Electric Fencing Blog

Touching an electric fence leaves a vivid and painful memory and the voltages are also high in comparison with standard mains electricity, because of this most will assume that the risk to life and limb must also be high. In fact, the opposite is true. Consider that hundreds of thousands of people throughout the world are “exposed” to the millions of electric fences every day—yet electric fences account for (but are not always the cause of) less than one serious injury per year worldwide. Compare that to thenumber of annual injuries and deaths that occur from human exposure to tractors, skid loaders, ladders, PTO shafts, balers, mowers, combines, bulls,stallions, shotguns, knives, etc. This is not to suggest that there is no risk.
There is, indeed, a small level of risk. And with risk, there is also liability to the fence’s owner.

The voltage being sent throughthe wires is high, but the current or amplification (amps) is very low. A220-volt shock will hurt just as much as a 10,000-volt shock, as long as the
current or amps are the same. Amps are what kills. Electric fence energisers put out high voltage (around 8,000 volts), but very low amperage or current (around 120 milliamps). This is 120 Thousands of an Amp ( normal mains electricity is 13 Amps). It should not even kill a squirrel.

This output is made safe in two ways, firstly by releasing the flow of electrons from the capacitor in regular pulses of about 1/300th of a second approximately a second apart. The amperage component of the electrical charge is greatly reduced to figures in the range
of 15 – 500milliamps. (The majority of units operate in the 100-150milliamp range)*. Compare this with two other scenarios.

1. Static Electricity when you touch a door, about 30000 volts at 5
   milliamps for 1/1000th. of a second, unpleasant but not lasting.
2. Mains Electricity. 220volts at 13 Amps and constant, unpleasant
   and regularly causes death.

The energy pulses through the wires. This means once every second for 1/300th of a second it sends a pulse of electricity down the line. The reason for the pulsating current is
that if the wires are touched and deliver a shock, whatever touches it has a chance to remove itself. If the current did not pulse (like most electrical appliances -  hair dryer, radio, toaster, etc.), then whatever touched it would continue to be shocked until the power went out or something pried them off.

With low amps and a pulsating current, electrical fencing is a safe product. It is the amperage within the electrical charge and the constant connection that makes electricity dangerous.

What NOT to do!

• Never Place your head near an electrified wire. Accidental head or neck contact
  can occur when pushing a voltage probe into the soil or when checking
  voltage. Be very careful when you do so to avoid head-to-wire contact!
• Never allow anyone else to touch a modern electric  fence. It is not a game!

What to do!

• Instruct all visitors and children to never touch electric fencing.
• The legislation that applies in Europe to fences accessible to the general public stipulates that an internationally recognised warning sign be displayed at the beginning and end of a fence and at every 50 meters interval

Warning: In 1991 an accidental fatality occurred when a young child’s head
contacted an electrified fence while the child was crawling on wet grass. The
fence was correctly installed and functioning properly. The energiser was an
approved unit. As a result, we strongly advise against allowing toddlers access
to any electrified fences. Also, due to this incident and others, experts now
suggest that human contact by an energised wire to the head and neck may be the
most dangerous point of contact. We urge all to especially avoid this kind of
contact.

* These figures vary between all the manufacturers.

Effective earthing of an Electric Fence is a perennial topic and needs to be well understood as many people still think you can skimp when it comes to adequate earth grounding. What we must all learn is the electricity must complete a full circle back to the energiser through the ground. Poor earthing will result in the reduced transfer of electrons from the ground back to the energiser invariably felt as a weak tingle or weak shocks.

The ground constitutes 50% of the electrical circuit but 90% of all problems originate at poor earthing, either at the earth stake itself or on the fence. Fortunately this is easy to rectify. Additional earth stakes may be added by driving them into the ground about 2m away from the existing stake and joining them together. Copper, Stainless Steel or Galvanized steel rods are best. Mild Steel is a poor option as it will react with the ground chemicals and rust. This layer of Rust will create a poor conducting barrier between the metal and the ground. This should only be used as a temporary measure. All rods should be located in permanently moist soil, under the building eaves, in a river bed, below a dripping tap or in an irrigated flower bed. In particularly dry weather the soil around the stakes may be watered. A legal stipulation requires that an electric fencing earth post to be more than 3m away from a household earth system.

Poor electron transfer from the fence back to the earth stake is less easy to rectify. If the fence extends over 500m in a straight line away from the main earth post it will be necessary to add an additional earth line to the bottom of the fence and bury a stake at those intervals. Wire is a better conductor than ground so a ground rod approximately every 500meters will greatly increase the effectiveness of the fence. This connecting wire does not need to be insulated from the ground BUT must be insulated and separate from the live wires of the fence

 A Earth Return Fence

In dry climates or where the soil is very sandy resulting in poor conductivity through the soil, it will be necessary to consider an Earth Return fence. This is where the fence is constructed from equal numbers of live and earth wires to remove the ground from the electrical circuit. The animal is required to touch both wires to achieve the desired effect. An earth post is still utilised to cater for current flow through the ground.

These measures will all contribute to maximising the potential of an electric fence and by improving its effectiveness, allow it to achieve its desired goals.

We received a call in the last few days complaining that one of our premier products was rubbish and disintegrating. This product, the Ranger Hotstop Electric Fencing Rope, is one of our top sellers and we offer a warranty on it. The complaint was immediately investigated and found there were a few inconsistencies, the rope had no date twine (a coloured twine indicating the date of manufacture is woven into the rope) and the metal filaments were the wrong type of metal. It was not ours.

There is a Copycat product that looks identical but sells for a few pounds cheaper. The rope utilises stainless steel filaments so the conductivity is more akin to that of a cheap rope whilst it has very little of the UV stabilising compound incorporated into the polyplastic threads.

The copycat is on the left in the image below and it is clear that the colour has faded and the plastic has become brittle and begun to fray badly as you would expect non-protected plastic too look like after having been subjected to UV rays in the sunlight. This has only been in the sun for 18 months.

The correct product is on the right and shows no sign of degradation after being in the sun for 14 months.

As the rope looks like a quality rope the unscrupulous vendors are selling it at a higher price than it actually warrants but cheaper than the quality rope that it is impersonating.

After pointing this out to the customer she recalled having decided to purchase our rope but then saw the product on a competitors outlet that looked the same but cheaper so bought it. As a PR exercise it was decided to supply the customer with a reel and hopefully we will get good mileage out of the issue.

The new standards applied by the European Committee for Electrotechnical Standardisation restricting the energy output of energisers on sale in Europe where they must adhere to either of the two standards.

60335/2/76A11 applies to all energisers below a maximum output of 5 Joules and covers most current energisers on the market.

60335/2/76A12 applies to all those above 5 joules output to a maximum of 15 joules. This regulation requires the energiser to reduce the output of the energiser below the 5 joule rating when a load has been experienced. This has resulted in various companies becoming inventive with their electronics.

An excellent solution has come from the German company Horizont who have released onto the market the horiSMART range of electric fencing energisers. These energisers have been manufactured using smart circuit technology that has the ability to detect the difference between a low residual resistance load (such as vegetation) or a contact load ( such as mammalian contact) and adjusts the output response accordingly.

Immediately after the first contact is initiated the power output is automatically reduced to 5 joules and an electronic assessment is made and the following decisions are carried out automatically;-

1. For continual non-mammalian contact, 60 seconds after the initial  assessment the circuitry kicks into maximum power to destroy casual vegetation that is touching the fence helping to keep the fence line clean and running efficiently.
2. For mammalian contact the energiser will automatically set the output at the lower rating and will remain there until the animal is clear of the fence – irrespective of how long that takes. Only when the fence is clear will the energiser automatically return to the running power. Even if the animal takes the unusual route of getting caught in the fence it will not be subjected to repeated, high energy shocks and is encouraged to extricate itself.
3. If there is a dead short to ground the circuitry will sound an audible alarm for your attention. It is possible to fit some models with a component that will send a text to your mobile alerting you of an issue with your fence.

The energisers have a built-in LED readout indicating the efficiency of your fence and this may be seen at a glance. There are further features indicating power input and grounding efficiency coupled with a five year manufacturers guarantee. The horiSMART range is available as either a mains power feed or powered by a 12v battery.

Horizont products are distributed online by Agrisellex Electric Fencing.

It is amazing the number of times I’ve been asked by a horse owner to look at a setup to evaluate why it is not keeping Neddy in. What is is about horsey people having difficulty in establishing where a problem is?

My first question is to establish what the fence voltage is running at and seven out of ten I cannot be given an answer. Very few have a tester and I’m afraid that is the only way to be able to RELIABLY establish what your fence is doing. The only other way is to grab the fence yourself and most are not too keen on that idea.

The next principle involves the earth post. Place ground rods in permanently damp ground and make sure you have sufficient soil/metal contact. Bear in mind that a length of mild steel will not be effective for long. Mild steel rapidly develops rust and this layer of corrosion is a poor electrical conductor. About 95 percent of all electric fence problems are due to poor grounding.

Please be very clear that wrapping the end of your fence around a tree is not going create a good fence. If your wires touch anything except a plastic insulator  you WILL be losing power. If your fence line is running in close proximity to another wire fence line it will create a current in that fence – this is called an inducted current created by a magnetic field that develops around the wires due to the pulsing of the electric fence system. This can result in a significant power reduction. Keep wires at least 10cm (4 inches) apart.

Old and poor wires usually have breaks and joins in them. Poor connections will result in a reduced current being transferred down the line. Check all those little wire filaments as best you are able. If you must join a tape the bare the wire filaments and twist them together outside the knot.

Joining Wires and rope

Get the maximum contact possible on your joins

Using electric fencing is not rocket science, follow just a few simple guidelines and any horse will be looked after. The important thing is to know what current is in your fence.

European badgers (Meles meles) are in the news again this week, this time as the focus of a study seeking to determine the efficacy of badger exclusion methods installed on cattle farms. Badgers are an important reservoir of Mycobacterium bovis, the pathogen that causes tuberculosis in cattle.

The study was conducted by researchers from both the Environment Agency and the University of Exeter. Farm buildings were subjected to a range of exclusion methods and these consisted of aluminium sheets, sheet fencing, solid fencing and electric fencing together with a “no change” control.

The scientists used infrared, motion-triggered digital cameras to record badger visits to farmyards, in general, and to specific areas in particular. Over the course of the initial surveillance period prior to the exclusion practice being installed, badger visits occurred on 59% of all farms, during as many as 71% of nights investigated.

All Badger exclusion measures significantly reduced badger visits to farm buildings. In fact, the anti-badger devices were 100% effective. Overall numbers of badger visits were impacted by the presence of an exclusion measure anywhere on a farm, but deterrence was most notable on farms where devices were installed on both feed stores and cattle housing buildings.

As was expected, excluded badgers simply used other sources of food within their territories and the areas targeted were quickly abandoned. The success of the exclusion measures is quite promising and suggests that badger-cattle contact on farms can be drastically minimized.

The improvised electric fence connected directly to mains. Direct electricity kills – Electric Fencing does not.

“Trashigang police detained a 16-year old boy yesterday after his hand-made electric fencing electrocuted a 65-year old man in Yonphu-Pam under Kanglung gewog.

The 65-year old man died on the spot on October 23 around 7.30pm when he accidentally stepped on the small electric fencing.

The man was returning home after leaving his cattle to graze a few meters below his house. Yonphu-Pam is about six km from Kanglung gewog.

Kanglung is about 22 kms from Trashigang.

The police, who were informed yesterday morning about the incident found that the fence was connected to a main circuit breaker (MCB) of 200V from a potato store near the suspect’s house.

Used to store potato seedlings, the potato house has an electric fan. The suspect, police said, had joined the naked binding wire directly to the store’s MCB.

In his statement to the police, the suspect confessed to have connected the fence with electricity and had switched on the MCB around 6am. “When he returned after breakfast in a hour’s time, he found the man lying on the ground,” police said.

The suspect who is a neighbour of the deceased also confessed that the fence was constructed for fun. He had pulled the fencing over a barred land about 200 meters from his house.

“The deceased stepped on the fence because it was not visible,” police said. “And the shock killed him before he could remove his feet.”

The suspect, class VI student will be charged for negligent homicide. Meanwhile the victim lived with his six children and wife in Yonphu-pam.”

Original report taken from Kuensel, Bhutan’s daily news site

The decision to use Electric Fencing situated in remote areas has been at a disadvantage due to the necessity of a regular power source normally supplied by a 12v recyclable battery. When using the larger 6 joule energisers drawing up to 500 mAmps this may be as frequent as every two weeks. Even then, as the voltage in the battery drops so does that in the fence as the energiser is a complex transformer converting the 9v to the running 6000+ volts. During recent years the development of advanced solar collection systems has changed the attitude of suppliers to this form of energy. In the past a panel could convert less than 5% of the energy available. However the efficiency of the modern monocrystalline panels run at nearly 20% and are better able to convert ambient light as well as direct sunlight to electricity. As a result a panel is no longer only suitable in the summer months and may now be used in the winter period as well.

Solar powered electric energisers work by first collecting and then converting natural sunlight through special paneling named solar PV panels. This energy is then diverted to power packs (batteries) ready to be released when the energiser draws power. The arguments for installing a solar electrified fence.

• A solar powered electric fence is able to run without access to mains electricity, this allows you to erect fences where it would usually be tough or not worthwhile. Isolated areas such as mountaintops or meadows can be contained without needing to struggle up and down every few days to replace the battery. A solar panel will energise the battery by day and the battery will provide energy to the electric fence all the time.
• Solar electrified fences are transportable Solar powered fence energisers are easy to move if you intend to relocate your fence to a different plot. This is particularly useful should you decide to relocate cattle to graze in different areas. Unlike mains charged fences which need to remain near to a power source, Solar powered electrified fences can be taken down and re-built anywhere they are needed.
• A battery will last longer by not being constantly drained of its charge. A battery who’s charge is maintained will last longer than one that is constantly being drained and recharged.
• Another common problem with energisers are power surges between the main source of energy and the fence system. Solar powered chargers just do not fail this way. They can’t because they are not hooked up to the main electrical energy source.
• The longer the section of fence you want to energise, the stronger the energiser you will need. These larger energisers will create a greater draw on the battery so a larger solar panel will be required.

When selecting a place in which to use your solar powered electric fence it is important to put thought to where to place the solar panel for the best exposure to the sun’s rays. The rest of your fence can be blocked by cloud but the panel must have access to as much direct sunlight as possible. Once you have decided on the placement of your PV Panels stop and ask yourself whether this panel will have sunlight year round or could a switch in season stop its access to sunlight. For this reason it is also advisable to check your panels once a month to ensure that they are constantly angled at an appropriate angle. In order to insure that an Electric Fence will remain functioning during the long winter months it is suggested that a larger than required panel is used. All modern panels protect the battery from over charging so there is no need to be concerned with batteries being damaged. A reasonable rule of thumb would be a 10 watt panel for energisers under 3 joules, a 20 watt panel for energisers over this.

There are tricks available to increase the output of a solar panel. A mirror placed so that it reflects suns rays on bto the panel will boost output. Care must be taken as it is possible to burn out the panel.