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                           CONSTRUCTION SPECIFICATION

                                        ELECTRIC FENCE (EF)

                                                  CODE 382

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).
            12.5 gauge
            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
          1. Steel
                                                                Fiberglass T-posts of at least 1-
             Only new "T" or "U" posts,
                                                                 inch cross-section.
              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.
              wire attachment.
                                                                 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
              be heartwood.

                                                                                         NRCS, GA
                                                                                      February 2011

   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.
          or equivalent.
                                                        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.
      2. Steel
                                                  E. Energizers
         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
      Brackets                                           minute.
                                                        A high impact weather resistant
         With charged wires, insulators for             case.
          steel and other conductive
                                                                                 NRCS, GA
                                                                              February 2011

         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
                                                     gate assemblies.
          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.
                                                                            NRCS, GA
                                                                         February 2011

          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
                                                    3. Other
          every 1320-feet.
                                                       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

                                                                               NRCS, GA
                                                                            February 2011

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.

                                                                       NRCS, GA
                                                                    February 2011

         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.

                                                                                NRCS, GA
                                                                             February 2011

      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

                                                                             NRCS, GA
                                                                          February 2011

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:
    UV-stabilized, high-density
     polyethylene twine with at least eight
     stainless steel or aluminum filaments.

    UV-stabilized, high-density
     polyethylene tape with at least five
     stainless steel or aluminum filaments.

    12.5 gauge smooth galvanized steel or
     aluminum wire.

    Electrified net wire can be used for
     small livestock.
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.

                                                      NRCS, GA
                                                   February 2011

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