Electric fencing explained

Electric fencing explained

Electric fencing can have many advantages over traditional fencing methods. Electric fencing acts as a psychological barrier and animals will learn to avoid it after their first contact.

An electric fence is a circuit where by an energiser powers an electrical current, which passes through the wire(s) at regular intervals and upon contact to the animal, then via the earth stakes in the earthing system back to the unit completing the circuit.

Electric fencing – equipment required

To create a circuit for the electric fence, the following items will be required:

Energiser

Energiser

The energiser is the item that powers the fence via a battery or mains source. The energiser does this by taking the charge from a battery or mains source and converting it in to a pulse of electrical current, which travels down the fence line giving a shock when an animal or person comes in to contact with it. When installed correctly, the shock given should be just enough to deter the animal or person without causing them any harm.

There are two main types of energiser available, battery powered and mains powered. Mains powered units are cheaper to run but are less practical depending on the location of the fence.

Power Source

Power source

The type of power source (battery or mains) that is used depends on the location of the fence line and the energiser.

Mains power is cheaper to run and more reliable, however it may not be the most practical solution depending on the location of the fence, as the energiser must be located in a covered building with an electricity source (i.e. mains plug socket). Mains power can still be used where fence lines are not in close proximity to a mains plug socket by using a HT lead cable (see below), however, this may be a more costly option.

Batteries are extremely portable and offer a range of options from 6v and 9v models with disposable batteries to 12v rechargeable models and solar options. The type of battery used often depends on the type of fence installed and the customer’s requirements.

Posts

Posts

The type of post used depends on the fence being installed. For permanent fences, treated timber posts should be used. For more information about the timber we use, including the different timber treatments available, please visit our Posts, netting and wire explained section.

For temporary fence lines, there are two options available, plastic or metal.

Plastic posts can be used with wire, tape or rope and come in a range of colours (green, blue, orange, white, yellow), sizes 0.7m, 0.9m, 1m, 1.3m and 1.6m. Plastic posts are easy to install, light to handle and easy to store. These posts can be used for most animals however they are less suited for use with cattle.

Metal posts are designed for use with wire or rope and the majority come with just one insulator sighted at the top of the post, although metal posts are also available with adjustable insulators . Metal posts come in sizes of 1m and 1.2m and are easy to install and store. These posts are ideal for use with cattle but can also be used for horses and other large animals.

Tape-rope-and-wire

Wire, tape or rope

All conduct charge in the same way, the only difference being the medium with which the current is carried. The primary concern for all electric fencing is visibility. For many animals an electric fence acts as a psychological barrier and they have to be able to see it to avoid it. This is also a consideration when choosing a colour – a product with a low visual impact from a human point is also much harder for an animal to see. Products which offer a higher contrast with the surrounding environment are more likely to be effective.

Tape is the most visible option available and comes in a range of grades and sizes to suit all budgets. 10mm, 20mm and 40mm tapes are available all in 100m or 200m rolls (40mm tape is also available in 250m rolls). When using tape it is important to use the correct size insulator to ensure that the tape does not move within the insulator which can cause damage to the tape.

Ropes are not as visible as tapes, however ropes are still a good alternative to tape. Although it may not be as visible it has a higher durability, making it an effective and more durable barrier to contain horses. Ropes are available in 6mm or 7mm sizes in 200m rolls (6mm rope is also available in 500m rolls). The ropes are constructed from polypropylene with multiple strands of stainless steel conducting wire threaded throughout. Stainless steel conductors are used as they have a good balance of conductivity and strength.

High tensile wire or specialist lightning/equi wire offers the highest durability out of all materials for permanent electric fencing for horses. There are two main types of wire available – standard high tensile wire and lightning/equi wire. Whilst being highly durable and super conductive, at 2.5mm thick, high tensile wire is not as effective as a visible psychological barrier. An alternative to this is a product called equi wire.

Lightning/equi wire is a 2.5mm high tensile wire that is coated in a high visibility polymer containing conductive radial fins connected to the central high tensile cable. The radial fins carry the charge from the central cable to the outer surface of the wire delivering a shock when contact is made. This product offers the highest level of durability whilst being highly visible, making it the ideal product for permanent electric equine fencing.

Polywire is a good budget alternative to rope and tape, however it is less durable and visible than both rope and tape. Different grades of poly wire are available with products containing three or six stainless steel conductors or a combination of three copper and six stainless steel conductors. Polywire is available in 1.2mm or 2mm sizes with 100m, 200m, 250m, 400m or 500m rolls.

A further option available for temporary fencing is to use an aluminium or galvanised steel wire. Both of these are highly conductive but also less durable than other options listed above.

Electric Netting

Electric nets

An alternative to standard electric fences, electric nets are available for uses such as containing sheep, poultry and goats or excluding animals such as foxes and rabbits. Electric nets are manufactured from polyurethane with metal filaments running through the horizontal strands (apart from the bottom base line). This is mounted on PVC posts.

Earthing

Earthing/grounding

Earthing or grounding a fence system is perhaps the most overlooked aspect of building an electric fence and is not just for safety purposes. The fence line is only one half of the circuit, the other half is the ground. The two together form an open circuit, when the animal touches both it acts like a switch and the circuit is completed.

The fence line operates efficiently as the electricity is carried through highly conductive filaments, but on the return pulse it is carried through the ground itself. It is recommended that a minimum of one x 1m earth stakes are installed for any fence application to a depth of at least 1m in the ground.

Connectors

Isolators and connectors

The most common connectors are plastic crocodile clips with stainless steel jaws. These are usually supplied with the energiser. When these are connected to the it allows the current to pass from the energiser to the fence. When using tape it is recommended that purpose made tape connectors are used.

Isolators are installed as part of a fence line, to allow a section of fence to be turned off rather than switching the whole fence off.

Gates

Gates

Electric fence gates are available in different styles depending on use and the animals that are being contained. The most popular are spring gates, however these may not be suitable for use with equestrian surroundings. In these situations a bungee gate or tape gate may be more suitable.

Testers

Testers

There are three main types of electric fence tester. Proximity testers detect energy from a short distance and emit a sound or display an LED to show the presence of power. These are useful in offering a quick indication that a fence is on, but are inadequate for fault finding or actual voltage readings. Testers fitted with ground probes to connect earth and fence, much as an animal does when shocked, can indicate the amount of voltage present on the fence and can be used to find faults.

This type of tester can be used to test the fence, the energiser itself and the earth, allowing the user to single out the element causing the problem. The third type of electric fence tester is a self earthing unit. Self earthing units use the body to make the earth connection allowing quick and accurate readings. Application of these units range from simple digital Kv reading to providing you with a direction indication for the fence fault.

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Additional items

Other items that may be required include warning signs (which must be displayed a minimum of every 50m if the fence line is along a public access way); lightning arrestors which act as a diverter switch for lightening, channelling lightening to ground to minimise damage to the energiser; tensioners for wire tightening; and reels (only for temporary fences) for containing any excess wire and for easy storage of wire when not in use.

Whatever your electric fencing needs, Suddenstrike Fencing has a product to suit, whether you’re looking for supply and installation or supply only. For more details on how Suddenstrike Fencing could help you with your electric fencing requirements, contact us on 01270 619147 or email mail@suddenstrike.co.uk.