110 vs 230 for universal power

[valhalla360]

Originally Posted by s/v Jedi

I only listed one citation, in post #28. From that citation I attach the measured efficiency:

Yes, you posted a link to a blogger who states the final efficiency but doesn't show their work. There's a reason teachers used to force you to show your work.

If we believe the blogger, where are the losses happening with a standard electric kettle?

A resistance coil stove transferring to the bottom of a pot, I can buy as a significant amount of the heat is going out into the air and more is lost transferring from the cooktop to the metal of the pan but a coil submerged in water and quickly achieving 212F, I'm not seeing where a lot of energy is being lost. Unless you are claiming the induction kettle is better insulated but that would be a function of insulation not induction. A well insulated standard kettle could achieve similar effects.

At the same time, there are energy transition losses I can see with induction. Induction by itself means some of the electromagnetic energy goes off into space.

PS: This isn't to say an induction cooktop is a horrible method just that any noticeable and reliable improvement seems unlikely when doing a good apples to apples comparison.

PPS: As mentioned by someone else, your standard electric kettle will shut itself off once it boils. So unless you are religious about watching a pot boil, odds are you will wind up burning thru more electricity from time to time...enough so that even if more efficient, you will likely use more in the long run.

[s/v Jedi]

Originally Posted by valhalla360

Yes, you posted a link to a blogger who states the final efficiency but doesn't show their work. There's a reason teachers used to force you to show your work.

If we believe the blogger, where are the losses happening with a standard electric kettle?

A resistance coil stove transferring to the bottom of a pot, I can buy as a significant amount of the heat is going out into the air and more is lost transferring from the cooktop to the metal of the pan but a coil submerged in water and quickly achieving 212F, I'm not seeing where a lot of energy is being lost. Unless you are claiming the induction kettle is better insulated but that would be a function of insulation not induction. A well insulated standard kettle could achieve similar effects.

At the same time, there are energy transition losses I can see with induction. Induction by itself means some of the electromagnetic energy goes off into space.

PS: This isn't to say an induction cooktop is a horrible method just that any noticeable and reliable improvement seems unlikely when doing a good apples to apples comparison.

PPS: As mentioned by someone else, your standard electric kettle will shut itself off once it boils. So unless you are religious about watching a pot boil, odds are you will wind up burning thru more electricity from time to time...enough so that even if more efficient, you will likely use more in the long run.

That is what you say now, but your previous post said that they were comparing something unrelated. You can’t change angles every post you make, it kills useful discussion. All other links I found and read confirm this, none of them confirm your statements

Also, a heat pump is much more efficient than a resistive heat element, so your theory that nothing beats a resistive element is flawed.

[goboatingnow]

I think of stand-alone inductive kettles were more efficient you’d see them offered for sale. Other then stove top inductive kettles , I’ve never seen a stand-alone product.

[Talbot]

One thing to consider if you intend to shift from 220 to 110 at some time is that your wiring neds to be sized for 110, as it will need to be able to cope with twice the amps of 220.
as regards 60/50 Hz - your biggest problem will be items that have an electric motor. 60Hx items running at 50Hz will be slower, but unlikely to take damage. 50Hz items running at 60 Hz will run faster than designed, and may get hotter than designed - thus reducing their expected lifetime.
Equipment that has a charger to different voltage e.g. laptop, phones etc, is converting to DC anyway and thus 50/60Hz is irrelevant.

[s/v Jedi]

Also, most appliances with clocks or using time for programs, like coffee machines, ovens, bread-makers, rice cookers, etc. all fail because they are synchronized to the power frequency for their time base.

[goboatingnow]

Originally Posted by s/v Jedi

Also, most appliances with clocks or using time for programs, like coffee machines, ovens, bread-makers, rice cookers, etc. all fail because they are synchronized to the power frequency for their time base.

Huh, anything recently I’ve opened with digital clocks or timers use their own time base.

[s/v Jedi]

Originally Posted by goboatingnow

Huh, anything recently I’ve opened with digital clocks or timers use their own time base.

That’s great. I remember buying our Zojirushi breadmaker which was the only one with crystal timebase so there were a zillion using mains frequency.

[botanybay]

Originally Posted by shimari

We have a UK boat in the US. We run everything at 240v/60hz. Our air conditioning runs at 230-240 at either 50hz and 60hz. I thought we'd have to replace the microwave, but so far it works fine. Our induction stove requires 230-240v and will run at 50hz or 60hz.

We plan to convert our outlets to 120v down the road by adding a small inverter, but in the mean time the only thing we've found that doesn't work at 240v is the battery charger for our Milwaukee tools.

I presume that any slips you'll be in will have 240v/50amp service in the US. I'd keep your main circuit as 230/240 50/60 ensuring your aircon etc all are multi-frequency friendly, and then use a small inverter to power your outlets at 120v/60hz regardless if you're plugged into 230/50 or 240/60.

I too have a UK boat in the US and happily run the boat through an isolation transformer and the big loads are all happy.

The one "fly in the ointment" is that something like half of the US docks are "split phase 240v" which have two 120v circuits 180 degrees out of phase. This is the same as most home dryers work on. The other half of the docks are two legs of a three phase circuit so the two legs are 120 degrees out of phase not 180 degrees. The only impact is that the voltage between the two legs is 208v rather than 240v.

Many 230v pieces of equipment don't care, battery chargers limit input current rather than output current, air conditioners are happy but start a little more sluggishly, microwave ovens definitely under perform.

If you then try to step the 208 down to 104 and run your 120v equipment then you will probably find more things which are not happy.

My solution is that the 230v bus runs at dock power and everything on that circuit is happy with anything from 200v to 260v 50hz or 60hz.

All of my 120v equipment runs off a dedicated inverter.

Running off of a 120v dock I step up to 240v through the isolation transformer and everything is happy.

One of the biggest advantages of 230v is the current on the shore power cord is half as much, smaller wires, lighter cables, no burned plugs due to pushing the current limit :-)

[Jef & Marin, Netherlands]

You might want to have fulltime 110/230V available.
In that case, do not underestimate the standby power taken by the inverters. In case of our Victron combi, that is clearly higher than advertised.
Luckily we have a quite simple Mastervolt Mass Sine 12/2000 that runs 24/7. It is advertised as having a standby power of 6W, but it takes only 0.4A at average of 13V, so around 5W of power. This is the non-energy-saving mode, it can be reduced with special settings. We run computers and a domestic fridge from it; a freezer will be added.
Also this one runs the watermaker, breadmaker, hot water boiler, tea kettle.
We can switch on the 2nd inverter (the Victron combi) for other equipment like the washing machine. Or the tea kettle, when the first one is already supplying the breadmaker or watermaker or so.


We have airconditioning, it can run off the solar panels, but we never use it. You might want to use it if you are in a hot marina (for instance in Boat Lagoon in Thailand), but in anchorages it is hardly necessary in a well ventilated catamaran. Sea water and the air above it are hardly warmer than 28-30C.

If I bought a new boat, I would save the weight and money of an air conditioning, especially if you want to be off grid. Will you run a generator to have air conditioning in an anchorage? I never meet sailors who do this. Except for power boaters who don't care about energy use anyhow.


Furthermore I worried that our single inverter might fail. This would mean no breadmaker, no watermaker, no fridge...... Trouble with the laptops.... So therefore we got the Victron combi as a backup.

The old Mastervolt inverter died less than 2 years later. I had set up the system so that I could easily change a few jumpers, and half an hour later we had 230V from the new Combi.


I think it is an excellent idea not to have a generator, but 2 really big house battery alternators on your engines. I visited a boat that had 200A 24V alternators, watercooled. They are very big, but lots lighter than a generator; and you have 2 of them.
They had a special slow-start feature, not to overload the engines when switched on.
When you have enough solar power, you will not use the generator often; and the fact that you only give little load to the diesels is not a worry, since it does not occur often.


I am a bit surprised you choose 48V instead of 24V. For electric winches, windlass and so, availability of 24V will be easier. On the other hand, if you want to change to electric saildrives after your diesels are obsolete or worn out, it makes sense.
With solar panels, you need to make sure that you can get solar panels and/or controllers that will charge 48V.


Good luck with your project!

[CaptTom]

Originally Posted by botanybay

...something like half of the US docks are "split phase 240v" which have two 120v circuits 180 degrees out of phase... The other half of the docks are two legs of a three phase circuit so the two legs are 120 degrees out of phase...

I was not aware that any marina power outlets used just two phases of 3-phase service. I always assumed it was split phase, like a typical residential service.

There is an older 50A standard, usually labelled "50A 125V," as opposed to the "50A 125/250V" which I think is more common now. Is that the difference? It would imply that you can't get over 125 out of either leg on the old style, so it wouldn't matter if they're not 180 degrees out of phase.

[valhalla360]

Originally Posted by s/v Jedi

Also, a heat pump is much more efficient than a resistive heat element, so your theory that nothing beats a resistive element is flawed.

Heat pumps are more efficient because they are not converting electrical energy directly into heat energy.

They are using electrical energy to capture heat energy either from water or air. and then "pump" it either in or out of the are being heated/cooled.

Are you suggesting a heat pump based kettle for boiling water?

So, not really relevant to the discussion of induction vs resistance heating.

[s/v Jedi]

Originally Posted by valhalla360

Heat pumps are more efficient because they are not converting electrical energy directly into heat energy.

They are using electrical energy to capture heat energy either from water or air. and then "pump" it either in or out of the are being heated/cooled.

Are you suggesting a heat pump based kettle for boiling water?

So, not really relevant to the discussion of induction vs resistance heating.

Not yet… laundry dryers already do it. I just used it as an example, because not the method, but the result is what counts.

In the case of the kettles I assume it has to do with loss of heat to ambient air, mineral deposits on heating element etc. There can be much speculation on causes, but fact is what the meter shows and that is that the good old kettle design in combination with induction technology is the clear winner.

We have 15 years of experimenting with electric galley behind us and tried different methods for everything we do/use often enough to make a difference. Not everything is better on induction: we found a rice cooker, and coffee machine are unbeatable for energy efficiency as well as results. Boiling water better on induction.

[botanybay]

Originally Posted by CaptTom

I was not aware that any marina power outlets used just two phases of 3-phase service. I always assumed it was split phase, like a typical residential service.

There is an older 50A standard, usually labelled "50A 125V," as opposed to the "50A 125/250V" which I think is more common now. Is that the difference? It would imply that you can't get over 125 out of either leg on the old style, so it wouldn't matter if they're not 180 degrees out of phase.

Unfortunately the 208V marinas and the 240V marinas use the exact same 50A 125/250 plug. Technically the plug is rated to these amperages and voltages. Often the guys at the office don't even know the two options exist, much less how they are wired.

The 50A 125V is just the 30A 125V plug modified to handle the larger 50A current. It is an oddball plug and a friend of mine who has that setup is always scrambling around for adapters as the marinas on the West Coast of the US and Mexico appear to rarely use them.

The two phases out of 3 caught me off guard when I first started researching the application of US power to a UK built boat.

Basically, for the three phase power there is neutral and three legs which are each 120v relative to neutral. Any leg to any other leg is 208V. It is much cheaper to buy a three phase output transformer (about $300/slip at some point in the past) and cycle down the dock using all three phases. For my marina the post has a 50A 125/250V plug with 208v provided and right beside it is a 30A 125V plug providing 120v. So it would be technically possible to get the three phase power by combining both plugs (not that I would recommend that. Better to have the marina put in the right plug as the wires are there.

In the case of a 240v setup it is technically called "split phase" or "single phase with a center tap" power. This is what is found in most homes for things like dryer circuits. The center tap is connected to neutral. Neutral to either hot end is 120v. Across both hot ends is 240v but each end is 120v away from ground.

A UK vessel will be wired with one lead close to ground (neutral) and the other at 240v relative to ground.

Some individuals will hook US 240v or US 208V directly to a UK boat and think everything is fine. It is true that ships neutral should not connect to ships ground. Thus all consumers should not connect neutral to chassis.

That said, the significant safety issue exists. Unless every circuit is independently fused with a double pole breaker (not just the shore power connection) then if you shut off the breaker for the air conditioner or hot water heater the wiring is still at the potential of the "neutral" which is now 120V relative to ground.

Even with a shore power double pole breaker, the only circuit breaker on the "neutral" side is that 50A or 30A shore power breaker as the power comes onto the boat. It can be quite a surprise when you grab the volt meter to verify power is off on a circuit and find out that the meter reads 120v on the equipment neutral with the breaker turned off!

An isolation transformer solves this problem by taking the output of the transformer and connecting the ship side side to neutral and ground and the other side is 240V. On the incoming side it makes no difference if the marina is wired with reverse polarization or whatever. You are just using two leads with a voltage between them connected only to the transformer itself.

Interesting I believe that if you are running purely resistive power (the easiest to think about) on a 240 split phase system connecting lets say 1000w to neutral/leg 1 and 1000w to neutral/leg 2 you will have ZERO current through the neutral connection. I don't believe this is the case for two phases out of 3, In this case with 1000w to neutral/leg 1 and 1000w to neutral/leg 2 there will be SIGNIFICANT current on the neutral. Probably on the order of the ratio of 208V to 240V (I could get out a calculator) but it is probably around 15% of the current. In either case if you turn off one of the loads the neutral current jumps up to the current on the other leg. An interesting problem occurs if the neutral somehow becomes disconnected between the boat and shore power. All sorts of weird things can happen because the ratio of resistance (or reactance) of each side determines the relative voltage. So, put a 1000w light bulb on leg1/neutral and a 10w light bulb on leg/2 neutral. Properly wired the neutral is carrying most of the current for the leg1/neutral circuit. Now disconnect the neutral. The low resistance of the 1000W bulb will see very little voltage and the 10W bulb will see way more than 120V. I have seen this and very odd to put a fresh bulb into the blown bulb socket and watch it immediately burn out while the big bulb on the other circuit glows dimly for a moment.

I am not an electrician so I might have used the wrong words to describe some of this but the upshot is both versions of power exist in US and Mexican marinas. Your system should be able to handle either version as it is too easy to find out after you plugged in :-(

The rest of the world is far easier!!! I do think I read somewhere that 85% of the worlds marinas are 230V 50hz :-)

[crayiii]

If resale value is important, think about where you are likely to sell the boat. It seems like south Florida is the fastest and highest value market so what I would do (and what we did do) would be to spec the boat with the system that is the standard there.

If you're sailing the world, I would think that you'll limit the time in marinas so it shouldn't matter that much.

It also sounds like money isn't much of a deciding factor so go DC with everything including air conditioning and then you don't need to worry much about the voltage or frequency at the docks. We installed a second battery charger that is 230v and have a cord accessible in a sealed hatch that allows us to run the charger in those countries that don't have US voltage. Then we just happily run all the 12v gear off solar, wind, and as needed, the shore power.

[PaulCrawhorn]

Only buy chargers / power supplies that are universal world power compatible.