High-voltage disconnect switch KMX-18

VITZROEM polymer type LA is a 18kV-5kA product that is used in KEPCO distribution lines and general high-voltagecustomers. To prevent explosion by hygroscopic deterioration, which accounts for most accidents in existing porcelaintype LAs, winding by FRP insulation material was conducted on the ZnO element and internal components, the interfacebetween FRP insulation material and polymer rubber housing was treated, and both ends of the polymer LA were sealedwith caps. The polymer was selected so that it does not scatter even in case of explosion. ● Excellent humidity tightness ● Light-weight in comparison to porcelain type LA(2.4kg) ● Prevention of secondary accidents (e.g. scattering of fragments) in case of explosion from internal temperature rise and expansion by arc arising from excessive fault current ● Resistor type disconnecting switch ● Creeping leakage distance: ≥645mm ● Insulated cover rubber product over the upper terminal side, preventing the penetration of rainwater Structure Overview Disconnector The disconnector prevents the accident spread by the quick separation of LA from lines in case of deterioration of ZnO elementin LA, which is classified into the coil type and resistor type. The highly reliable resistor type disconnector was selected becausethe discharge voltage and waveform can change in the coil type, while stable discharge voltage and waveform are maintainedin the resistor type. The following table shows the test results of disconnecting time-current characteristic curve.