South Coast Sailboats
120v Shore Power Setup with three
I had created a 120V
shore power electrical system for use at the dock and when the
boat is being serviced. Basically, there is receiving outlet mounted
in the base of the transom. This is where we connect the boat
to the dock, we then run a twenty-foot heavy extension cord to
where we would normally plug into the dock. Before plugging into
the dock, we install a four-foot extension that has three outlets
and a GFI (ground fault interrupter) circuit built in. This is
what we plug into the dock power. For convenience, this feeds
two duplex outlets. One mounted in the cotpit, and one mounted
inside near the keel winch. Additionally, there is one more feed
that first goes to a standard wall switch, and then to a duplex
box mounted up in the battery compartment in the bow. This is
used to power a 120V battery charger that is in place and hooked
up to one or the other series of batteries mounted in the bow
I have been fighting the corrosion thing for
many years and when it comes to electrical systems, I have figured
out a thing or two.
Some insights: When wiring in your shore power
systems consider the following:
First for my wire, yes it is braided or mulitstrand
wire (#14-2 with a separate insulated ground wire). This is wire
meant for industrial grade extension cords. I like multistranded
wire much more than solid wire (even in lighter wire) because
it is more flexible, not prone to snap or break where kinked.
It also when setup properly, will last for many years without
degrading and corroding. All my AC wiring is made from this same
type of wire. I used this for "the cattle prod" line,
as well as for box to box wiring.
Second, the boxes I used were simply outdoor
grade with rubber seals and snap over covers. In the two positions
where I was not using special boxes, they are standard galvanized
metal boxes with Stainless Steel cover plates.
Third, all connections with or without metal
crimp on connectors should be coated, dipped or otherwise impregnated
with something called No-Lox. No-Lox can be purchased at any electrical
supplier as well as Home Depot. It is non-conductive, and is similar
in appearance to automotive grease on color and consistence. It
prevents the air and moisture from making it's way up into the
mulitstranded wire. Cover the wire with No-Lox before adding a
crimp connector, and also brush on more over screw down connections.
By giving the wire ends a decent air/water seal, the corrosion
is stopped before it can start. This is also a very good idea
for the battery terminals.
Also, in place of metal boxes, you might
consider the current crop of plastic boxes. They are of reasonable
quality, won't rust, and should provide good long-term service.
To answer a specific question, why not wire
directly to the boat? The simplest answer is for flexibility.
I keep my boat in tidal waters (at QCYC tides rise and fall 7-10
feet, in can simply disconnect (it has give). I also like being
able to coil up the line and store it way when it is not being
used. The double plug line allows for very easy hookups with a
minimum of fuss and bother.