www.iFourWinns.com

The Mercathode and Volvo Penta "Active Corrosion Protection" units are NOT galvanic isolators. They monitor the potential around the outdrive and if they detect it is at a level so as to give high rates of corrosion, they apply a correcting potential to counteract it. They enhance and extend the life of the anodes. Certainly for the Volvo one, it's only calibrated to suitable for use in salt water

This was earlier in the thread;

"The Galvanic Isolator blocks electrolysis currents from flowing in the ground conductor of your shore power hookup. It provides approximately 1.2 volts of isolation to isolate electrolytic voltages from the dock but yet pass safety currents to ground in the event of a short circuit, or power leakage on your boat."

If there is one, it will be fitted somewhere between the hull mounted power inlet socket and the AC board. It basically isolates the boats ground from the ground of every other boat connected to shore power in the marina. Otherwise, your boat's anodes might be trying to stop corrosion on all the submerged marina metalwork and other boats as well as on your own; and once they were (very quickly) used up, your outdrive would become the anode for all the other boats!!  I can never figure why they FW ever fit shore power to a boat without the Galvanic Isolator, but they do because of cost I imagine. ( mine has shore power but no GA, but I never use the shore power so it doesn't matter).

Graham

I stand corrected. I guess I find it confusing too. But my point on anodes still stands. If you are at Brookville there are some older boats and some with metal hulls so stray current is a high possibility. Check your anodes regularly

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2008 Horizon 260 VP 8.1 Gi