I'm chiming in late to this thread.  What I did was similar to what
has already been discussed.  I kept all the outlets in the van on one
circuit.  The supply to this circuit can switch between the exterior
shore power plugin, and an inverter located in the secret compartment
next to the water tank.  I also had the failed stock westy circuit
breaker syndrome.  I replaced this with a 15A one I scavenged from a
power strip.  I also used a ground fault circuit interrupter outlet
to protect all the outlets in the van.  To do the switching I used a
double pole double throw switch.  One set of contacts turns on the
inverter when that supply is selected.  The other set switches the
hot lead to either shore power or inverter.  I was concerned about
lack of ventilation in that cabinet where the 400W inverter
is.  There is a hole in the bottom of the cabinet above that
space.  I have kept a small probe thermometer stuck down in that
hole, and have been surprised how little the amount of temp rise
it.  Even after several hours of running the fridge on the inverter
it only rises a few degrees.

A few more improvements I'd like to add would be a circuit for a
battery charger that would only be energized when on shore power, and
an indicator light that would glow when there is power to the
outlets.  That would confirm if I was on inverter when not plugged
in, or that the shore power was actually working if I am plugged
in.  Now I use one of those outlet testers with 3 lights to make sure
the shore power is really on.

Edward

At 01:43 AM 2/22/2009, neil N wrote:
>On Sat, Feb 21, 2009 at 7:57 PM, David Beierl <dbeierl@attglobal.net> wrote:
> > At 10:51 AM 2/21/2009, Dug Smith wrote:
> >>
> >> the circuit breaker and replaced it with a GFCI socket (with a power on
> >> light),
> >
> > Ouch.  Not safe, mate.  The ground-fault protection is nice, but
> > losing the breaker puts your wiring at the mercy of the breaker on
> > the other end of your supply cord, which in an RV place is liable to
> > be at least thirty amps.  You really, really need to put some kind of
> > fifteen-amp protection back, either fuse or breaker, it's a real fire
> > hazard otherwise; and one that your insurance company will fall on
> > from a great height if the situation arises and they find out.
> >
>
>
>
>Thaaaats what I'm talkin' about! (referring to my earlier "Dennis" quote)
>
>In my uneducated manner, I liken the Westfalia camper 115VAC wiring
>system to a "simplified" portion of residential wiring. Power in,
>breaker, circuit wiring, load.
>
>And proper grounding is important too.
>
>Meter is optional. <grin>
>
>Cheers,
>
>Neil.
>
>--
>Neil Nicholson '81 VanaJetta "Jaco"
>
>http://tubaneil.googlepages.com/
>
>http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines