ONLOAD TAPCHNGERS ARE REQUIRED WHEREEVER THERE ARE VERY FREQUENT AND HEAVY FLUCTUATIONS OF THE INCOMING VOLTAGE AND ALSO WHEN THERE ARE SEVERE LOAD FLUCTUATOINS IN THE DOWN
THE LINE FEEDER . THE HIGHER BUS VOLTAGE ALSO HELPS TO KEEP THE TAIL END VOLTAGE IN THE DISTIBUTION SYSTEM INWITH BETTER...
Though the long rod insulator has acreepage distance of 45 mm/kv Ifeel the protected creepage is not 50% of the total creepage. please try with antifog type insulators which have enough protected creepage distance.Further any chance of chemical fumes outlet in the wind direction?