Jim,
You are correct about the isolation xformer and the code, but I will never
connect the safety line from the shore. This may be against code, but I
would never jeopardize my hull to someone else's electrical fault. This
action presents only risk and zero value. It certainly does not add more
safety. A safety earth from your hull provides both adequate safety and
eliminates the risk of electric corrosion.
Steve

"Jim Woodward" wrote in message
om...
Steve:

Joao started this thread in three places, so we have more going at
rec.boats, but I wanted to respond here to one thing:


"Steve Lusardi" wrote in message
...
You should not use the hull as either a return path or a safety earth.
In
all cases, somewhere on the inside of the hull, there should be a welded
plate with multiple threaded holes or studs for all your earth
references AC
or DC. Never use the safety earth connection from shore power, you must
supply your own from this plate. Only connect the phase and the neutral
line
from shore power. Never connect neutral to safety earth anywhere, but at
this plate for on board AC generators. snip

This is a violation of ABYC and NFPA rules. If you are connected to
shore power without an isolation transformer (which I view as
essential on any boat), you must use the shore power green ground and
white neutral. Never make an onboard connection from neutral to
ground when on shore power. You must use the shore ground because it
is to that ground (at the marina's service entrance) that the neutral
is referenced.

If you have an onboard AC supply, either genset or inverter, this
requires switching, because when you are off shore power you will
connect green to white at one point on the boat. Most larger
inverters (those intended to be wired permanently) do this for you
with a relay.

Jim Woodward
www.mvfintry.com