article
INTRODUCTION
HOW AN ELECTRIC FENCE WORKS
PLANNING
ENERGIZER INSTALLATION
FENCE CONSTRUCTION
FAULT FINDING
REGULATIONS AND SAFETY POINTS
TERMINOLOGY

ENERGIZER INSTALLATION
MAINS POWERED ENERGIZERS

Mains energizers should be installed by mounting on a wall, under cover and out of the reach of children. It is also advisable to mount the energizer in a position where it is less likely to be damaged by machinery and away from flammable materials. All Stafix energizers are supplied with detailed mounting instructions, which should be read before installation.

Once the energizer has been mounted, connect the ground system to the green ground terminal marked by the symbol . Correct grounding is important. Connect the red terminal (or yellow 1/2 voltage terminal) to the fence line with leadout cable. See FENCE CONSTRUCTION for more information on leadouts.

BATTERY POWERED ENERGIZERS Battery energizers should be mounted on a post or stand which is not accessible to the animals. Connect the red (positive +) clip to the positive battery terminal and the black (negative -) clip to the negative battery terminal. As with mains energizers, you require a good ground system. Install a good ground close to the energizer and connect this to the green ground terminal on the energizer. Connect the red power terminal to the fence line.

Battery energizers which run off internal dry cell batteries e.g. Strip grazers, can be connected directly to the fence wire. For best results push an ground rod into the earth and connect to the ground terminal on the energizer. If there is insufficient power at the end of the fence line, position the energizer in the center of the fence line.

SOLAR POWERED ENERGIZERS Solar powered energizers should be positioned near the center of the fence line, away from shadow or animal contact. In the southern hemisphere face the panels north and in the northern hemisphere face the panels south. The panels should be set at an angle that maximizes the sun’s rays; this will vary depending on the latitude. As a general rule, solar panels should be set with a tilt angle equal to the latitude plus 10% or 15%. For the maximum efficiency it may be necessary to adjust the tilt angle of the panels at different times of the year.

Having the panels on an angle also assists in keeping the panels clean, but the panel should still be cleaned frequently. In New Zealand set the angle at approximately 45 degrees.

  • Never set a panel horizontally.
  • Solar panels should be bolted to a mounting post which holds the panel firmly in the correct position.
  • Keep the energizer, battery and solar panel as close together as is practical.
    Connect the panel to the battery and then the Energizer to the battery.
  • Do not connect the energizer directly to the panel.
  • Keep the energizer and the battery under cover and out of the weather if possible.
    Install a good ground system.

GROUNDING
Grounding is the most important component of any electric fence system. Over 80% of all electric fence problems are attributable to poor grounding. It is important to understand how and why you need to install an effective ground system. For an electric fence to be effective a circuit must be completed. When an animal touches the fence, the circuit is completed through the ground, or earth wires, and the current flows back via the ground rods to the energizer. There are two recommended grounding systems.

GROUND EARTH RETURN This system has all the fence wires "live" and the circuit is completed when the animal touches the wire and the electrons flow through it to the ground. This system is recommended when soil conductivity is good.

INSTALLATION Choose a site which is damp all year round. (The site can be some distance from the Energizer itself).

This site should be:

  • At least 33ft from other electrical earths or telephone cables. (In fact, 330ft is best although this is not always possible).
  • Not connected to sheds or concrete footings which are poor grounds.
    Protected from stock and machinery.
  • Drive a minimum of three 6'6" galvanized or copper earth rods into the ground. For large energizers and dry sandy soils extra earth rods may be required. Place the ground rods at least 9'9" apart.
  • Connect all the ground rods together with one continuous wire (use insulated 12½ gauge cable) and clamp to the ground rods.
  • Good grounding around dairy sheds is very important as cattle are particularly sensitive to stray voltage.

Note: Do not connect two or more energizers to the same ground system.

FENCE EARTH RETURN
This system has alternate "live" and ground (neutral) wires. The circuit is completed when the animal touches both of these wires at the same time. The electrons flow through both the ground and down the ground wires. This system is recommended when the soil conductivity is poor.

INSTALLATION

This system requires two grounds; the main or primary ground and secondary grounds.
The main or primary ground is set up as described in GROUND EARTH RETURN.
To install the secondary grounds, drive the ground rods along the fence line at approximately 0.6 mile intervals. These are connected in parallel to the ground (neutral) wires on the fence. This helps reduce induction and improves the effectiveness of the main ground.
Connect the ground (neutral) wires on the fence to the main ground using insulated cable.
When installing cable under gateways remember to run a cable for the ground (neutral) wires.


BENTONITE GROUND SYSTEMS In particularly dry areas, a Bentonite ground system is recommended. Mix 10 lbs of Bentonite and 5 lbs of coarse salt into a slurry. Dig a hole which is 4ft deep and 3" in diameter. Place a Stainless Steel ground rod into the hole and pour in the slurry. Connect the ground system to the energizer in the same manner as previously described.


BI-POLAR FENCING
The Bi Polar fence system works by sending out two simultaneous pulses of energy down the fence line; one pulse is negative in respect to ground, the other pulse is positive in respect to ground. When installed, the energizer passes half its output voltage on to the negative charged wire and half its output voltage on to the positive charge wire.

In a Bi Polar fencing system each wire is insulated, in the same fashion as they are in a ground earth return system. The major difference being that when the wires are joined in parallel, they are joined to form two different circuits; a negative pulsed circuit and a positive pulsed circuit. The system requires two leadouts from the energizer; one for the circuit that will be negatively pulsed and one for the circuit that will be positively pulsed.

Note: The Stafix battery range of energizers cannot be used in Bi-Polar Fence System.

Using the Bi-Polar system, an animal can receive a shock by:

  • Making contact with the positive or the negative charged wires, thus completing the circuit through the ground.
  • Making contact with a positive and negative charged wire simultaneously.
    Setting up a Stafix Mains Energizer in a Bi-Polar system Install the Mains Energizer on a wall, undercover and out of the reach of children. Install a ground earth system.
  • Connect the insulated cable from the ground system to the half power terminal (yellow) on the energizer.
  • Connect the leadout from the negative pulsed wires to the ground terminal (green) on the energizer.
  • Connect the leadout from the positive pulsed wires to the full power terminal (red) on the energizer.

TESTING YOUR GROUND
If your fence is not giving the shock you expect, it is most likely to be your ground system. Always check the ground first. The ground is half the effective circuit in an electric fence system.

The main causes of an ineffective ground are:

  • Insufficient ground rods.
  • Badly connected wires, or wires of different metal types joined together.
  • Poor connections to the ground rods.
  • Ground rods too close together.
  • Ground rods not long enough.
  • Depth is important to good earthing as it ensures that part of the ground rod is always in damp soil.

TESTING YOUR GROUND EARTH RETURN

Create a dead short by placing enough steel stakes against the fence line to reduce the voltage to 1000 volts or less. These stakes should be at least 330ft from the ground system.
Connect one clip from your Stafix Digital Voltmeter to the last ground rod. Connect the other clip to a small stake placed in the ground at least 3ft from any other ground rods.
The reading on the Voltmeter should be 0.3 kV or less. If it is greater than this, the ground system is inadequate and more ground rods will need to be added.

TESTING YOUR FENCE EARTH RETURN

Do this test as close as possible to the end of the fence line.
Place a steel rod or stake at least 1ft into the ground, preferably into damp soil.
Measure the voltage between the ground wires and live wires on the fence and then between the steel rod and the live wires.
The voltage between the ground stake and live wire should not be more than 0.3kV greater than the voltage between the live and ground wire.
If the difference is greater than 0.3 kV then check the ground return wire for loose connections. Also remember to check the live wires. If the live wires are alright you will need to add more ground rods along the fence line and attach these to the ground wires.

LIGHTNING PROTECTION
Lightning can cause serious damage to your energizer. When lightning strikes close to (or directly on) an electric fence, it causes a massive surge in voltage which flows back to your energizer to find the quickest path to earth.

The only fail safe method to avoid damage occurring to your energizer during an electrical storm is to disconnect it from the fence line and from the mains power supply. For safety reasons, never disconnect the energizer during an electrical storm.

A practical alternative to this is to install a Stafix Lightning Diverter Kit. The kit contains all the components needed including a choke. The choke creates a blocking effect for the extremely high voltages caused by lightning. The voltage is blocked by the choke and diverted across the arrestor to earth. The ground system on the lightning arrestor must be as good as, or better than, the ground system for the energizer.

For the best possible protection install the Lightning Diverter as close as possible to the energizer. This can either be in the leadout or in the first section of fence line. Full instructions are supplied with each kit but the diagram below depicts a typical setup.