Friday, December 4, 2020

Re: [electricboats] Grounding.

Then there are those of us without thru-hull fittings and use outboard propulsion.  Many/most(?) of us lift our prop out of the water when the boat is moored and charging at the dock.  There's not a lot of incentive to electrically bond the boat to the water in such cases.  And when charging, shore AC ground is typically brought onboard, passed to any AC appliances (and charger) and those are thereby grounded.  I'm not much interested in grounding my pack DC circuit to that same ground, defeating the isolation in the charger.

I'm a bit confused about the point made earlier about possibly needing to fuse battery negatives also if you don't ground the negative.  It seems to me that as long as every positive source is fused, then even if one of them ends up shorted to, say, a chassis, then if something shorts the negative to that chassis you still would have the positive fuse blow and the chassis would then be floating again.  If the concern is about the human safety of having that chassis accidentally being 'charged' and connected to +V, adding fuses to the negative lines still won't eliminate that risk since those fuses would have to pass much more current than that required to stop a heart.

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