There are two different types of high tensile fences on my place. The original fence was built to hold and protect sheep so it is a five strand high tensile that reaches down to about 5 inches above the ground. The new fencing, which was installed in 2017 and was built for beef cattle, is only three strands and terminates about two feet off the ground.
The original fence is a nightmare to weed whack under during the summer months to keep the fence as hot as possible so I ended up moving all the bottom insulators up as high as they would go so I can get the weed whacker under the bottom line and keep it clean. Like I said, that fence is a real pain.
Now all of this fencing is powered by a 26 Joule 120V energizer. This baby really pulses, and if the fence is clean, it will sustain about 8,000 volts across the entire system. By mid-June, the juice starts to leak out due to the wet green forage growing along it, and the fences max out at about 3,000 volts. This is by no means suitable for training cattle, or any other animals for that matter, so I was lugging the portable solar charger around for a few weeks just to make sure the interior fencing was well recognized and respected by the new tenants this year.
So, I was happy that the cattle were all staying behind the fences lately despite the low voltage. This weekend I learned why that is.
On the five strand original fence, all the lines are charged all the time.
On the newer three line fence that we built, the charged lines are staggered so the top line is hot, the middle line is connected directly to the ground, and the bottom line is also charged (hot). This is called a Pos/Neg fence.
I had heard in the past that despite the lower readings on the fence, the fact that the subject was immediately grounded upon contact would make the zap a lot “hotter.” I am here to today to confirm that this notion is true.
I forgot to turn off the fence Saturday morning and while walking back from checking the cattle I decided to climb though the fence to move something really quickly. My hand was around the ground wire when the back of my neck contacted the high line on the fence.
A pure blue ball of pain engulfed my vision. I involuntarily screamed. It felt like there was lava shooting out of the back of my head, out the soles of my feet, and up my spine. I was still very conscious despite the pain and immediately thought in my head, “I have got to get off this fence” and threw my body to the ground. I was safe, but boy was my head scrambled. I checked to see if I was actually smoking, and finding no evidence of having been cooked, I moved on with my day.
That shock was many magnitudes worse than the other fence. Having the ground immediately available for the voltage to move through my body made a huge difference in the delivery of the training stimulus. In other words, it really hurt.
So, I can now report that two things have been confirmed. Building a fence with a ground wire in the middle is a great way to deter animals from leaving your property and one would also assume it deters predators in the same way. How can this help you? Well if your fence isn’t holding charge the way you’d like due to lack of soil moisture, this is the way that I would recommend you design it.
Here’s a quick video to show how to set up a Pos/Neg fence if you’re using electric netting. It also describes some issues to beware of when running a Pos/Neg fence set up.