Home Farming: Electric Fencing Pt. 1

As stated in my previous post I have opted to use electric fencing both to help contain my birds and to exclude other animals (rodents, feral cats, and true predators such as foxes and cyotes). The principle of electric fencing is simple: An energizer produces a very high voltage (generally between 3,000 and 12,000 volts) in controlled pulses of 1/10,000 of a second once every second. Seperate wires lead to both the fence and a ground rod system. When an animal touches both the fence and the ground simoultaneously, when the fence is energized, it completes the circuit and recieves an electrical shock.
To some electric fencing may seem cruel, however it is far more humane than the alternatives. When properly installed electric fencing is infinately safer than any other fencing system. When an animal is "hit" by an electric fence it recieves a high-voltage, high-current pulse of electricity, however this pulse of electricity lasts only a tiny fraction of a second. This pulse is rather painful (as I personally found out last week), however it contains so little energy that it is physically incapable of injuring an animal or person. Thusly electric fencing is more of a "psycological barrier" than a "physical" one. Conventional fencing, such as barbed wire, relies on either sharp edges or physical restraint of animals, either of which can kill either a person or an animal.
The picture above is of my upgraded electric fence controller setup. After both doing the math and considering the options I opted to purchase an AC-powered electric fence energizer, on the grounds that it would cost about the same as purchasing two batteries, a dedicated charger and a (decidedly substandard) backup fence energizer. The unit I purchased is the Zareba Systems A50LIL (if you ask me the name is rather ironic, since the second "L" means "Large Cabinet"). It is a 2-joule low-impedance energizer which, (unlike my B10LI self-contained unit) can accept Zareba's "Storm Guard" module, a purpose-built surge arrestor intended to mitigate the effects of lightning strikes to the fence. Since my fence controller is located inside my house I plan on installing both this and a true "lightning arrestor" on the fence line itself. Considering the extreme power of lightning I feel that it's worthwile taking every practical measure to mitigate it's effects on my property... As before, the two new danger signs (the two 10KV signs and the Authorized Personnel Only sign) I printed off myself.


After the heavily-insulated leadout wire leaves my house it first stops here: the "Fence Control Post." The post itself is temporary as I plan on replacing it with a pressure-treated 4x4. In addition I plan on adding seperate cut-outs for the top and bottom wires, as well as a third cutout for temporary garden fencing (for when I plant a garden next year).
Though it is not visable in this picture the leadout wire is bent several times to serve as a lightning choke. The short-radius bends discurage the high direct-current lightning stroke from continuing along the fence wire, and finding an easier ground...









Which leads to this: My temporary, "Home-Brew" lightning arrestor setup. Here I pushed a short ground rod into the earth and placed a solidly-bonded grounding wire just outside of the 10KV arcing range from the fence wire, right next to the leadout wire. This was an "emergency measure" I took last night, due to the predictions of severe weather over the next three days. After today's rather absurd lightning storm I felt that this system was well worth my time... Thankfully I don't think I got to find out if it worked or not...
I plan on replacing this system with a true lightning arrestor with a fully-buried 8-foot ground rod as soon as is practical. Here you can also see a new fiberglass rod with two insulators for the new permanant exclusion fence. Hopefully I will get to post about that tommorow...