I need to correct myself.. The statement above is probably not true "When the ground distribution wire is carrying current, because the wire has some resistance, it develops a voltage with a DC component"
Thinking about this more, it is not likely that a DC component (i.e., shift in the AC waveform) is developed by putting current on the ground line. Possible.. but not likely.. There will however still be an AC voltage on the ground line if it is incorrectly used to carry current.
Yandina has some good technical stuff on their site and paragraph 4 here also describes how voltage gets induced on the ground line: http://www.yandina.com/electrolysis.htm As mentioned, a marina with GFCI outlets would not allow this.
If you look around the internet, you will generally find that AC will not cause electrolysis, it is only caused by DC. So it is a little confusing that AC on the ground line would lead to a problem. Maybe the AC interferes with how the zinc works?
Also interesting is the use of a capacitor in these ground isolators
http://www.yandina.com/GIsolCap.html
This must have been written before GFCI plugs became common because I believe if you need the capacitor, you have the condition which trips GFCI. If your marina has GFCI outlets, you could not use the capacitor, you would be forced to correct the leakage in the boat AC wiring..
Thinking about this more, it is not likely that a DC component (i.e., shift in the AC waveform) is developed by putting current on the ground line. Possible.. but not likely.. There will however still be an AC voltage on the ground line if it is incorrectly used to carry current.
Yandina has some good technical stuff on their site and paragraph 4 here also describes how voltage gets induced on the ground line: http://www.yandina.com/electrolysis.htm As mentioned, a marina with GFCI outlets would not allow this.
If you look around the internet, you will generally find that AC will not cause electrolysis, it is only caused by DC. So it is a little confusing that AC on the ground line would lead to a problem. Maybe the AC interferes with how the zinc works?
Also interesting is the use of a capacitor in these ground isolators
http://www.yandina.com/GIsolCap.html
This must have been written before GFCI plugs became common because I believe if you need the capacitor, you have the condition which trips GFCI. If your marina has GFCI outlets, you could not use the capacitor, you would be forced to correct the leakage in the boat AC wiring..