There are many different thoughts, ideas and perceptions when it comes to basic electric fence building. There was a time when many people in the industry considered electric fence to be a waste of time and money. However, when a fence is designed and built properly using a low impedance charger, there are few circumstances in which it will not work.
Let's begin with the energizer or charger. Chargers come in several basic models - 110V or 220V models, solar powered with battery backup models and small D cell battery-type models for temporary use. If electricity is available, 110V or higher models are probably the most reliable. The solar panel type chargers cost more initially and require more maintenance.
Most chargers are rated in joules, but, since I don't know what a joule is or how it works, I look for the number of acres or miles on which a particular charger is rated to be used. When purchasing a charger, it is important to buy one that is rated for more than is really required. As time goes by, you quite possibly will find yourself building more fence than was originally planned through the subdivision of pastures.
The charger is the heart of your electric fence system and should be installed and maintained in accordance with the manufacturer's recommendations.
There are many types of wire available. Polywire is made up of strands of "plastic string" with fine metal wire interwoven within the strands. Metal wire ranges from aluminum to steel and comes in many different gauges. The two most common types will be polywire and a 12 ½ gauge hi-tensile smooth wire.
The polywire works very well in temporary fencing and fence that is seasonal in use, such as cultivated pastures where tractors may make several passes across the field. When installing a new cross fence in a pasture, I recommend using a polywire instead of a steel wire. Often what seems to work well on paper may not work quite as well in the field. By using polywire, the fence can be rolled up and moved with more ease than a steel wire.
A hi-tensile fence is a more permanent fence than a polywire. It is not easily rolled up and moved, but it makes a strong fence. It will not "give" as much as a polywire will, nor will it deteriorate as quickly. The wire is a better conductor of electricity than polywire and will be a better deterrent to livestock.
Regardless of whether it is a single polywire or a hi-tensile fence, the wire should be 34 to 40 inches off of the ground. The line posts should be spaced about 45 feet apart. If sagging is noticed between the posts, you can add additional posts. When a fence crosses a terrace, more posts may be needed to maintain the proper ground clearance.
Remember that when designing your electric fencing system, sometimes your imagination is your biggest limitation.