The circuit which is protected from the strokes of lightning with the help of a protection device is known as lightning arrester. Here the lightning strokes are nothing but surges with high transient voltage, arcs of isolation, spark, and surge currents because of lightning, etc. These devices are used to defend the power systems by forwarding the high voltage surges in the direction of the ground. And these power systems and over headlines can also be protected by using ground wire or the earthling from the direct strikes of lightning.
The arrangement of these devices can be done on the towers, transmission poles and buildings to give a secure lane to the voltage & discharging current. Here these can be occurred during the strokes of lightning toward the ground to defend the system from the induced problems of lightning.
Working Principle
Lightning arrestor working principle is, once the voltage surge travels throughout the conductor then it reaches the location of the arrestor where it is installed. So it will break down the insulation of the lightning arrestor for a moment, so voltage surge can be discharged toward the ground. Once the voltage of the system falls under the fixed value, then the insulation will be restored among the ground & conductor. Further, the current flow toward the ground will be stopped.
Types of Lightning Arrester
Generally, lightning arresters are classified into different types. The construction of lightning arrestors is different based on its type but the working principle is the same. It provides a low resistance pathway to the surges in the direction of the ground. The types are
Horn Gap Arresters
As the name suggests, this arrestor has two metal rods in horn-shaped. The arrangement of these metal rods can be done around a small air gap. The distance between these two rods can be increased because they increase from the gap. The metal rods are located on ceramic insulators.
The connection of the horn can be done by connecting it to two dissimilar wires. One side of the horn can be connected to the line throughout a resistance & choke coil whereas the other side is grounded efficiently.