Current Leakage

[elevy]

How can I tell if there is current leakage in my marina?

Thank you in advance for your help!

Ed

 

[mistercomputerman]

Here is a good explanation and test:

http://www.tri-statemarine.com/uncategorized/electric-shock-drowning/

 

[elevy]

Here is a good explanation and test: http://www.tri-statemarine.com/uncategorized/electric-shock-drowning/

Thank you Mistercomputerman!

 

[ttmott]

That's fairly easy. With a DVM measure voltage between the ground and neutral of the dock receptical; your boat should be disconnected from the shore power during this part. Write this "baseline" value down. Now connect a bare copper wire to one lead of the DVM and then drop into the water then measure to both the ground and neutral of the same receptical. Take those two measurements and subtract from each other. So now you should have four values; baseline receptical ground to neutral, receptical ground to water, receptical neutral to water, and receptical ground/neutral differential to water. Now, the ground to water should be close to zero, and the baseline receptical ground to neutral should be very close to the differential value described above. If not that means someone or something is leaking into the water from the same electrical supply system and they are rather close buy. You shoul use extreme caution during this process as if there is a significant leak it can be very hazardous. Now run the same test with your boat connected to the shore power ensuring all systems remain in a steady predictable state (either on or off). If you then see a difference from the previous measurements then your boat has a problem.
you may need to do frequent measurements between the shore power ground and neutral as this value will change depending upon other loads (boats) coming on and off.

 

[Sum Escape]

mistercomputerman,
Thanks for the reminder. I started this thread a couple years ago on ESD. All should be aware of hazards of swimming in marinas, especially fresh water ones!!!
http://clubsearay.com/showthread.php/47341-Swimming-in-Fresh-Water-Marinas-Don-t-do-it!

And a good article from Boat US

http://www.boatus.com/seaworthy/eline/shock0812.asp

 

[Rxflyer]

I would always assume that there IS stray current at the dock...if not your slip, could be the next one over. Scary stuff...