International Cruising Power: Transformer?

[ExchangeGeek]

Are transformers common for cruisers who sail internationally?

I'm considering a transformer so I connect to either 50 or 60hz ShorePower but I'm also considering just using my current charger and installing inverters for all my AC needs.

I'm importing a European catamaran into the US and want to use the Aircon while in a marina. I also plan to add a 110V inverter and a few new 110v outlets so I'm planning to spend some cash on good parts.

The Leopard already has a galvanic isolator, a genset but no inverters. I like the idea of using inverters for all AC needs and it lets me focus on redundant DC charging solutions; solar, Shore Power, Genset.

[redneckrob]

Originally Posted by ExchangeGeek

Are transformers common for cruisers who sail internationally?

I'm considering a transformer so I connect to either 50 or 60hz ShorePower but I'm also considering just using my current charger and installing inverters for all my AC needs.

I'm importing a European catamaran into the US and want to use the Aircon while in a marina. I also plan to add a 110V inverter and a few new 110v outlets so I'm planning to spend some cash on good parts.

The Leopard already has a galvanic isolator, a genset but no inverters. I like the idea of using inverters for all AC needs and it lets me focus on redundant DC charging solutions; solar, Shore Power, Genset.

Keep in mind that if you have a 3.5 kW inverter, which will typically match what you'd get out of a 30 amp 110V shore power connection, you'll need to provide it 292 amps of 12V DC power. I have been unable to find any 300 amp 12 volt chargers that would provide that, if you find any I'd love to get the source. If you don't have that, you're draining the batteries and unless you go with a big lithium chemistry bank you're not going to have enough to power AC on a bigger boat with what your existing charger and batteries are putting into the inverter.

As for the rest, as I and others have discussed in several threads, the voltage switch is trivial with lots of isolation transformers available to handle it. The frequency switch isn't really practical, so you have to deal with that somehow or ignore it and accept any issues it might cause mostly with motors running too fast or too slow, depending on your combo.

[ExchangeGeek]

Many thanks! I've read some of the previous posts but its hard to sift through what works and what doesn't as people often contradict the previous author!

I'm hoping to learn what other cruisers have done. It seems like the most common solutions are to use a large isolation transformer to ensure the boat gets consistent power and to couple that with a combination charger/inverter.

[redneckrob]

Originally Posted by ExchangeGeek

Many thanks! I've read some of the previous posts but its hard to sift through what works and what doesn't as people often contradict the previous author!

I'm hoping to learn what other cruisers have done. It seems like the most common solutions are to use a large isolation transformer to ensure the boat gets consistent power and to couple that with a combination charger/inverter.

There are lot's of places in cruising with contradictions, say anchors or catamaran vs monohull. Electricity, on the other hand, is electricity, so either you can convert 50 hz to 60 hz using box X or you can't, there's no contradiction possible. If you hire a good electrician or electrical engineer to at least design your system it will save you a lot of grief and possibly even death, electricity isn't something for amateurs. An isolation transformer isn't for ensuring "consistent power", if it get's dirty power it will pass it right through to you, if it gets under or overvoltage power it will pass that right through also, with a few exceptions of specially designed transformers that also adjust voltage. It's possible to get an isolation transformer that also converts 220 to 110 or vice versa, but it's important to understand that's a very different thing than "consistent power". You also seem to be confusing the role of an isolation transformer vice a charger/inverter. If you got a charger big enough (which I still maintain isn't practical at this time but would love to be proven wrong) it would probably be multivoltage input so you wouldn't necessarily need a multi-voltage isolation transformer (except for the galvanic isolation it provides, a completely different topic). So they're really two different solutions to a problem, not a combined solution. Again, I can't recommend enough that you hire an expert if you don't have any expertise in this area, it's probably one of the least conducive to safe DIY activities you can engage in on a boat without at least some background and experience.

[Paul L]

We have two isolation transformers onboard a 120/60hz boat. They have been jumpered to drop 240 to 120 for the last 3 or 4 years. When we are in a marina berth we buy a local dock plug and put it on our dock cord. This gets us 120/50hz on the boat. So far everything has worked, including air con, with the 50 hz, except my Hooker, which trips a breaker on 50hz.

[ExchangeGeek]

Paul, thank you very much for taking the time. I'm still just gathering intel and I'm glad you took the time to share your experience.

Many, many thanks.

[sailon46]

My Bene 51.4 has European set-up but also a 120v step down transformer that handles inexpensively the US power with plugs in every cabin x4 and salonx2.
Ernie on the Mary Jane

[ExchangeGeek]

Thank you very much Ernie. The more international folks I meet the more transformer-based solutions I see. Thank you for taking your time to share your setup with me. -Steve

[john61ct]

Setting aside huge loads like aircon, clothes driers, electric ovens, HWS

Another approach is, the only shore power connection is your world power universally compatible battery charger(s).

Then the AC loads and circuits on the boat are run off the House bank through inverters.

This lets you mix and match 110Vac and 240Vac appliances as you like, even sensitive 50/60Hz ones, fed by any marina power pedestal worldwide,

or your genset, or by a robust alternator setup while off-grid, reduces the need for (or runtime of) an AC genset, especially with a big LFP House bank.

No transformers nor transfer switches required!

Even those huge-amp loads above could be accommodated, but that gets expensive.

Some just use dedicated circuits for those, separate from the inverter-powered ones.