Every one I have seen was isolated neutral.
There is a 3 wire plug on 120v 30a and 4 wire plug on 240v 50a. That is the
The bonding jumper is in the post or in the service panel that feeds the post
if the post is not where the service point resides.
Trailers are wired with a 4 wire, separate ground and neutral.
There isn't a good ground connection, so if there was a problem with the
electrical, and a connected ground/neutral, there exists the probability
that it would electrify all the metal in the vehicle.
Tying the ground and neutral together only applies in fixed location
buildings, not anything mobile or portable.
Isolated neutral. The power feed from the RV park already had the
ground and neutral broken out seperately -- you don't get to recombine
Even moble homes that are set permanently in place have to have the
neutral isolated in the odd chance that something goes wrong with the
ground connection, so the neutral doesn't energize the trailer's metal
framing through the equipment ground.
The real answer is that depends. If the camper has a generator or
inverter to supply electric power the answer is not as straight forward
as some of these answers would have you believe. The campers transfer
switch is unlikely to switch the neutral although some do. If the
neutral is not switched by the transfer switch and it is bonded at the
on board supply it will remain so even when you are running on park
power. One simple way to avoid these problems is to use the cord for
the park hook up as the transfer switch. Since the cord cannot be
plugged into two places at once that will keep the bonding point of the
on board power from getting connected to the park power outlet. With
this method the on board AC power supplies are connected only to a
receptacle that the on board AC wiring can be connected to when it is
not connected to a park outlet.
The neutral has to be bonded or a ground fault current cannot flow back
to the source and trip the Over Current Protective Device (OCPD). You
bond the neutral of a separately derived system for the same reason that
you bond the neutral of a service which is to provide a low impedance
path for fault current to return to it's source.
Ground Fault current is exactly why they can not be bonded. When plugged
into campground outlets that are invariably Ground Fault type and of course
have the ground and neutral bonded somewhere downsstream, the ground must
be isolated in the trailer. If not there the campground GCFI will trip
because some of the return current will flow in the ground wire. Once in a
while you find an RV that has them connected inside the unit. To get power
when plugged into the campground reciprocal they must use a two wire
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