Nice work Wes!
You definitely did your homework here, thanks for the detailed write up.
I have been reading all of the posts about this and learning a ton.
That DPDT switch certainly helps keep things from coming in contact  with
each other.

Having a ready wired inverter at a moments notice can be a very useful
thing.

Doug

----- Original Message -----
From: "pickle vanagon" <greenvanagon@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, April 14, 2009 4:43 PM
Subject: Electrical setup: Photos and details

> I wanted to send an update on the big electrical project that I undertook.
>
> My goal was to make the AC/DC systems work together like they "should", so
> that the battery can power the A/C outlets via an inverter when no shore
> power is available, and the shore power can charge the batteries and run
the
> DC system when shore power is available.
>
> For AC->DC conversion, I settled on the Truecharge 10tb:
> http://www.xantrex.com/web/id/185/p/1/pt/7/product.asp
> I chose it because:
> *) It is a true multistage charger, capable of delivering 10 amps (in
total,
> but it can deliver all of them to either battery).
> *) With 10 amps, it can charge the system pretty fast, and if at some
point
> in the future I need to garage the van for a month, I can just plug in the
> van for a month and it will safely maintain the batteries.
> *) The manual for it specifically endorses using to support DC loads off
the
> battery.  Many other chargers I looked at warned against using the charger
> while DC loads were connected (not good for a camper), while some were
> ambiguous.
> *) It is compact enough to fit in the hidden electrical compartment with
the
> outlet/circuit breaker.
>
> For the DC->AC conversion, I chose an AIMS 800 watt inverter:
> http://www.invertersrus.com/pwrin800w.html
> This inverter has a nice feature I didn't find in any other inverters
> (except much bigger ones): the cooling fan is thermostatically controlled,
> so the inverter is silent unless it is under a large load.  It is also
> reasonably compact.  Another plus is that it is easy to disassemble (a
> necessity since the fuses are inside.)  This made it easier to wire up
> external leds and an external switch.
>
>
> To supply the outlets from the correct power source, I used a double-pole
> double-throw switch as a transfer switch.  I used this one:
>
http://www.mccampingsupplies.com/index.php?main_page=product_info&products_i
d=7845
> It is rated for 20 amps, has standard screw terminals for the connections,
> mounts in a standard electrical switch box, and even comes in brown!
> This is an on-off-on switch.  In my setup, up means inverter power, down
> means shore power, center means nothing.
> My original plan was to use a 3pdt switch, and use the third pole as a
power
> switch for the inverter.  I only found "component" 3pdt switches, however,
> and after beginning the installation using these, I decided it wasn't
really
> a good solution (it certainly wasn't "code", whatever that means in this
> case).
>
> Note: another possible choice would be an integrated converter-charger
like
> they have in big RV's.  This probably would have its own automatic
transfer
> switch.  I ended up not going this route because I wanted something that
> would usually be silent, and because I wanted something that was small
> enough to fit in the hidden compartments.
>
> Wiring details: the truecharge is hardwired into the shore power line
> upstream of the transfer switch.  Downstream of the transfer switch is the
> Pass and Seymour GFCI outlet, which also feeds (and protects) the hidden
> outlet.  (The stock 15a circuit breaker is upstream of everything on the
> shore power line).  (As I mentioned in an earlier email, the GFCI outlet
has
> an *very* slight buzzing when running off the inverter.  I may try a
> different brand of GFCI in the future, but listmembers and the Pass and
> Seymour service people have convinced me the buzzing is harmless).
>
> As mentioned before, the truecharge is located inside the hidden wiring
> compartment.  The inverter is located under the drivers seat.  My
subwoofer
> amplifier used to be located in the hidden wiring compartment, and has now
> been moved to the hidden space under the passenger seat.  Since our van
has
> the stock swivel seats, this involved cutting some sheet metal with a
> dremel.
>
> The auxiliary battery is a Walmart group 41 battery with the receipt taped
> to the top so I know where it is should I have to collect on the warranty.
> The batteries are joined by 6 gauge wire and a stancor relay (located
under
> the passenger seat, since that simplifies wiring the amp off the aux
> battery).  The relay is fed off the firdge relay.  Although I haven't done
> it yet, I plan on using an Altronix 6062 timer relay off the fridge relay
so
> that the firdge can be set to run on DC for an hour after shutting the van
> off, so that it can be run on DC during short stops without worrying about
> accidentally draining the aux battery all the way.  I ran 2 feet of 6
gauge
> wire from the alternator to the starter (which is connected to the
starting
> battery by the stock 0 gauge wire) so that the alternator can deliver its
> full charging current to the dc system.
>
> Photos:
> Here is the transfer switch and outlet:
> http://people.cs.uchicago.edu/~wes/vanpics/closeup.jpg
> The red button is wired as a remote power switch for the inverter, and the
> leds are wired as remote power and fault leds for the inverter.  Note that
I
> bothered to paint the outside of the switch and led housings brown!  The
> thing to the right is our propane detector.  It controls a solenoid on the
> propane tank.  When the alarm goes off, it beeps, flashes, and shuts off
the
> propane.  We haven't had any problems with nuisance trips.  Notice the
> on/off switch: this shuts off the alarm *and* the solenoid.
>
> Here is a bigger view to see how it looks overall:
> http://people.cs.uchicago.edu/~wes/vanpics/overview.jpg
>
> The circuit breaker has been moved to the inside of the cabinet next to
the
> hidden wiring compartment.  I forgot to take a picture of this, but it
looks
> just like it did before.
>
> The only other evidence of the whole operation is from the cutting
> underneath the passenger seat.  You can see the list in the carpeting:
> http://people.cs.uchicago.edu/~wes/vanpics/underseat.jpg
>
>
> I should say: this project took me significantly longer than I
anticipated.
> Even more so than usual.  I mean a really really long time!!  The problem
> was that I kept changing my mind about the best way to do things.  I think
> the way I settled on was pretty good, so if you're looking to do something
> similar and need more information about what I did let me know.
>
> -Wes