Failures of Lightning Air-Termination Rods Fixed by Spacers

Abstract

Air-termination rods with height above 2,5 m must be fixed to objects by for example spacer bars to ensure proper separation distance. Commercially available spacer bars are suitable in laboratory conditions only. Real-life scenarios show weak points of this solution. Dirty or wet spacers do not fulfil proper isolation strength to ensure proper separation distance. This changes the km factor used to calculate the separation distance. The paper presents laboratory tests for clean spacers, wet spacers and a few real photos of damage caused by spacer bars.