Dry Type Transformers

They are transformers covered under vacuum with OG coils and epoxy cast resin; AG coils are transformers in which both cast resin and resin-absorbed prepreg.

They are produced with the power range of 160 – 25000 kVA up to 36 kV voltage level with the option of natural air-cooled (AN) or fan-cooled (AF). (Power increase up to 50% is provided by using cooling furnace.)

  • Low Facility Cost
  • It can be placed to the places where it is close to load. So, cabling cost is low.
  • It shall not need oil collection pits,
  • Fire-protection and protective barrier,
  • Specially building and design construction
  • Low Operation Cost
  • Idle and load loss rates are low.
  • They do not require very often maintenance.
  • They are environmentally friendly.
  • Since they have no cooling liquid (transformer oil), there shall be no leakage.
  • They do not contain unhealthy gas and chemicals.
  • It provides longer transformer life with the low thermal and dialectic aging compared to the oily type transformers.
  • It does not require maintenance.
  • It may be enough to control with eye as just protective and preventive maintenance.
  • High Reliability
  • Resistance to short circuit and perfect high resistance against electrical impulses and it is more useful with high capacity effect supporting overload.
  • It is highly resistant against humidity and moisture. It can work in the humid and in the places where condensation is high.
  • In case it is deactivated for long time, there is no need to dry it when it is operated again.
  • Compared to oily type transformers, its characteristics of being charged with short-term overload.
  • It has the characteristics of being able to be overloaded with the 50% of the nominal power with the forced cooling fan addition.


EFG Cast Resin Dry Type Transformers are produced according to the standards accepted in whole world.

  • According to IEC 60076-11, Climatic C2 ,Environment E2 ,Fire Behaviour F1
  • HD 464 S1
  • HD 538.1 S1
  • EN 60726
  • VDE 0532
  • ANSI C57.12.01
  • Safety
  • It is hardly inflammable and it has self-extinguishing
  • It is resistant against fire and it has no risk of leakage that may cause environmental contamination.
  • It shall not contribute to fire. So, it is safe and environmentally friendly.
  • They shall not cause very big damages and losses in short circuits arising out of the system.

Range of products and area of use

  • Distribution type transformers (160 – 3150 kVA)
  • Mono-phase transformers
  • Power transformers (4000 – 25000 kVA)
  • Level-changing transformers under OLTC load.
  • Rectifier type transformers
  • Water and air-cooled transformer with IP54 protection class (Submarine, Marine, Vessel and Oil Drilling Platforms)
  • Wind power turbine transformers (Maintenance and repair may be made in tower)
  • It minimizes fire and explosion risk in the environments in which people intensely live such as subway, tunnel, mines, airports, shopping malls, schools, hospitals, skyscrapers.
  • It may be produced external and enclosure type depending on the protection classes of IP20, IP23, IP33 optionally.