Originally Posted by Oliver L.
aren't we getting lost
here a bit?
you have 230 VAC 50 Hz. Everywhere in the US you have 230 VAC 60 Hz available. So what's the big deal?
I am now close to US waters, and aside from my "reverse polarity" indicator lighting
up when I connect to 230 Volts with two hot legs, not much is happening. In Germany
, every plug is reversible, i.e. you never know where the hot or neutral leg will be, and therefore all equipment
is built such that it really doesn't matter.
The thing you have to watch out for is pumps and compressors. Power input increases by 3rd power of the frequency, and therefore a 50 Hz system might become overloaded if run at 60 Hz. I got a dual frequency compressor
from Webasto, and fortunately Japan
is half 50 and half 60 Hz, which is why you can buy Iwaki pumps which are suitable for both frequencies.
New style (electronically commutated) pumps don't care about frequency, so you can use them anywhere.
I have yet to figure out where potential problems could lurk. NOWHERE in the whole boat do I have a piece of equipment
which has a neutral-earth connection - and if so, the GFCI would trip instantly. If it doesn't, you are good to go - assuming your marina has the ground conductor connected (they usually do).
One problem is that some vessels in Europe
(And especially England) tend to only have single
pole breakers on the branch circuits much like most US boats on 110V circuits.
Assuming that the vessel has a 32 amp shore power circuit breaker (common in Europe) and is double pole (as it should be). That can be the only breaker in the "Neutral" circuit.
So, if you hook Line 1 of US 240V split phase (single phase) power to hot, and hook line 2 of US 240V split phase (single phase) to neutral you do in fact get 240V sinewave power.
However, let's take a 5A branch circuit which is wired with an ampacity of let's say 10A. If the "Neutral" (which has been connected to Line 2) was to be shorted to ground the first circuit breaker to protect the wire would be the 32A double pole circuit breaker for shore power coming on the boat. The wire would then potentially get hot and start a fire.
An additional risk is that someone turns off the circuit breaker for let's say the hot water heater and then wants to work on it. The "Neutral" is still hot at this point and the first circuit breaker is the 32A shore power circuit breaker.
Now, I will definitely agree that I would NEVER work on the AC system of a boat with shore power connected. There are just too many potential problems and it is just prudent.
On the other hand, European and English
vessels have had Whole Boat 30ma Ground Fault Interuption as a default for some time. That is a double pole device and so a "Neutral" which is really Line 2 which shorted to ground would trip the Ground Fault.
In the case of a boat with single
pole breakers, an Isolation Transformer gets everything back to something sensible as Neutral gets bonded to ships ground (or in the case of a floating ground system is completely isolated from ground).
That said, many people do just hook it up...
One other observation, about half of the US pedistals which provide "240v Power" are actually two lines out of a three phase circuit providing 208V between the two phases. The voltage between neutral and either line is 120V, the voltage between the two lines is 208V.
I find it is better to use a step up isolation transformer which takes in 120V and creates 240V power so the voltage is always right.
I use the Victron automatic input adjusting 3600 watt transformer. If I provide the input 120V it outputs 240V, If I input 208V it outputs 208V, If I input 230V it outputs 230V, and if I input 240V I get 240V.
It happens it can be programmed to output voltages near 110V automatically also but not as useful a feature for you.