Electric fences are used to prevent pests from entering the fields, but for those who have never handled them before, it may be difficult to understand what parts are necessary. This time, I will explain the parts necessary to introduce an electric fence.
Parts required for installing an electric fence
The general structure and mechanism of an electric fence is as shown in the figure below. Supports are set up around the fields, fence lines (electric wires) are stretched, and the fence lines are connected to the main unit (red equipment in the figure, also called this unit).
Body (this machine)
It is a device that powers the electric shock that flows through the electric fence. Various products are sold by each company. The point to be selected is the "effective distance". This is a measure of the main unit's ability to handle up to the length of the fence line.
If the distance of the fence wire actually stretched is at the very limit of the effective distance, there is a possibility that a sufficient electric shock cannot be given. The reason is that even a slight leakage of electricity can easily affect the entire electric fence. ※ Leakage is a phenomenon that occurs frequently in electric fences. For example, if plants touch the fence wire, a short circuit will occur and the voltage will drop significantly.
The length of the fence line depends on the size of the site where the electric fence is installed. Expressed as a formula, the fence line distance is calculated by multiplying the perimeter by the number of steps.
As an example, let's consider an example of installing an electric fence in a field with a perimeter of 1000m.
First, let's consider wild boar countermeasures as an example. A two-tier fence is commonly used as a fence line method for wild boar countermeasures. Therefore, the total distance of the fence line is 1000m x 2 steps = 2000m.
Next, consider deer countermeasures as an example. In the case of deer countermeasures, it is necessary to install the lower level so that deer cannot pass through it, and the upper level so that deer cannot jump over it. For that reason, it is arranged in four stages with an interval of about 30 cm. In this case, the total distance of the fence line is 1000m x 4 stages = 4000m.
If the effective distance is 3000m as the standard of the main body, it can be handled with the above wild boar countermeasures, but with the above deer countermeasures, the effective distance will be shorter than the actual fence line distance. increase.
In such a case, it is better to choose a higher power main unit or divide the area to be enclosed into multiple units and install each main unit.
Power supply to the main unit
A power supply is required to operate the main body of the electric fence. There are various types, such as a type that operates on dry cells or batteries, a type that connects to a household power supply with an AC adapter, and a type that stores electricity generated by a solar panel in a battery.
In most cases, the specification of the main unit will give an indication of how long it can run. For example, in the case of this model , it will be about 30 days (set to operate 12 hours a day) on battery drive. *Varies depending on usage conditions.
In general, the longer the effective distance, the higher the output and the greater the power consumption, so the operating time will be shorter. Of course, the working time will change depending on how many hours a day you work.
If the battery consumption is high, the number of battery replacements will increase accordingly, and there will be a risk that there will be times when the voltage is not applied due to battery consumption, so it is a good idea to check in advance.
Stakes for fixing the body
In the case of most models, it is recommended to install the main unit with the main unit floating above the ground in order to avoid short circuits, overturning, submersion, etc. For that purpose, it is necessary to separately prepare wooden stakes sold at home centers.
*There is also a type that comes with a grounding rod that also functions as a support.
Output high voltage line
The main unit and the fence wire are not directly connected, but the output high voltage wire is connected between them.
A ground wire for grounding the main unit and the ground. The shape of the ground bar differs depending on the product. There is a type in which a single long metal grounding rod is driven into the ground, and a type in which multiple relatively short grounding rods are connected.
The former is suitable for cases where the surface of the ground tends to be dry, and the latter is suitable for cases where the surface is not dry and the geology is easy to insert.
Fence line (electric wire)
Most of them are nylon cords woven with stainless steel wire. There are 3 types and 6 types with woven stainless steel wires.
The 3-prong type has excellent cost performance, while the 6-prong type reduces the risk of disconnection and has high conductivity.
Areas with electric fences need to have areas for people to enter and exit. A gate clip is needed here. Connect the fence wire to the gate grip and hook the hook on the grip to the insulator to complete.
The number of steps x the number of entrances/exits is required.
Struts & insulators
Various types of poles for fence lines are sold by each manufacturer. Also, each manufacturer sells insulators that are shaped to fit the struts.
Struts and insulators are not compatible with other manufacturers. It is better to buy a set from the same manufacturer.
When installing an electric fence, it is necessary to install hazard sign boards at appropriate intervals in easily visible places. As a guide, install one sheet every 50 to 100m.
Tester (Voltage detector)
After the first set up is completed, the voltage of the fence wire is finally checked. As mentioned above, if grass or other objects come in contact with the fence wire and cause a short circuit, the power of the electric shock will be halved and the battery life will be shortened.
The voltage may drop due to a short circuit in an unexpected place, so check the fence wires evenly.
The above will be the parts of the electric fence that are generally required. There are other products that can be conveniently used depending on the situation, such as weed control sheets for electric fences (with a grounding function), so it is a good idea to consider them according to the environment of the installation location.
Also, after installation, check the installation status of the electric fence regularly and check the energization status with a tester.