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Electric Fencing > Electric Fence Manual

SELECTING THE RIGHT ENERGISER To optimise the performance of your electric fence, it is essential to select an energiser capable of performing under your prevailing fence conditions and suited to your application. The following factors should be considered when making this decision.

IS MAINS POWER AVAILABLE? – It is generally preferable to use mains power when it is available. Mains energiser's are easier and more economical to run as there are no batteries to maintain. THE DISTANCE OF WIRE TO BE ENERGISED – Daken provides an estimate of the expected range of our energiser's powering a single well insulated wire under favourable conditions. These estimates have been achieved in actual tests and act as a useful guide. THE CONDITION OF YOUR FENCE – A fence that may be subjected to leakages such as heavy weed growth, overhanging foliage, or poor insulation, will require a more powerful energiser to effectively power your fence than under normal conditions. THE TYPE OF ANIMAL YOU WISH TO CONTROL – The response of different types of animal will vary with the size of the shock. The appropriate shock should be designed to bring about the desired reaction from the animal that you wish to control. Often the coat of the animal provides effective insulation in which case a higher voltage shock is necessary to overcome the insulation (for instance – sheep). “Educated” animals do not require as large a shock as do animals encountering electric for the first time.

EARTHING In practice, poor earthing causes most problems, which occur with electric fences. In order for the animal to receive a shock, there must be a good current flow from the pulsed output terminal of the energiser to the animal, and back to the earth terminal. Therefore, it is imperative that the earth terminal is well and truly earthed. Never use water pipes, windmill, or household earth rod for your electric fence earth, because there is a definite risk of shock under certain conditions. EARTH STAKES One of the best systems for adequate earthing is shown below. This consists of a series of galvanised steel posts driven at least 1.5 metres into the ground, and positioned at least 3 metres apart, in a straight line. The posts are connected to each other, and to the earth terminal of the energiser, using galvanised nuts and bolts. Alternatively, you could use a length of galvanised water pipe instead of the steel posts, but it is harder to drive in and is difficult to connect to the earth wire satisfactorily. The earth stakes should be located well away from your house, and at least 10 metres away from the earth peg of your house wiring. If possible, it is best to locate them as close as possible to the start of the fence, and in permanently moist ground, such as near a creek, dam, trough, or septic absorption trenches.

FENCING WIRE The type of electric fence wire you use will depend on the type of fence your are building. STRIP GRAZING These are two main categories of wire generally used for strip grazing. These are plastic twine and 1.6mm soft galvanised wire. The plastic twine, such as “Daken Hot Tape” and “Daken Poly Wire” consists of several strands of plastic (orange or white polypropylene) intertwined with a number of strands of fine metal wire, which act as conductors. The advantage of these types of fence wire is that they can be easily reeled in for transport or storage, easy to handle, are highly visible, and can be simply joined with a knot. The disadvantage is that, although they are UV stabilised, they have a limited life when exposed to the sun. The life may vary from 12 months to several years, depending on conditions. A further disadvantage is that Poly Wire and Hot Tape are generally less conductive than galvanised wire, and are therefore more suitable for only short runs of fencing. Recent developments in Poly Wire products has seen the introduction of “Daken Heavy Duty Polywire” which provides superior conductivity, improved visibility, and extended life – thus overcoming the shortfalls of standard plastic strip grazing wires, whilst retaining the advantages. The 1.6mm galvanised wire provides extended life, but is generally more difficult to use, being harder to roll and join, and more prone to twisting and tangling than plastic twine.

WIRE JOINING When joining wires in an electric fence, any of the commonly used knots will suffice. However, the following points should be considered. 1. The knot should provide multiple contact points for conducting the electricity. 2. The know should not weaken the wire too much. 3. It should not flex after the wire is strained. 4. Loose ends should be cut back close to the knot to avoid short circuits. Two types of knot, illustrated below, have been found to give satisfactory performance.

When joining Poly Wire or Hot Tape, it is preferable to separate the wire strands so that they may be twisted and joined together. Both ends should also be knotted to take the fence strain. In order to provide electrical continuity in the fence, you will also need some kind of line clamp and removable connectors. It is very important that all metal components in your fence are galvanised. Any brass, copper, or aluminium will corrode, leading to bad electrical joints and loss of pulse strength.

FENCING INSULATION It is essential that your electric fence is properly insulated along its full length. Insulators are designed to take all wire types on wood or steel posts, and special clips are available for fibreglass posts. The following diagram shows some of the methods of insulating your fence at internal corners, external corners, and at straining posts. PORCELAIN INSULATORS – are generally regarded as being a longer life insulator, but are more expensive, more difficult to put on, and can suffer from cracking. PLASTIC INSULATORS – are easy to use, offer optimum insulation, and are relatively inexpensive. Good quality plastic insulators such as those manufactured by Daken are UV resistant and therefore offer a longer service life.

FENCE CONSTRUCTION STRIP GRAZING Fences for strip grazing come in many forms. Most commonly they are fully portable, single wire fences as shown below. All the components of this fence are easily installed and can be moved by hand quite efficiently.

SEMI-PERMANENT FENCING For semi-permanent fences, steel posts are most convenient as these enable you to have two or more pulsed wires. Daken Pinlock “Y” Insulators or Daken Steel Post Insulators are often used here because of their ease of application. Only light strain assemblies and low wire tensions are required.

PERMANENT FENCING The wire in a permanent electric fence must be strong enough to take the mechanical strain during fence construction, and be strong enough to withstand the animal pressures it likely to be subjected to. If you are fencing trained domestic stock, a lighter gauge wire is suitable. When controlling untrained animals, or other animals that will be trying to cross the fence, such as kangaroos or emus, a heavier gauge wire should be used. Post spacing's will depend upon the terrain, the number of wires, and the level of physical security required. A wide variety of posts can be used, including timber, steel, and fibreglass posts. Insulators must be used on all steel and wooden posts, while special clips are available for use with fibreglass posts. Earthed wires should never be insulated in the fence. Some of the many arrangements for permanent electric fencing are shown below:

3 Wire Fence on Steel Posts

5 Wire Fence on Wooden Posts

6 Wire BI-POLAR Fence

SUGGESTED WIRE SPACINGS Some of the possible wire spacing's for permanent electric fences are shown below

REINFORCING EXISTING FENCES You can successfully extend the life of your old fences, or improve the holding power of an existing fence, by the addition of one or more pulsed wires. To discourage kangaroos, pigs, and wild dogs, often only one wire is required, placed low down and out from the bottom of the fence.

Simple reinforcement of cattle fences requires a single wire at about 75cm from the ground. Depending on the condition of the old fence, it may be necessary to use insulated standoff wires to keep the pulsed wire well away from the old wires. Standoff wires may be spaced well apart, depending on the risk of tangling with other wires.

The Daken Pinlock Standoff is most suitable for this application because of its ease of application and the lower initial cost. Where high side loads will be applied, such as over the crests of hills or around corners, Daken Porcelain Standoffs are recommended (pictured below).

GATEWAYS – IN PERMANENT FENCES It is not usual to try to electrify an existing steel gate, but the pulsed and earthed wires must be carried past the gate to continue the fence. The wires are generally taken under the gate, as shown below.

You should use Daken Insulated Underground Cable to connect each pulsed wire, and the earth, to its mate on the other side of the gate. This will make fault finding easier and help minimise the effects of faults, if they do occur. It is recommended that Daken Cut-out Switches or Curl-on Connectors are used on one side of the gateway. This allows for easy disconnection of the fence for testing. HANDY TIP – Make sure the ends of the black poly pipe are turned over to avoid water penetration. A further low cost alternative for gateways in permanent or semi-permanent fences id Daken Tape Gates or Daken Spring Gates. Both are easily installed between wooden posts and include a gate handle, gate anchors, and adjustable tape or springs.

GATEWAYS – IN TEMPORARY FENCES To form a gateway in a temporary fence, you can use a Daken Gate Handle. Two possible arrangements are shown below. In diagram A, the arrangement means that opening the gate will disconnect the entire fence past the gate. Diagram B shows an arrangement where the fence remains active, whether the gate is open or not. Note that the gate handle should always be installed so that it is only connected to the pulsed wire when it is hooked in. In other words, when the gate is opened, the handle and wire are no longer pulsed.

Diagram A

Diagram B

CREEKS AND DAMS There is a problem with maintaining a pulsed wire at an effective height over irregular ground such as creek beds. Many different solutions have been tried, with varying degrees of success. The general ideas are illustrated below:

FENCE LAYOUT The overall layout of your electric fence system deserves careful planning, because the amount of care taken at the planning stage will determine the amount of time you have to put in to checking and maintaining your fence in the future.

LENGTH OF RUNS It is better to have several short runs of fence leading out from the energiser, rather than one long run. Diagram B is the sort of layout, which can develop when a fence is added to as time goes by. You can see that the pulses must travel from “X” through “Y” almost completely around the boundary to reach “Z”, passing two branches on the way. In Diagram A there are three (3) distinct runs of fence, each kept as short as possible, and each having no more than one branch. Compare the effects of a fault at “F” – In Diagram A, only one short run of fence is seriously affected. In Diagram B, almost the entire fence system will be put out of action, or at least seriously affected.

BRANCHES In many electric fence layouts, “branching out” is unavoidable. If you have to take a branch out from a pulsed wire, do so as close as possible to the energiser, and keep the branch as short as practical. When there are a number of wires branching out, it may be necessary to install a “feeder” line. Feeder wires are often made of heavy gauge wire, carried at, or near, the top of the fence, where they will not normally be touched by livestock. The use of a feeder line is shown in the following diagram.

The feeder wires should be kept well insulated, well clear of the ground, and have a low risk of being damaged. If a pulsed wire is needed on the same fence, then a normal pulsed wire is run along the fence at its normal height, as well as the feeder. This pulsed wire should be supplied from the distribution point at the end of the feeder wire, not from the energiser end. This arrangement will minimise the effects of any faults on the pulsed wire, and also provides a useful voltage checking point near the energiser.

SUGGESTED LAYOUT The following layout represents a good electric fence layout – sections of the fence are easy to isolate, making fault finding simple. With this layout, you only have to perform the following checks to ensure that the fence is working:

A. Disconnect the energiser at point 1. Check the energiser output voltage. If satisfactory, reconnect and go to point 2. B. Disconnect fence at point 2. Check the voltage at point 2. If satisfactory, reconnect and go to point 3. C. Disconnect and check voltage at points 3, 4 and 5 similarly. If each check is satisfactory, then you know that the entire fence is working. If any check gives a low (or zero) voltage reading, then you know that there is a fault somewhere around that loop.

LIGHTNING PROTECTION A common cause of breakdowns of electric fence energiser is lightning strikes. During electrical storm activity, high voltage lightning strikes may be conducted along electric fences to the energiser – causing damage to the circuitry. It is recommended that during electrical storms, your energiser be disconnected from the power source as well as from the fence. This is the only fool proof defence against lightning damage. As this is not always practical, Daken has developed a range of devices that will assist in reducing the risk of lightning damage. THE DAKEN MAINS SURGE ARRESTOR – has been designed to protect your mains powered energiser from high voltage surges coming through the mains power source. The Mains Surge Arrestor is designed to absorb the surge before it reaches the energiser. THE DAKEN LIGHTNING DIVERTER KIT – is designed to divert high voltage strikes coming along your fence line. Lightning Diverter Kits are required on both live and earth wires, and should be located as close as possible to your energiser.   MAINTENANCE A regular maintenance programme should include the following: 1. Clear your fence line of grass and weed growth. 2. Clear away bracken, branches, or other debris that may have fallen on the fence. 3. Check for slack or broken wires. 4. Battery maintenance for solar or battery powered energiser's 5. Testing for voltage drops along the fence to identify short circuits. TRAINING STOCK It has been well established that trained stock respect electric (and ordinary) fences more than stock, which are simply put into a paddock with an electric fence. Training requires only that your stock should be put out for about 24 hours in a small holding yard, with a full strength pulsed wire around the boundary. They should be under some kind of pressure to test the fence (e.g. Hunger). Sheep are best trained when they are just off shears. Cattle and pigs respond very quickly to training at any time. You should take particular care when training horses so that they have plenty of room to run when they first experience an electric fence. Reduced power is preferred for horses.

© Steve Cselka 2002 - 2006