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Why Electric Fences Fail Final.pdf
Why Electric Fences Fail
by Dean R. Oswald Animal Systems Educator University of Illinois Extension

Dean Oswald - Animal Systems Educator

7104 E 2480 Street, Kewanee IL 61443

Why Electric Fences Fail 309-853-5449

(January 2010)

Animals Not Trained To Fence: Electric fencing is a "psychological barrier". When livestock receive a weak shock they will go through the fence. A strong shock will be remembered and maintain control. Skimping on Power Source: Minimum species voltage for animal control: Cattle 4-5,000v; Sheep & Goats 7-9,000v; Horses 3-5,000v; Predators 5,000v; Pets 3,000v; Garden Pests 4,000v; Wet vegetation or snow load will reduce power. Size and purchase a low impedance charger from a reputable supplier.

Poor Grounding: Chargers should have a minimum of 3 ground rods placed 10 ft. apart. Mixing metals (steel & copper) causes corrosion and weak shocks. Do not install ground rods within 50 ft. of grounded electric service. Additional ground rods are needed throughout the system.

Surge and Lightning Protection: Install a surge protector at the power source to protect expensive chargers. 75% of problems come from the power company. Lightning protection is also necessary to protect the charger from high voltage strikes. A lightning choke, (figure A) diverter and 4 ground rods (figure B) are needed minimum 65 ft. from the charger.

Wires too tight to posts: Staples driven all the way in. Wires need to expand and contract past the posts.

Vegetation or snow covering bottom wire: Install a cut-off switch to reduce load. (Figure C)

Poor Quality Insulators: Buy quality products that have UV light protection.

No Voltmeter: You are just guessing without one! (Figure D)

Kinks in Wire: Prevent kinks wire will always break.

Inline strainers or wires too close together: Off-set strainers and don't space wires less than 6 inches apart to prevent grounding out.

Changes in Wire Size: Larger wires carry more electricity. Don't power a fence with poly-wire or small conductor.

Over-tensioning hi-tensile wire: 150-200 lbs. psi needed. Use notched tension springs that indicate wire tension.

Conclusions: Not all posts and electric fence supplies are created equal. There are many differences in quality, durability, and cost. Plan your fence carefully. Make a detailed supply list. Shop Around! Compare supplier prices and quality. Negotiate prices on carton/case/pallet lots.


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