How can I run a European system (50hz 240v) in America (60hz 120v)?

[Dsanduril]

A floating neutral system is the absolute perfect place for what Americans call a GFCI and what the rest of the world calls an RCD (residual current device). A GFCI works by measuring the difference in current between the hot and the neutral (or even two hot legs if configured correctly). The presumption is that if there is a difference in current the other piece of the current is flowing to ground somewhere, hence the moniker "ground fault".

But it is really measuring the current between the two legs of the circuit - they really should be identical. We have a floating neutral and every circuit has a GFCI/RCD. If for some reason there is fault and electricity is flowing someplace other than where it is intended then the unit trips and the circuit is open (both legs with the right device). Perfect for floating systems (pun intended).

[Edit] in fact the code in the US requires the installation of GFCI outlets in places where no earth safety ground is available.[/edit]

[Pansatonic]

Originally Posted by wingssail

...when the neutral is grounded it makes every outlet box, every appliance case, every grounded bit of metal on the boat into a potential shock hazard...

You have a half empty glass viewpoint, make the glass half full instead with proper protection devices correctly installed.

[Pansatonic]

And whats up with the "FLOATING" definition?

Do you mean a TT system??

The TT systems i have experience with is behind a locked door with a key given to certified personel. And this is for a good reason. Ok your bathroom shaver outlet can be a TT one but its not a system, its a device.

[Pansatonic]

Originally Posted by wingssail

...I just don't like living in a space encircled by potentially hot, exposed, bits of metal...

You already are surronded by high AC voltage. But as long as no salt, vibration, age or loosening connections happens you will be fine. Same as weather forecast, becouse you dont like the idea you dont want a weather forecast.

Bound neutral and ground in one only location, and let your GFCI and fuses tell you when salt is trying to kill you.

[s/v Jedi]

Originally Posted by Pansatonic

A normal return path can be touched UNTIL its not normal any longer. How will you know when its not? GFCI as an detection device will not tell you.

Why is a design where potential life saving fault detection can not be used, a good thing? (relating to your thumbs up). Truly curios.

I’m sorry but you’re wrong. Grounding the neutral does not provide safety ever since metal appliance parts are not connected to neutral anymore.

It’s the same as arguing that double isolated is dangerous because the appliance is not grounded. The thing is that it’s different from what you’re used to, but what you’re used to may be ore dangerous. In fact, any repair work on appliances is done with an isolation transformer for safety, break all galvanic coupling with ground.

[EngNate]

Whaaaaaattt?? There's a lot of mis information going here, I wish I had more time to sort it out. And, how did it get here from the simple question of converting US/Euro power....

The assertion that the convention that's been adopted worldwide for about 100+ years (ground bonded to neutral) is wrong, is wrong. The term 'floating neutral' is wrong - it's floating ground or bonded ground. Bonding ground to earth is another thing, more below. I will point out that there are commercial inspected vessels with primary electrical systems 480 Volts and up that are floating ground, and there is no conclusive determination that one system is safer than the other. The convention is that domestic supplies have ground-neutral bond. If there's shock potential on 'grounded' parts under any conditions then there is/are fault(s) in the wiring, and eliminating the g-n bond is sure not the solution. GFI's work on either system, on the basis of all current canceling out between the current-carrying conductors, any that 'goes missing' from the intended circuit, regardless of where it goes, causes an imbalance that is detected. That said, if there is no path back to the source then no current can flow and there will be nothing to detect. If there is no current flow through you, you will not get a shock (though it doesn't take much), regardless of the potential.

When a connection to the earth is made, it is to include the earth in the equipment grounding circuit. The earth isn't ground, but becomes grounded with respect to that system and its source of power.

The OPs OQ was answered, power converter or all 50/60 equipment and a 50/60 transformer. The inverter scheme is more an option for already made systems and often a good solution for smaller N American yachts going to Europe where they find power very expensive and often limited.

I've put a number of posts here in the past, and recently some on TF, on ground-neutral wiring, faults and fault currents due to improper G-N connections.

[Pansatonic]

Im not wrong, its really simple.

A complete circuit means returning to the source, call that return common or neutral or floating ground, call it bob if you want. But the circuit wants really really badly to return back to mummy.

Bob will come home using the back door even if you renamed your front door to floating door. Bob will always come home because he craves his mummy cookies really bad.
Even if you live in a hot air balloon completely isolated from earth far below, or by renaming your cookies to floating cookies. Bob will come home to mummy even in unusual ways.

Only way to see if bob takes the backdoor entrance is by installing a door detector. The only simple way that detector can work is by having a trusted reference, the good old dog that both Bob and mummy know.

Backdoors is detected by using a GFCI, and only way a GFCI works is by having a reference. Prinicipale of a gfci detector is the same on earth with a 120v leg and a 200kg copper grod rond, and the same is true in a hotair ballon with a 329,8v leg whith a reference of the ballon basket chassie.

Now, you can rename everything above to whatever names you are comfortable with including floating. But renaming things does not change physics. Your transformer creates a return leg that your appliances will use, if your appliances finds another unusual way back to the transformer it will, despite you calling it floating.

I would recomend stop using the name floating becouse it only confuses.

But heck dont bother listen to me. Instead read Victrons excellent pdf Wiring Unlimited.

https://www.victronenergy.com/upload...limited-EN.pdf

After you read it and understand it tell me what your system does that makes it not needing a gfci for fault detection.

[Pansatonic]

Originally Posted by s/v Jedi

...In fact, any repair work on appliances is done with an isolation transformer for safety, break all galvanic coupling with ground...

By the way, this is also wrong. Many reasons an IG workplace (isolated ground) is used when working with electronics, and safety is not one of the top 10 reasons. I would say noice is most important reason, you cant measure accuratly when half of kilometre away a electric train passes by. Or your ac starts. You need a reference point that is "Isolated" from whatever else.
Also by definition things you are measuring are not "working" correctly, it can be broken so your voltage delta needs to be "floating" with reference to earth.

Lots of reasons but safety is not a driving reason, this is proffesionals in a controlled einviroment. IG einviroment for an electronics work is absolutly not a reference in the way you mean. You can even argue that its the opposite.

[Jpernick]

For a multi frequency tolerant European wired boat, can an isolation transformer / galvanic isolator be used to convert split phase 4 wire US shore power to single phase 3 wire bonded neutral / ground aboard? Is a shore side RCD happy with this?

[Dsanduril]

Originally Posted by Pansatonic

...Backdoors is detected by using a GFCI, and only way a GFCI works is by having a reference. Prinicipale of a gfci detector is the same on earth with a 120v leg and a 200kg copper grod rond, and the same is true in a hotair ballon with a 329,8v leg whith a reference of the ballon basket chassie...

That's simply not how a GFCI works. There is NO connection on a standard, single-phase GFCI to earth. There is a connection to the hot and neutral legs of a single circuit. The GFCI is a differential current detector. As you said, Bob likes to come home, and a GFCI checks to make sure Bob is coming home exactly as you expected, by going out the hot wire and coming home on the neutral wire for the same circuit. If even just a little bit of Bob, the tip of his pinky finger (5mA, 30mA, whatever portion the circuit designer selects) decides to come home by some other route - any other route -, or decides to go somewhere other than home, the GFCI opens the circuit.

The idea of a PE ground is antiquated, and even the codes are accepting more and more cases, with each release, of systems that are not required to be grounded. The whole point of a grounded neutral was to provide a low resistance fault path so that you trip a breaker rated for the full load of the circuit. That's a very coarse and crude approach, but it worked for the technology of the time. You provided a way for a whole bunch of electricity to flow during a fault and that tripped a breaker.

Now we can install devices that measure differential current down to a few mA, and other (or combined) devices that can check for insulation faults and sparking. Those devices are far superior in terms of safety than having a PE ground create a trip on a breaker that is rated for the full circuit current.

[EngNate]

In the Victron publication all the drawings of recommended circuits that include a source of AC power show ground and neutral connected at the source. The one exception is the incoming grid, where the bond is on shore at the transformer or distribution panel. There seems to be some conflict in the information. On one hand they present the potential hazard of the bonded configuration but then go on to provide that configuration in their examples. Sorry, I'm going off now, have to go fix another boat...

[Pansatonic]

Originally Posted by Dsanduril

That's simply not how a GFCI works. There is NO connection on a standard, single-phase GFCI to earth...

Read it again, i wrote referenced. I did not write connected. The reason i write referenced is becouse "ground/earth" is only a point of view. To measure to detect you need a reference. For example. You are standing still in a train going 100mph, to determine your speed you need a reference, if you measure against earth you are going 100mph but if you measure with train as reference you are traveling 0mph.

And exactly as you say earth might not be a correct reference in different installations, therefore i am writing a reference and not a connection per se becouse i agree.

[s/v Jedi]

You guys are still wrong

You need ground, and a grounded neutral for the RCD to work. Yes, that is correct. The RCD activates when you are being electrocuted. The device detects that and interrupts the circuit to save you. (Someone explained that it is a differential device, comparing current between phase and neutral, unconnected from ground. The reason that it needs ground and a grounded neutral to work correctly is because without that, you can’t be electrocuted)

So what is even better than a functional RCD? How about a system where you can’t be electrocuted to start with? Wouldn’t that void the need for functional RCD’s? In a floating system (exactly how it is called) there is no galvanic coupling with ground whatsoever. There is no “back door” for Bob to use.

Then the Victron documentation. It surely includes a floating system, it’s right there on page 61 (IT network). Even compares it with the safety transformer for bathrooms.

[Pansatonic]

Originally Posted by s/v Jedi

...How about a system where you can’t be electrocuted to start with? ...

A unused potato peeler wrapped in a thick styroform stored in a gally drawer for two years will break becouse it knows its on a boat. But your electrical wiring will never fail becouse you said the magic words floating.

You are telling me when your loads finally take a different path back to mummy becouse of a faulty wiring, those cute electrons using human flesh as aid will not be felt becose they where supposed to be floating.

I have a bigger chanse waking up with Jennifer Lopes then your magic floating spell words will protect your wiring.

[john61ct]

I hate it when my bias against bad spelling and grammar cause me to discount an author's credibility.