Oil immersed transformers


Conservator Type Transformer

The transformer adopts vacuum oiling, ensure stable insulation performance
  • oil immersed rectifier transformer
  • distribution power transformer
  • 5mva transformer
  • kiosk substation
  1. oil immersed rectifier transformer
  2. distribution power transformer
  3. 5mva transformer
  4. kiosk substation

The high and low voltage windings are made of oxygen-free copper,Good electrical conductivity,saving energy

Adopt high quality  oriented cold rolled silicon steel sheet,  greatly reduce the no-load loss and no-load current

The transformer adopts vacuum oiling, which can completely eliminate bubbles in the coil and ensure stable insulation performance

Vector group Dyn11,Reduce the influence of harmonics on power grid and improve the quality of power supply

Related product parameters

Main specification

Transformer type

oil immersed transformer



Rated power


Rated voltage

Up to 36KV  


 Single or Three phase


off-load and on-load

Winding material

Copper or Aluminum

Iron core

Silicon steel sheet or amorphous alloy


50Hz or 60Hz   

Vector group

Dyn11  Dyn5

Insulation class


Dielectric liquid

Mineral oil / Vegatable oil

Cooling way



 Corrugated oil tank or radiator



Environmental Temperature

-25 ~  +40 ℃



oil level gauge

transformer tank

pressure relief valve

Tap changer

Oil Thermometer


Factory Test

For each transformer are prepared and issued a test report, in accordance with IEC 60076.  except for routine tests, we also offer type tests and specialised tests to meet all customer requirements. We make what matters work for our customers in a safe and reliable way. 

power transformer testing.jpg

Routine test

 a) Measurement of winding resistance

 b) Measurement of voltage ratio and check of phase displacement

 c) Measurement of short-circuit impedance and loss

 d) Measurement of no-load loss and current

 e) Dielectric routine tests

 f) Tests on on-load tap-changers, where appropriate

 g) Leak testing with pressure for liquid-immersed transformers(tightness test)

 h) Tightness tests and pressure tests for tanks for gas-filled transformers

 i) Check of the ratio and polarity of built-in current transformers

 j) Check of core and frame insulation for liquid immersed transformers with core or frame insulation

  Type test

 a) Temperature-rise type test

 b) Dielectric type tests

 c) Determination of sound level for each method of cooling for which a guaranteed sound level is specified

 d) Measurement of the power taken by the fan and liquid pump motors

 e) Measurement of no-load loss and current at 90% and 110% of rated voltage

  Special test

 a) Dielectric special tests

 b) Winding hot-spot temperature-rise measurement

 c) Determination of capacitances windings-to-earth, and between windings

 d) Measurement of dissipation factor(tanδ) of the insulation system capacitances

 e) Determination of transient voltage transfer characteristics

 f) Measurement of zero-sequence impedance(s) on three-phase transformers

 g) Short-circuit withstand test

 i) Vacuum deflection test on liquid immersed transformers

 j) Pressure deflection test on liquid immersed transformers

 k) Vacuum tightness test on site on liquid immersed transformers


Varelen offers a complete range of power and distribution transformers designed to grant the reliability, durability, and efficiency required in utility, industrial, electrical distribution substations, power generation, voltage regulation, mining, traction and commercial applications. Transformers can be used for indoor or outdoor applications and can be provided with off-load and on-load tap changers.

Related Content

Oil immersed transformer

Oil immersed transformer

Pad mounted transformer

Pad mounted transformer

Special Distribution Transformers

Special Distribution Transformers


Contact us

Varelen Electric Co., Ltd

Information submitted... Later, please