HV/MV Equipment
Gas-insulated Current Transformer up to 550 kV

Grid Solutions > HV/MV Equipment > Instrument Transformers > KSKEF

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Gas-Insulated Combined Metering Unit (CMU)

The KSKEF has a top core design with composite insulator for voltages up to 550 kV. It is designed to provide both current and voltage measurement from a single device and uses the same components as the individual CTs and VTs. The primary coil for the VT and the core box of the CT are both housed in the head, on top of the insulator.

The internal insulation is provided by SF6 and the KSKEF is compliant with IEC, IEEE or equivalent standards. Ideal solution for adding metering capability to either a new substation installation or a site being upgraded where space is a premium.

Key Features

  • Space and costs savings
  • Long term accuracy stability and insulation
  • Decades of on-site experience
  • g3 capability - green gas for grid with very low global warming potential


  • Rated voltage: 123 kV to 550 kV
  • Frequency: 50 or 60 Hz

Current Transformer Data

  • Max. thermal current: 5,000 A
  • Short-circuit current: up to 80 kA / 1 sec
  • Rated dynamic current: 200 kA peak
  • Secondary cores: up to 8

Voltage Transformer Data:

  • Thermal burden: up to 3,000 VA
  • Voltage factor: 1.5/30s or 1.9/8h
  • Secondary windings: up to 3