[alberg30] Winterizing A-4 and othe rthings.

[Guy Lalonde]

Gordon, here is how you can test for leakage currents (as per Don Casey).

With your shore power cord plugged into the boat but not into the dock (generators and inverters off & disconnected), using a voltmeter make sure there is no AC voltage between the grounding socket in the dock receptacle and the grounding blade on the cord plug. Then set you meter to the highest DC Amp setting, switching down as needed. Put the red probe on the dock's ground receptacle and the black probe on the cord's ground blade. If you have a reading, you have leakage. A positive reading , it is damaging your underwater fittings. A negative reading, you are damaging your neighbours' boats.

A galvanic isolator in your grounding wire should block all galvanic current and the meter should read zero, although some isolators pass a few milliamps which your zinc should handle). If reading more than 15 milliamps, the isolator is not preventing corrosion.

For more info check out Casey's "Sailboat Electrics Simplified" at www.internationalmarine.com.

Guy
Cyrena #466
  ----- Original Message ----- 
  From: Gordon White 
  To: alberg30 at onelist.com 
  Sent: Tuesday, October 26, 1999 6:59 AM
  Subject: Re: [alberg30] Winterizing A-4 and othe rthings.


  George - regarding chargers - I have had a West Marine isolated automatic charger on Brigadoon II for three years. She was last out of the water in the spring and I could detect no electrolysis, though of course that is a possibility. My understanding is that if the charger is isolated by a transformer, no problem exists. Am I wrong?  Is there a way to test for leakage currents? If the main switch is "off is the system not isolated from the water? 
      A couple of years ago a friend visited and when he plugged in to my pier power his polarity alarm went off. Since then I have reversed the leads from the pier to my panel in the house. I hope that corrects that problem, though I do not know whether it was simply that his boat and my pier "disagreed" or whether the pier was hooked up wrong in a generic sense. 
      I now have one of the Schumacher 1 1/2 amp maintenance chargers ($24.95 at Wal-Mart) on the battery on the little outboard. There is no metal in the water when the engine is tilted up, as I always leave it, so I do not think I have a problem there. 

                          - Gordon White 
    
    

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