Low voltage on fence Some unusual faults Radio interference
LOW VOLTAGE ON FENCE
The most common electric fence fault is low or insufficient voltage on part of a fence system.
A fault finding chart is shown below.
A few points stand out:
Always check voltage at energiser first with the lead out wires disconnected.
Check the obvious,
e.g. is the energiser switched on
If voltage at energiser is normal, check earth before fence.
Once you have been through the initial steps you may need to check your fence.
If you have a large fence system, the value of cut-out switches is now obvious.
By process of elimination, beginning at the first cut-out switch [at the end of the lead-out wire] you can narrow down the area at fault.
When the area at fault is disconnected, voltage in the rest of the fence should rise.
Well placed cut-out switches in your fence system will help isolate sections of your fence line to help trace fence fault locations.
A digital voltmeter is a very important part of your fence maintenance equipment.
Notes :
A voltage variation may occur because of an energiser change, an increase in fence line length, changing climatic conditions, seasonal growth over wires, insulation breakdown, etc.
Improving the earth system may assist the fence line voltage, but does not negate the necessity to remove critical faults from the fence line in order to preserve a high degree of efficiency.
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SOME UNUSUAL FAULTS
Electric shocks from Sheds or Waterpipes
This can be caused by one of the following:
Failure to observe instructions for "earthing"
A spot on the wire where the insulation has been removed and has shorted to the metal work in the shed .
If in doubt, disconnect the lead out at both ends and try another fresh wire run out in a temporary manner for the energiser to the fence line.
No Voltage at all on the Fence Line
Cause could include:
a break in the wire between the earth stake and the earth terminal on the energiser
broken lead-out wire
a short from the lead-out to the shed as described above
a live wire entangled with such material as a dead wire or wire netting in an obscure place.
ENERGISER NOT OPERATING.
Fence line wires other than the electrified portion also becoming live
check first for faulty insulators on the electrified lines
look for any stray wires that may have hooked into both wires to form a link between them
if no fault can be found then ground both ends of the wires carrying unwanted electrical charge
Power transference caused by a combination of induction and capacitance will have little overall effect on the operation of the electric fence system.
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RADIO INTERFERENCE
Loud "clicks", coinciding with the energiser pulsing can occur in poor radio reception areas or conditions.
Problem solving checklist
Check radio and power supply ensure all electrical connections are correct.
Energiser earth must be at least 10m [33ft] from other electrical earthing or large metal objects above the ground [Refer Earthing].
Lead-out wire should not run parallel with overhead power supply or telephone wires
Fence faults poor joints, partial shorts or cut-out switch fault can cause problems.
Walking or driving with a portable radio tuned to medium or long wave and 'off station' is a convenient way to locate electrical leakage.
A suitable volt meter will also assist with locating faults.
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