An electric fence energizer converts mains or battery power into a high voltage pulse. The energizer releases this pulse on to an insulated fence line about once every second. The pulse itself is only around 150 microseconds long.

This pulse is commonly referred to as the “shock” and is felt by any animal which touches an electrified fence. When the animal makes contact with the fence the circuit is complete. It is at this point the animal receives a shock. The diagram below shows how the current flows from the energizer down the fence line and through the animal. The current then flows through the earth back to the ground system and completes the circuit. It is the shock which deters the animal from putting pressure on the fence line

An electric fence is a psychological barrier rather than a physical one so the animal must be educated to respect the fence. The pain that an animal feels is short lived and does not physically harm the animal, unlike barbed wire which can cause severe cuts and long lasting pain whilst also damaging the hide.


Always use insulated cable when connecting a ground system to the energizer to ensure that no wires come into contact with sheds etc. This is particularly important with milking sheds as cows are very sensitive to even very low voltages in this environment. An electric fence ground system should not be connected to any plumbing system, including disused water pipes or old bore casings, nor should it be connected to any other grounding device. An electric fence earth system should be at least 133ft away from any other electrical earth system or telephone earth system.
Each energizer should be connected to its own ground system and this should not be connected to any other ground system. Do not connect two or more energizers to the same electric fence.
Never connect any fence energizer to barbed wire of any description. Do not attach an energizer or electrified wires to any post of any overhead power line unless authorized to do so.
Try to avoid erecting a fence which runs parallel to or runs under power lines. Where this is unavoidable the crossing should be underneath the power lines and as near as possible at right angles to the lines.Where a fence is in the vicinity of overhead power lines, no fence wire should be higher than 6’6″ above the ground.

The sign should also display the words ELECTRIC FENCE or show the symbol depicted.

Any lettering should be indelible, at least 1″ high and it is recommended that the color of the sign be yellow with black inscription. In areas prone to bushfires, power the fence line from the 1/2 voltage terminal or turn the energizer off on days of extreme fire danger.

Can an electric fence kill a human?

Well it did not kill you for three reasons. First, electric fences are designed NOT to kill you. Second, with that in mind electric fences are designed to deliver high voltage and low amperage