Electric fencing is becoming increasingly common in South Africa as homeowners look for ever more effective ways of safeguarding their property.
One of the best things about how electric fencing works is that it acts as a physical barrier for would-be intruders.
When used along with other security measures such as an alarm system and CCTV cameras, an electric fence can offer the peace of mind that homeowners crave.
What Is An Electric Fence & How Electric Fencing Works?
An electric fence, as the name suggests, is an electrified barrier that prevents unauthorized people from gaining access to a property or keeping animals within a confined area.
When a would-be intruder touches the fence, they complete the circuit and receives a shock.
The fence does not carry a constant electrical charge, but rather a short burst of current every second. This electrical pulsing prevents the typical grabbing effect that happens when a person is electrocuted.
The fence also does not carry a lethal voltage and is meant to deter rather than cause serious bodily harm.
How Can An Electric Fence Bolster Your Security?
The security advantages of an electric fence are threefold.
Firstly, the fence and accompanying warning signs act as a psychological barrier. Intruders are less likely to attempt to break into a property that is well secured and risk injury or worse.
Secondly, the fence acts as a physical barrier. It might be the case that a determined prowler can bypass the fence, but it will slow down their progress. Most culprits are unwilling to go through the trouble, to begin with.
Lastly, a good electric fence is linked to an alarm that can alert you and your security company of a crime in progress. Such a system is designed to detect and warn of an imminent breach, such as when a person attempts to short or cut the fence.
Where Can Electric Fences Be Installed?
Electric fences can be installed in three main places:
- On top of an existing wall – if you already have a perimeter wall around your property, you can choose to install an electric fence on top of the wall. This is the most common type of electric fence for residential properties. This design is known as a wall top electric fence.
- On top of an existing fence – it's not just concrete walls that can be secured with electric fencing. You can also bolster your mesh or wire fence that surrounds your property. The advantage here is that the electric fence is installed using the existing posts, cutting costs on materials and equipment. This design is called a piggyback electric fence. Please note that you cannot electrify a mesh or wire fence and to do so would be illegal.
- As the main fence – although not used for residential applications, you can have an electric fence as the perimeter barrier. This design is called a standalone electric fence and is commonly found in ranches, large farms, national parks, and maximum security areas.
Electric Fence Equipment
An electric fence is made up of a few different parts that work together to deter intruders.
You can think of the energizer as the heart of the electric fence.
This equipment is responsible for sending the appropriate amount of current through the wires and at the appropriate intervals. Some energizers are outfitted to detect and warn in case of a breach of the fence.
The energizer may also send a signal to the homeowner and/or security company in case of a breach.
The equipment may be powered from the main power source or battery powered. You can also power it from the main source and have a battery backup that can last anywhere from 4-10 hours.
Cables are designed to pass on the current from the energizer to the wires and back to the source.
The cables are also specifically built to carry the voltage without melting or other damage.
Additionally, the cables also link the wires to ensure that they are all charged.
You need the wires to carry voltage along the fence.
The wires will give an electric shock when touched. These are also insulated to avoid charging the posts in case of metal posts.
The grounding rods are metal poles that are anchored to the ground to help complete the circuit.
The posts may be made from wood or steel and help to support the fence or wires in the case of a free-standing fence.
Wall top or piggyback fences use wall-top brackets which can vary in size, shape, and design depending on the type of wall or fence.
You need a way to warn people of potential electric shock.
Most governments, including South Africa, mandate that you put up clear warning signs along the length of the fence.
8 Basic Electric Fence Requirements To Comply With Regulations
Electric fences fall under the Electrical Machinery Regulations Act, part of the Occupational Safety Act.
The regulations were amended and updated in 2011 to cover residential electric fences. Failure to abide by all the rules may lead to a hefty fine and even possible jail time.
Here are the basic requirements you need to be aware of:
- Electric fences are installed on walls with a minimum height of 1.5 meters.
- Electric fences can only carry a maximum of 9900 volts.
- Where angled brackets are used, they may only angle on the inside of the boundary wall and no more than 45 degrees. You also need your neighbour's consent if the brackets angle towards their property.
- There should be a minimum distance of three meters between each post
- You should have a minimum of three earth spikes every thirty meters.
- Only an electrician licensed as an Electrical Fence System Installer and registered by the department of labour may install an electric fence.
- You must have an electric fence system certificate of compliance (EFC) for your electric fence.
- You must have yellow warning signs at least every 10 meters if the fence is located along a public pathway or roadway.
3 Mistakes To Avoid When Installing An Electric Fence
There are three mistakes to watch out for when installing an electric fence.
Wires are too tight – it may seem like a no-brainer that the electric fence wires should be tight. You need a little bit of slack to give the fence an elastic effect. Otherwise, the wires are prone to breaking in case of harsh weather or coming into contact with objects.
Using different metals – when different metals mix and carry current, electrolysis is likely to occur. This in turn causes corrosion and makes your electric fence weak and prone to breaking and other damage.
Inadequate earthing – please follow the set-out regulations for earthing your electric fence. Use good quality galvanized ground rods to ensure that you create a complete circuit from and to the energizer. Poor grounding means weak shock.
Electric Fence Care & Maintenance
Most electric fence installers are happy to offer routine maintenance and regular inspections. Please check with your installer and also ask about the warranty, particularly for the energizer.
For your part, use a voltmeter to check the voltage periodically. Check different parts of the fence to make sure it's working as it should. You can also visually inspect the fence for signs of corroded, broken, or otherwise damaged wires and replace them accordingly.
Finally, stand next to the fence when it is raining and listen for a clicking noise. This noise indicates a short in your fence.
Electric Fence Common Problems
1) Problem: Energizer is on and connected but there is no voltage on the fence.
Probable Cause: Broken, disconnected, or corroded ground-return or live wire on the fence. Inspect these wires and replace them as necessary.
2) Problem: Energizer is not working and there is no voltage at the terminals.
Probable Cause: Check that there is power from the mainline. Next, confirm that the input circuit and fuse are working properly. It is likely they are blown. Also, ensure that the terminals are not corroded and that the energizer is switched on. Otherwise, your energizer may be faulty.
3) Problem: No voltage in one section of the fence.
Probable Cause: There might be a dead short across the wires, a faulty ground rod, or broken wire. Inspect these areas and make the necessary corrections.
Frequently Asked Questions
Who Can Install Electric Fence Systems?
Only electricians with an Electric Fence Installer certificate can install an electric fence system. As per the relevant legislation, the homeowner is held liable in case of any issues. Please make sure that you use a certified installer.
Does My Electrical Certificate Of Compliance (COC) Cover The Electric Fence?
No. Electric fences fall under the Electrical Machinery Regulations while the COC falls under the Electrical Installations Regulations (EIR). You still need an Electrical Fence Certificate (EFC) to be compliant.
Why Do I Need An Electric Fence Certificate (EFC)?
Electric fences are regulated under the Electrical Machinery Regulations within the OSH Act. You need this certificate to ensure that you comply with the necessary regulations. This certificate is valid indefinitely provided you do not make any major changes to the electric fence.
An electric fence is a must-have for any homeowner who takes their security seriously.
Contrary to popular belief, these systems do not use up much power. Most homeowners see a small difference in the electric bill, usually less than R25 per month.
Electric fences can be very effective when used in combination with burglar alarms, CCCTV cameras, and even guard dogs.