Electric fence

There is only one way to do any electric fence, security, animal control, game fencing, properly and it is with correct earthing.

Regrettably 9 out 10 security fences looked at for repairs, are way off correctly earthed ranging from completely incompetent to could have possibly done better. Completely incorrect is unfortunately the most common. Many fencing companies now will not even repair a fence unless they installed it – basically having to tell a client that there fence was badly installed often does not go down well

Energizer manafacturers recommend at least 3 earth spikes spaced at 1m at or at least near the energizer itself. Now, already most installations that i see only have one and many none with one ground spike being at the fence. Lets face it, why would the energizer manafacturers waste time printing this if it wasn’t required or neccessary?? IT IS REQUIRED AND IS NECCESSARY!

Energizers work on very basic electrical theory that in order to get a shock, a circuit should be made. Hence, if you touch only a live wire, the circuit needs to be made through the live wire, through the body to ground and then back to the energizer to complete the circuit. If there are two few earth spikes, then the part of “through the ground and back to the energizer” FAILS!

Its really sad to see an expensive and full installation (especially on game fence) that is incorrectly or badly earthed, sometimes only with a few earth spikes. It would have been easier on the pocket to have done a really cheap installation with small energizers, lower wire quality but correct earthing. You would be achieving in principle exactly the same shock value! In one installation a game fence was seen to have 10 earth spikes (to few energizers which compounded even further to bad game fence) spread over a 10km distance. Thats one earth spike per km and NONE at the energizer. Since as i am not mentioning the installer, i’ll say it “THEY WERE COMPLETELY RIPPED OFF!” Fortunately the repair and correction was not to severe and the fence easily broken to correct. Basically this fence should have had in the region of 100 earth spikes (one per 100m) and 3 for each energizer installed. For the installation in this case, 103 earth spikes and NOT 10. (the ground in the area was suitable to spread out)

One factor that is not that easy to get around is very dry areas. Dry soil conditions and types does affect the earthing ability of a region which becomes problematic for fence installations. Solutions do vary but the most obvious is more earth spikes. They are not cheap, at around R25 to R60 each, but compromising on a large installation, well laid out, for a few earth spikes is really just wasting money at the same time.

If your fence is not earthed at around 30m intervals (or even better less), then it is not as effective as it could be and should probably get it checked out!