Buying a Cat - which electrical system?

[paul28]

I've been looking at Cats for sale and many are 240 volt systems.

I've seen some threads on converting boats electrical systems from 110 to 240 Volts and vice versa. However, not found one on which system is better when choosing a boat.

Planning to buy a boat in the next year and sail in the US for a year then do a circumnavigation.

Is one system preferable over the other? Do you need to install a transformer in the boat so you can deal with different marina setups around the world?

I imagine that depending on where you buy there may be a discount (for example a 120 V boat for sale in Europe Vs a 240 V boat for sale in the US)

[Spartanacus]

A 240/230 system can always be stepped down to 120/110 ... not so the other way.
Unless you are a full time dock sailor as many are, the DC system has more importance, 24V is way better than 12V ... look there first.

[valhalla360]

Originally Posted by Spartanacus

A 240/230 system can always be stepped down to 120/110 ... not so the other way.
Unless you are a full time dock sailor as many are, the DC system has more importance, 24V is way better than 12V ... look there first.

You can certainly step 120v up to 240v but that's not really a driving consideration.

The bigger question is do you have devices that are hertz sensitive. A good number are not impacted by hertz but changing 50hz to 60hz and vice versa is more difficult than voltage (though it's really not that hard).

It's really about where you expect to be long term. If it's mostly in 240v lands, 240v is advantageous and vice versa if mostly in 120v lands.

[Jeannius]

I had my boat built as 120v even though I am European because I'd be spending the first few years of ownership in a 120v area. I did subsequently add a 240 > 120v transformer for around $100, and add an appropriate shore-power inlet so that I could power my battery charger and air conditioning at the dock.

This did work for the air-con as the units would work even though they were now getting 120v/50Hz rather than the 120v/60Hz they were designed for. I did check this with the manufacturer before doing this.

Unfortunately the battery charger wouldn't work as it wouldn't accept the low frequency. I got round this by adding a 240v/12v charger directly from the shore power.

Now, to finally get to the point... It is relatively easy to change a 120v boat to 240v because the original wiring in a 120v boat will be bigger section to handle the larger CURRENT requirements. It is harder to go from a 240v boat to 120v because you will probably need to increase the section of the wiring to cope with the larger current passing through a 120v system.

[LeeV]

Originally Posted by paul28

I've been looking at Cats for sale and many are 240 volt systems.

I've seen some threads on converting boats electrical systems from 110 to 240 Volts and vice versa. However, not found one on which system is better when choosing a boat.

Planning to buy a boat in the next year and sail in the US for a year then do a circumnavigation.

Is one system preferable over the other? Do you need to install a transformer in the boat so you can deal with different marina setups around the world?

I imagine that depending on where you buy there may be a discount (for example a 120 V boat for sale in Europe Vs a 240 V boat for sale in the US)

Buy one with both already installed if you can.

[mark_morwood]

Originally Posted by Spartanacus

A 240/230 system can always be stepped down to 120/110 ... not so the other way.
Unless you are a full time dock sailor as many are, the DC system has more importance, 24V is way better than 12V ... look there first.

Careful, that's not really true for either of two interpretations of this that I understand:

1. If you are just trying to adapt shore power to the boat, you can get transformers that will work to either step up or down, so no difference. In both cases you might have frequency problems, 50hz v 60hz with some motors.

2. If you are rewiring a boat from one to the other, then switching from 240/220 to 120/110 requires replacing the boat wiring as well as the outlets to support the same power in the circuits. At 240V, the current is half that at 120V at the same power, so the 240V wire has a lower Amp rating and will be overloaded if used in an equivalent 110 system.

If you don't need high current shore power (e.g. Air Conditioning) then you can do what we did, which is run all AC on the boat only from the inverter from the batteries, and only connect your shore power inlet to dual voltage battery chargers that charge the batteries. This model works with either 110 or 240V on the boat and either 110 or 220/240 on the dock. It also supports either 12 or 24v DC battery systems.

[RELENTLESS 1]

Same position as OP. The Boat is ordered and production starts in December, so my coin flip is November 15. We will be 2-3 seasons in the Med, 2 in Carib (w/East Coast US for summer) then a season or so in South Pacific then back to the West Coast for 5 years or more depending on health, agility, etc.

SO....we are setting the boat up to not be at Marina's much. We have 900AH, LiPo4 Lithium, 1.3KW Solar, Watt and Sea, and our hope is Nigel Calders Integrel generator when needed.

The manufacturer is all about weight and encourages 220V vs 120V which they will substitute for an added cost. Appliances are not an issue what else would help with my decision?

[yeloya]

Originally Posted by Spartanacus

24V is way better than 12V

I am not sure on that.. 24 V is mostly used on big boats, 55 ft or over to reduce the amperage, hence the thickness of the cables, thereby the weight and the cost of wiring.
However, since most of the instruments/electronics on mass market are 12 V , they need the equiment to convert 24 V back to 12 V. Their system is usually more complicated when inverters, combo systems are also involved.

Cheers

Yeloya

[Spartanacus]

Originally Posted by yeloya

I am not sure on that.. 24 V is mostly used on big boats, 55 ft or over to reduce the amperage, hence the thickness of the cables, thereby the weight and the cost of wiring.
However, since most of the instruments/electronics on mass market are 12 V , they need the equiment to convert 24 V back to 12 V. Their system is usually more complicated when inverters, combo systems are also involved.

Cheers

Yeloya

I jumped the gun on the 240 to 120 ... was thinking only of ease of conversion and in the US converters are cheap and available in both ways same price.
Now 24VDC vs 12vdc is another matter ... 12V at 2 bucks a foot for 2 ga cable is pricey, you benefit weight and price wise from lower gauge of wire with 24V.
24 to 12 step down reducers are cheap (starting at about 10 bucks) and reliable.
24V is best for solar charging cuz you can wire 2 panels in series ... less wiring and less cost/weight

[paul28]

Originally Posted by LeeV

Buy one with both already installed if you can.

Is this common? Buying a used boat and I have not seen any described this way.

[paul28]

Originally Posted by mark_morwood

If you don't need high current shore power (e.g. Air Conditioning) then you can do what we did, which is run all AC on the boat only from the inverter from the batteries, and only connect your shore power inlet to dual voltage battery chargers that charge the batteries. This model works with either 110 or 240V on the boat and either 110 or 220/240 on the dock. It also supports either 12 or 24v DC battery systems.

Did you have to rewire the boat quite a bit to achieve this?

I've read of systems that allow you to run A/C off of batteries, so that may not be a limitation

[Sand crab]

Originally Posted by paul28

Is this common? Buying a used boat and I have not seen any described this way.

I have but they are not common.

[LeeV]

Originally Posted by paul28

Is this common? Buying a used boat and I have not seen any described this way.

Here’s a copy/paste from a cat online:
“The first upgrades, where all new navigational electronics, radar, AIS transmitter, a complete 110v system to supplement the existing 220v system, a new inverter charger.

Features:

110 and 220 service...”

I’ve seen a handful like that. I’ve also heard from a broker that he recommends to new buyers having both systems installed for ease of selling if they’re in a different world location from where they bought it.

[xhogpilot]

I bought a Lagoon 440 two years ago which has a genset putting out 220/50hz. It can be easily reconfigured to put out 60hz, but...

We have had no issues having a "European electrical boat". All of the Air Con units are able to take either 50 or 60 hz. Many air con manufacturers (dometic) have stopped making their units 50/60 hz, but they are just now ginning up the assembly line to manufacture them once again (December '19).

All my March pumps are also 50/60hz.

The other high draw items include Watermakers and dive compressor, both of which I power strictly from the genset...never from USA shore power.

What all this means is that you can sit on your boat at the dock plugged into 230volt/60hz and run air conditioning as well as battery chargers (if configured)without a problem.

As for power tools and computer/tablet/cell phone, you can charge the batteries with or without an inexpensive inverter because that battery doesn't care about Hz.

I've bought cordless power tools that can be recharged onboard.

As to other appliances, take a look at this website. We've purchased things like hair dryers and coffee makers from them in Houston.

http://eastwestintl.com

Any questions, PM me.

Regards.