How do you prevent electrical corrosion in a marina

[CascadeThumper]

Galvanic isolator works for me.

[alansmith]

Originally Posted by senormechanico

To a barnacle, maybe it's like a warm foot bath or a tanning bed...

Senior Mech, that is one of the best of the week jokes....good on ya!

[Thumbs Up]

If you have a Volvo sail drive it will be electrically isolated from the engine ground so no worries there. I would be good to figure out why the marina is "hot" because aside from corrosion issues there are electric shock drowning issues. If you have an A/C clamp meter you can test every power cord on the dock. They should all read pretty close to zero amps if you clamp it around the cord. If it registers any current then that is what is going into the water and probably to the boats around it (which could be causing an amperage reading from those cords as well). Find the hot boat/boats and go from there.

[mitiempo]

Originally Posted by Thumbs Up

If you have an A/C clamp meter you can test every power cord on the dock. They should all read pretty close to zero amps if you clamp it around the cord. If it registers any current then that is what is going into the water and probably to the boats around it (which could be causing an amperage reading from those cords as well). Find the hot boat/boats and go from there.

Not AC, but DC. The AC hot and neutral should cancel each other. There should be no AC current on the ground. The corrosion causing current will be DC that enters the boat from the AC ground wire. It will be traveling from any badly wired boats on the same circuit.

[billknny]

It's the internet, you'll get lots of advice. Some good, and some downright dangerous.

DO NOT disconnect the ground wire from your shore power connection, that would be dangerous. A safety ground wire has to be grounded AT THE SOURCE OF THE POWER. That is on shore for shore power, at the generator, at the inverter, or at the isolation transformer. Yes, that means connections have to change as your power source changes.

Yes, disconnecting the ground wire can make SOME kinds of corrosion less likely, but there are other ways to fix that problem. If dosconnected it means that you can not be sure you have and effective safety ground for your boat.

http://www.rjwsurvey.com/uploads/Grounding.pdf

[Thumbs Up]

This topic can lead down a "rabbithole". A lot of people leave it to experts. But the "experts" disagree. See, there is the AYBC standard that always said that your AC safety ground needs to be tied in to your bonding system as well as your DC ground. The European standard does not require this but does require ground fault circuit interrupters instead. The main issue is safety, not corrosion. It is mainly DC currents responsible for corrosion issues but the path is always through the bonding system connected to the underwater metal parts of the boat. It would be interesting to debate the merits of the two standards but might leave some people more dangerously confused than they/we already are. The O.P. has ordered a "corrosion management system from the US" (galvanic isolator or ?) (also leads me to believe that you are not in the US mr. O.P.). So if we can hear back from you as to what you bought and maybe to which standard your boat is wired or if you could tell us anything at all about your system maybe we could give some advice. My opinion is that it is better to have the underwater metal ungrounded, and unbonded and rely on ground fault devices for safety.

[Cadence]

Re: isolation transformers. I think they are a good idea. Just a precaution, I wouldn't lean over the side holding on to a bonded shroud, for instance, and touch the metal receptacle box on the dock. Chances are you would be OK but could get knocked on your butt.