Nearly three weeks since new equipment
supplied by Veco NA re-installed on yacht, and working perfectly. Here are latest emails from distributor's rep. and my response (cut and pasted).
I am pleased to hear that the replacement system we supplied is working satisfactorily.
There has been much discussion between Veco S.p.A., Veco-NA, and the fabricator of the Keel Cooler
, and the general consensus is that at this point in time there is no evidence to suggest that there has been any type of mechanical failure of the Keel
Cooler, but that it was almost certainly the result of a stray current of some magnitude being impressed on the Keel
Cooler from an outside source. Veco NA is currently waiting for the original equipment
to arrive here for further analysis, as unfortunately it was not shipped to us before Peterson Marine
closed for their holiday break.
I note that you have had several parties make tests on your electrical
systems, but I have seen no mention of whether or not you have any form of galvanic isolator
or "Zinc Saver" installed on your incoming shore power
ground wire. When I mentioned this fact during our phone conversation you stated that you were not aware of these devices or if one is installed on your vessel. These items are required by ABYC to be installed on all new boats, and are designed to prevent harmful DC stray currents, such as that which most probably destroyed your Keel Cooler, from entering a vessel via the AC shore power ground. A "Zinc Saver" is designed to block these harmful DC currents while still providing the required safety
protection to occupants from potentially lethal AC wiring
faults on board. As a condition of Veco NA having provided a complete replacement Keel Cooler system to you free of charge, we require that, if a galvanic isolator
device is not already installed, that one be installed at the earliest possible opportunity to lessen the possibility of repeated failures of the Keel Cooler and/or other thru-hull fittings, zincs, propeller
It must be understood that any survey
of the electrical system
on a vessel is only relevant to the time that was performed. It can in no way be taken as a definitive bill of clean health
, as there are so many possible outside anomalies that may not have been present at the time of the survey
, and this is especially true if the vessel is connected to shore power and no galvanic isolator installed."
Two weeks after new equipment installed and system continues working per specs. I can confirm that the boat is equipped with a galvanic isolator and a combiner, which prevent stray current from leaving the system.
Accordingly, I believe this was not the problem. Further, I have had input from two parties who suggest the following may have been the cause;
1. "where this would come from is via the compressor
and the copper compressor
vapor discharge line to the keel cooler (condenser)."
This seems related to the following suggestion:
2. "Electrolysis cannot occur on an isolated piece of metal in salt water
. It is all at the same voltage but if it is isolated no current can flow so there is no electrolysis.
When it is connected to another piece of metal, ESPECIALLY if the other piece is a different metal, you just created a shorted battery
and electrolysis will start.
By following the wrong advise and bonding everything in the boat you are creating batteries where it is unnecessary and making electrolysis problems worse."
I don't know myself. What I do know is that the other thru hull
equipment on the boat, which include two A/C units, watermaker
, genset and the Yanmar
auxiliary have never experienced a problem.
Ditto for the previously installed AB refrigeration
system , SSB
and all the other electronics
. The boat and equipment have performed beautifully
With respect to your "general consensus", I am not surprised to hear that the manufacturer, supplier and NA distributor claim that " there is no evidence to suggest that there has been any type of mechanical failure of the Keel Cooler "
while acknowledging that the failed equipment has never been inspected because it hasn't been received. What else would they say publicly.
To me, as a professional pilot, this is akin to the NTSB releasing a statement that the aircraft lying in pieces on the ground could not have been the cause of the crash, without inspecting the wreckage. But that's just me.
I'm still happy that the equipment continues to function properly, despite my spouse asking me if it's still working every time I come home from the boat.