NATURAL RESOURCES CONSERVATION SERVICE
ELECTRIC FENCE (EF)
PERMANANENT ELECTRIC HIGH- All other wood posts must be
TENSILE FENCE treated with a minimum of 0.4
I. MATERIALS lbs/ft3 of chromate copper
arsenate (CCA-Type A, B or C),
A. Wire or equivalent.
Use only new wire that meets the
Minimum 3-inch diameter (2½-
following minimum specifications:
inch diameter for Osage orange;
Class 3 galvanized
1½-inch for eucalyptus).
170,000 psi tensile strength 3. Other
B. Line Posts and Stays Fiberglass, rigid plastic, and
All line posts need to be at least 6- polyvinylchloride solid round
feet long. sucker rod of at least 5/8 inch in
Fiberglass T-posts of at least 1-
Only new "T" or "U" posts,
constructed of high carbon steel,
and weighing a minimum of 1.25 Trees may be used for line posts in
lbs/foot exclusive of anchor plate. rocky or frequently flooded areas
where holes cannot be dug or
Studded, notched, or punched for
fences are difficult to maintain.
Use low value trees for posts.
2. Wood Trees should be properly aligned,
Acceptable species include black and have a diameter breast height
locust, red cedar, Osage orange, of at least 4-inches.
and Australian ironwood 4. Stays
(eucalyptus). All bark must be
At least ⅜-inch diameter steel,
removed. At least one-half the
fiberglass, or rigid plastic.
diameter of red cedar posts must
C. Corner, Brace, End, and Gate Posts material posts must be high
density polyethylene or high
1. Wood density polypropylene with ultra-
Acceptable species include black violet stabilizer, or porcelain that
locust, red cedar, and Osage withstands at least 10,000 volts.
orange. All bark must be For non-charged wires on wood
removed. At least one-half the posts, use staples that are at least
diameter of red cedar posts must 9 gauge, class 3 galvanized.
be heartwood. Minimum length for softwoods is
1½-inch, and for hardwoods is 1-
All other wood posts must be inch.
treated with a minimum of 0.4
For non-charged wires, use
lbs/ft3 of chromate copper manufactured clips, or minimum
arsenate (CCA-Type A, B or C), 14 gauge wire on steel line posts.
Offset brackets made of
Corner, brace, end, and gate posts galvanized high tensile spring
must be at least 8′ X 5″. wire and an insulator of high-
density polyethylene with ultra-
Horizontal brace members must be violet stabilizer or porcelain that
at least 8′ X 4″. withstands at least 10,000 volts can
be attached to standard barbed
Landscape timbers cannot be used wire or woven wire fence to
provide transmission line and/or
for posts or brace members.
to protect a standard fence.
Minimum 3-inch diameter high- Install electronic energizers or power
carbon steel pipe weighing at least fence controllers according to the
7 lbs/foot, is galvanized or coated manufacturer’s recommendations.
with a rust-resistant metal paint. Installation should meet the following
Pipe ends must have a water-tight minimum specifications:
A high-power, low-impedance
Horizontal brace pipe can be 2- system with solid state circuitry
inch diameter high carbon steel capable of at least 5000 volt peak
that weighs at least 3.6 lbs/foot, is output and a short pulse that is
galvanized or coated with a rust- less than 300 amps in intensity,
resistant metal paint. finished within .0003 of a second,
D. Insulators, Fasteners, and Offset and a rate of 35-65 pulses per
A high impact weather resistant
With charged wires, insulators for case.
steel and other conductive
Be powered by either 12 volt the post after every 4-inches of
battery capable of operating three depth.
weeks without recharging, solar
cell, or household electric current Set steel pipe in concrete that
of 110 or 220 volts. If the length extends 1-inch below the bottom
of fence requires an energizer of of the pipe, and slightly above the
more than 4 joules, a solar soil surface.
charger will be needed on the 2. Braces (See GA Fence Drawing
battery systems. Nos.1&2)
The ideal voltage for control of all
Bracing is required at all end,
species is 2000 volts or more.
corner, gate, and pull assemblies
The minimum voltages for
livestock control are: Single H-braces or floating angle
Cattle - 1600 braces are required for all end and
Sheep/Hair Goats - 2000
One and two wire interior fences
Hogs/Horses/Meat Goats - 1200 do not require brace assemblies,
Size – As a rule of thumb, the but wire should be tied off at least
energizer should be capable of every 1320-feet.
producing one joule of energy for
Use double H-braces in deep
each mile of planned fence when
sands, or where soil remains
average energy loss to the system is
saturated more than 6 months
expected. Each joule will typically
during the year.
provide enough power to fence 25 to
40 acres of pastureland. Set the center line of all
II. CONSTRUCTION horizontal brace members 6 – 9-
inches below the top of the post.
(See Georgia Fence Drawings)
A. Corners, Braces, Ends, and Gates Anchor horizontal brace members
to brace posts with a minimum
1. Posts 3/8″ galvanized pin or spike
Set posts for all fence assemblies driven through the post that
at least 36-inches deep, in holes penetrates the horizontal member
with a diameter at least 2.5X the at least 4-inches.
post diameter. The top of posts
H-braces must have a tension
should be at least 2-inches above
member consisting of 2 complete
the top wire.
loops of 9 gauge smooth single
Backfill wooden posts by strand, 12 gauge double strand, or
thoroughly tamping soil around 12.5 gauge high-tensile wire.
One end of the loop is attached to Maximum spacing on all line posts is
the anchor (corner, end, or gate) 75-feet without stays, or 150-feet
post 4-inches above the soil with stays placed every 50-feet
surface, and the other end is between the posts.
attached to the brace post at the 1. Steel
same height as the top of the
horizontal brace member. Twist Drive posts at least 20-inches into
the loops to provide rigidity to the the ground. The top of the post
brace assembly, or use in-line must be at least 1-inch above the
strainers on high-tensile wire. top wire.
3. Corner and in-line pull assemblies 2. Wood
Use a double H-brace corner post Drive or bury wood posts at least
assembly for any angle where 24-inches into the ground. The
fence alignment changes more top of the post must be at least 2-
than 20 degrees. inches above the top wire. If post
holes are dug, backfill by tamping
One and two wire interior fences the soil around the post at every
do not require brace assemblies, 4-inch depth.
but wire should be tied off at least
Drive fiberglass or other synthetic
Corners where fence alignment material line posts according to
changes 20 degrees or less will manufacturer’s recommendation,
use a 5 inch diameter post or at least 20-inches in the soil.
installed 48-inches deep. Lean The top of the post must be at
the corner post 2-4 inches toward least 1-inch above the top wire.
the outside of the curve.
If trees are used instead of line
Use a double H-brace assembly posts they should be closely
with tension members at intervals aligned with the fence, and be
not to exceed 1320-feet in straight spaced at distances no greater
line fence sections. Use braces at than the line posts. Do not attach
shorter distances in uneven wires or insulators directly to
terrain. (Typically, grade changes trees. When trees are used, a
of > 15%). Terminate and tie off treated or hardwood buffer board,
wire at the center anchor post of or comparable non-conductive
the pull assembly. If desired cut- material should be installed
off switches could be installed at between the insulator or wire and
these locations. the tree.
B. Line Posts C. Wire and Spacing
A minimum of one wire in the fence will Space the remaining wires to
be electrified. The number of wires and ensure control of the animals of
spacing shall be designed to accomplish interest. Typically, wires are
the desired result of the fence. Table 1 spaced closer toward the bottom
suggests wire spacing for various of the fence than at the top.
2. Interior Fence
Interior fences can be constructed
Table 1. Recommended Wire Spacing of one or more wires, with the
Animal Type Wires Spacing fence height being two-thirds the
from shoulder height or nose height of
ground the grazing animal.
(inches) Space the wires to control the
Cattle 1 28-34 animal of interest with the top
wire at least 2-inches below the
Cattle 2 18-28 to 34
top of wooden posts and at least
Hogs 2 8-16 1-inch below the top of steel
Cattle 3 18-30-42 posts. Table 1 suggests wire
spacing for various animals.
Hogs 3 8-16-24
3. Fastening and Tension
Horses 3 20-34-46
On perimeter fence, attach wires
Cattle, 4 12-22-32- to the side of the post closest to
Horses 42 the livestock, except on corners.
Sheep, Goats 4 8-16-24-36
Avoid driving staples in-line with
Cattle, 5 8-16-24- the wood grain. When using
Horses 34-44 slash cut staples, place the staple
Sheep, Goats 5 6-13-21- parallel to the grain then rotate in
30-40 the direction away from the cut
Deer/Predator 6-8 6-12-18-
Control 26-36-46- Use in-line strainers on each wire
56-68 to maintain at least 150 lbs.
1. Perimeter Fence To monitor tension, install a
tension spring in the second wire
A minimum of four strands with
from the top before applying
the top wire at least 42-inches
tension to all the wires.
above the soil surface.
Non-charged wires may be continuity. Use copper clamps
attached to steel posts by use of with copper wire and copper rods.
manufacturer's clips, or by two
turns of 14 gauge galvanized The ground wire(s) of the fence
smooth wire. may be connected to the same
ground as the energizer or
Wire should be able to move separate ground with the same
freely between the fastener and size and depth requirement.
the line posts.
More ground rods may be needed
If stays are used, wires will be for system to function properly.
attached to stays in a manner that
prevents stay slippage along the Do not use the grounding system
fence. for other existing applications,
such as power poles, breaker
D. Ground boxes, and milk barns. Separate
All electric fences must be the fence grounding system from
properly grounded. The energizer any other grounding system by at
ground wire should be connected least 25 feet.
to a galvanized pipe or rod 1/2 E. Lightning Protection
inch or larger in diameter. Bury 3
feet of ground rod for each joule Install external lightning arrestors.
of energy output. Ground rods Place lightning arrestor grounding
should be buried where soil rods at least 65 feet from those of
remains moist for best results. the energizer.
Drive sufficient 6 ft. to 8 ft. rods
into the ground at least 10 feet Use at least one more ground rod
apart to provide the required on the arrestor than was used on
amount of ground rod. Connect a the energizer. Attach the
continuous ground wire from the lightning arrestor to the wires of
energizer to each rod or pipe with the fence. Install a lightning
a galvanized steel or aluminum choke in the fence line
clamp. Copper rods with copper immediately between the
wire may be used if the energizer lightning arrestor and the
terminals are stainless steel or energizer. The lightning arrestor
copper. If energizer terminals are ground must be better than the
not stainless steel or copper, do energizer ground for it to function
not use copper ground rods due to properly, because lightning will
corrosion at the connection and seek the least resistant route to
subsequent loss of electrical ground.
A spark gap may be used in lieu expandable, coiled, high tensile,
of a lightning arrestor. A spark 12.5 gauge wire attached to an
gap is a small gap between a hot insulated handle.
wire and a ground wire. Set the
gap slightly beyond the point that The number of wires shall be
electricity normally sparks. determined by the fence objective.
Overhead or underground
F. Surge or Spike Protector transmission lines will be used to
carry electricity past the gate to
For protection of 110- or 220-volt the remainder of the fence.
energizers, install a surge
protector between the energizer
and power supply. I. Floodgates
G. Insulated Wire An electrified floodgate may be
To cross gates and areas where used instead of a non-electrified
electrical shocks to humans and floodgate. The electrified
livestock should be prevented floodgate is constructed by
(e.g., working facilities, watering stretching an electrified wire
facilities), use insulated across the drainage above high
galvanized wire. For water flow level. Attach droppers
underground burial, use wire of 12.5 gauge high tensile fence
designed for burial. Placing wire, galvanized cable, galvanized
buried wire inside plastic pipe chains, or equivalent to the
helps to decrease the incidence of electrified wire at a spacing of 6-
short-circuiting. Install so water inches. Droppers should extend
does not stand in the conduit pipe. to within 10-inches above the
When overhead transmission is average normal water level or to
used, height should be sufficient the normal recommended fence
for movement of livestock and/or height above the stream bottom.
equipment. Do not use insulated Connect the floodgate to the
copper wire due to corrosion at electric fence with double
the splice and lack of tensile insulated cable through a cut-off
strength. switch and floodgate controller.
If flooding is expected to last for
H. Gates an extended period, switch the
Electrified gates may be floodgate off.
constructed of a single straight
wire, galvanized cable, or
polytape with a spring-loaded TEMPORARY ELECTRIC FENCE
insulated handle or an
Use temporary fence to divide permanent
pastures, not for perimeter fence.
One of the following can be used to create an
acceptable temporary electric fence:
polyethylene twine with at least eight
stainless steel or aluminum filaments.
polyethylene tape with at least five
stainless steel or aluminum filaments.
12.5 gauge smooth galvanized steel or
Electrified net wire can be used for
Install the number of wires at the appropriate
spacing from the ground to control the
animal of interest. See Table 1 for suggested
Use posts that are good insulators and easy to
move. Space posts to maintain the
appropriate fence height.
If the temporary fence is attached to a
permanent electric fence, use an alligator-
type clip for the connection.
Other criteria such as insulators, wire quality,
and energizers will be the same as the
permanent electric fence criteria.