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<DIV><FONT face=Arial size=2>Gordon, here is how you can test for leakage
currents (as per Don Casey).</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>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.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>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.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>For more info check out Casey's "Sailboat Electrics
Simplified" at <A
href="http://www.internationalmarine.com">www.internationalmarine.com</A>.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Guy</FONT></DIV>
<DIV><FONT face=Arial size=2>Cyrena #466</FONT></DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A href="mailto:gewhite@crosslink.net" title=gewhite@crosslink.net>Gordon
White</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A href="mailto:alberg30@onelist.com"
title=alberg30@onelist.com>alberg30@onelist.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, October 26, 1999 6:59
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [alberg30] Winterizing A-4
and othe rthings.</DIV>
<DIV><BR></DIV>George - regarding chargers - I have had a West Marine isolated
automatic charger on <I>Brigadoon II</I> 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? <BR> 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.
<P> 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.
<P>
- Gordon White <BR> <BR> </P></BLOCKQUOTE></BODY></HTML>