Medium Voltage Oil Cooled Potential Transformer

Medium Voltage Oil Cooled Potential Transformers of single core for metering purpose are commonly used. Di-electric strength of the oil-impregnated paper insulation is preserved by hermetic sealing of the transformer.

Our product specification is as follows

Applications Metering, Protection
Construction Outdoor resin cast
System Voltage Upto 33kV
Type Single/three phase, multi-core/ratio
Accuracy class
Metering 0.2, 0.5, 1.0
Protection 3P
Primary Upto 33KV
Secondary 110V AC


  • Oil / Paper Insulation.
  • High insulation reliability.
  • Metal parts corrosion resistive.
  • Porcelain bushing suitable for polluted atmosphere.
  • Easily accessible to LV terminals.

Main features -

  • The unique ‘filling’ composition of oil results in a compact design
  • For measuring,protection and open delta with one or two or three or four secondaries
  • Most standards available (IEC & IS)
  • Highest voltage for equipment: 3.6 - 145 kV
  • Rated voltage factor: 1.2 continuous & 1.5 for 30sec or 1.9 for 8hrs
  • Rated Secondary Voltage: 110/√3V or 110V
  • Frequency: 50 or 60 Hz
  • All external iron parts are MS painted for protection against detrimental effects of atmosphere and chemicals
  • Flexible design to meet special customer requirements such as high burden, creepage and high altitude
  • All gaskets are below oil level ensuring positive oil sealing
  • The winding is insulated with special paper, which has high mechanical and dielectric strength as well as low dielectric losses and good resistance to ageing.
  • Heating in a vacuum dries the windings. After assembly, all free space in the transformer (approximately 60%) is filled with clean and dry quartz grains.
  • The assembled transformer is vacuum-treated and impregnated with degassed mineral oil.

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