Victron Galvanic Separation

A galvanic isolator prevents or reduces electrolytic corrosion, also known as galvanic corrosion. It blocks low-voltage currents entering the boat via the ground wire of the shore power cable. These currents can cause corrosion to the boat's underwater metals, such as the hull, propeller, propeller shaft, keel bolts, drives and engine block.

The galvanic isolator consists of two diodes that are connected anti-parallel. When connected in this way, the diodes allow current to flow in both directions, but only above a certain voltage threshold. The diodes conduct current where the voltage is approx. 1.4 VDC.

The isolator is installed directly behind the boat's 230V connection. The increasing voltage from the galvanic isolator is higher than the potential difference between metals. As a result, this voltage will not allow current transfer and thus the galvanic isolator will prevent electrolytic current. Nevertheless, if a (higher) voltage fault occurs in the AC circuit, the diodes will let current through and the residual current device will interrupt the circuit.