"Edgar" wrote in message
...

"Capt. JG" wrote in message
easolutions...
I've recently had an interesting, perplexing, and disturbing situation
come up. I connect my boat in the usual way to the dock box supplied A/C.
It can easily sit for a week (without me visiting) or more during the
colder months here, especially during the holiday season between late
November and early January.

I believe it's a 20 am circuit. In any case, I have very modest A/C
requirements when I'm not on the boat, namely, maintaing the two bilge
pumps and keeping the two batteries (starting and house) topped up. I
have a newish 30 amp rated cord, and the charger is very new, as well as
the batteries. Haven't had any problems aboard, as far as circuit
tripping or even a fuse popping. I tested both bilge pumps, and they work
fine, dumping the small amount of water without a problem.

In the last month, I've arrived at the dock to find that the dock box
switch in the off position three times. The first time I chalked it up to
me forgetting to switch it on when I arrived back at the slip. The second
time to my neighbor perhaps switching it off by mistake. However, the
third time I did some checking. My neighbor didn't do it (hasn't been to
his boat in over a month), the marina hasn't been working on the docks
(check with the maintenance guy), and I haven't been there to forget
(unless I forgot going, which is unlikely LOL).

When I spoke with the maintenance guy on the phone, he went down to take
a look, then tried to claim that it was an old cord (it's less than two
years old, shows practically no weather wear, and the terminals look
fine - no charring/pitting - on either end). The boat connection is
secure with a ring lock, so none of that flies. I'm fairly certain that
no one else who has a boat has even been around this last month, except
for possibly the rich guy on the end tie who rarely leaves the dock.

So, I'm left with a couple of possibilities... either someone has been
deliberately turning off the A/C (not necessarily maliciously) or
something in the box is tripping the switch. Am I missing something?
Could it be something else?


1. If the switch in the dock box is also a circuit breaker you should be
aware that some of these are very hair trigger and if you have fitted a
large charger with a transformer in it the current to build up the flux in
the transformer can be very high for a couple of milliseconds and some
breakers will trip at that point. I had this trouble on my boat which ,
having come from USA, has a lot of 110v stuff on board.
I fitted a 2:1 transformer to run it off 220 volts and it tripped all
power to the whole of the dock finger every time I connected. Spoke to the
transformer manufacturers and they said this transformer (rated 21/2 kw.)
takes 300 amps for a few milliseconds before it stabilises. They said this
is a common problem in marinas where boats are fitted with isolating
transformers.
Acting on their recommendations I fitted a'current limiter', which seems
to be a capacitor about the size of a quarter, in series on the input side
and problem was solved.

Well, I don't have a high end charger... and I don't run ac when I'm not on
the boat.

2. Sometimes people come to the marina to work on their boat and find that
there are no vacant sockets available for plugging in their tools so they
are apt to unplug someone at random and may forget to switch back on when
they go home. Perhaps it was the maintenance guy you refer to and he is
just putting up an excuse by blaming your cord.


This is what I think.... he's probably aware of it right now. :-)

The plug next to mine is typically empty, but it's possible someone needed
both.

It's a mystery of the sea I guess.



--
"j" ganz @@
www.sailnow.com