Grounding rod Q for electric fencing

Boondox · Sep 19, 2004

Back in the days when we had only chickens, we pounded a single six foot grounding rod behind the coop and ran a single 165 foot length of electrified poultry netting. Now, with sheep, we often run as many as five lengths of electrified sheep netting and the voltage has dropped from 6000V to 2000V at the fence. Still stings, but not the level of deterrent we need with the coyotes, stray dogs, and occasional fox or coon checking things out.

We went with a single grounding rod only because here in Vermont there are very few places where the soil is free enough of rock or stone ledge to pound the suckers in. But about 100' from the fence charger is our pond...and the berm of that pond is absolutely free of stone. If I sank five grounding rods full length in that berm, spaced five feet apart, connected them all and ran that ground wire underground in conduit back to the charger, would that be sufficient? What gauge wire should I use for that leg? Is 100' too far away from the source?

Pete

v8dave · Sep 19, 2004

Use the pond as a ground it's a great idea. Run the ground back as bare wire, not in conduit. It may help increase the potential near the fence. It might not either, but it won't hurt.

I've had good survivability or copper wire burried for antenna ground systems. So, I'd use copper wire because I think it may last longer in direct burial (than steel or aluminum). Bury a copper wire of #12 to #16 in size. Pick the size of the wire based on cost and survivability in the earth, you're not going to have much voltage drop because the current is the milliampere range.

rockinmywaypa · Sep 19, 2004

sounds good. the books recommend 10 ft spacings though. why not just use the 12.5 ga high tensile wire, it will carry the ground every bit as good as the live charge. My manual states not to go farther than twenty ft. away from charger with first rod so maybe it makes a difference. The edge of the pond is going to be one heck of a good grounded area.

heehaw · Sep 20, 2004

do you have any electric poles close?? if you do, tie to the ground they have on that pole, it goes to the bottom of the pole and has a little circle of wire at the bottom..maybe it will get down to damp soil and make it work better.
heehaw

Boondox · Sep 20, 2004

( do you have any electric poles close?? if you do, tie to the ground they have on that pole, it goes to the bottom of the pole and has a little circle of wire at the bottom..maybe it will get down to damp soil and make it work better.
heehaw )

No, unfortunately. The power line comes in nearly 250' away and there's exposed granite between the coop and that ground. pb

Boondox · Sep 20, 2004

( Use the pond as a ground it's a great idea. Run the ground back as bare wire, not in conduit. It may help increase the potential near the fence. It might not either, but it won't hurt.

I've had good survivability or copper wire burried for antenna ground systems. So, I'd use copper wire because I think it may last longer in direct burial (than steel or aluminum). Bury a copper wire of #12 to #16 in size. Pick the size of the wire based on cost and survivability in the earth, you're not going to have much voltage drop because the current is the milliampere range. )

Direct burial makes sense, especially considering the distance I'll be running it. The plan was to run a shallow trench (say 18" deep) from the coop to the grounding rods since that's the route I take when dragging logs home for firewood. Snagging the wire would be a bummer!

So I'm hearing the distance shouldn't be a huge issue..?

Pete

heehaw · Sep 20, 2004

can i assume this is an electric fence charger, not a solar unit, so electrical power is close?
if so, and the ac power is a 3 wire system, hot wire, neutral wire and ground wire, connect to the ground wire, along with the ground rods and everything else you do.
heehaw

Soundguy · Sep 20, 2004

Your voltage drop may not all be insuficient ground. Fence faults will sap that power as well. Doesn't take much mor ethan a blade of grass to provide -some- level of fault. Add that up over hundreds of foot of live wire/tape.. and you may have some decent faults.

Soundguy

Boondox · Sep 20, 2004

Thanks, Chris. We do our best to keep the grass mowed short where the fence goes, but it grows so fast it's hard to stay on top of it. And with the length of fence...

Going forward we're thinking of installing semi-permanent hi-tensile wires as a perimeter...and using that to charge the mesh as we rotationally graze the sheepers. So the grass issue will be minimized. Make sense?

Pete

heehaw · Sep 20, 2004

i missed something, are you hooking your fence charger to some kind of fence, other than solid single strand electric fence wire? all the chargers i have messed with, don't have the power output to handle being hooked to other type fences. i tried an 8x10x6 chain link dog pen once, and it just wouldn't power the fence..thats where their rating of ???miles comes in..
heehaw