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	How does an electric fence work?

All installations have to be on an ”open circuit”. The outgoing wire must be fully insulated to avoid ”shorts” to earth. This means using good quality insulators and avoiding vegetation or other items touching the fence wire.

An electric fencer, which can be either mains or battery powered, sends an impulse of energy along conductive wire at approximately one second intervals. When the conductive wire or fence is touched by an animal the current passes through it to the ground and causes it to feel a shock. As the animal recognises that the fence produces pain, it will learn to stay away from it, so the fence is both a physical and psychological barrier.




	The drawing explains the current flow without animal contact - “open circuit” - no flow!




	The drawing explains the current flow with animal contact.


	In all cases a first class earth system is important.


	Visibility of an electric fence is very important too. The animal will remember the shock it received and will respect the fence as a pain barrier. To obtain maximum long term effect, a training period of 24 to 48 hours during which the animal is allowed to touch the fence and receive a shock is essential.

		The choice of the right materials

The basic principle is to obtain a correct balance between the different components of an electric fence. Using a powerful fencer with a low conductivity wire, badly installed and not well insulated or maintained, will give poor results and unsatisfactory service.

The fencer
This is the heart of the system! There are many models available depending on the power supply and output required, the fence length, and the type of animals to be contained or excluded.

Mains fencer 230V: for long and permanent fences. High voltage impulse and low amperage. Mostly used for more than 10kms of fence line.

Dry battery fencer 9V: for short, movable or temporary fences. Ease of moving and flexibilty are the main considerations with adequate output for the job.

Battery fencer 12V: for portable and semi-portable fences and for the longer subdivisions. These can easily be combined with solar panels where prolonged operation with minimum attention is required.


	There are three important rules to respect: • a very good earth system is essential • first class insulation to ensure conductivity to the end of the line • a high standard of installation


	The earth system


	Installation Mains fencer 230V: Drive a minimum of 1 x 1m galvanized earth stake or more may be required in some instances depending on ground conditions and the fencer capacity.) into the ground (see drawing), connect it firmly and water the area around it.

Hint:
Use high voltage 20 (kv) double insulated cable to connect the earth stake to the fencer.

Installation, hints and tips

Tip:
Never, ever connect the earth of the fence to the house earth. It must be outside and a minimum distance of 10m from the house earth.e

Tip:
If the fencer is powerful and the ground very dry, increase the earth system by driving additional galvanised steel stakes (0,5m or better 1m long) into the ground, 3-5 metres apart, connect them together and to the earth terminal. Test the earth system. .

9V or 12V battery fencers:
Hammer the earth stake firmly into the ground. Make a careful and firm connection with the special wire supplied.
Permanent fence, very long fences or very difficult earth conditions:
To increase the earthing and the efficiency of the fence use an additional earth wire which is regularly earthed or an alternating system of live and earth wire (especially to deter game, pest and very difficult to control animals).
Earth Testing
With the fencer on, test the earth as follows:
- put one hand on the far end earth rod or the connecting wire,
- put your other hand on the ground (or use a voltmetre).
In case of a slight electrical shock, improve the earth by adding stakes, tightening connections, or, if very dry or sandy soil, watering the area round the earth stakes until no shock is felt.


	Insulation


	The fencer Ensure all connections are correct, especially those of the fencer power supply from the mains or battery.

Hint:
Use a line tester or a voltmeter which will tell you the voltage level at the fencer output and an the fence line.


	Electrical conductors (polywires, tapes, ropes) Use the fence tester to confirm that there is adequate voltage on the fenceline: push the point of the tester into the ground and place the loop firmly against the wire. Check if there is sufficient voltage.

Tip:
Connect the earth system and the fence to the fencer terminals with a sheathed conductive cable. If there is a “ticking” the current flows.

Fault finding

Check in the following order:

Operation
Mains: check if the unit is plugged into the mains socket properly and that it is live.
9V dry battery or 12 battery: check that the battery is not flat. Check terminals and connections are clean and tight.

Fencer
Most fencers are equipped with an operation indicator light flashing in the rhythm of the impulses at about 1 second intervals.
No impulses or regular but weak impulses: disconnect the fence and check the voltage with a voltmeter or the energy by drawing a spark. If this is okay check the fence. Otherwise check the fencer with your dealer.

Earth System
Check if your installation is correct, according earth testing (see top of page 3).


	Insulate the lead through the wall with a piece of rubber tube


	Lightning arrester
	max. 10mm distance


	Switch

Fencer

			Regular and careful cleaning

		Earth stake


	Straight length of wire through the insulator

		Solid connection to the electrified wire


	Fence It is important to make a visual check but also to CHECK THE LINE VOLTAGE with the help of a VOLTMETER: Start at the fencer end of the line and work your way along to see where the voltage falls away: No voltage = break. Reduced voltage = short. To identify the short or break.