When you build an electric fencing system it’s important to do it right the first time, says a B.C. producer and fencing specialist.
“Electric fence has been around for years but has often been very poorly installed and with poor equipment and so it’s not very effective,” says Rob Davidson, a sales representative for PowerFlex Fence, who also farms near Creston, B.C.
There are a number of components that make up a good electric fencing system:
Davidson suggests that 3,000 volts should be the minimum output for any electric fence, but what is really important is to make sure you get the correct power (joules) for the application, as the higher the joules the more fence you can run with it. For example an energiser that puts out 37 joules is capable of powering 220 miles of cattle fence (enough for about 2,500 acres), whereas one with a 22 joules output can handle fences for about 1,200 acres. A general rule of thumb is that one joule will power between three to five miles of fence.
But remember to plan for growth. Purchasing an energiser that is a little larger than you need at the moment will give you the option to add more fence in the future.
In remote areas the only option for power is solar panels. They work well, but can be expensive to buy. Davidson recommends using a plug in system, wherever possible, for reliability, convenience and economy. “Half a mile of wire from a plug in energiser is way cheaper than purchasing solar panels, and then you can monitor it from home, so it’s a real advantage to plug them in,” he says.
Grounding is very important. The grounding system is used as an antenna that collects electrons travelling through the ground for miles, so if the ground field isn’t big enough it won’t collect what is needed.
You will need to have a five foot ground field around each ground rod and they need to be touching, so the ground rods can be 10 feet apart. More surface area is better, so having a ground rod that is 5/8″ diameter is better than ” diameter. It is also important to have enough, so a rough rule of thumb is one ground rod for every two joules of power output. Rods should be at least six feet long. The type of soil makes a difference; sandy soils need more ground rods than good mineral rich soils.
Rust does not conduct electricity, which is why it’s important to choose good quality, galvanised wire that will not rust, says Davidson. The size should be at least 12.5 ga to conduct enough electricity. “Wire is similar to hose and water, so a little tiny hose won’t put much water through it, and a small wire doesn’t run much electricity,” says Davidson. The number of wires needed will depend on the size of the animal. One wire may be sufficient for mature cattle, whereas for a calf or sheep three to five wires may be necessary.
A volt meter that you can take out into the field to test the voltage in the fence is a necessity. It will also tell you the amperage draw and allow you to detect any shorts and where they are. Some energisers now have built in LCD displays that also show voltage and can also come with remote control fault finders. More advanced models also offer options to manage the fence system and remotely adjust the output.
NEW HI-TENSILE FENCE WIRE
PowerFlex Fence recently introduced a new hi-tensile wire, manufactured in New Zealand, which has a much heavier 130 gram Zinc/ Aluminum coating than traditional galvanised wire with a 100 per cent zinc coating. Although slightly more expensive, it’s stronger with a 120,000 psi tensile strength and claims to last twice as long as ordinary galvanised wire.