A fellow has a boat that has two 3 phase input plugs at 125 amps in the EU. His marina only offers one 3 phase socket.
In order to run all of the boat, he needs to split the one 3 phase cord into two outputs of 3 phase.

How can he do that? I do suppose his total amps will be limited to 125A, but at least the whole boat can get some power, rather than just half the boat. This is a very large boat.

 

I would assume that outlet in any marina has overcurrent protection ( as well as GFCI). So you should be allowed to branch of and use splitters as long as they are done properly for that environment. If you do trip it, you will have some explaining to do.

 

I would assume that outlet in any marina has overcurrent protection ( as well as GFCI). So you should be allowed to branch of and use splitters as long as they are done properly for that environment. If you do trip it, you will have some explaining to do.

Marina power ports usually have ELCI circuit protection, like GFCI but at higher detection level to trip off.

So there is no inherent reason 3 phase wiring cannot be extended and split to another power inlet?
Such as have one cord from a single 3 phase marina dock outlet into a junction box, which has 2 exiting 3 phase cords with female end sockets to plug into the 2 boat's male 3 phase connection ports? Thus powering the boat's entire electrical system? Of course whole thing is limited to 125A not 250A currents.

 

What is unknown is what the two 3-phase shore power inlet connections are for. Are there actually two independent 3-phase systems on the boat??? I find that difficult to imagine, unless it is a RATHER LARGE "boat".
Consider the possibility that the two connectors might be to allow phase rotation correction for a three phase motor.
BUT, if they are simply to feed two independent electrical systems, then using a splitter could work. But I am trying to imagine what sort of boat would actually require 250 amps three phase service.