Essential & Useful Accessories - Earth Stake or Earth Rod

This blog should help you to understand one of the most essential and useful accessories of an electric fencing system - the Earth Stake or Earth Rod.

Earth Stake or Earth Rod - A Guide:

Most electric fencing problems are caused by poor earthing.  Having a good earth system connected to your electric fence will ensure a system that works effeciently - this is often over looked but is perhaps as important as planning the fence layout or choosing the right energiser.

Always bear in mind that all electrical circuits must form a complete loop from the positive (live) to the negative (earth) terminals of the supply circuit.  This means in electric fencing that the ground (earth) is just as much a part of the circuit as the fence line and the animal is the missing link that completes the loop.

An electric fence system is a circuit.  You require an energiser, electric fencing (ie rope, tape or netting) and an earth stake.  Once the fence is installed and an animal touches the fence the circuit is complete and the animal gets a zap.  See diagram below:

electric fencing cow earthing

 

 

 

 

 

Installation of an Earth Stake or Earth Rod

The earthing system is an integral part of an electric fence's performance.  There must be a clear return path through the ground to the earth stake back to the energiser in order to complete the circuit. Keep earth stakes away from domestic earth systems, and at least 10 metres away from any other earth installations, ie. those used by telephone or electricity supply companies. Never use steel water pipes or steel framed buildings as an earth.  It must also be away from any tree roots and/or foundations of a building.

  1. First, work out how many earth stakes you need. Larger fence energisers exerting more power, or longer fence lines with higher potential leakage, require substantially more earthing. As a rule aim for 1 metre of earth rod for every joule of energy, ie. a 5 joule energiser will require 5 metres of earthing. Your earth stakes should be at least 4 metres apart.
  2. You need to link your earth stakes together with lead out cable, which you then connect to the energiser's earth terminal.

An example of an effective earth system could be: three 1 m steel stakes driven fully into the soil approximately 3 m apart and joined together (and if possible buried in the ground) with 2.5mm galvanised steel cable.  This is then connected t o the earth terminal of the energiser with lead-out cable.  Always try to install the earth system in a permanently damp area.  If this is not possible, water the ground around the earth stakes in dry weather conditions. For particularly poor earth conditions  (sand, peat, gravel, very dry soil, snow or frozen ground) it is possible to increase the earth efficiency by :

1.increasing the number of earth stakes
2.by running an earth return wire in parallel to the fence line and connecting it to earth stakes at regular intervals

electric fencing - how earthing works

 

 

 

Further Considerations

  1. Bear in mind that an earth system installed in winter, which is adequate for winter conditions, may not be suitable for summer. This may explain any substantial loss in power on your electric fencing over the summer months.
  2. Vegetation will also complete the loop causing the output voltage of the energiser to drop.  Therefore it is very important to keep any growth on the line to a minimum to ensure the animal receives the maximum shock from the Energiser.

 

Testing your earth system

To test an earth stake installation. firstly short out the live fence line to the ground, either with a metal stake or by laying the fence line on the ground for about 100m and at least 30m away from the energiser.

Switch the energiser on.

Measure the voltage between the ground and the earth stake with a meter.  if this is above 200v the earth installation is inefficient.  Check the connections or increase the number of earth stakes.  If you get a shock from the earth stake before you short the fence line then there is a poor earth and possibly a fault on the fence line as well. (check for vegetation on the line or faulty insulators).

 

Earth Stakes or Earth Rods are available in our On Line Shop

 

If you have any other questions for us then either

Give us a call on: 01620 860058

Or drop us an email: [email protected]

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