Lesson 3. Fencing Systems — Appendix C

20 Common Mistakes to Avoid When Building a Good Electric Fence

Wayne Burleson, Range Management Consultant
Absarokee, Montana

1. Poor earth grounding: Lots of folks still think you can skimp when it comes to adequate earth grounding. What we must all learn to do, is install several ground rods – at least three that are 6 to 8 feet long, galvanized, and attached with good ground clamps. The electricity must complete a full circle back to the charger through the ground. Poor grounding gives weak shocks. Think of the ground rods as radio antennas — the more reception, the better the shock.

2. Using different types of metals: Don’t do it. When you hook up steel wire to copper, something called electrolysis happens and the metal becomes corroded, making a poor contact and weakening shocking power.

3. Inadequate animal training: Each and every animal must learn that the fence hurts, so please build a handy training fence, preferably on heavy wet soil. Flag the fence for visibility, and entice the animal to test the fence.

4. Fenceposts too close together: (Note: This is for interior cross fences). Well-intended government agencies recommend lots of fenceposts in their fencing specifications. Fifty-foot spacing on flat land is just too close. You want the fence to act like a rubber band. When something runs into the wire, you don’t want to break all the insulators or knock posts out of the ground. If the posts are spread apart far enough — say 80 to 100 feet — the wire will just bend to the ground and pop back up.

5. Too many wire tie-offs: Again, fencing specifications may call for braces every quarter mile wire (1,320’) to tie the wire off. However, even 5,280 feet is OK, and actually adds more elasticity in the fence wire. This reduces the chance of wires breaking.

6. Wires tied tight to each fencepost: The wires must float (move) past each line fence post. This is needed to maintain elasticity (that rubber band effect).

7. Building new fences near old existing fences: Old fence wires seem to be always moving somewhere and coming in contact with the new electrified wires. This almost always causes a complete short in the fence, and away the animals go.

8. Bottom wire in contact with heavy, wet vegetation: Wet grass will suck lots of juice out of any fence charger. Hook up the lower wires separate from the other wires, and install a switch for the lower wires that you can turn them off when the grass is tall. Brush is another problem — buy a BIG charger. When you check a smooth wire fence, drive your vehicle so the wheels will drive over the vegetation and knock some of it down. Four-wheelers work great for this. Don’t spray under the wire. You will end up with some  weeds growing there.

9. Poor quality insulators: Be careful here. Sunlight deteriorates plastic. Buy high quality, long lasting insulators. Usually black ones are treated to resist degradation by ultraviolet light. Poor quality insulators may turn white or clear after a few years in direct sunlight and shatter like glass.

10. Staples driven in all the way: When using plastic tubing as an insulator, don’t staple it too tightly. A staple may damage the tubing next to a ground wire, causing a hidden short.

11. Solar panels not directly facing the sun: This seems almost too obvious to be a problem, but a solar panel won’t function at its potential if not properly installed. Please read the instructions.

12. Don’t electrify barbed wire: An animal can get caught up in the barbs, and the shock from a big charger could kill the animal.

13. Kinks in the high-tensile wire: A small kink in stiff wire will always break. Also avoid hitting this kind of wire with a hammer, as this will easily damage the wire, causing a break. Always cut out a damaged section of high tensile wire and splice it. A hand-tied “square knot” makes the strongest splice.

14. Installing in-line strainers close together: Wires will flip together once in awhile. If in-line strainers (wench-like gadget to keep the wire tight) are installed one above the other, they will sometimes hook up. Separate in-line strainers by a fencepost and they will never catch on each other. 

15. Wires too close to each other: Keep them at least 5 inches apart. When you and a partner are building fence, make a 5” mark in ink on your pants the height of the wire –  saves time. Use 31” top wire for cows.

16. Wire stretched too tight: Use inline-strainers that pull just enough to get the sag out of the wire between the fenceposts.

17. No voltmeter: Without a voltage meter to check how hot a fence is, you’re just guessing. Livestock will find a low voltage fence is a joke and walk right through it.

18. Wire too small: The larger the wire, the more electricity it will carry. Don’t skimp here, especially if you are going long distances. 12.5 gauge wire is good for over 20 miles of hot fence.

19. Inadequate charger: A wimpy fence charger gives you a wimpy fence. Don’t skimp here because this is where most fences fail. Build a strong fence and hook it up to a great big fence charger.

20. Too busy to check the fence: Yes, these fences are much easier to build and fix. However, without routine checking, they tend to slip and lose effectiveness. Once the animals become untrained, it takes an extra effort to retrain them. Solution: carry a small repair kit with you at all times, install switches away from the charger, turn the fence off and make the necessary repairs as routine as moving the mineral mix.