Re: European SM 240V looking to plug in 240V US Marina

Eric Freedman

Hello Dominique,

I believe you have the wrong plug as you do not have a ground..

You want a 50 amp twist lock plug. It has 4 connections for USA boats. For European boats you use only 3 of the 4 connections.

The green/yellow from the boat goes to the green in the plug.

The blue from the boat goes to the black in the plug .

The brown from the boat goes to the red in the plug. .

The white neutral, is not used.


The neutral wire is used on USA boats to get 110 volts between the black or the red.-this is not used.



Fair Winds


Amel Super Maramu #376



From: [] On Behalf Of Dominique Guenot
Sent: Thursday, May 14, 2020 6:28 PM
Subject: [AmelYachtOwners] European SM 240V looking to plug in 240V US Marina



My understanding: 

sv Viva #374 is wired for Europe 240V with 3 prongs; Phase (hot), Neutral, Ground

Ala Wai Marina in Hawaii does have 240V with 3 prongs, 2 Phases (hot)  and  Neutral. No ground, plug protected by a breaker at the Marina socket..
110V is coming between one phase and neutral. Then 240V is coming from the 2 phases.

I bought a socket NEMA L6-30P wich is fitting the Marina socket.   

My questions are:
1-How do I wire this NEMA L6-30P socket to replace the European Socket?

I foresee 2 mutually exclusive options: 
11- wire one US phase in the European Neutral
12-combine the 2 US phases in the European Phase 
Both options seems wrong ... 

2-Do I have to install a 30A "galvanic isolator" - as I have seen in previous threads - if the Marina socket is protected by a breaker?  

Any advice and tip will be greatly appreciated.
Dominique Guenot
+1 917 826 0945
sv Viva #374


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