how does an electrical leak detector work ?

[Brann-]

Hello,

I've read numerous posts explaining how one can detect a ground leak, and they all involve unplugging a battery terminal and taking a reading between the battery terminal and the now unplugged cable.

My aluminium sailboat is fitted with a VDO leak detector which is always can take a reading without unplugging the battery whatsoever. I've tried to look up its installation instructions but I haven't been able to find them (it seems the model has been discontinued).

Does someone know how these things work, and how I could mimic their operation to take a leak reading with an ammeter without unplugging my batteries ?

Thanks a lot !
Brann

[Captsteve53]

Before I get to technical i suggest you look at this very nice designed Australian system then get back to me:

https://www.youtube.com/watch?v=A868tFawAjI

There are clamp type meters (Fluke) and others that will measure leakage with out any disconnections.

Have seen the above fitted on several metal boats with great success

Cheers Steve

[Captsteve53]

Kent company still sells these VDO Leakage meters and presumably can repair or offer advice as:

Leakage Current Tester | KENT Marine Equipment

Cheers Steve

[noelex 77]

Originally Posted by Brann-

Does someone know how these things work, and how I could mimic their operation to take a leak reading with an ammeter without unplugging my batteries ?

There are other alternatives, but the best way of wiring an aluminium boat is so the positive and negative wires are never connected to the hull.

Shorts can develop, as well as minor current leakages from devices such as autopilots where carbon build up can cause some connection to the hull. Even a high resistance connection is not desirable. The VDO meter checks the isolation is still in place.

You can test the meter by making a deliberate connection between the hull and battery negative or battery positive (use a low value fuse in this wire as a precaution). The VDO meter should show a fault in both cases.

[mcarthur]

Revisiting an older thread... we have the same VDO meter on aluminium hulls. I can’t find a manual, and it seems they are discontinued items. I’d rather try and understand why we have 1 red negative led showing now than install anything new.
Any ideas?

If I do have all a new detector, the only one I can find is Seabis - are there others, or has anyone experience with seabis?