Investigation of the insulation performance of the insulator covered with Lichen

The results of an investigation of the dielectric strength of lichen-contaminated insulators removed from actual transmission lines of three different countries are reported. All of the insulators showed low equivalent salt-deposit density. It seems that lichen on its own cannot cause flashover of the insulators. Flashover may be caused only if the thickness of the lichen is very great and/or there is superposition of salt