Your post contains an anomaly. First you said infinity between ground and neutral. Then you said the resistance on the panel was low also, .001 ohms.
Which is it? With the
shore power DISconnected it should be an open circuit.
With the shorepower connected, there would be a very low resistance between the white and green as they are connnected at the shore main breaker box. They SHOULD NOT be connected on your boat (imho).
If your AC ground AND AC neutral wires are both connected to the bonding system on the boat end, I suspect what's happening is that the load you are imposing on the shorepower is causing enough voltage drop on the shorepower cord to cause a slight (but just enough) AC voltage to be impressed on your bonding system to give the diver the heebeejeebies.
For example, say you have 120 volts at the
dock end. If your total current draw on the boat is enough to drop the line voltage to 114 volts at the boat (assuming the shorepower wires are all the same gauge), the neutral and ground wires are parallel connected at the shorepower AND boat ends, they will drop 1/3 of the total voltage drop while the black or hot lead drops 2/3 of the voltage. This means that at the ground connection to your boat you have 2 volts AC on your bonding system. This is measured between the
water (actual ground) and bonding system. That doesn't sound like a lot, but if you're immersed in
salt water it is enough to give you a tickle. It's also not doing you zincs any good.
If that's the case, make sure the Green wire (ground) is the only AC wire connected to your bonding system (if even that).
There is disagreement about whether or not to connect ANY part of an AC system to your bonding system, but I'll leave that to another poster. On my boat which is relatively lightly equipped as far as AC goes, The only thing connected to my bonding system is thruhulls and a couple of zincs.
The
battery negative is separate as well.
I live on a sandy point with canals and docks for each house. Our grounding system at the house is typical with a ground rod outside of each house connected to the ground/neutral inside the house ac panel. The problem arises when there's a big load at the house and the weather's dry.
The ground rod is trying to keep the panel's neutral at ground potential, but the sand is DRY DRY DRY. Consequently, my ground wire to my
dock wasn't exactly ground potential. I had about 1.5 volts AC+ about 0.5 vDC as well. I fixed that by driving a couple of
bronze rods into my beach at the low tide line. I connected them together with # 6 copper wire with
bronze clamps, and tied this to the green shorepower feed to the dock.
Just before I connected the rods to the house ground
wiring, I measured what kind of current I was bypassing. At the above voltage (1.5vac) I measured 0.5 AMPS AC. Not ma. Half an amp AC.
Needless to say, my zincs last a lot longer than they used to.
Sorry for the long post,
Steve B.
Linear Mode
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