electrical devices there are two basic components, the
positive field and the negative field. The positive field is
the active power or current flow of electricity consisting
of voltage and amperage. The negative field in most common
forms of electrical applications is the medium that connects
the positive field back to itself establishing the flow of
power (commonly referred to as ground or earth). The easiest
way to envision this is with a light switch. When the switch
is on it connects the positive wire to the negative wire
allowing power to flow through the bulb and illuminate. In
electric fence the positive is connected to the fence
material and the negative is connected to the earth or soil.
Relating electric fence power to the imagery of the light
switch, when the animal, who is standing on the negative
field (earth) touches the positive field (fence) it is like
the light switch and the light bulb combined. Its body
connects positive to negative and is also illuminated at the
Supplying power to an electric fence is a
much greater challenge than powering a household device.
Voltage, which is the driving force of amperage, degenerates
when it meets resistance. In our household devices the path
that electricity must follow is clean and direct, usually
over a very short distance. In electric fence applications
however, electricity must flow from the fencer through the
fence, into the animal and back through the ground over an
undetermined distance with very poor conductive conditions.
The voltage can deteriorate in these conditions to the point
of becoming inadequate. It is important to understand that
the animal will only feel the amount of power that returns
to the fence charger through the earth regardless of the
amount of power in the fence. Therefore fence chargers must
produce enough voltage to accommodate deterioration and
still be effective.
Studies conducted by PAMI, a
Canadian testing organization, indicate that it requires
approximately 700 volts to penetrate the hair, hide and hoof
of short-haired livestock. When fencer power falls below 700
volts the animal will not feel a shock because the voltage
is to low to break down the impedance of the animals body.
We recommend a minimum of 2000 volts of active fence power
to insure effectiveness.
WHY USE ELECTRIC FENCE
Electric fence is the most effective form of livestock
control for one very simple reason. It offers the same kind
of natural emotional response that large animals are
accustomed to in the herd environment. In other words in
every herd of large animals there is a pecking order. The
genetically dominant animals in many cases, regardless of
size, become the accepted leader. The lesser animals of the
herd respect that position. When an animal with a lesser
social position challenges the dominant authority they are
met with an immediate and sometimes violent response.
Electric fence treats these animals in a manner that they
naturally respect. A shock from a low impedance fencer is
quite intense and establishes the same emotion in the animal
as if it were kicked or bitten by the herd boss, but without
With the exception of barbed wire,
electric fence is the most economical fencing that can be
installed. Considering that the shock of the fence is the
greater deterrent and not brute strength, the need for
elaborate bracing is unnecessary except with high tensile
Reduced repair and maintenance of electric
fence also adds to the economical value. Over long periods,
electric fence requires far less consumption of time and
money to maintain over most rigid products.
Fence load is a combination of
many factors. The length of the fence, the number of strands
and condition of the wire or tape, splices in the wire,
connections, broken insulators that create shorts, and
foliage growing on the fence all contribute to fence load.
Proper fence design, construction and maintenance, along
with an adequately powered fence charger, makes for an
effective, economical means of livestock control.
electric fence is a less-than-ideal environment on which to
conduct electricity. Along the course of the average fence
there are many conditions which will divert or impede the
flow of electricity. Collectively, these conditions are
known as fence load.
Weeds or vegetation growing on
the fence line are the most common culprit contributing to a
heavy fence load. Green plants draw voltage and amperage
from the fence to the earth. Other circumstances can rob the
fence of voltage and amperage. Cracked or broken insulators,
or insulators of poor design will allow electricity to leak
to the fence post and return to earth. Sagging or broken
wires can contact uninsulated wires or the ground. Wet
weather will magnify all of these problems. When enough
conditions exist to draw all of the electricity produced by
the fence charger from the fence, the fence is said to be
Rusty wire, poor splices, or wire of
insufficient diameter to carry the flow of voltage and
amperage also contribute to fence load. These problems do
not draw voltage and amperage to earth, but they do impede
the flow of electricity along the fence, contributing to the
Even the length of the fence contributes
to the fence load. The longer the fence, the less ability
(or greater capacitance) it has to store the energy supplied
by the charger. On very long fences, capacitance can be a
major contributor to fence load.
with quality components, installing an adequately powered
fence charger, and good management practices are the key to
keeping fence load under control.
Improper grounding is the cause for
90% of the problems experienced with electric fence. Think
of the ground system as an underground antenna, the more
electricity it is capable of collecting the greater the
shock sensation the animal will recognize.
recommend 3 - 6 foot ground rods spaced 10 feet apart for
proper fence charger grounding. We want to ensure that you
have maximum fence efficiency.
A good way to test
ground rod efficiency is to place a metal rod, 12 to 18
inches long, in the ground about 3 feet from the ground rod.
With a volt meter contact the short rod to the ground. If
you read more than 500 volts you need to add another ground
rod or replace the ones you have with longer ones.
areas where heavy snow and ice are an issue, you may need to
take additional grounding measures. Most people don't
realize that neither snow nor rainwater will conduct
electricity. Frozen ground also reduces the flow of current.
When animals are to be left out in electric fenced areas
during frozen snowy conditions you can improve the electric
fence function by running a 12 1/2 gauge wire, on or just
below the surface of the ground, connected to the fence
posts. This wire is attached to the ground terminal of the
fencer thereby creating maximum conductivity when the animal
touches the fence, even in snow.
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