[VACList] Wiring an Inteli-power and other electrical stuff

["John Sellers" <sellersj@xxxxxxxxxx>]

Virginia,

There has been some discussion about this on the list in the past.  The
problem with the old polarity indicator light is that if you plug into a
2-wire outlet with the polarity reversed, the shell of the trailer is
then connected to 120 V through the light.  Whether the lamp lights will
depend on how well the shell is grounded by other means such as the
tongue jack.  If the shell is not grounded the shell will be hot.  If
the reverse polarity light were a little neon lamp this wouldn't
represent much safety hazard, but the incandescent lamp that Airstream
used could pass enough current to kill you.

If you have any doubt at all about the safety of your AC connection I
would recommend grounding the shell to a metal stake (pipe, rod, etc.)
driven a couple of feet into the ground.  Connect to the shell with a
good stout wire--#12 or so. If the ground is dry, pour a couple of
buckets of water around the ground rod.  That way if there is an
outright short circuit from the 120 V to the shell (which could happen)
the ground rod will conduct enough current to blow a fuse.

If you do this, disconnect the trailer from the AC source when rigging
up your ground--if the shell is really hot you might electrocute
yourself hooking up the ground rod.

> We had the trailer plugged into our 60 year old guest house (just a shack 
> really) that is ungrounded and the polarity of the outlets is uncertain.  I had 
> been working on the 12V wiring when my 4 year old son touched the shell and 
> said it felt funny.  The rest of us couldn't feel anything but the polarity light 
> was ON, and I did have a 12V short that I was investigating.  Needless to 
> say, I unplugged the trailer from the shack and replugged it into a known, 
> properly grounded outlet. I also solved the 12V problem.  So, can a 12V charge shock 
> a small child or do we have a more serious AC problem that I need to worry 
> about?  I recall reading that the reverse polarity lights in some models are a 
> hazard themselves.

He could probably feel a low current than older folks because the skin
on his fingers is not as thick.  Kids are also more susceptible to
electric shock than bigger folks.  This is nothing to take chances
with!  12 V is not a problem, but I think you have an AC problem.  IF
your reverse polarity light is on and the trailer is only grounded
through an accidental means like the tongue jack, there will be some
voltage on the shell.  This is a hazardous situation.  

Good luck,

John Sellers
WBCCI/VAC #1587
1960 Pacer