It has been some time since we have had this discussion on the List, and I don't dock, so my memory is a bit fuzzy about it.
I seem to recall that grounding the green conductor to boat ground completes a loop with the other end being the green conductor connected to earth ashore at the marina's main power point and that this creates a possibility of currents in this loop and that is not a Good Thing. Big ships do, or at least used to, not connect the neutral to the hull. All the current carrying conductors were above ground. If everything was correct, that is - there was no electrical leakage - then one could stand in a wet bilge and grasp a hot wire with impunity since the hull was isolated from all electricity. It was called the "bathtub system" I suppose because the electric system was entirely contained like water in a bathtub. This system does work well but you have to have a way to detect ground faults and correct them quickly. Like you, I am sure there are more knowledgeable folks on the List who can set us straight on this matter. Please speak up. (Where are you Arild?) Norm S/V Bandersnatch Lying Julington Creek FL N30 07.68 W081 38.47 > Hi Norm, > This is for the benefit of folks who do dock their boats. > Whether using an isolation transformer or not the docked boat ought to meet the safety requirements by having the shore cable ground conductor connected to the boat ground. (ie: Engine block and the negative terminal of the 12Vdc system) > However, if you connect the shore ground to boat ground you complete a circuit between own boat and the other boats in the vicinity and due to dissimilar metals in the water a DC leakage current may exist, causing damage due to electrolysis. > If you connect the shore ground to boat ground through a galvanic isolator you may be safe and possibly free of damage. > Then there is the question about whether to use a capacitor across the galvanic isolator and what harm does AC leakage do if any? > Andina or other folks may volunteer to explain the effects of AC leakage? > Cheers > Ahmet _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://liveaboardonline.com/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardonline.com/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
