Electric Fencers

Electric fencing systems have been developed to stop the free movement of animals across pasture. They are semi permanent solutions that can be extended, altered, or removed with ease. Allowing grazing to be divided up and/or protected from livestock access.

The systems consist of plastic or wooden posts , insulators, conductive wire/rope/tape and an electrical energiser unit. This unit can be mains, battery or solar powered, it sends short electrical impulses along a conductive wire (tape, rope, etc). These impulses are between 0.1 and 0.3 milliseconds long and occur at approximately one-second intervals. When the conductive wire or fence is touched by an animal (or human) the current passes through it to the ground and causes the animal to feel a shock The shock is sufficient to alarm an animal but not to harm it. An animal soon recognises a fence when touched will give out a shock and will learn to stay away from it so the fence is both a physical barrier and a psychological barrier.

Such an electric fence works for containing animals as well as preventing access by unwanted animals.

The education of animals to the effect of electric fences is critical to their function. Fences must be constructed in such a fashion so that well insulated animals i.e. sheep, goats and horses in thick rugs! can still receive a shock.

Electric Fencing Problems

EARTH / GROUNDING

INSULATION

CONNECTIONS

Flat/ Batteries

It is essential to regularly check your electric fence battery and recharge it when necessary. Thus it is a good idea to have more than one battery available for use. A flat or low-charged battery can render an electric fencing system useless.

Earth / Grounding
Probably the largest cause of poorly performing electric fence systems.

An electric fence energiser must be earthed and electric fence/tape/rope must not.

All electric fencing energiser must be earthed. Without this properly functioning the circuit does not complete and NO shock will be felt. Because all situations will vary it is not possible to give a cast iron rule but for all practical purposes it is not possible to “over “ earth an electric fence energiser.

If the electric fence energiser comes with a earth stake for normal UK conditions this should be sufficient For larger 12v and mains energisers it is necessary to purchase earth stakes separately. They should be galvanised and a minimum of 50cm long. The most powerful energisers will require 2 or 3 earth stakes with each earth stake being up to 150cm long, all connected together with wire 6 feet apart.

Soil conditions will effect earthing , moist clay /loam will be much more conductive than dry sandy soil . The simple test is to put your hand on the earth post if you can “feel “ electricity then the earthing on your energiser is not adequate and extra earth stakes should be used .
TIP

During dry periods simply watering the earth stake regularly can improve performance noticeably.

Ensure all connections are clean and tight and that the stake is sufficiently deep in the ground (minimum 50cm).

It is essential each electric fencing energiser has its own earthing. NEVER connect to a ground stake/ earth rod that is already connected to a mains supply or another electric fencing energiser.

Locate ground rods where they are highly visible, and not likely to interfere with mowing or cultivating and are not likely to be damaged from and or cause injury to livestock or people

Insulation.

If you have read the section above you should now have a high performance earth system.
This section covers the need to protect the fence from foreign bodies. It is essential you earth the energiser and not the fence.

If anything is touching the live line / lines of your fence and the ground it will act to earth the fence. This drains the power available affecting both the distance the energiser can cover and the strength of shock energy it can deliver the effect is more pronounced during damp or wet periods. This additionally drains batteries quickly****

The most common culprit is long grass or weeds particularly with permanent fences where the area under the fence does not get grazed. The only real solution is to remove the plants causing the problem. If regular strimming is not possible weed killer is an effective solution.
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If it is not possible to manage the “weed” growth affecting the fence line a more powerful energiser may well be necessary to compensate for the power loss.

Ensure no branches or twigs are touching the fence.

If you are using wooden posts rather than plastic ones you must use proper electric fencing insulators to ensure the current will pass along the fence. By twisting the tape (rope) around the wooden post you run this risk of earthing the fence especially in wet/damp weather.