Sizing wire and grounding for an electric fence charger?

[hockeyoligist2]

A friend wants to run an underground wire from a fence charger in his out building to his garden 200' away. He has deer problems. Since it is high voltage and low amps I would think a small gauge wire would be fine. He wants to run a single #16 thwn in conduit, which he has a 250' roll of, and drive a ground rod just outside his building. I'm kinda thinking the ground rod should be closer since he has very sandy soil and dry weather during the summer. He irrigates the garden but the soil between the two points would have poor conduction IMHO.

 

[broadgage]

A #16 will be ample for the output of an electric fence controller, even smaller would do since the output is a tiny fraction of an amp.

Despite this, I fear that the proposed installation wont work well, or even at all.
Electric fence controllers produce brief pulses of a few thousand volts, the energy per pulse is small so as to render the shock non fatal. If the output is connected to 200 feet of wire in conduit, the capacitance and leakage current to earth may be too great for it to work properly.
Also, I think that wire is only rated for 600 volts ? the output of an electric fence controller is several times that, even if only in brief pulses.

The location of the ground rod will be fine, the general mass of the earth has effectively zero resistance, so distance is of no concern.

It would be better to place the electric fence controller near the fence.
If line power cant be economicly run to it, then consider a battery operated unit.

 

[iMuse97]

When I was younger, growing up on the farm, we ran from the load side of the fencer (as it was called) to the fence with whatever insulated wire was available. You keep the fencer in the barn somewhere, and run your fence from that point.

Knowing what I do now, I'd probably recalculate some of that, but it does sound like what you are proposing will work fine. I don't understand the ground rod. Granted it's been quite a few years since I've seen one of these installed, but I'd think you want the deer to be the grounding electrode.

 

[broadgage]

Any type of insulated wire should be fine if of modest length and suspended in the air, as pointed out above that is how it used to be done.
However I have my doubts about the effectiveness of 200 feet of wire in a presumably buried or grounded conduit, due to leakage and capacitance.
If the wire can be run overhead, preferably on insulators, then it should be fine. Most electric fence controllers can handle many hundreds of feet of fence, and the controller wont "know" the difference between an overhead wire, and a longer fence.

As regards grounding, all electric fence controllers require a ground, either from a rod or stake installed for the purpose, or often the fence controller is mounted on a metal post or stake that also forms the ground.
In order that the animals may get a shock there must be a continous path for the current. From the output of the controller, to the metal wires of the fence, via the animal and its hoofs to the earth on which the animal stands, and through the general mass of earth back to the controller via the ground rod.

Due to the high voltage and low current, a relatively high resistance ground is fine and no elaborate grounding means is needed.

remember that animals unused to electric fences may stampede at and through it, despite getting a shock.
In time they learn to avoid it.

BTW, if the animals do get through, do make certain that they are ALL on the right side of the fence when re-erecting it !

 

[SG-1]

Look at the instructions for the fence charger. Ours recommends 3 ground rods spaced 10ft or so apart. Try it with the rod(s) close to the charger first. Modern chargers will output 5KV.

I have both insulated wire & uninsulated fence wire run inside PVC conduit. The uninsulated wire inside the PVC is inside the barn, about a 30ft run. The insulated wire is in PVC that goes under a gate, "U" shaped section. Both have been in operation 15 years or more with no problems. I think the wire size is fine.

The only concern I have about a 200ft run in PVC is if the pipe fills with water. I recommend that he uses a one mile rated fence charger. Put plenty of arrestors at the charger. That was our biggest problem, the charger getting destroyed during thunder storms.

I have heard stories of deer jumping 12ft fences.

A dog might be cheeper.

 

[ptonsparky]

We bought the heavey insulated wire for electric fence and buried it in pvc conduit from barn to beginning of fence. Maybe 250 feet or more. Three ground rods spaced about 8' apart on the end of the barn farthest from the SE. We used the same insulated wire We haveya three wire fence with upper and lowere Hot & center grounded. Several miles. Good luck on keeping deer out. The bunny rabbits usually get what the deer don't.

 

[ceb58]

A friend wants to run an underground wire from a fence charger in his out building to his garden 200' away. He has deer problems. Since it is high voltage and low amps I would think a small gauge wire would be fine. He wants to run a single #16 thwn in conduit, which he has a 250' roll of, and drive a ground rod just outside his building. I'm kinda thinking the ground rod should be closer since he has very sandy soil and dry weather during the summer. He irrigates the garden but the soil between the two points would have poor conduction IMHO.

Since he irrigates the best method for the deer is motion detector sprinklers. A buddy has been using them now for three years and swears by them. He had tried every thing, elect. fence, moving objects and numerous other things. He put the MA sprinklers in and hasn't had any destruction.

 

[hockeyoligist2]

Thanks all. We ran the conduit, wire, and drove a ground rod just outside his building Friday. Everything is working fine for now, but time will tell. I pulled in a string just in case we have to do something different later on.

 

[hockeyoligist2]

Since he irrigates the best method for the deer is motion detector sprinklers. A buddy has been using them now for three years and swears by them. He had tried every thing, elect. fence, moving objects and numerous other things. He put the MA sprinklers in and hasn't had any destruction.

He has 4 of them and they work good, but he can't use them during the winter. He plants a cover crop of clover and other stuff over the winter and they destroy it.