How Do Managed Electric Fences Work?
There are many different types of electric fences out there. There are some that are used to keep animals in (or out), some that offer very basic security, and others that are very sophisticated and usually part of a much larger integrated perimeter security systems.
What many people don’t know is how those managed electric fence systems work and how they can help you to keep long fence lines around high-security sites safe from breaches.
Monitoring Voltage and Short Circuits
The simplest way to explain how managed electric fences work is to say that they are designed to monitor the voltage and short circuits on the fence. As most people know, when you touch an electric wire, whether it’s on a fence or not, the voltage or current will change because you are changing the circuit.
So, at a fence line level, monitored electric fences have energizers that can monitor the voltage and current on the fence and that trigger a signal whenever there are fluctuations that are outside of standard parameters.
Whether it’s vegetation that touches the fence, an animal, or a person, when it changes the normal operation of the fence, the signal is sent.
Radios and Comms Cables
Now that you understand the basics of what happens at the electric fence energizer when there is a short somewhere on the fence, the next thing you need to know is how that signal travels to someone who can do something about it!
Usually, this either means there’s a radio at each energizer, or there might be a buried communications cable along the fence line. Both do the same thing – send any alarm signals generated at the energizer to your guardhouse or security office.
Electric Fence Management Systems
Once the radio or comms cable that connects all the energisers and fence zones on your fence line together have sent an alarm signal, you need some way to interpret that signal.
On simple one or two-zone electric fences, that could mean something as simple as a strobe light and a siren, but on larger, more complex electric fence systems, you will need digital equipment to stay on top of what’s happening on your fence line.
Electric fence management systems usually have a digital layout of your site with all the zones marked, and when a signal is received for a particular zone, that zone will light up and probably have an audible alarm.
If you have other electronic security on your fence line, like lights and cameras, your security team can turn them on for that zone so that they can see what’s happening and where and respond accordingly.
Some electric fences also have a tag reader at each zone, so that a security officer needs to be present to acknowledge the alarm – which confirms that they’ve been to check out the cause of the short and alarm.
Electric fence management systems can do more than that, though. Some can be set to turn down the voltage or even turn off during certain parts of the day – like when there are members of the public present in a particular area. They can also log all the events that happen on the fence, along with the security response.
Simpler Than It Seems
As you can see from this admittedly simplified explanation of how electric fence management systems work, there’s nothing inherently complex about the system itself. The fence monitors shorts, sends a signal to your management system, and that records and triggers visual and audible alarms.
There are a huge variety of different managed electric fence systems and combinations of equipment out there, so there may be a few differences along the way. But most of the electric fences out there work on the same principles.
Of course, the equipment that does this is complex and technical, and it’s always a good idea to have a specialist install any electric fence. There are so many little things that have to be done correctly to ensure that any electric fence not only works but also is safe that it’s really not something you want to DIY!
