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Grounding a Travel Trailer & Antenna

Jul 29th 2012, 22:41

dksac2

Joined: May 24th 2012, 23:18
Total Topics: 0
Total Posts: 0
I'm going camping next week and for the first time will be taking my 2M/440 radio and power supply with me.
I have a fiberglass pole about 10 feet taller than the trailer with a J Pole antenna.
My plan is to put 2 four foot ground rods into the ground which is moist and pour some rock salt in as I go and keep the ground wet.
I will have a Diamond 3000 lightning arrestor connected to the coax going to the ground rods and will ground the power supply and radio to the ground rods also, at least that is the plan.
This is not the best of grounds, but any sign of lightning and the antenna comes down and all is disconnected.

My main question is should I also run a gound wire from the rods to the frame of the trailer also, or no grn wire to the trailer at all. With the built in generator powering the power supply, I'm not sure how it might work out with no ground.
I don't have a good 12V hook up inside the trailer so I planned on using the generator which is built into the trailer and my power supply to power the radio.
I might be better off putting in a 12V ten guage wire and running just off of the batteries and not using the power supply with the generator.
Any thoughts on which way to go. Is there more risk of trouble using the generator. I'd like to be able to use the generator because I will be using the trailer in some ECOM situations and would like the generator to help power the radio equip. I have a 37 gallon fuel tank for the generator, so I have a long run time with it.
The generator is a factory built in 4K and is grounded to the ground pins of the electrical outlets.

Thanks, John KF7-VXA
Jul 30th 2012, 01:17

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0

Hi John,

http://www.arrl.org/electrical-safety
As the articles on this page explain, OSHA does not require portable generators to be grounded. I suggest reading the articles if you need an explanation.

Similarly, the use of rock salt is often frowned upon these days due to possible damage to the environment.

Zack Lau W1VT
ARRL Senior Lab Engineer


Jul 30th 2012, 04:54

dksac2

Joined: May 24th 2012, 23:18
Total Topics: 0
Total Posts: 0
Thank You for the reply. My main concern is that I want to bleed off static from the antenna and coax before it gets to the power supply and radio and I was concerned that if I put a ground rod in the ground and hooked it up to the lightning arrester that I would create a ground loop between the coax hooked to the radio and power suppy and the ground (third pin) in the 120 v electrical socket attached to the built in generator, it's not a portable, which makes this different somewhat.
I want to make sure my equipment is protected, from what I read, as the generator is a built in unit and is grounded to the frame of the travel trailer, it looks like I should ground the lightning protector to the frame of the travel trailer to bleed off static and have no other ground other than the 3rd pin ground in the plug and electrical socket.
In the case of any storms approaching, the antenna will be taken down and all connections disconnected. My main worry is damage to my equipment as I ruined a power suppy once because I put up a temp antenna and static from a far away storm was inducted into the antenna and coax. I don't want that to happen again.
Lightning is not the worry, static and not having a ground loop by grounding the frame of the trailer is the worry. From what I saw, I should not ground the trailer frame to a ground rod, but let the grounding in the trailer 3rd pin in the outlet and a ground wire from the lightning arrestor to the frame of the trailer take care of bleeding off any induced static.

I just want to get it right. I take grounding and safety seriously and want to do it right. I know what to do at home, this is something different. The articals were good.

73's John
Oct 22nd 2012, 23:43

K7EVI

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
As a full time RVer, The worst part of extra ground rods, wires is forgetting to remove them when you pull out. A near lightning hit will destroy most anything electronic, a static drain and spark plug shown in a recent ARRL letter is a VERY GOOD idea. This goes between the CO-AX center conductor and ground. I have used a piece of bare copper wire 2 foot buried a few inches down in the ground to drain off static on the RV - it works. ALSO not asked, however, if you use an inverter, most inverters have the neutral floating and if you are not careful with power cords you use, (AC/DC Radios!) (or are also using generators) you can run 60V AC to ground and Blow up the inverter.
I use very little AC equipment - everything is 12V DC and I use a gas engine and a car alternator to charge batteries when the solar panels do not keep up.
Good loop should not be a problem EXCEPT with inverter. Grounding to the coach frame, then to a ground wire/rod
Oct 22nd 2012, 23:51

K7EVI

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
As a separate comment as it has been my most frequent rescue:: Do not use the vehicle battery to run any camp related equipment. You can charge both batteries off the vehicle alternator with an isolator, but not with out. On campouts, I regularly have to jump start 4 or more vehicles because people ran car radios or lights for hours on the vehicle battery. --- Or left the trunk lid up for some light!

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