Troubleshooting your electric fence
Electric fence revolutionized how we graze livestock in the Midwest. Now we can inexpensively cordon off pastures to suit our changing forage needs. It can boost our productivity, and all for the minor labor of moving a few strings of wire or tape. But with all that moving sometimes comes a little trouble. Shorts foil us. And, an electric fence with no electricity equals cows on the run. So keep your fencing toolbox up to date with a few handy fence-testing tools.
There are several different tools or methods to see if your electric fence is working.
Popular favorites are the Fault Finder, Smart Fix and Fence Compass tools. If you build much electric fence, this tool is as handy as a pair of pliers. This gadget tells you several things at a glance. It tells you if the fence has a short as well as the output voltage of the fence. If the fence is shorted out, it also tells how much of a short it is by the amperage and which direction the current flow is. The greater number of amps the bigger the short. For example, if your fence voltage is 6 to 7 KV with 5 amp draw and you previously tested the fencer at a clean-fence reading of 9 KV and 0 amp draw, your job is done. This should be enough to turn cows away from the fence. But, if your voltage reading is less than 50 percent of normal and the amp reading is 10+, it is time to find and fix some problems. The amp readings on these testers are cumulative so there could be multiple shorts.
Scenario #1
Let’s assume, you are checking a fence with the tester and there is no voltage reading. Your first stop is the charger/energizer. Test it and troubleshoot it. If it is on and clicking, turn the charger off and disconnect the fence lead line. Turn the charger on and test it for voltage. If there is high voltage (same as when purchased), the problem is with the fence. In this case, it could be a broken wire, a bad splice joint, or anything that is not allowing voltage through. If the charger is clicking and there is low voltage, or if it turns on and won’t click, there is a problem with the charger. Take it to your local MFA for service.
Scenario #2
Livestock is going through the electric fence when there is adequate voltage.
This happens when the animal is not getting grounded and not feeling the “shock.” Add more ground rods or install a hot-ground system. Properly checking the ground system is easy and should be done yearly. You will need a digital volt meter or a fault finder with a ground probe and built-in digital volt meter to do this.
Correctly install fencer and turn fencer on.
Go 100 yards away from the fencer and short the fence voltage down to 1,000 volts. This can be done by placing t-posts or anything metal on the hot wires and shorting out your fence.
With a digital volt meter, place the ground probe about three feet from the ground rods, and check their voltage reading. Ideally you want this reading to be less than 300 volts. You need to add more ground rods if it measures greater than 300 volts.
Think of the ground system as a big antenna collecting all the positive electrons the short has funneled from the fence and dumping them in the soil.
This is a measurement of “stray voltage” that is not being captured by the ground rods. If it is significant, a better ground is in order.
Another way to solve this problem is to make a hot/ground fence. This is done by alternating wires on multi-wire fence from the hot or positive side of fencer and grounding the opposite wires. This fence takes ground condition variables out of the equation. Electron flow through the ground is slower when the soil is dry or frozen.
Knowing your fence system and tools before there is a problem will makes troubleshooting much easier when there is a problem.
Allen Huhn is a farm supply product manager for MFA Incorporated.