Hotwire around run

Quote:
Your husband is correct -- to a point.

Grass, specially wet or damp grass will short out the wire.

Before I installed the hot wire I cleaned to bare earth. Pretty much maintain it that way, with occassional hoeing, but I primarily use a round-up generic to keep it clean. Total circumference of my run is 100'. I have hoed the ground maybe twice since spring and sprayed an additional 3 or 4 times.

Grass grows extremely fast here in S. Louisiana.

Regarding shorting the fence, it depends on the impedance of the fence charger. We have approximately 2.5 miles of electric fence that we control our cows with. Our fence charger is rated at 150 miles. (not a typo). We have a little red solar charger for our garden (rated at 15 miles with grass all around it) So if you have a 100' perimeter, and you have wet grass, you will have some reduction but the wet grass also provides a better ground for the critter climbing on, in, through it. so the short will go through the animal. In essence, no real difference. you will hear the fence shorting on the grass, but the only thing that will remove the voltage better than a body is a metal to metal short. If you have a failed insulator and the fence is shorting to a metal fence post, you can hold on to the charge wire, with no scream or bad language. Grass has greater resistance than bodies do. Grass under your fence will actually provide a better ground than bare earth, and will also show predator movement around the perimeter. Trust me on this one, I have real world screams to prove it. Concrete unless constantly saturated is a horrible conductor, so you may actually decrease the effectiveness of your fence by putting concrete under it.

The other issue is resistance in your conductor wire. If it is small steel wire, it has greater resistance. We use barbless barb wire. Double strands, strong as nails (literally) and 10GA so very little loss to resistance. There is 7000v at the charger, and 7000v 2400 feet away on a two wire non-grounded fence.

You can test this if you like and see for yourself. Galagher makes an electric fence 'tester' that will show you the voltage and direction of the short. Our fencing is overgrown with grass and weeds most of the summer. We clear it in the spring so the deer don't just run through it. It constantly reads 7000v with a minimal short even when fully overgrown. The difference between a 3000v shock and a 4000v shock is not noticeable, they both hurt like the dickens. Now imagine that on your nose when you are completely oblivious to the situation.

Grass can be an issue, but thats what weed wackers are for. If you are having problems with the voltage through your wire, make sure you charger is large enough for the job. if you already have a charger, get a tester and see what is actually happening before changing plans or spending money on extra materials.

As far as ground rods, the 6 - 8 foot reference is an average for soil moisture across the US (true story). if you have ground water at 18", 8 ft of ground rod will not get you any better ground than 24". It is in water, so it really depends on you situation. If you soil is dry for 3', you need 42 to 48 inches of ground rod. If you have very rich thick topsoil. like in Iowa, you may only need a 12" rod and thats just to make is sturdy. On our 2.5 miles of fence we have one ground rod that the charger is grounded to. Thats it. There is grass under all of our fence, and we have plenty of impedance from our charger to work through any dry spots. You can hear the cows a mile away when they hit it.

So OP how many ground rods do you need? One. but if your fence were mine, and I wish it were, I would ground the metal fabric, and ground the charger. If you had my charger, I would say, ground the charger. But a 2' piece of rebar can be has at most home stores for a buck or 2 so throw one in right at your fence, and put a cheapo chinese c-clamp on it, and clamp it directly to the fence.

Just my .02.

Thank you all for your suggestions. I tested the fence out this morning with a ground rod (rebar) driven 3 feet deep. We are currently in a severe drought (3/4 inch of rain since June) so I figure if I have a good ground at this depth, I should be good during a normal year. I used a multimeter as I don't have a fence tester and checked from hotwire to ground (probe stuck in 1/2 inch) and hotwire to fence. I checked at intervals of approx. 5 feet around the entire perimeter of the fence. At every point, I had large deflections on the meter, can't really read the exact voltage as my charger is a pulse charger. I think I'm good to go with the hotwire. One thing I think helped with the fence being grounded is I recycled a bunch of old T posts from a barb wire fence we removed on the property. These had most of the paint already off, but if you were using new posts you might not get the same results.

So my hotwire is set on 4" extensions at 4" and 12" above ground level.

I do have a 1/2 mesh hardware cloth apron extending out approx. 12" around the permiter so I think the combo of hotwire and apron will discourage any diggers. I also have a very secure coop. We had an old 3 room house on our property that had been previously used as a feed room. I have completly secured all openings with hardware cloth and even underpinned the house with same. All of our chickens are in the coop at night with the poop door closed. I know we have several predators in the area including coons, oppossums, skunks, snakes, bobcats, hawks, and feral cats. I always keep a live trap baited with sardines around the outside of the run. I've managed to catch several large coons in the trap and relocate them to coon heaven!