Most electric fence owners have seen a fence charger damaged by lightning. This damage can be costly and often means 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 this lightning protection is going to completely eliminate damage to your charger, but it can mean the difference between a low cost repair and 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 the charger cord connected to it.
Some chargers don't have external access to the fuses, so another option is to replace the original plug with a fused plug. This fused plug has two internal fuses that can be easily replaced if a problem occurs.
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. Because lightning seeks ground by the path of least resistance, it is important to find a route to the ground other than your charger.
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 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.A lightning diverter gives 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.
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.
Lightning strikes can be quite severe and damaging. We make no claim to be able to completely prevent 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.