run 120v or 230v through the wire.

If the boat was wired for 230v 16a shore power, shore power to circuit breaker box wiring will need to be upgraded for 30a or 50a to be used at most US marinas.

While correct in as far as you go, one must remember the load (power rating) of the appliances that you intend to use.

For instance, 2000W hot water jug requires 2000W regardless of whether is made in European or USA. Your USA appliance will be drawing twice the current compared with a 230 V unit. So add a couple of appliances to the circuit and you will find the breaker popping!

[DotDun]

Originally Posted by Wotname

While correct in as far as you go, one must remember the load (power rating) of the appliances that you intend to use.

For instance, 2000W hot water jug requires 2000W regardless of whether is made in European or USA. Your USA appliance will be drawing twice the current compared with a 230 V unit. So add a couple of appliances to the circuit and you will find the breaker popping!

1) You are absolutely correct that one must consider the power required on each branch circuit to determine if that wire/breaker is suitable for the task.

2) If by 'water jug' you mean water heater, your example is flawed. Keeping the same 2000watt @ 230v resistive water heater, it will magically become a 544watt @ 120v resistive water heater and fit well within the power delivered on the original wiring. It'll simply take longer to heat water.

My boat was wired to EU standards using 10a and 16a breakers on the branch circuits. Each circuit with receptacles carried a 16a breaker with appropriate wire gauge. Works fine with 120v, albeit each circuit is now only capable of 1920w/va vs. the original 3680w/va.

[Wotname]

Originally Posted by DotDun

1) .....

2) If by 'water jug' you mean water heater, your example is flawed. Keeping the same 2000watt @ 230v resistive water heater, it will magically become a 544watt @ 120v resistive water heater and fit well within the power delivered on the original wiring. It'll simply take longer to heat water.
.......

I see we are comparing apples and oranges .

You are taking the 230V (2000W) water heater and supplying it with 120V and so your figures are correct.

I was thinking more of the electric kettle and plugging in a 120 V (2000W) USA unit into this boat. Thus the current draw will be double (rounded off figures) when compared with a 230 V (2000W) European unit.

[goboatingnow]

Originally Posted by Wotname

I see we are comparing apples and oranges .

You are taking the 230V (2000W) water heater and supplying it with 120V and so your figures are correct.

I was thinking more of the electric kettle and plugging in a 120 V (2000W) USA unit into this boat. Thus the current draw will be double (rounded off figures) when compared with a 230 V (2000W) European unit.

Most conventional EUropean outlets a rated at 3000w. Hence the wiring is good for about 15 amps. ( in fact it is usually rated for more ) hence you have outlets of about 1600w in 110 land without wiring changes. This may be more then enough for most people. That would mean just rewiring any high power consumers like water heating etc

Dave

[Stu Jackson]

Why not simply look at ther size of the wires that are there, and compare them to what should be there for USA current? THEN and only then will you know.

[Cheechako]

Originally Posted by Stu Jackson

Why not simply look at ther size of the wires that are there, and compare them to what should be there for USA current? THEN and only then will you know.

Yes, although it sounds like the surveyor already looked. At any rate, it's probably one of the easier items to redo compared with other boat problems! How extensively do you use AC? If you're not running a heater or heavy load the wiring may be fine. Find what size it is and approx lengths and determine your maximum loading with what you have. If I remember right much house wiring is 15-20 amps.

[goboatingnow]

Originally Posted by Cheechako

Yes, although it sounds like the surveyor already looked. At any rate, it's probably one of the easier items to redo compared with other boat problems! How extensively do you use AC? If you're not running a heater or heavy load the wiring may be fine. Find what size it is and approx lengths and determine your maximum loading with what you have. If I remember right much house wiring is 15-20 amps.

Some European boats are wired as ring main circuits. Hence the ring could have 40-60 amp capacity. This gives you far more lee-way. The previous posters are correct. You need to actually look at what you've got.

Dave

[SuenosAzules]

This is a very loaded question about the suitability and condition of the AC electrical system. I for one, would spend alot of time going through the vessel looking at the electrical system making sure things were complaint with CFR and ABYC E-11 reccomendations. One thing I will do at the stsart of the inspection is power everything up on the panel to see if any breakers pop. Some boat owners will over amp the circuits with upgrades and will place stickers on the panel so as to not run one thing with another.. Very dangerous and good way to short a circuit out or even cause a boat fire. I normally will spend hours inspecting these systems on bigger yachts, especially older ones. I have hundreds of pictures of "home projects" where I was amazed no one got killed on the boat prior to the survey.

[DSDman]

My boat is 220 wired and the survey said the same thing. Then I started thinking about it. Why go 110? It's worked fine for almost 30 years. I can order any appliance I want in 220 v so just leave it alone. I have a step down transformer from 220 to 110 when required and a couple of 12 v to 110 for small things. Now as things go bad or if I have to replace wires I will replace with heaver wire so that one day I might decide to switch it over and it will just require breaker changes. but so far, no problems.