• Question: Explain how a lightning arrestor works

    Asked by 268ngrj1723 to Bernerd, Joseph, Ken, Peter on 14 Jul 2017.
    • Photo: Joseph Olwendo

      Joseph Olwendo answered on 14 Jul 2017:

      a lightning arrestor will always be made of a metallic material that is raised high above the building and is directed to the ground. when there is lightning (i.e moving charges air molecules) directed to your building, the electrons in the metal rod will be repelled and they will move to the ground where they get neutraulized by the earth (we at times talk of eaarthing). we know from electrostatics that like charges repel and unlike attract. the coming electron in the lighning will repel the electrons in the arrestor making them move from the metal to the ground and this get neutralized hence avoiding any damage from the lightning

    • Photo: Bernerd Fulanda

      Bernerd Fulanda answered on 14 Jul 2017:

      Dear Ngrj
      lets start here – Lightning, is a form of visible discharge of electricity between rain clouds or between a rain cloud and the earth. The electric discharge is seen in the form of a brilliant arc, sometimes several kilometres long, stretching between the discharge points.
      The possibility of discharge is high on tall trees and buildings rather than to ground. The lightning arrestors are metal bars that extend from the top of the building to the ground from a point above the highest part of the roof. The conductor has a pointed edge on one side and the other side is connected to a long thick copper strip which runs down the building.
      The lower end of the strip is properly earthed. When lightning strikes it hits the rod and current flows down through the copper strip. These rods form a low-resistance path for the lightning discharge and prevent it from travelling through the structure itself, and this “arrests” the electrical charge than protecting the occupants of the building