From: John De Armond
Subject: Re: Campground Electrical Hook-up????
Date: Fri, 07 Jan 2000 16:24:46 EST
Newsgroups: rec.outdoors.rv-travel

Allen Malone wrote:

> I thought that the neutral bonding should occur at power the source which in
> an RV may be the generator, an inverter, or externally at the shore power
> source and, that the RV power panel is like any secondary distribution panel
> and should not have a neutral / ground bonding at that point.  Perhaps I am
> confused... would not be the first time!

You're correct.  I was trying not to generalize too much from my
MH.  In it the neutral and ground strips are bonded.  I think that
was permitted when mine was built in 82.  The NEC has a bunch of RV
exceptions that basically make what we have legal so I'd not wager a
guess about any of this without studying the NEC.  And since NEC99
weighs about 10 lbs, I gotta be in just the right mood :-)

> I believe that it has only been in recent years that a four wire connection
> (to do it right) that includes the neutral circuit has been required.  Older
> dryer outlets were designed to provide only 240 VAC (no 120 VAC) and used
> three prongs to carry the two mains plus a ground.  While it is true (in
> many countries / most of the time) that 120 volts will exist between one of
> the mains and ground, using such a connection would require that the ground
> conductor carry current back to the distribution panel.  This can cause a
> potential fire problem due to overheating since the ground wire is
> frequently a smaller gauge than the main conductors  as well as creating a
> potential safety problem for anyone working on the system who does not know
> that was done.

The NEC at least since NEC93 (and probably before) has required that
the ground wire be the same gauge as the power wires.  Previously,
yes the ground could be a gauge size or so smaller.  I'm not sure
when the 4 wire plug requirement for dryer plugs came into effect. 
I know it's in NEC96.  I no longer have 'em back any further back
than that.

> I believe that recent construction now uses a four prong plug which implies
> that the neutral is carried to the dryer outlet.  That is the required
> starting point to do what you recommend.  Using a pigtail to connect the RV
> power feed into the dryer outlet is a way (not quite as convenient) to
> avoid possible circuit breaker tripping by avoiding the possibility of
> simultaneous RV and dryer use.  Another consideration for anyone
> contemplating this type of installation is that you may want to consider
> GFCI protection on the outdoor circuit that goes from your house to your RV.

Based on years of experience in operating catering trailers which
have wiring quite similar to RVs, I have a very dim view of GFIs on
the main power feed.  Just too much leakage, particularly in
commercial gear, to make the connection work.  GFI in the outlets is
good - you're past all the house wiring and extension cords.  A 50
ft cord that's been out in the dew a few days can absorb enough
moisture that it will trip a GFI with nothing plugged into end.

BTW, just got ADSL installed for this machine.  Bitchin'!!!!  I'm so
close to the central office that I'm getting the full 1.4mb/sec
thruput.  Indeed, if BS.net was not throttling the bandwidth, my
connection would be good for 8 mb/sec according to the install
tech.  If you have ADSL available where you live, GET IT!  Life goes
in circles - this brings me back to where I was with the T-1s when I
had the ISP 8 years ago :-)

John