Maintenance of Substation Insulators Without Power Shutdown

IT is essential to maintain the integrity of electrical substation apparatus and associated equipment to ensure the availability of uninterrupted power. Cement plants must maintain continuous production and avoid the high cost of unscheduled interruptions. Periodic substation surveys will determine the integrity of the equipment. Where the condition of apparatus and porcelain insulators are less than satisfactory, service can usually be accomplished without power interruption. The integrity of porcelain insulators is of special importance because of the nature of contamination prevailing in the area of a cement plant. Metal oxides and sulphides adhere to the insulator and become an electrolyte in water, thereby increasing leakage currents to dangerous levels where flashover can occur in the event of high voltage transients. Flashover of the insulator can cause damage to the insulator, damage to apparatus, and interruption to service.