Landstrom

Landström is a nautical term that means connecting the boat's electrical system to the one on land. On large ships, you connect to a high-voltage installation on land, via a coarse cable. On board the ship there is then a transformer station and a switchgear that distributes the electrical energy to the ship's various consumers. It means an environmental gain that commercial vessels have access to shore power because you then do not need to run your engines or auxiliary engines while stationary in port.

On leisure boats this usually means pulling ashore a shore power cable to an electrical cabinet that is placed on the bridge. You then get 230 volt AC voltage on board. On board the boat, the shore power cable is connected to a special electrical center with earth fault circuit breaker fuse and further to grounded electrical sockets. Usually the boat's battery charger is connected to the shore current, the battery charger then supplies the boat's low-voltage system with power.

As the negative pole of the charger often coincides with the protective ground of the shore current and the negative ground in keel bolts or engine blocks, this means that the metal parts of the boat that are mounted under the water surface are exposed to a strong galvanic corrosion. This may be due to the ground point of the electrical grid having a different potential to that of the water, and if the boat is moored in salt water, corrosion increases. The problem is remedied by fitting a protection transformer such as Galvanic separators or Isolation transformers.