Fencing in winter when the ground does not provide proper grounding
Winter fencing is a challenging chapter in areas where the ground freezes and becomes covered with snow or ice. When animals do not have direct contact with bare, unfrozen soil, standard electric fencing does not work as intended. There is a way to solve this.
How does an electric fence work?
A typical electric fence consists of an energizer that sends short, pulsing voltage shocks through the fence wire. The energizer is connected to the fence wires and to the ground, usually via grounding rods driven into the soil.
When an animal touches the fence while standing on the ground, the circuit is completed: the current travels from the energizer through the wire, through the animal, into the ground, and back to the energizer via the grounding system. It is this closed circuit that makes the shock felt.
For grounding to function properly, some level of moisture is required in the soil, both where the animal is standing and where the grounding cable enters the ground.
Difficulties with grounding
The problem in winter is that frozen ground, snow, or ice does not conduct electricity the same way moist soil does and therefore cannot provide sufficient grounding. In practice, ice and snow act as insulators.
The same phenomenon occurs during very dry weather, when there is too little moisture in the soil for proper grounding. The animal does not achieve adequate contact with the ground, the circuit is not completed, and the shock is absent or very weak.
This is usually manageable as long as the animal has no motivation to challenge the fence, which is typically the case in winter when there is no grazing and feed is provided inside the enclosure. If you test the fence with a simple voltage tester that does not include a ground probe, it will usually show a reading, making it easy to believe the fence is functioning correctly.
The fence may appear intact, but to the animal it feels harmless.
The solution
One way around this is to connect both the live and the ground directly to the fence wires.
In practice, this means running the wires in pairs. The distance between the wires in each pair should be small enough that the animal can touch both at the same time when placing its nose against the fence, but not so small that the wires risk touching each other. A centimeter or two works well, provided the wires are properly tensioned so the upper wire cannot slacken and fall onto the lower one.
When the animal touches both wires, the circuit is completed directly through the body, which contains moisture, without relying on the ground for conductivity. The result is a stable effect even during winter.
If you use four fence wires, you will therefore need to run eight separate wires arranged in pairs. The live cable is then connected to the live wires, and the grounding cable to the ground wires. This is a highly effective way to ground a fence, and the effect can be strong, so avoid using a more powerful energizer than necessary for the type of animal and the length of the fence.
There are also ready-made solutions known as polytape. These are wider bands, often several centimeters across, with both conductive and grounding strands woven into them. The principle is the same as with paired wires: the animal makes contact with both live and ground simultaneously, regardless of soil conditions.