Condition monitoring of post insulators and surge arresters

The EXCOUNT II condition monitor was originally designed to measure impulse and resistive current in gapless metal oxide surge arresters. However in this study, it was determined that it can be applied to estimate the amount of insulator surface pollution and the associated need for washing the surface. AltaLink is establishing a schedule to monitor the contamination and download leakage current readings in order to set trigger levels for washing station post insulators. The benefit derived from this approach allows hot washing at lower levels in order to reduce the possibility of flashover at elevated pollution levels. This will help in decision making to maintain a more reliable power delivery system.