hardworkingstiff
Senior Member
- Location
- Wilmington, NC
I've heard of a few problems with corrosion in marinas. Reading articles on the WEB about it seems to indicate that although the grounding system of the marina wiring is involved, it is usually not the cause.
Thinking about this some more, I had the thought that the only reference to ground with the electrical system are the ground rods at the service disconnect and the grounding system of POCO.
So, what happens if the POCO grounding starts to develop some resistance and the water the boats are in becomes a competitive parallel path back to the substation? The boats are supposed to have the engines bonded to the AC ground conductor and that would allow any metal on the boat in contact with the water to carry AC current from the AC grounding system into the water and back to the substation. Any degradation of the AC system neutrals or grounding connections would tend to raise the current flow on the marina ground conductors going to the boats.
In general, I've always been taught/told that AC current does not cause corrosion. I've read some people say that's not quite true, but the current level has to be pretty high. Usually, electrically induced corrosion is from a DC source (that's how dissimilar metals corrode, they set up a DC cell).
The question I would like to throw out for comments is, under what conditions would the marina wiring actually cause the zincs on the boats to corrode? Please understand this is not a question of how the AC ground system is part of the corrosion cells formed when boats are in conductive water and plugged into a common grounding system.
Thanks in advance for any comments.
Thinking about this some more, I had the thought that the only reference to ground with the electrical system are the ground rods at the service disconnect and the grounding system of POCO.
So, what happens if the POCO grounding starts to develop some resistance and the water the boats are in becomes a competitive parallel path back to the substation? The boats are supposed to have the engines bonded to the AC ground conductor and that would allow any metal on the boat in contact with the water to carry AC current from the AC grounding system into the water and back to the substation. Any degradation of the AC system neutrals or grounding connections would tend to raise the current flow on the marina ground conductors going to the boats.
In general, I've always been taught/told that AC current does not cause corrosion. I've read some people say that's not quite true, but the current level has to be pretty high. Usually, electrically induced corrosion is from a DC source (that's how dissimilar metals corrode, they set up a DC cell).
The question I would like to throw out for comments is, under what conditions would the marina wiring actually cause the zincs on the boats to corrode? Please understand this is not a question of how the AC ground system is part of the corrosion cells formed when boats are in conductive water and plugged into a common grounding system.
Thanks in advance for any comments.