This type of electric fence is usually installed on top of an existing solid fence. Its main function in that instance is for deterrence to would be intruders, a barrier for climbing animals such as cats as well as an early warning alarm signal, in the case of an intrusion. If an electric fence is wired correctly, it can function as an alarm system which will sound a siren as well as automatically alert patrolling security personnel. An electric fence will increase the effective height of the existing fence by its own height, making it even harder for intruders to scale it.
On this type of electric fence, the piggy-back brackets are attached to the posts of an already installed solid fence. The fence will span the full height of the bearer fence. This type of installation is done to enhance the security of the existing fence by providing an extra layer of security between it and the target. When wired correctly, this electric fence will provide an early warning system by way of sounding an alarm in the case of a breach or even tempering. The energizer may be linked to the main alarm system and will alert the security patrol personnel in case of any breach or tempering.
This is a full height electric fence which relies on its own straining and intermediate posts for its structural strength. The fence needs to provide a structurally strong physical barrier as well as deliver enough voltage through the fence wires, needed to serve its main purpose. Freestanding fences are intended to be a second line of security, but they are also widely used as self-sustaining physical boundaries. If these fences are wired correctly and used with the correct energizers, they may also work as an alarm system.