How Does an Electric Fence Work?

How an Electric Fence Works

Electric fences are an excellent solution in the management of land that is used as pastures or for grazing. It is a safe and effective way to contain livestock. These fences are also used to protect property, animals, and gardens from damage caused by pest animals and predators. But what exactly is an electric fence, and how does it work?

What Is an Electric Fence?

Electric fences have been a powerful and versatile tool for farmers and ranchers since the development of the first electric fence in 1938. Today, there are a wide variety of electric fence types, both permanent and portable, that farmers and ranchers use all over the world. An electric fence is a physical and psychological barrier designed to contain livestock to a particular area and to prevent unwanted animals from entering the area.

It accomplishes these goals by delivering an unpleasant (though not harmful) shock to animals that seek to cross the boundary. Animals quickly learn that touching the fence is painful and learn to avoid it.

Electric fences are some of the most effective barriers available for containing livestock for several reasons, including:

  • Safety: A sharp, short shock is painful and disconcerting but causes no lasting damage to animals. It encourages them not to wander too near the fence in the future.
  • Easy Installation: Traditional barrier systems can take at least twice as long to construct as an electric fence.
  • Durability: When it comes to livestock containment, traditional barriers are often subject to intense wear and tear due to contact from the animals. Because livestock soon learn to be wary of an electric fence, they avoid it. This adds to the fence’s longevity.
  • Affordable: In addition to being more durable compared to traditional barriers, electric fences cost less—up to 50% less.

How Does the Fence Work?

Electric fences may seem like magic if you’re unfamiliar with how electricity works, but in truth, they’re relatively simple—which is a good thing! It makes them easy to maintain and repair.

Amps, or electric current, can only flow when there is a completed “circuit,” or connection between a positive and a negative terminal. You encounter this concept every day when you power on or power off any electric device. You see, powering on a machine completes the circuit so that current can flow through the device. Powering off a device breaks that circuit temporarily, depriving the machine of power.  Essentially, when you “open” a switch, you’re breaking the flow of electricity or powering off the machine. When you “close” the switch, you’re enabling the flow of electricity or powering on the machine.

For example, when you turn on a flashlight, you close the switch that allows current to flow from the positive terminal of the battery, through the lightbulb (which then lights up), and then to the negative terminal of the battery. When you turn the flashlight off, you’re opening that switch. The flow of the electric current stops and the lightbulb goes dark.

In the case of the fence, the circuit is much larger. The electric fence charger has a negative terminal and a positive terminal. One end of the enclosure is attached to the positive terminal. The other end is grounded via the negative terminal and attached to galvanized grounding rods set into the earth. While the soil itself isn’t conductive, the moisture in it is. The current, therefore, flows through the wire—at least, until something interferes with it.

How Does an Animal Get Shocked?

Remember, electricity must flow from the positive to the negative terminal—in this case, from the charger to the ground. When animals are standing on the ground and touch the fence, they close a new “switch” that consists of their own body, and the current briefly flows through them, giving them a shock. When animals move away from the fence, they break the circuit, stopping the shock, and allowing the electricity to flow through the wire unimpeded. Humans wearing insulated footwear may still be shocked, but the effect will be less intense. Birds landing on a wire (and having both feet on the same wire, not touching the ground) will not be shocked.

  • February 21, 2021