Al - Not "exactly" anywhere.
Just to some metal part that is part of the body shell or the frame.
All a separate ground from the frame is for is additional "insurance."
After all, our cars and trucks don't have ground connections. Static
charge from the tires rolling on the road and the air passing over the
body bleeds off through the carbon blacks in the tires, and through my
leg when I step out (ouch!). Of course most of our tow vehicles don't
have 120VAC connected to them except for engine block heaters, which
usually have grounded plugs and are not shorted to the engine.
> Which brings up another question..where does the ground wire from the
panel usually connect to the trailer frame and by what type of
connection?
Al - According to modern standards neither the neutral nor ground bus in
the panel is not supposed to be connected to the trailer body or frame.
The ground wire from the ground bus is supposed to be connected to the
ground bus in the pedestal, and that in turn connected to the
ground/neutral bus in the main park panel. The trailer panel ground
should not be connected to the body shell or the frame.
> I have some 20ft. good cables but the two cables are molded together
for much of the length and besides I wouldn't want to leave them out for
the taking.
Al - Doesn't need to be heavy gage like jumper cables but that's OK if
one is handy.
My trailer has an uninsulated copper braid that has a crimped lug
fastened to the shell by a screw and tooth washer inside the
converter/drain valve compartment, where the ground conductor and clamp
is stored while traveling.
>
> Other than tripping over the connection is there ANY downside to doing
this?
Al - Oh, the bother with fooling with something that probably won't ever
do you any good. Like a fire extinguisher.
Pinching your finger with the clamp.
> Do I understand this right..? If the pedestal and the Trailer Park are
wired correctly this "Alligator Strap" has no purpose and does nothing
under any occurrence..??? But if pedestal or beyond (toward source) in
park is miswired then you have successfully grounded your trailer...???
Al - If everything is done right and nothing ever goes wrong you don't
need ground wires and fire extinguishers, or GFIs. Or circuit breakers
for that matter.
>
> Sounds good (and easy) to me but I wonder why I have never seen this
done in any park that I have paid any attention to.
Al - Few bother with it. Your car isn't solidly grounded either. So you
get a static shock sometimes. How many people have you heard of being
seriously shocked or killed and the cause being an ungrounded trailer?
Now that the AC wiring ground wire is not connected to the trailer body
shell/frame (unless your trailer is from before the code was changed) the
danger from improperly wired or defective RV park wiring is virtually
eliminated, if your trailer is new enough to be in conformity.
> What about the previous statement by Dr.G.J.(I think) that a ground rod
must be at least (3 or so feet) a certain depth into the earth and
diameter of rod must be fairly hefty (can't remember exact dimension).
Al - More like 8 feet, he wrote. It needs to go down to the constantly
damp dirt, the virgin clay hopefully. Copper or galvanized iron fresh
water pipe is pretty good as long as it doesn't connect to plastic just
under the ground. The main park panel's ground rod should be one of the 8
foot ones, plus the main panel is connected to the utility company's
ground wire. And all the ground clamps should be tight and uncorroded, if
you can believe it.
>
> Assuming bad wiring at your pedestal and now you have 120v returning to
park water pipe, and assuming all park is piped with underground steel,
wouldn't the guy who comes along and hooks up at the pedestal next to
your
pad be in for a "surprise jolt" when he connected his water line? Or at
any other pad in the park for that matter...???
Al - No, because underground metal pipe is pretty well grounded. Though
it isn't buried 8 feet deep in most latitudes it contacts the dirt a lot.
If neither your trailer's panel ground nor neutral busses are strapped to
the body shell/frame no current will get from the pedestal into the
trailer body shell/frame.
>
> Al you certainly seem to speak from a position of authority and
expertise. As does Dr.GJ. I look forward to all your posts. With all due
respect, might I inquire of your electrical background?
> After all electricity should be a bit more serious to us laymen than
what kind of pookey to patch a leak with.
Al - No authority, just a little expertise. I took Basic Electricity and
Basic Electronics in High School, taught by a retired Radio-TV station
installation engineer (PhD in Electrical Engineering), then majored in
Industrial Technology in University. I am not a licensed electrician nor
an electrical engineer.
As I have dealt with and done electric repairs in rental units for 20+
years off an on I have studied basic electrical wiring on a
"do-it-yourself" level, following up behind electricians, catching and
fixing their goofs (I'm sure I didn't catch them all!), and have read up
on RV wiring in electric wiring books, which are based on the National
Electric Code. It's really very simple once one decides that he is
willing to learn.
Dr. J is a real Electrical/Electronic Engineer, not exactly an
electrician, but EE's learn about grounding and have way more than just
the background to readily understand what is meant when reading electric
codes, which for the most part are written so "anyone" can understand if
they will pay attention. House and travel trailer wiring isn't
electronics.
Al - There has been a lot of argument over the years about the best ways
to ground power wiring and electric equipment, so we out here just have
to go with what the consensus of electric power engineers say as
expressed in the code. Like when I pointed out that RV power supply is
different from mobile and manufactured home grounding; I got that from
the electric code, not from my own observation or ideas.
The ground wire in romex used to be a lighter gage than the power
conductors, like 2/12g with 14g ground but now the ground wire gage
matches the power wires' gage: 2/12g with 12g ground.
The houses I grew up in and the one I live in now don't even have ground
wires except on the kitchen range. Like 2/12g and 2/14g. Don't touch the
kitchen sink faucet and the refrigerator at the same time!!