The spraying work of PRTV anti-pollution flashover coating should be carried out by a construction team with construction qualifications and mature construction experience. The main requirements for spray-on coating are as follows:
The coating should be flat, smooth and free of bubbles.
The power frequency wet flashover voltage of coated insulators should not be lower than that of uncoated insulators.
At a salinity of 20 kg/m3 and above, the ratio of the pollution flashover voltage of the coated insulator under the same test conditions to that of the uncoated insulator shall not be less than 1.5.
During the service life, the coating should not have crack, chalking, peeling and falling off under natural conditions, and can work reliably for a long time. The outdoor service life is generally not less than 5 years.
a) Tack-free time
The surface drying time is not more than 45min (25℃±20C, 40%～70%RH).
b) Curing time (hard dry)
The curing time is not more than 72h (25℃±20C, 40%～70%RH).
The spraying work of the PRTV anti-pollution flashover coating should strictly follow the coating instructions. Before coating, the insulators should be cleaned, and moisture and oil stains should be wiped off. The construction should be carried out under weather conditions without rain, dew, and sand.
The metal parts at both ends of the equipment should be wrapped and protected during the construction of the PRTV anti-pollution flashover coating, and protection should be done during the spraying implementation, and the operation of adjacent equipment should not be affected. The implementation of the spraying of the PRTV anti-pollution flashover coating should be carried out after the completion of the insulation test of the electrical equipment, and the electrical equipment with unqualified insulation should be processed and replaced before the PRTV anti-pollution flashover coating is sprayed.