Electric Fences in Urban Areas: A Safe and Regulated Solution

Electric fences are designed to prevent animals from accessing or exiting a particular area and are regulated to ensure they operate safely. Existing laws prohibit the sale, installation, or use of an electrified fence connected to a source of electrical current unless the current is limited and regulated by an energizer controller that meets specified standards.

Despite high voltages of over 5000 volts, electric fences are much safer than one might assume. Hundreds of thousands of people worldwide encounter electric fences every day, and electric fences account for less than one serious injury per year worldwide. This is compared to the numerous injuries and deaths that result from human exposure to machinery, animals, and weapons.

The safety of electric fences in urban areas is achieved through two main factors: the voltage and the current. While the voltage is high, the current or amplification is very low, with figures ranging from 15 to 500 milliamps. This is a small fraction of the amperage used to power machinery and utensils, such as a cooker, which may draw up to 30 amps.

Electric fence energizers put out high voltage, around 7,000-8,000 volts, which gets the animal’s attention. However, they reduce the deadly amps to a very low amperage, usually around 120 milliamps. Modern fence energizers use low-impedance circuitry, which charges a capacitor by a solid-state circuit and releases the charge with a thyristor. This results in a controlled voltage delivery and a shorter shock pulse, lasting only a few milliseconds.

The pulsating current in electric fences is also safer than continuous supply because it allows animals or people to remove themselves from the source of electricity. The muscle contraction caused by the shock is transitory, and the affected animal or person can retreat from the fence. In contrast, continuous supply results in a grabbing effect that can be dangerous and makes it impossible to release the source of the current.

In conclusion, electric fences in urban areas are a safe and regulated solution for controlling access to certain areas. While they may seem dangerous due to their high voltages, they operate with very low currents, and their pulsating current allows targets to remove themselves from the source of energy.

Farms

Electric fences are effective for animal containment and exclusion in urban areas. However, there are concerns about the safety of electric fences for humans. This white paper aims to provide evidence-based information on the safety of electric fences for animal containment and exclusion in urban areas with proper installation.

Safety Features of Electric Fences

Electric fences installed in urban areas if installed properly can be safety used with minimum risk of harm to humans. These features include warning signs, insulators, and ground rods. Warning signs are essential to ensure that humans know the electric fence's presence, avoiding accidental contact. Insulators help prevent electrical arcing and ensure that the current flows through the wire instead of through the fence posts. 

According to a study by the University of Minnesota Extension, electric fences installed with proper safety features, such as warning signs and insulators, significantly reduce the risk of injury or harm to humans (Schulte et al., 2012). The study also found that electric fences designed for animal containment purposes in urban or rural areas are low impedance voltage, which is not life-threatening to humans. While touching an electric fence does cause a harsh shock, the low number of amps used in the fence prevents this from being serious or deadly. As electric fences use high voltage but low amplitudes, injuries caused by them are very rare.

Proper Installation of Electric Fences

Proper installation of electric fences is crucial for the safety of humans. The installation should be installed according to manufacturer instructions, warnings, and placards or by a professional with experience in installing electric fences. The electric fence should also be installed according to local regulations and standards.

A study by the University of California Agriculture and Natural Resources found that proper installation of electric fences significantly reduces the risk of injury or harm to humans (Linn, 2005). The study also recommended regular inspections of electric fences to ensure that all components are in good condition and that there are no loose or damaged wires.

Maintenance of Electric Fences

Regular maintenance is essential for the safety of electric fences. Neglecting to maintain an electric fence can result in irregular operation and ineffective containment of exclusion. Regular inspections should be performed to ensure that all components are in good condition. Any damaged or broken parts should be replaced immediately. The fence line should be kept clear of any vegetation or debris that may interfere with the operation of the fence. If a solar energizer is utilized, the battery, charging system (if applicable), and energizer should be checked regularly with proper electric fence testers to ensure that they are functioning correctly. In the instance of a mains energizer (110v), the energizer cannot be located outside in the weather and needs to be connected to a GFCI-protected outlet.

References:
Burrows, G. E., et al. (2004). Electric Fencing for Serious Graziers. University of Nebraska-Lincoln Extension. Retrieved from https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1286&context=extensionhist
Linn, J. G. (2005). Electric Fencing Basics. University of California Agriculture and Natural Resources. Retrieved from https://anrcatalog.ucanr.edu/pdf/7249.pdf
Schulte, B. A., et al. (2012). Fencing Systems for Livestock Production. University of Minnesota Extension.