How To Build/Install An Electrified Fencing System To Keep Predators Out:
Equipment needed To Build Your Electric Fence:
Mains Energiser 7.5 joules or higher for large installations, smaller for hobby installations ..... 5.5ft - 6ft 3" fence posts or 4" fence posts.... builders 2mm steel tying wire .... 5 x 3ft/1 meter (minimum) earth rods .... earth wire 2mm and double insulated live wire .... Cut out switch .... quality screw-in insulators .... staples .... 5" nails ..... Note: Do not use the proper twisted electrical fence wire because it goes rusty almost straight away. Do not use wire less than 2mm because it will break or thicker than 3mm because it is too hard to work with .... Avoid the "Angle" type earth rods and avoid earth rods made from concrete reinforcing iron. Only use galvanised solid round bar approx 3/4" diameter.
Tools Needed:
Sledge hammer .... hammer .... post mallet or preferably a post driver .... pliers/wire cutters .... rechargeable screwdriver/drill .... steel "hoking bar" (5ft crow bar) .... 3ft spirit level.
Fence off as large an area as possible which may include a lot more area than what you may need. The reasons are that it is easier to have more space than not enough and this will involve only doing the job once.
Place your fence posts in a way that wildlife can move around your fenced area because if you block their routes then they may try to go through your fenced area to get to where they need to go. Allow a through-way of around 3ft between your electric fence and any physical boundary for wildlife movement.
When fencing off your area watch out for areas where pests can gain advantage by jumping or digging under the perimeter of the fence. This can be areas like waterways or depressions in the ground. High spots like mounds or rocks, even trees can aid a predator to access your enclosure and attack your livestock.
Position your fence away from tree branches which may interfere with your fence in windy conditions, or trim well back these trees.
Do not enclose in your electric fenced off enclosure electricity, water or telephone supplies which may need to be accessed by repair men and their equipment.
Do not enclose flighting ponds/lakes used by large water birds like swans or herons which may end up crashing in to your electrified fencing.
It is suggested that 1.3 meter/54" is high enough to stop foxes jumping, but if you want to be really safe then have a higher fence. This would of course require higher posts which can be more troublesome to install. Higher posts are more prone to becoming looser over time due to wind or fence wires pulling on them. Or you can extend the post height by about 1ft/300mm by screwing treated timber to each post and attaching an extra wire or two.
Another way is to install a small secondary fence on the outside of your main fence about 24"/600mm high approximately 4ft to 5ft away from the main fence. This small fence will consist of half as many smaller posts (maybe a 5ft post cut in two? and a post every 10 metres with wires pulled tight) and just 2 wires (live on top, earth below) then link up live and earth wires to your main fence. This set up would stop any fox or dog making a running jump at the main fence in an attempt to clear it, and is cheap, very effective and does away with the problem of loosening fence posts .... Any fox or dog that can clear this set up will be on a motorbike and called Steve McQueen.
Installing Posts:
First are your corner posts. Corner posts are the strength of all fencing. Corner and end posts (gate posts) really need to be square to secure properly, but you can get by with standard round posts. Corner posts will need to be well in to the ground and braced at 45 degrees on the inside (3 ways) and directly opposite the pull of the wire. This means that if your fence was in the shape of a rectangle or square, then the "braces" will be in the direction of diagonals if drawing a line internally from corner to corner. The braces need to be a minimum of 3/4 of the way up the height of the corner post. This way the braces can take any pressure applied to the wire which will try to pull in the corner posts if not supported correctly by bracing them. Your corner posts need to installed level and upright, and this means using a spirit level repeatedly. If your corner posts are not installed perfectly upright, then the rest of your fence posts may be out of line with each other putting strain on the wires. Because corner posts are the strength of your fencing, it would certainly be beneficial to use longer thicker posts and have them knocked or dug in to the ground as deep as possible, because when the wire is pulled tight the corner posts take a lot of the pressure. Any weakness in your fence will become apparent after a good wet spell where the ground becomes soft and then movement can take place with posts which are under pressure from tight wire.
When you have correctly installed and supported your corner posts, then attach a line "string" tightly from post to post at ground level. This will give you your straight line from corner post to corner post so that you can install your perimeter posts in a perfectly straight line between corner post to corner post. The posts should be installed at spacings of 5 or 6 meters, but you may have to alter distances to suit and install at shorter distances if the ground isn't flat and rises or, depressions in the ground require fence post to be located in away that these ground deviations have posts which will allow the bottom wires to be no more than 2"/50mm) above ground level. If this cant be done, then you may have to physically remove high ground spots or fill in ground depressions, so the bottom wires of your fencing system are at the maximum distance above the ground in these areas (2"/50mm).
When positioning posts and knocking/pushing them in to the ground, you need to check during installation that they are going in at an upright position so all posts are as near as possible all "in line". If not re-adjust to suit.
You will need 54"/1325mm of post above ground (preferably more) to have enough height to deter animals such as foxes and your electric live wires should be right to the top.
The posts which are the beginning and end of your wire, where you will attach the wire strainers and end insulators. These posts are better if they are square posts as when tightening the wire with the ratchet strainers, because the strainers have to be offset the tightening of the wire can try to twist the post around in the ground. If these fence posts are square then this twisting can be a lot less or none existent. You can use round post but square posts are better the only thing is square posts are harder to knock in to the ground, but being as the start and end post are usually gate posts then perhaps concrete?
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Photo: 1. Post Strainer that comes at least 3/4 of the way up the post to take any strain that tight wires will put on the posts.
Photo: 2. A wire strainer which will pull back and re-position a post that is having pressure applied to it by tight wires in the opposite direction.
Photo: 3. A short post knocked in to the ground to hold firm the "strainer post".
Live & Earth Wires:
After locating and securing your fence posts, place the 1st wire an earth wire 2"/50mm from the ground and pull tight and staple. Then fix your insulators 2"/50mm above the earth wire. This is your first live wire which will be just 4"/100mm from the ground. Then another earth wire, then a live wire, then an earth wire and again a live wire all at 2"/50mm spacing's. This will keep out small pests like rabbits/hares, some mink and hopefully stoats. Then after this place a live wire every 6" and an earth wire centrally in between. This will ensure that the small animals get maximum deterrent shocks. After 2ft/600mm from ground level you can extend the distance between wires to 4"/100mm to the top of your posts. All live wires in insulators of course.
You must have an earth wire (connected to earth) as your second wire from the top, as any airborne animal which touches a live wire at the top of your fence (or anywhere else) will not get a shock, so an earth wire next to live wires ensures that airborne animals will most likely touch a live and an earth wire together so receiving maximum shock voltage.
All live wires should be fitted to the fence posts with proper insulated connectors. Never fix a live wire on to a fence post with anything else otherwise a direct short will take place rendering your electric fence totally useless.
All earth wires can be fixed directly to your fence posts. The means of how you do this are up to you as long as they can never come in to contact in any situation with live wires. All earth wires should be joined together on the opposite side of the posts at 2 places along the run of the fence and at these places they should be connected to an earth rod to ensure maximum shock voltage.
All live wires for the first 300mm/1 ft above ground need to be pulled very tight with ratchet type insulators. You can use these on every live wire to the top if you prefer, but the tightening of the wires near the top should be done with caution as this can put pressure on your corner posts and weaken the system.
All earth wires for the first 300mm/1 ft above ground need to be pulled very tight before fixing to the fence posts.
All live wires should be joined (linked) together in at least 2 places on the fence to ensure an unbroken supply of voltage to all wires. This is done by using all of your wire off cuts to join one wire to another. Make sure only live wires are connected and no earth wires are included .... sounds obvious but it is easily done in error.
All other live and earth wires from the 300mm/1ft mark to the top of the fence posts need to be pulled tight before fixing on to the post or in the insulator.
Pulling the wires tight avoids the chance of them touching or sagging which would cause a direct short and render the installation useless.
If you pull the higher wires too tight then this can pull the corner posts in slightly so making the wires become loose over time. This is why the corner posts need to be properly braced and rigid.
You must check after finishing this installation that .... No live wire is in contact with any earth wire or fence post or is positioned anywhere else but inside the insulated fence post fixing. Also there must be no sagging on earth or live wires so that they could ever come in to contact with each other or any other object at any time. In other words all wires must be tight and properly positioned and fixed. You must also check that no other object can come in to contact with your fence at any time.
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Photo: 1. The bottom fence wires showing the first wire, an earth wire fixed to the post. Then the first live wire and alternate wires afterwards, this will ensure maximum voltage in to the attacking animal.
Photo: 2. The back of the first/end post with all of the earth wires connected together & then take them to earth/ground rods..
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Photo: 1. Wire Ratchet Strainer for pulling lower wires very tight.
Photo: 2. Live Wire Insulator. The best and easiest to install. Drill 1/8" or 3mm hole in post first. Work out around 0.14 euro each.
Earth Rods/Ground Rods:
Your energiser needs a separate earthing system to your fence. Place your energisers earth rods in good 365 day damp ground, at least 3 in number and 2-3 meters apart not more than 20ft away from the energiser. Join up the energisers earth rods with insulated earth wire so all 3 earth rods are joined together then take your insulated earth wire back from the nearest earth rod to the energiser and connect. The earth wire should be at least 2.5mm and well insulated. This energiser earth set up should be no more than 20ft away from the energiser and at least 50ft away from a building mains earthing system, or overhead electricity supply pole earthing system, or any ground based telephone cables and ground based electricity supplies. Note: Electricity supply pole earthing systems can run for at least 30 meters away from the poles in at least 2 directions in Ireland.
For the earth wires around your fencing, position and install at least 2 earth rods next to your fence on the inside of your fence perimeter and connect to the earth wires. These earth rods need not be positioned together but at equal distances around your fence installation in good earthing ground .... 365 day damp ground.
All earth rods should be installed so they are at least 900mm/3ft in to the ground. Do not install in dry/sandy/rocky soil. This type of soil/ground is no good for earthing this type of electricity supply. Find a damp but not wet ground area.
Gateways:
At all and every gateway an underground link of both earth wires and live wires in completely separate protective tubing such as hosepipe should be made to connect each side of the fence on both sides of the gateway.
The gate itself should be electrified from top to bottom to stop animals climbing up the gate to acquire entrance to your field.
Any bracing struts on the outside of the fence should have a run of both earth wiring and a live wire to deter animals walking up the strut and simply jumping over the top of the fence. Animals such as stoats, squirrels, mink, cats and pine martins will and can do this if the braces aren't electrified. A live wire will not be enough, you must secure an earth wire to the full length of the bracing post also in away that any climbing animal comes into contact with both wires.
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Photo: 1. Electrified Gate. Very simple to do, just run your wires in the same way on your gate to stop animals climbing up them.
Photo: 2. Happiness! Energiser producing full voltage with no problems or drop in current. Tested and showing above 6000 volts. Your energiser should be of a power which suits the size of your fence.
High voltage kills vegetation.
Electric Fence Energiser manufactures claim that the voltage from the electric fence will keep in check any vegetation. Well here is proof of that, but you have to get all earth problems sorted out so maximum voltage is achieved. See in the photo where the grass has come in to contact with the live fence the voltage has killed the grass. It also kills soft rushes as well. It is by producing the maximum voltage that kills vegetation on contact and you will only achieve this by installing your system correctly. Anything else is useless.
Live Supply & Earth Wire Connections:
The live wire from your energiser has to be a double insulated 1.5mm or larger wire. If this wire is to be laid or buried underground it will need to be in a protective pipe such as the heavy gauge plastic water pipe.
If the fence is situated a good distance from the energiser, then (and maybe always) a simple on/off switch purposely made for electric fences should be installed at the entrance to the electric fence. This will make operating, testing and maintenance to the fencing system a whole lot simpler without endless walking backwards and forwards to the energiser.
When connecting copper wires on to your fencing wires for earth and live connections, there are purpose crocodile clips available, but these could be knocked accidentally and a bad or no connection may occur. You can attach your wires directly to the fence, but copper causes some kind of reaction with galvanised steel and causes the galvanised wire to corrode, so I connected short bits of off cuts of galvanised steel to my fence wires, then attached the supply and earth wires to these. So any reaction only takes place on the short off cuts which can easily be replaced without affecting the fence in any way.
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Photo: 1. Join (link) all individual live wires together in at least 2 places to ensure a 100% supply to all live wires.
Photo: 2. Isolating Switch. Install at the entrance to your fenced field. Saves much time walking backwards and forwards and also prevents you getting an accidental zap from the fence.
Photo: 3. Electrified Post Strainer. Where post strainers or bracing struts have to be on the outside of the fence, an earth and live should be run most of the length to stop pests climbing up them to gain access over the top of the fence.
Maintenance Of Your Electrified Fencing System:
Basically it just means keeping vegetation down once per week or every 2 weeks depending on season. If you add chicken wire around the bottom of the fence, this may add extra security for small animal pests, but vegetation will grow in to the chicken wire. A way around this is to spray this area around the perimeter with weed killer but not great if an organic set-up, in fact it wouldn't be allowed. Another way to check vegetation is to lay 9" blocks flat on their sides between your fence posts. This would check vegetation growth and be too heavy for small animals to move, but would be expensive. Being as 9" concrete blocks are less than 4"/100mm high when laid flat, they are an ideal sized vegetation and small animal deterrent, also they force any animal up straight on to the live wires. They don't blow away and last forever. A good strimmer is a good idea but care must be taken as strimmers are known to get caught in low wires when cutting undergrowth.
All ways check for animal digging around your fencing and check for this daily.
Problems & Fault Finding Of Electrified Fencing:
If the "earth fault" light is in operation on your energiser, then obviously you have an earth fault. The fault is the earth installation for your energiser, which means you haven't followed the guidelines above or the ground isn't suitable. If the ground isn't suitable then move your earth rods. If this isn't possible then add more earth rods or move the energiser to another location so the earth rods can be better re-located.
Some energiser earth faults do not always show until the full load is applied, meaning the whole electrified fence. If you are only using a few strands of wire in your fence, then some earth faults do not show. But put a long multi-wire fence load on the energiser and any fault will soon show. One way of identifying an energiser earth fault is by placing a radio about 30ft away from the energiser and plugging it in to the same electricity supply that the energiser is using. Modern energisers have very good suppression systems, but if there is an earth fault, an audible click will be heard quite clearly on the radio when the energiser pulses. This "radio click" should disappear when the earth fault is rectified.
If there is a fault with the fence wire system, low voltage or low voltage and the earth fault lights will light up on the energiser.
Low voltage could be excess vegetation or some other objects touching the live wires on the fence. Just walk the fence and inspect. Remove all objects and clear vegetation.
If the low voltage and the earth fault warning lights light up. Then check that no fence earth wires have come in to contact with fence live wires. Someone may have accidentally hung something or leaned something against the fence causing this direct short. Maybe a tool, a spade or fork, even a coat hanging on the fence causing 2 wires to touch. If the fence is clear, then try the radio trick near the energiser for a faulty energiser earth.
If the low voltage lights come on when it is raining or afterwards when the fence is wet. You could have a faulty fence insulator which you may be able to find by a clicking noise when you are right next to it.
Do not use old insulators as the plastic does break down over time leading to voltage leaking. This will just mean low voltage at your fence and earthing of your system which will be time consuming to discover.
Nothing lasts forever .... Check all parts of your installation regularly and repair before any problems arise, otherwise the first you may know of a problem is when your poultry have been attacked.
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Photo: 1. Post Spacer. When using ratchet wire strainers you will need to use a spacer block on the post to "kick" the wires out off the line of the fence, otherwise the wires could touch post strainers.
Photo: 2. The other end of the Ratchet Wire Strainers .... End Line Wire Insulators which are just pieces of insulated shaped plastic that you tie to the fence. Note: That these too have to be kicked off the fence with blocks to avoid wire touching any post strainers.
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