View Full Version : Grounding

11-11-2014, 08:21 AM
I’m going to stick my foot in my mouth here and offer some thoughts and experience on grounding for Ham RV’er’s .
Over the years I have dealt with “Grounding” situations in everything from Power Production to house wiring to automotive electrical systems and everything in between, any real electrician or engineer will tell you what might look like a ground “AIN’T NESSISARLY SO”.
But in order to keep things simple (hopefully) I will recommend the following.
1. The “SINGLE POINT GROUND RULE” for Ham Radio should be kept in mind so that ALL station equipment (Chassis, frame, cabinet grounds) tie together at one single termination point or buss-bar.
The idea here is to eliminate “GROUND LOOP” so the equipment ground does not act as an antenna thus helping RF get into places that it’s not wanted.

2. When creating a “BUSS” to frame connection and / or frame to ground rod connection, these point’s should be soldered (if possible) or bolted (not just a self-drilling sheet metal screw if it can be avoided ) , (use #10 copper wire (or larger) for these) the connection point should be clean (no paint or non-conductive coating ) do not trust just the drilled hole and bolt threads to make the connection.
3. All connection points should have a thin coat of grease or other anti-oxidant compound, especially those made outside the living area at the frame, etc., etc.
See K0BG’s site, http://www.k0bg.com/bonding.html for more information.
4. ANY GROUND is better than NO GROUND, in most places you can “SPUD” in a 4 foot rod with a gallon or so of water with not too much effort, remember you’re a “portable” operation so keep it simple and easy to pull in order to move on when ready.
5. DO NOT TRUST camp ground electrical systems to be properly grounded (unless a ground rod is clearly visible and even then some are questionable).
6. ALWAYS use good quality connection hardware, COPPER or BRONZE connectors are available at most home stores and all electrical suppliers, ALWAYS use an anti-oxidant when making connections to dis-similar metals ( copper to aluminum ect.).

As something of a side note:
Many years ago the U.S.G.S. undertook a survey of “GROUND POTENTIAL” in the United States, their findings and maps can be found in several places on the web.
Bottom line here is, “GROUND POTENTIAL” is not the same in Colorado as it is in Florida ( there are of course variations in all area’s) and unless you are equipped and prepared to do your own testing you shouldn’t worry too much about it (just be aware).
What I have tried to present here is a “RULE OF THUMB” approach, everyone will find a bit different variation that will work for them, so please no flames!

11-11-2014, 09:00 AM
Quite true John another thing I have tried to do with my "tin can" is bonding of the aluminum siding. I work for a local camp ground part time and am still finding things previous owners have done that just makes me shake my head. Sub panels that aren't ground wires used as neutrals great things like that. My suggestion to any one that has an RV buy a $5 tester that plugs into an outlet and leave it there. Most of the better camp ground pedestals have as much metal under ground as they do showing but that alone does not mean it is a great ground but it can't hurt. Yes soil conductivity does vary a lot across the country I have been on tower sites that have automatic salting systems used with their grounding.

11-13-2014, 10:23 AM
Grounding is an interesting issue: I too subscribe to the single point theory.. That said everything in this house is grounded to the frame (Chassis) this INCLUDES the shore power green wire (yes it really is green) I also have an aux ground, basically this is a 3-foot long screwdriver with a #10 wire bolted to it, It lives in my electrical bay normally but if I'm not connected to a "Shore" ground, I can push it in .

Everyone yammers about how antennas need to be grounded... Actually they need to be completed. a DIPOLE is a complete antenna, needs no ground, (Save for lightening protection).

11-13-2014, 10:34 AM
I always thought intentional grounding was a 10-yard penalty.

11-15-2014, 07:04 AM
The $5.00 "IDIOT LIGHT" is a good idea Ted !
I have seen even good RV Manufactures make wiring errors every once in a while (never hurts to check).

Antenna Grounding / counterpoise, is a whole different "Bag Of Worms" and something for another thread , and here again I would refer to K0BG's web site for mobile installs (Alan has done a lot of good work and a good presentation on this subject).

Campground wiring can leave a lot to be desired, especially in some of the "OLDER" campgrounds and State Park's where the wiring was put in many years ago and never upgraded to handle the load demand of newer RV's.

I have a permanently mounted "Panel Meter" to check line levels ( sag or buck) and in some places it's interesting to watch the neighbors A/C unit or refer unit kick on and off (tells you a lot about the campground wiring) but for most people a simple "multi-meter" and knowing how to properly use it will serve the same purpose.

Sometimes just being aware of the operating conditions (both those you can control and those you cant) can save some headaches.

11-15-2014, 01:00 PM
I was at a camp ground in northern NH and the power point was a plastic box laying on the ground with no cover 15 amp big box outlet attached to #14 indoor romex. Usually camp ground wiring is 5 sites on a 100 amp sub panel throw in a nice hot day and things get dicey.

11-15-2014, 07:48 PM
Antenna Grounding / counterpoise, is a whole different "Bag Of Worms" and something for another thread , and here again I would refer to K0BG's web site for mobile installs (Alan has done a lot of good work and a good presentation on this subject).

Could we get a link in the Useful Links forum?

11-16-2014, 06:15 AM
As requested Wade !