Victron Energy Galvanic Isolator VDI-16

The Victron Energy Galvanic Isolator VDI-16 is an essential piece of kit for boats fitted with an AC shore power connection. It prevents electrolytic corrosion of the boat’s underwater metals, like the hull, propeller, prop-shaft, etc. by blocking low voltage DC currents from entering your boat via the shore power earth wire.

The galvanic isolator consists internally of two diodes which are connected in anti-parallel configuration. When they are connected in this way, the diodes allow current in both directions but only above a certain threshold voltage (the voltage at which diodes conduct is about 1.4 VDC).

As the forward voltage of the diodes in the galvanic isolator is higher than the potential difference between metals, conduction is prevented and no electrolytic current can flow. However, if there is an error voltage in the AC circuit (which will be higher than 1.4V) the diodes will allow current through the earth wire, allowing the RCD in your mains consumer to safely disconnect the boat from shore power.

This isolator is installed directly behind your boat's 230VAC shore power inlet, has a maximum current capacity of 16A, and is IP67 waterproof rated.

Please note: under normal operation the isolator will only become warm (max. 20°C increase in temp), however, under a ground fault condition it may become hot so it is important to mount it vertically (to allow the cooling fins to dissipate maximum heat) on a heat proof surface.