Galvanic isolator - warning or protection?

bobgarrett

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I fitted a galvanic isolator at the start of this season, tested it and all seemed fine. Since then I have been in numerous marinas without problem. Today, in a new marina, having plugged in I get a single warning light indicating DC leakage.
So the question is does this mean I should stay unplugged, or does it mean I can plug because I am protected? The instructions with it don't seem to state the answer.
Thanks for any expert advice as being a Sunday the supplier is unavailable.
 

VicS

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I fitted a galvanic isolator at the start of this season, tested it and all seemed fine. Since then I have been in numerous marinas without problem. Today, in a new marina, having plugged in I get a single warning light indicating DC leakage.
So the question is does this mean I should stay unplugged, or does it mean I can plug because I am protected? The instructions with it don't seem to state the answer.
Thanks for any expert advice as being a Sunday the supplier is unavailable.

It means there is a current flow and you are not protected.

But what make is the GI . There may be some info available on line.
 

VicS

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It means there is a current flow and you are not protected.

But what make is the GI . There may be some info available on line.

Continued a little later

If you could determine the polarity of the DC leakage you would know if its going to cause you any problem of not. If the boat ( anodes etc) are anodic compared with the incoming shore power earth there will be as a small risk of enhanced corrosion. If cathodic there should be no risk.

Measurement of the current would enable an assessment of the magnitude of the risk.

I am not going to explain how to do either of the above. If you understand and feel competent do it, otherwise don't.

Your boat is not going to fizz into oblivion in a few minutes so brief connection of the shore power should not be a problem.

Disconnection of the shorepower earth would overcome the problem if really necessary but not really advisable.

I dont think a neural / live reversal will cause the problem but its worth checking .......... as a matter of routine!


Neutral earth reversal might be the cause but the pontoon RCD should trip if you put much load on.
 

bobgarrett

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I have separate indication of earth/live/neutral being swapped and all OK so it is earth leakage.
The unit is from safeshore marine so I will await their advice as I emailed them because none of their documents are clear. I am not connecting as I bought the unit after damage sustained somewhere last year.
 

ianj99

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I use an isolating transformer. Cost more, is bulkier but nothing to go wrong and provides total isolation of all shorepower wiring including the earth. So there is no way a circuit can be established for galvanic currents to flow. This also means leakage from my vessel cannot affect those nearby.
 
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