Medium Voltage Power Transformers — Dry Type


VPI dry-type transformers are engineered for unmatched reliability and durability. With fully resin impregnated widings, superior thermal stability, and low-maintenance operation, VPI transformers deliver consistent performance indoors or outdoors. We provide a broad range of VPI transformer designs and configurations, each fully compliant with industry standards and ready to be tested to ensure reliable performance.

  • Capacity: Single Phase: 100 to 5 MVA; Three Phase: 300 to 8 MVA

  • Voltage Class: up to 25 kV

  • BIL: 125 kV

  • Winding Material: Copper, Aluminum

  • Insulation Class: 220⁰C

  • Temperature Rise: 150 ⁰C, 115 ⁰C, 80 ⁰C

  • Frequency: 60Hz, 50/60Hz

  • Cooling: ANN, AFN

  • Taps: typically +/- 2 x 2.5%, other taps are available

  • C&C size: customizable to fit any enclosure size.

  • Sound Level: meets IEEE C57.12.01, lower sound level available

VPI - Vacuum Pressure Impregnation

Cast Coil Transformer

Cast coil power transformers’ primary and secondary windings are encapsulated in a solid epoxy resin under vacuum, which ensures void-free insulation with minimal partial discharge. The hard casting offers the greatest degree of protection against dust, moisture, and other harsh environmental conditions, making them reliable in both indoor and outdoor applications. The impulse voltage withstand capability of cast coil transformers is higher than conventional dry type trasnformers and is comparable to liquid filled transformers. Furthermore, the smooth, solid cast design eliminates gaps, making these transformers virtually maintenance-free over their service life.

  • Capacity: Single Phase: up to 5 MVA; Three Phase: up to 8 MVA

  • Voltage Class: up to 25 kV

  • BIL: 125 kV

  • Winding Material: Copper, Aluminum

  • Insulation Class: 180⁰C

  • Temperature Rise: 130 ⁰C (standard), 115 ⁰C, 80 ⁰C

  • Frequency: 60Hz, 50/60Hz

  • Cooling: ANN, AFN

  • Taps: typically +/- 2 x 2.5%, other taps are available

  • C&C size: customizable to fit any enclosure size.

  • Sound Level: meets IEEE C57.12.01, lower sound level available

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