Three Pole Disconnector (20kV)

Three pole disconnectors are designed for mean voltage use in the national grid and are able of mounting vertically or in the horizontal position. Also, the mounting on both wooden and cement colognes are possible with the handling to be operated via a special rod called LoadBuster device.

System Specification

This product is designed for use in three phase overhead distribution grid of 20kV. The purpose of it is the isolation of the grid according to the IEC 62271-102 and IEC 60694 standards with their use to be graded at 630A nominal current. The single pole disconnectors are usually installed at both sides of the circuit breaker in 150/20kV or 20kV capacitor bays or else at 20kV earthing resistors.

Electrical Characteristics

  • Nominal Voltage: 20kV
  • Maximum Voltage: 24kV
  • Nominal Frequency: 50Hz
  • Nominal Current: 630A
  • Short Circuit Level: 10kA rms/25kA peak
  • Short Circuit Duration: 3sec

Operating Conditions

  • Ambient Temperature: min: -25oC to max: 45oC
  • Altitude: Up to 1000m above sea level
  • Relative Humidity: less than 95%
  • Ice Coating: max: 10mm
  • Pollution Level: moderate heavy
  • Wind Speed: 150km/h
  • Other: snow & fog


Type of Disconnector Code Creepance Distance (mm) Insulator Material
Normal insulation KDN-SPD24P40 400 Porcelain
Heavy insulation KDN-SPD-24P53 530 Porcelain
Heavy insulation KDN-SPD-24S61 610 Silicon Rubber