another electrical thread....

[snowleopard]

i have a socket with built-in RCD. some marina power supplies cause it to trip, even if i have nothing connected to the socket. is it likely that the cutout is detecting earth leakage on the shore side of the supply?

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[halcyon]

Your RCD only measures current through the socket, what happens up stream will not effect it.
Wander about induction from something up stream causing a spike?
Have you any neons or the like on the socket.?

Brian

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[MainlySteam]

I have seen reports of tests with small generators having floating neutrals (such as the small Honda's) where an RCD downstream of the generator would not work reliably for reasons which were not explained. However, the reported important result was that they would not always detect an imbalance rather than reporting they operated spuriously. But extrapolating from that a possibility (and only a slight one at that) is that some problem with the grounding of the neutral in the marina's supply might cause what you experience if it only happens in certain marinas and not randomly.

As you are probably aware, if the downstream side goes to a boats own ac system random RCD tripping is often through leakage in the damp/salt environment. I accept what Brian says, that the cause is likely to be on the boat

Our own boat has a fixed RCD in its shore power inlet and I have never experienced what you describe - not that we visit many marinas, not that many of them around here /forums/images/icons/smile.gif.

John

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[Mike21]

If socket at marina damp, can cause rcd's to trip when you plug into it

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[Talbot]

Would reverse polarity cause this?

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[charles_reed]

If your internal ring main goes anywhere where it might be under salt water (ie in the bilges or a damp locker) you might get that reaction from your RCD, as I do.

DON'T go hunting for it with the shorepower connected - you're liable to give yourself an unpleasant shock.

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[Trevethan]

We had this problem last winter. But mostly the RCD on the stanchion went ..
S
pent days trying to isolate problem. poking things with a multimetre.

At one point I was thinking it must be the battery charger Before ripping it out and buying a new one, I remade my cables, still didn't help, then I unplugged the neighbour's supply and plugged into another socket. pop went that one. --

So I remade her cable, which had been leaking to earth.

It was a massively frustraing experience cos it would go all the time.
I guess you'll want to check between your fittings and your RCD I guess? Maybe a slightly damp socket somewhere?

Good luck

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