F Separi - Distribution Electricity Company, Mazandaran, Iran
S Zandi Poryan - Electrical Engineering Department, Seraj Higher Education Institute, Tabriz, Iran
M.R Samakooh - Distribution Electricity Company, Mazandaran, Iran

The damaged of the insulators is the most effective elements of the outage in the networks. The statistics of events and cases of overhead distribution lines (20 KV) of Mazandaran, is studied and evaluated, with regard to the role of insulators. At the end, by simulation of a real network in EMTP environment, temporary short circuits and also the role of damages of the insulators in this point will be evaluated.

Distribution lines, Safety and Reliability,Events Caused by Insulators, Temporary Short Circuits