Lightning Protection

Almost every electric fence owner has experienced the problem of having a fence charger damaged by lightning. This damage can be quite costly and really upsets your whole routine, not to mention the frustration of chasing loose livestock. It's not only a hassle to pack up your charger and send it away for repair, but when your livestock realize they don't get that sudden jolt when they come in contact with the fence, they seem to say to themselves "ROAD TRIP" and away they go.

We're not saying that this lightning protection is going to completely eliminate damage to your charger, but it can mean the difference between a low cost repair or having to replace the entire unit.

You need to protect both the input (120 volt source) and the output (fence) side of the charger. There are two options for the input side. One is the use of a power surge protector (MPS). Some studies have shown that the majority of damage is caused by surges from the utility side. The power surge protector is the easier of the two to install. This simple device plugs into your grounded receptacle with your charger cord connected to it.

Some chargers don't have external access to the fuses, so the second option you might want to consider is to replace the original plug with a fused plug (MFP). This fused plug has two internal fuses that can be easily replaced if a problem should occur.

Now for the output side. This is the side that usually takes the blunt force of a lightning strike to the fence line. Most chargers have some type of lightning surge protection built into their circuitry, but if a lightning strike gets past this, it usually means money out of your pocket for a costly repair or replacement. Since lightning naturally seeks ground by the path of least resistance, our discussion centers around giving it an easier route to ground other than through your charger.

So here we go:

When initially installing your charger, always follow the manufacturer's recommendations regarding the ground bed and connections. This is of utmost importance if you want your charger to operate at peak efficiency. The first thing on the charger should be an electronic spark suppressor. This is to hooked onto the hot terminal with the one wire and the ground terminal with the other wire. It is also helpful to mount a 2nd one on the line connecting your lightning arrestor to independent ground rods. The lightning choke coil (MLC) is to be mounted between the charger and the fence. The MLA-I arrestor is to be on the fence side of the lightning choke coil..As the surge of electrical energy caused by a lightning strike travels through the choke coil, the inductive loops of the coil cause a reverse flow of current. This in turn generates a magnetic field which adds time to the current flow. Since lightning always take the path of least resistance to ground, the surge is routed away from your charger.

This brings us to the lightning arrestor. The lightning arrestor and its ground bed should be at least forty feet from your charger's ground bed as well as any other existing home or utility grounds, water supply systems, milking systems . It should have as many ground rods as the charger, preferably one more.

We carry two different types of lightning arrestors, the twin tower porcelain (MLA) and the Koltec weatherproof plastic arrestor (MLA-I). Both give the lightning surge an easier path to take by diverting it to the ground bed of the arrestors. They are mounted on a fence post with a jumper wire connected to the top of the unit from your top hot wire. The bottom connection on the arrestor goes to the series of ground rods mentioned previously. The portion of the surge that doesn't make it to ground here should be stopped by the choke coil mentioned earlier.

For those of you who don't want to leave anything to chance, there are several styles of disconnect switches that can be used to further isolate your fence from your charger during lightning storms. You would need to use one on the hot line.. This is mounted at a convenient location near your charger's lead out wires Before a storm approaches, open the switch, which will isolate the lead wires from the fence and ground bed, and unplug the charger from the 120 volt power source. Of course, you must be there to do this. But short of a direct lightning strike to your charger, it will be protected.

Kencove has put together a lightning/surge protection package that will protect both the input and output sides of the charger without putting a crimp (no pun intended) in your budget. A package is outlined below.

Lightning strikes can be quite severe and damaging. We make no claim to be able to totally prevent this damage. However, the lightning protection measures discussed above could mean the difference between a low cost repair or total replacement of the charger. For the best protection, unplug the charger and disconnect it from the fence before severe storms.