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Originally Posted by osirissail
"Double down" on that - your set up is very dangerous, not only to yourself but to other people. It will work, - but - you do not have any fault protection when you do not use the shore power neutral.
U.S./North American and European/World power supplies both use a "neutral" and a "hot" wire. The difference between them is the North American supplies 110-120 Volts and the other supplies 220 volts.
In order to operate high power equipment without the liabilities of very high amperage, the North American system makes available a third wire (normally colored red) which when bridged with the black wire results in 220-240 volts.
By connecting that third wire - red - to your European neutral you are putting power/voltage on your primary return wire which is supposed to be kept at "earth ground" voltages. The measured voltage from a "neutral" line to a "safety ground" - green wire should be zero. In your setup you would be reading 110-120 Volts on a voltmeter.
On U.S./N.A. boats this would activate the "reverse polarity" warning light. Do you have such a light on your European power system?
As mentioned, in case of a fault like a short from an appliance to its case or cabinet anybody touching that case/cabinet and also touching a natural earth ground would be electrocuted - unless they can really react quickly they would most probably die. In case of a fault that shorts your boat's neutral to any underwater metal parts of the boat like propeller, bonding system, etc. you would most probably electrocute anybody swimming around your boat.
Although your "quick fix" works, it relies on everything else in the boat being perfectly proper. If you have a genset, you might cause serious problems with it by setting up shore power this way.
Although expensive to purchase, the proper and simple fix is to use a transformer to double the U.S./N.A. 110-120 voltage up to 220 volts and not "hot wire" your boat's neutral. Most marinas I have visited in the Caribbean have these transformers available for free or for a fee.
If the marina operator/management has any "electrical" sense they would be horrified at this set-up as their shorepower circuit breakers would most probably never trip in the event of an excess current drain caused by your boat - and - most likely the shore power cable and/or something else would start a fire which could destroy your boat and/or marina property.
That is why it was mentioned that if your boat is insured most likely you would not be able to collect anything once the insurance company found out that you "hot-wired" your boat's neutral.
Other than all the above, it you are comfortable taking the risks, go for it.
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again let me counter with proper
electrical analysis.
In
Europe, it's very common to find both floating neutrals or in fact indeterminate polarity. Only a fool in 230vac land assumes the Neutral isn't " hot " ( and you will be reminded on that every time you touch it ) the boats
appliances will function ( and CE requirements dictate)
safety even under floating or " hot " neutrals.
Many many boats will be wired to incorrect polarity shore power and will have no indication of issues. ( there will be no issues )
Hence you will find no " reverse polarity " lights. In fact loads of people in
Europe will never know what the real polarity of the mains is. ( on land and on boats )
Furthermore the boat, unlike NA boats. Will be fitted with a RCBO, which will protect the boat and trip if there is any neutral or hot to earth faults.
And yes it would be better to have breakers on the " neutrals " but it's not the end of the world
So stop making ill informed " insurance " statements. You have neither knowledge of his insurance nor the
electrical situation the boat is designed to handle
To suggest a European boats insurance would be invalidated by reverse or floating onboard neutral is nonsense.
I mentioned to the OP , that the process is in theory correct. yes it does generate one or two extra fault modes and I certainly wouldn't consider it without an RCBO installed.
Quote:
Although expensive to purchase, the proper and simple fix is to use a transformer to double the U.S./N.A. 110-120 voltage up to 220 volts and not "hot wire" your boat's neutral. Most marinas I have visited in the Caribbean have these transformers available for free or for a fee.
If the marina operator/management has any "electrical" sense they would be horrified at this set-up as their shorepower circuit breakers would most probably never trip in the event of an excess current drain caused by your boat - and - most likely the shore power cable and/or something else would start a fire which could destroy your boat and/or marina property.
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While this is indeed safer, it's not because it solves any of the above issues. It's primarily be cause it isolates the ground return path to exclusively the other leg of the transformer output. Not because it fixes any polarity issues persay. Equally the OP could wire split phase US to a 1:1 isolating transformer and get onboard 220vac that way too.
In my opinion all boats should have mandatory 1:1
safety isolating transformers anyway. But that's a different issue entirely
Ps explain the genset issue ?. I'm intrigued
Also explain this statement
Quote:
If the marina operator/management has any "electrical" sense they would be horrified at this set-up as their shorepower circuit breakers would most probably never trip in the event of an excess current drain caused by your boat - and - most likely the shore power cable and/or something else would start a fire which could destroy your boat and/or marina property.
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The OP boat is essentially an " appliance " both spilt phase hots to his boat will be fused by the marina. On board he has a RCBO , the fault mode you describe cannot occur as of he has an undetected on board neutral fault( on his isolated on board neutral) , ( AND his RCBO has inexplicably failed) the shore breaker on the relevant split phase will trip.
So folks stop being hysterical, just think about the systems and how they interact.
( ps of course not if you have a old US made domestic valve
radio from the 50s on board , then it's not safe !)
Dave
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