An Electric Fence Primer for the Total Beginner Part I

Discussion in 'Predators and Pests' started by OldGuy43, Oct 10, 2011.

  1. OldGuy43

    OldGuy43 Chillin' With My Peeps

    Searching on this site I've found lots of useful information about electric fences, but nothing geared to the complete newbie. All posts seem to assume some understanding of how an electric fence works. Since I've installed several in my day and have a degree in electrical engineering I thought it might be a good idea to remedy that situation.

    First let's answer some questions you may have:

    {1} "Will an electric fence harm my chickens, kids, neighbors, dog, cat, lama, camel, armadillo etc?"
    No. A properly installed electric fence will cause no damage. They are completely safe.

    {2} "Will my electric bill go up?"
    Not enough so that you will notice.

    {3} "Do they require a lot of maintenance?"
    With proper planning and careful initial installation almost none.

    {4} "Are they expensive?"
    On a cost per foot basis they are the least expensive fence you can build for keeping out predators and pests. By themselves however, they are not effective for keeping your flock in its proper place.

    Having read all of that you've decided that an electric fence will fulfill your needs. Now we'll get down to basics, the basics of electricity that is. Consider a basic electrical circuit, a battery and a light bulb. Current flows from one post of the battery through the light bulb and back to the battery. The bulb lights. Disconnect any one of the four connections or cut either of the wires, no light. Why? No complete electrical circuit. Everything from that light bulb to the computer your reading this on works on that basic principal.

    Now if you've ever changed a light bulb in your car you've probably noticed that they only have one wire. "How can this be?" you ask. "OldGuy43 said that we had to have a complete circuit for the bulb to light." Simple, in a car the second wire is replaced by the metal body of the car. "Than why don't I get shocked when I touch the car?" Because electricity always looks for the path of least resistance. You aren't it. There's a lot more to it than that, but for our purposes that's enough.

    With that knowledge we are now ready to discuss how an electric fence works. The first part of the circuit is the wire. It carries the current. The second half is the ground or earth. Coming into contact with the wire closes the circuit and you get shocked. Ouch!

    The obvious question is, "Why just "ouch" instead of "Call 911"? The answer is twofold. First fence chargers put out a lot of voltage and not much current. It's the voltage you feel, but the current that kills you. As an example my charger is an extremely powerful one and puts out 1250 volts, but only about 1/100th of a watt. The second is duration. The charger (also know as the energizer) only puts out for a very short period of time. (Reminds me of my first wife. [​IMG] ) Again, using my charger as an example, one 4000th of a second per second. That's why you can let go.

    Now it's time to start buying the supplies you'll need to build your electric fence. We'll start with the charger/energizer/transformer. (I've seen them called all three.)

    WARNING: Do not think you can get by without one. I only mention this because I was once asked to come out to a farm to figure out why an old-timer's new electric fence kept killing his hogs. I visually (Thank God!) traced the wire back to the barn, looked around and asked, "Where's your fence charger?" His answer scared me pale, "Oh I ain't got me one a those." he said. "I jus' plug 'er inta the wall here." The whole Tennessee Valley Authority was just waiting for anything to get near that wire. ZAP!! (True story)

    First you have to decide where you need it. If your run is close to an electrical outlet a 110v. unit is the most cost effective. Other options are battery powered and solar powered. Both are usually more expensive, less powerful and less reliable. Next you need to determine how long your fence will be. Remember that's the distance from the charger to the end. Chargers are rated by the length of fence they will handle, and I always like to go about 25% over on this. If you live in an area where it gets extremely dry or the soil is not a good conductor such as sand you'll want to go even longer. Do not buy one of the pet containment system chargers. Many aren't pulsed and are low powered. Not what we want to control predators and pests.

    Next: Selecting the wire.
    https://www.backyardchickens.com/forum/viewtopic.php?id=583754
     
    Last edited: Oct 16, 2011
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  2. rebelcowboysnb

    rebelcowboysnb Confederate Money Farm

    [​IMG]
     
  3. harveyhorses

    harveyhorses Chillin' With My Peeps

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    Thank you! That sounds remarkably like the talk I got from my father when I was helping him install our first one, 40 years ago. The only thing that has really changed is the fence or wire type.
    Am I doing something wrong with the 'fence tape' because it seems to burn out a lot for me. I like the visibility, but I want something to deliver a real wham.

    My father was able to hold the fence and ask one of us to hand him something, just so we would feel the shock. [​IMG] To this day I rarely trust someone when they say the fence is off!!
     
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  4. chick-a- doodle

    chick-a- doodle Chillin' With My Peeps

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    Question for OldGuy43....

    Somewhere, in all my internet searches, I read about this man who had a chicken run surrounded with typical poultry hex fence. I believe it is aluminum??? Anyway, he said he just hooked his charger up to the wire of the run and it was "predator proof" plus kept the chickens away from the fence. No where have I read this, but this one man's experience. And, I have not been able to find that article or comment since. Now, if this is a legit way to use an electric fence charger, it would save a lot of time and money to charge one's chicken run this way instead of with wire and insulators, not to mention, such a large coverage area, that is top and sides. I assume his run was a wood frame. What do you think, because, if it is valid, I might give it a try for my chickens. [I have a small charger, like 4 miles, I think.] Your comments, please!
     
  5. OldGuy43

    OldGuy43 Chillin' With My Peeps

    I see several problems with his "solution".

    First thought; Aluminum is not a good idea for electric fencing because of the likelihood, over time of galvanic corrosion reducing the amount of electricity getting to the fence, and you can't solder aluminum.

    My second thought is no run is completely "predator proof". (Did this fellow say how long he'd been using his fence?) Next, while wood makes an acceptable insulator when dry, when it rains the water will give you an excellent path to ground, and the fence won't perform its primary function. Last, you'd have to keep the fence wire off the ground and clear of vegetation. That would leave you with a gap at the bottom of the fence and provide access for smaller predators.

    All-in-all, I'd have to say not a good idea long term.
    SIDEBAR: I have seen our birds lean up against the fence soaking wet and no upset. Just my observation. [​IMG]
     
  6. chick-a- doodle

    chick-a- doodle Chillin' With My Peeps

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    Thanks, OldGuy43! I don't know how long this man had his fence, or any other details, except, he felt it had worked for his needs. But, I'm not willing to risk the investment of my chickens on one man's experience I hardly recall when there is so much wisdom here on BYC.

    Ummm, just an idea that popped in my head....if a person were to weave elec. fence tape through their hex netting, woulld that resolve the issues you mentioned? I feel the answer is, Not going to work for the same reasons hex netting alone does not work, but, I have to ask!
     
  7. OldGuy43

    OldGuy43 Chillin' With My Peeps

    I gave my thoughts on fence tape in Part II of the primer:
    While I've never used fence tape or rope I have some very definite opinions on the subject. While it's probably easy to work with it's outrageously expensive. Okay, so I'm cheap. My second objection stems from the fact that the conductor that is woven into the tape or rope is aluminum (see above). Next consider that the aluminum conductor that is used is more the size of a foil than wire, hence it's more prone to breakage. Another problem that I can see is that while the conductor may break the rope or tape may be intact leaving everything after the break unprotected with, unlike a smooth wire fence no visible indication that a break has occurred.
     
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  8. chick-a- doodle

    chick-a- doodle Chillin' With My Peeps

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    Thanks again, OldGuy43. I am going to read the next section about selecting the wire. It's good to have as much information as possible, and I'm definitely out of my comfort zone with this topic
     
  9. OldGuy43

    OldGuy43 Chillin' With My Peeps

    No problem. Just realized, there is a second issue with weaving the tape/rope into the hex wire. It will make contact with the wire so the wire would still have to be well insulated from ground.
     

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