Grounding and Testing

What is a Ground System?

A ground system is the most important component of any electric fence system. If an electric fence is not properly grounded, it will be much less effective.

It consists of a number of ground rods (stakes) that pass electric current back from the soil to the energizer (charger). The larger the energizer and the longer the fence line, the more ground rods are required.

How does grounding work?

For an electric fence to give an animal an electric shock, electrical current (produced by the energizer) must complete a circuit. The current from the energizer flows along the wires, through the animal’s body, down through the soil to the ground system, then back up to the energizer. If the ground system isn't working properly, the animal won't get an effective shock.

What factors will affect the Ground System?

Dry, sandy and non-conductive soil types limit the current flow to the ground rods. If you have soil that is not well suited to grounding, use additional ground rods, choose a better location for the ground system, or use an alternate method of grounding such as ground wire return.
Vegetation touching the live fence wires allows current to leak, causing the fence to “short” and voltage to drop. Check the fence regularly to make sure that long grass and overhanging branches are not touching the live fence wire.
Using a mixture of metals in the ground system will lead to electrolysis. This may cause the parts of the ground system to disintegrate in a short period of time. For example, never use copper wire with galvanized ground rods.

Choosing the Right Ground System

Ground Systems - All Live

An all live ground system is recommended where soil is conductive (most moist soils are conductive). When an animal standing on the soil touches the fence, the circuit is completed and the animal gets a shock.

Ground Systems - Ground Wire Return (Hot/Ground)

A ground wire return system is recommended where soil is not conductive (most dry or sandy soils are not conductive). The fence is constructed using both live and ground wires. When an animal touches a live and a ground wire at the same time, the circuit is completed and the animal gets a shock.

Selecting a Site for the Ground System

A suitable place for the ground system is:

• At least 33 ft (10 m) away from any other ground system (i.e. telephone, house power line, etc.)
• Away from livestock or other traffic that could interfere with the installation
• Where the system can easily be accessed for maintenance
• Ideally, where there is damp soil all year round (i.e., a shaded area or under the drip line of a building).

NOTE: If it is not possible to locate the ground system in close proximity to the energizer, you may be able to use the existing fence line to connect to a remote ground system. In dry weather, it may be necessary to water the ground system in order to improve soil conductivity.

Setting up a Ground System

Ground Rods

The number of ground rods required depends on the type of energizer being used to power the fence and soil condition. Refer to information supplied with your energizer for the correct number of ground rods to use.

For long ground rods (5’–6’ length):

• Space the required number of 5–6 ft (2 m) ground rods (page 25) at least 10 ft (3 m) apart.
• Drive the ground rods deeply into the soil, at least 10 ft (3 m) apart. Make sure that the ground rods protrude out of the soil at least 4 in (10 cm) so they can be easily connected.
• Join the ground rods in a series using ground clamp (page 25) and underground cable (page 26).

For temporary fences using short ground rods (T-Handle, 3' length):

• Insert the rod at least 6”-12” into the soil.
   

Testing the Ground System

1. Turn off the energizer.
2. At least 330 ft (100 m) away from the energizer, short circuit the fence by laying several steel rods (or lengths of pipe) against the fence. In dry or sandy soils, drive the rods up to 12 in (30 cm) into the soil.
3. Turn on the energizer.
4. Use a digital voltmeter to measure the fence voltage. It should read 2 kV or less. If not, repeat steps 1 to 3.
5. To check the ground system, attach the voltmeter's clip to the last ground rod and insert the ground probe into the soil at the full extent of the lead.
The voltmeter reading should be no more than 0.3 kV. If the reading is higher than this, the ground system is insufficient. See the grounding checklist, add more ground rods, or find a better location for your ground system.

Ground Checklist

Check your ground system to make sure:

• All wires are joined securely.
• Connections to ground rods are secure.
• Ground rods are at least 5 - 6 ft long and at least 10 ft apart.
• There are a sufficient number of ground rods.
• All parts of the ground system are made of the same metal.
• Ground rods are buried deeply in the soil.