There are many reasons you could be installing an electric fence. They are used to keep in livestock like sheep, goats, cows, and pigs. They are also used for horses. In more urban areas, they may be employed to keep pets safely in their yards, or wildlife out.
The purpose of the electric fence changes how powerful it should be. Most electric fences fall between 2,000 and 6,000 volts. 10,000 volts is the highest allowed by international regulators, but this is very rarely needed.
Types of Electric Fences
As I mentioned earlier, the purpose of the electric fence is going to change the voltage. The location can also change the voltage, though not as much. If you live in a very snowy place for instance, the manufacturer will suggest a higher voltage to get the same effect. This is because the snow can interfere in the fence’s ability to ground well.
Cows and Pigs
Cows and pigs require a middling voltage. This is due to their size but also lack of insulating fur. Typically, fences are run between 2,000 and 4,000 volts. Bulls are more aggressive, so they need to be at the top of the range. Calves should be allowed a lower voltage if possible. In the winter, you may need to slightly raise the voltage because the animals have more fur. For best results, make sure to space the wires according to animal size.
Sheep Llamas and Goats
Goats tend to test fences or try to jump them, so make sure you have it set up sturdily. Because of their woolly coats, sheep, llamas, and goats need a higher voltage of between 4,000 and 5,000.
Horses
Horses are large but also extremely sensitive animals. You do not want to exceed 3,000 volts on your electric fence when containing horses. A range of 2,000 to 3,000 is best. When constructing the fence, avoid sharp objects and barbed wire, as these could injure your animals if a horse is spooked and runs into the fence.
Pets and Nuisance Animals
Pets usually respond well to between 700 and 1,000 volt fences. This same voltage will also repel common nuisance animals like racoons, squirrels, and foxes. Beginning the wires close to the ground is crucial, as many of these animal species like to dig.
Larger Wildlife
If your fence is designed to keep out larger animals such as alligators, boars, wolves, bears, deer, or mountain lions then 5,000 volts is a good rule of thumb. As always, keep in mind the size and mobility of the creature you are trying to dissuade.
Measuring the Strength of your Electric Fence
You may have noticed that when shopping around, electric fences are measured in three separate ways. These are Voltage, Amperage, and Joules. What do these measurements mean? How do they relate to one another? Here I will explain each one, why it is important for electric fencing, and how to measure them.
What is Voltage?
Voltage refers to how energetically the electricity is pushed from point A to point B. Voltage is what gets the electricity through the skin and muscles to the nerves. Therefore, most guides on how high to have your fence use voltage. Voltage is the most useful measurement when talking about the shock the fence will deliver.
How to Measure Voltage:
Voltage can be measured with a multimeter. This is important to test regularly as it will ensure your electric fence is working properly. Depending on the size of the fence, voltage drops may be the most effective way to detect issues in the fence such as plant overgrowth.
What is Amperage?
Amperage refers to how much electricity is in the system. This measurement is ideal when talking about powering your electric fence – most fences require a certain Amperage (or supply) of electricity from the circuit.
How to measure Amperage:
Just like voltage, Amperage can be measured with a multimeter. However, the only time you will want to do this is when hooking up the fence to its power source. At this time, you will double check that the power source has an appropriate Amperage for the fence model. Too little, and the fence will not work. Too much, and the fence could explode, spark, or melt.
What are Joules
Joules is a measure of distance. A Joule is the amount of energy required to move a tennis ball one meter. In electric fencing, Joules are used to describe how long the fence can be before the voltage drops.
How to Measure Joules:
The consumer will not usually measure joules. If you do want to measure them, simply multiply the number of watts in the fence (using a multimeter) by the time it takes from turning the power on, to detecting a charge at the end of the fence. This time is usually measured in fractions of a second, so it can be tricky to measure.
Can an Electric Fence Kill You?
An electric will not usually kill you. The important measurement here is not voltage, but amperage. Voltages as low as forty-two have been known to kill, because sufficient amperage reaching the heart is what causes damage. For a risk of death to occur, a current of .1 amps needs to be present.
The higher the charge goes after that point; the more likely death is to occur should a shock happen. In an electric fence, you only get about .01 amps unless the fence is malfunctioning.
Will an Electric Fence Hurt Your Animals?
The short answer is yes, and no. Electric fences are designed to cause mild to moderate pain. The pain makes the animal unwilling to touch the fence again. However, unless you have an otherwise sickly pet this is very unlikely to do permanent damage. A broken fence can be more dangerous, as can a pet becoming stuck in one. Then there are risks of death by electrocution or severe burns. Therefore, it is important to keep the fence in good repair.
Final Thoughts
Electric fences provide many benefits when housing animals, chief among them keeping them safely in place. However, it is important to select the correct voltage, amperage, and joule load for your fence. A properly working fence is highly unlikely to cause injury.
The voltage needed in your fence will depend on the type of animal being enclosed, so make sure to respond accordingly. The size and fur coat of the animal dictates the voltage, although other factors can contribute. When in doubt, the manufacturer always has the most current information, and is typically happy to advise you.
Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.