Lightning and Surge Protection
Lightning is the bane of an electric fence charger. The conductive wires of an electric fence create a good-sized metallic net vulnerable to lightning strikes, and the huge charge created by lightning striking the electric fence wire will commonly follow the wire until it reaches the electric fence charger–which it may threaten, damage, or destroy. Lightning can also create power surges in AC electric lines carrying house current, and like any other electrical appliance from light fixtures to computers, such surges can harm electric fence chargers. For both reasons electric fence chargers generally come equipped with internal fuses that tend to interdict severe surges and help to protect the charger. However, a powerful or nearby lightning strike stands a reasonable chance of doing considerable harm before the fuse actually blows, and power surges coming through the AC line can do damage without reaching the heat threshold needed to blow the fuse. Therefore, it is worth getting additional protection.
There are two ways of protecting against lightning on an electric fence. One is by installing a "lightning choke" (product 01-36B). This makes the charge traverse a series of parallel loops–a process that generates powerful magnetic fields which in turn interfere with passage of the big charge and reduce it before it can reach the charger. The other way is to set up a "diverter" that allows a big charge to open an electrical pathway that by-passes the charger and reaches the ground through a grounding system–either the fence’s regular ground rod system or one especially installed for the purpose of lightning diversion that is superior to the regular system, having at least one more ground rod than the regular system. Product 01-35 is a combined lightning choke and lightning diverter that requires a separate lightning-diverting grounding system; and product 01-36 is a "storm guard" placed near the charger that diverts the charge to the system’s own ground rod and does not require installation of a separate ground rod.
None of this deals with lightning and other surges coming in through the house current. What can deal with them (so long as they are not too powerful) is a surge protector (product 01-36A) that works like the surge protectors commonly used to protect computers and other indoor electronic gear. One can also place two one-amp fuses (product 01-20) in a fused plug (product 01-21) that will tend to keep powerful surges from reaching the charger.