EARTHING YOUR ENERGISER
Why earthing is important
Earthing site
Types of earth system
Testing your earth
system
WHY EARTHING IS IMPORTANT
- Lack of adequate earthing is one of the most common causes of poor
performance of electric fences.
- A correctly installed earthing system is essential.
- The earth stakes form part of the total electrical circuit which
begins at the LIVE 'fence' terminal on the energiser, follows the lead-out, then continues
along the fence, through the animal, into the soil and back to the earth stakes and
returns to the energiser.
- The circuit back to the earth terminal is completed by the stake
and the wire connecting it to the energiser.
- If any part of this circuit is broken, no current will flow and
the animal will not receive a stock.
- Most difficulties occur from the contact between the soil and the
stake.
- If this is poor, as it often is, the flow of electricity is
restricted.
- This is the same as saying that there is a very high resistance
between the stake and the soil.
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EARTHING SITE
- Select an earthing site that is regularly moist, at least 10
metres [33ft] away from:
an earth stake for another electrical system
- any telephone earth stake
- any plumbing system including any disused system
- any building using structural or reinforcing metal in contact with
the ground.
- Finding moist ground may require siting of the earth system some
distance away from the energiser.
- SPECIAL NOTE : Regulations prohibit the
connection of two or more energisers to the same electric fence.
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TESTING YOUR EARTH SYSTEM
- To test the effectiveness of the earth, create a dead short on the
fence line at least 100m [330ft] from the earth stakes.
- Using an electric fence voltmeter at the earthing site, place one
terminal on the earth wire, extend the probe as far away from an earth stake as possible
and push into the ground.
- If a voltage reading in excess of 400 volts is obtained, the
earthing system is inadequate and more earth stakes will need to be installed.
- If after the installation of 12 earth stakes the earth voltage
still exceeds 400 volts, extend the earth wire to continue as a bottom wire along the
fence line until a more wet area or greater conductive type of ground is encountered.
- Install more earth stakes in this new area and join them to the
extended earth wire
- Some energisers indicate inadequate earthing by a flashing warning
lamp.
- If using another type of energiser, test the earth voltage
regularly so that changes may be observed and steps taken to correct any voltage
variations.
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