230 Volt shore power

Problem to solve (why):

To be able to use shore power in Europe, and everywhere else that use 230 Volt line voltage.


  • No change to the stock installation on Horizon

  • Enough power to run AC and water heater (but maybe not at the same time)


  • Buy a step-down transformer. 3kva peak, and 1.5kva continuous power is sufficient.

  • Exchange the power terminal to standard 16Amp shore power terminal.

  • Ensure it’s isolating by checking that shore ground and boat ground is separated (otherwise it isn’t truly isolating)

  • Tie down on shelf in sail locker will keep it dry and safe.

  • Make/buy 3 shore power cables, 5/15/25 meters.

  • Make an adapter cable that converts European terminal (male) to US terminal (female).

  • Shore power is connected to the transformer, and the transformer to the boat.

Try this link:


Or search "UK power tool transformer/converter".

Isolation transformers

Safety and prevention of galvanic corrosion

Source: https://sites.google.com/site/catalaocml/home/boat-technics/galvanic-corrosion

The best solution to avoid galvanic corrosion and at the same time prevent any unsafe situation is to install an isolation transformer to connect to the shore-side supply.

The isolation transformer eliminates any electrical continuity between shore power and the boat. The shore power is fed to the primary side of the transformer and the ship is connected to the secondary.

The isolation transformer completely isolates the boat from the shore ground. By connecting all metal parts to the neutral output on the secondary side of the transformer, a GFCI will trip or a fuse will blow in case of a short circuit.