An excellent dissertation on the subject. Thank you.

If this light were something down in the hull and the very salty
environment, or if it were something that was on and active more than
a few minutes a few times a season, I would isolate it for exactly the
reasons you state. Note that I am NOT using the mast as a return path
but have a complete black wire to the ground bus to which the mast is
connected anyway.

I actually do understand the issues which is why I am comfortable
violating them in this limited case but its instructive to all to stir
up these little debates.

--

Roger Long



"Steve Lusardi" wrote in message
...
Rodger,
The risk is electrical corrosion and the generation of stray
currents. Although it is also important in a car, it is more
important on a boat in salt water, as salt water is an incredibly
good electrolyte. Each electric consumer must have its own return
path. Never use a bond for a return path. In fact, bonds should be
avoided if at all possible, because bonds can act like antennas.
Your goal is to create circuits only where there is a consumer.
Stray currents cause corrosion and wood rot. Stray currents can be
caused by a multitude of things, like dissimilar metals
(electrolysis), auto transformer action from RF emissions and safety
earth connections to shore power. Sources of stray currents are
notoriously difficult to detect, let alone find. We use sacrificial
anodes to fight against electric corrosion, but they are a Band-Aid,
not a cure. How often have we seen bronze propellers wear out, but
we know that if we take the same propeller and toss it into the
ocean for a hundred years it will reemerge as pristine as when it
was tossed. If you violate the rules, be prepared for the
consequences.
Steve

"Roger Long" wrote in message
...
Well, excuuuse me.

Please, tell me the risks.

--

Roger Long



"Steve Lusardi" wrote in message
...
Rodger,
You didn't ask a question. You made a statement. Unless your
question was "Why should I not be considered stupid because I
knowingly violated code without understanding the engineering
behind the code?" If that, in fact is your intention, I'll leave
my opinion unstated. If you would ask what the risks are, I would
tell you.
Steve