ELECTRIC
FENCING
MANUAL
ELECTRIC
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Use at least one 12½ gauge double insulated cable as your leadout. Two or more joined in parallel are better, as this lowers the resistance of the wire. See the table below For "Wire Resistance". Leadouts can be run either overhead or underground. Underground is preferred, as there are less chances of the leadout being interfered with by high vehicles. Where leadouts are being run underground in high traffic areas, it is recommended that the leadout cable or cables are run through irrigation tubing as an extra safeguard against damage. Using insulated cable as a leadout has several advantages.
The longer a leadout wire, the greater it's resistance. Resistance of the wire is one of the biggest problems to overcome. Larger diameter wires create less resistance and therefore better current flow.
The table above shows the Ohms resistence of galvanized steel fence over 1 mile. The lower the Ohms the lower the resistence. |
Different metal types have varying resistances. For example, 1 mile of 11 gauge aluminium wire has only 18 ohms resistance. Aluminium wire makes an excellent leadout over very long distances but it is at least double the price of conventional steel wires. |
Always connect your live and ground wires in parallel at both ends of the strain.
There are several ways of installing a strainer assembly, the most important thing to remember is that it must be able to withstand the strain applied to it.
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SINGLE STRAINER ASSEMBLY This simple end assembly provides an economical alternative. it is best suited for hard ground and short strains.
DIAGONAL STAY ASSEMBLY This construction is more effective and rigid than the single type.
BOX ASSEMBLY The box assembly is best suited to very soft ground or in areas where there is a lot of ground movement. |
WIRE TIES
When tying off the wire at the strainer post it is important to make a good strong self locking knot.
TYING OFF END STRAIN INSULATORS
It is important to make a good strong knot when tying off end strain insulators. Use a simple twist knot, wrapping the wire around itself at least 4 times, keep the insulator within 8" of the strainer post to prevent animals pushing between the insulator and strainer post.
When tying off end strain insulators always tie the wires so they strain from the center of the insulator.
WIRE
For most fences it is recommended that 12½ gauge high tensile wire be used. if you have long leadout wires or have corrosion problems (from salt spray etc.), then a heavier gauge wire such as 10 gauge or 8 gauge should be used. NOTE: Never electrify barbed wire.
WIRE JOINS
Incorrectly joined wires can be a major cause of power leakage. When joining wires together in the middle of a fenceline use either a figure 8 knot or a reef knot.
WIRE TENSION
Wire on an electric fence does not require the same tension as conventional fences. The recommended tension is between 180 - 220lbs (800 - 1000 Newtons).
JOINT CLAMPS
When clamping wires always use Stafix joint camps to ensure positive contact between the wires, in turn preventing loss of voltage. It is advisable not to use clamps of different metals as there is a high risk of causing electrolysis and accelerating corrosion, increasing the resistance on the fence line.
POST INSULATORS
High quality insulators are important in preventing leakage from the fenceline Stafix insulators are designed for use with today's high powered energizers.
They are made from UV stabilised high density polyethylene and have moulded sheilds to protect them from "tracking" i.e. current flowing across an insulator from an electrified wire to the post.
The following insulators are also available, however, they are not recommended for use with high powered energizes:
Supershed Insulator Heavy Duty staple-on insulator for wooden posts.
Nail On Insulator For wooden posts.
Insultube available in 4" and 6" lengths and suitable for 12½ gauge wire.
By using offsets (also known as "standoffs or outriggers") to run electrified wires:
When attaching offsets to an old existing fence, it is important to check that all wires are in good condition. Broken wires can come in contact with the electrified wires and cause shorts. Be sure to space outriggers no more than 16-22 yds apart. Position the offsets as close to the line posts as possible for rigidity.
Stafix has a large range of offsets which can be attached to either existing wires or can be hammered into wooden posts.
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WIRE OFFSET These are attached by twisting them around fence wires. They come with either porcelain or pinlock insulators.
STEEL OFFSET These are for driving into timber posts. They are available for fixing to the top or the side of the post and are driven directly into the post.
FIBERGLASS OFFSET These can be driven into timber posts (drill a pilot hole first) and can also be used for most concrete posts. They are available in 12" lengths and come with either a fixed nylon clip or with a moveable steel clip. |
When crossing gateways it is recommended to use insulated 12½ gauge cable buried at least 12" underground. In heavy traffic areas, run the insulated cable through irrigation tubing for extra protection before it is buried. Ensure that the ends of the tubing are turned down to prevent water from entering.
Overhead crossings are not recommended as they are susceptible to damage.
Points to remember:
FLOOD GATES
Flood gates are ideal for use in creeks, river beds and other areas prone to flooding.
Strain a wire between two posts (one on either side of the creek). Clamp on lengths of galvanized chain hung at intervals of 6". For large animals this can be increased to 12". The length of the chain is kept to 12" above the lowest average water level.
The flood gate controller (energy limiter) is connected between the fence and the flood gate. This limits the amount of power on the flood gate during a flood so that the remainder of the fence continues to have a high voltage. Placement of a cutout switch is recommended where there is a likelyhood of water levels remaining high for extended periods of time.
Temporary fencing gives you the versatility to strip graze, make temporary paddocks or pens, protect trees, gardens or other areas from unwanted damage caused by rodents and other animals.
Intensive grazing has a number of benefits:
Intensive grazing is ideally suited to cattle and sheep but can also be used for other animals such as horses, goats, and deer. Cattle can be grazed using a single wire. If mixed aged cattle are being grazed together then two wires may be required.
SUGGESTED INTENSIVE GRAZING METHOD
Generally the fence is moved daily and the distance it is moved is based upon the number of animals being grazed and on the quality and quantity of available pasture.
A back fence should also be erected to stop the animals from returning to the areas already grazed, thus allowing a quicker recovery of the pasture.
Sheep and Goats can be grazed in the same manner as cattle but require three wires instead of a single wire. Alternatively, portable netting such as Flexinet may be used.
Deer require at least four wires. For any other animals that are being grazed, wires can be set up depending on the animals height.
Stafix Politape and Poliwire are ideally suited to temporary fencing as they are extremely flexible and light, yet very strong and they wind easily on to fence reels.
