Practical Application of Pollution Standards: Issues & Questions
by Darcy Ramalho de Mello

Insulators must withstand normal operating voltage but also overvoltages that can lead to disturbances, flashovers and line outages. Reduction in performance occurs mainly through pollution depositing on insulation surfaces that forms a conducting or partially conducting layer when wetted. The focus of this presentation is to review problems with the practical use of existing standards that guide selection and specification of insulators for polluted service environments. Cases from power utilities are discussed as examples of such problems.