To keep the transmission line or Substation in healthy condition it is utmost essential that all the insulator Strings are in extremely good condition. The above detection of insulator strings Scanner detection is based on the induction effect. The Scanner is slid over the insulators at a definite distance.

 

Transmission lines or Sub-Stations located near polluted areas having Sulphur, salt, ash, conductive dust, etc face serious problem of deposition of this on porcelain insulators. Dust being conductive reduces the creepage path. Onset of winter when we observe Dew formation Voltage dips, tripping of EHV lines is a common phenomenon.

 

Deposition of sulphar, salt, ash, conductive dust, etc makes Insulator string weakest in EHV System which eventually produces flashover of insulator string. These un-warranted tripping
produces heavy voltage surges and severe mechanical stress on system. The recurrent tripping of this nature may result in major break-down. To keep the system in perfectly healthy condition
i.e having No Break-downs the only solution is PID testing and replacement of faulty insulator in Hot line maintenance.