"Chuck Baier" wrote in message
om...
Our marina has a problem at some slips with stray current. Some of the
boats are loosing zincs at a fast rate while others are not. Looking
for some help in trying to resolve this and what kind of equipment
will I need. Thanks. Chuck

When I was evaluating the effectiveness of those zinc "fish" anodes that you
hang from the boat, I used a clamp-on DC ammeter to measure the current on
the fish's wire, and on my AC shore-power cable (I don't have an isolation
xfmr or diodes). You might measure the DC currents on all the boats'
shore-power cables to see if there is a pattern or a particular offender.
Ideally, I suppose there wouldn't be any DC (or AC) current measured if you
pass the power cable through the ammeter clamp. Take several turns of the
cable through the meter clamp to increase the measurement sensitivity. You
should probably also check any other shore-connections while you're at it
(cable TV, phone, etc).

I've only tried this on my own boat, but I am assuming that any massive
stray current has to come from a shore connection. The polarity of the
measured current is probably important to figuring out what is going on. Of
course, this is all just a theory...

Regards,
Paul
s/v VALIS