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.