Hermetically Sealed Transformer
Hermetically Sealed Transformers are produced with power up to 2500 kVA under voltage level up to 40.5kV in single or three phase design. Also, these transformers are cooled naturally by the mineral oil (ONAN) method. The used tap changer can be off-load or on-load tap changer and these transformers can be used for indoor or outdoor environments.
Hermetically Sealed Transformers are manufactured in a way that does not allow the air to be in contact with the oil and which is done by using special vacuum chambers under the transformer cover and also by adjusting the oil’s pressure according to the factory environment. Therefore, as there is no moisture in the tank, the deterioration in oil caused by oxidation is minimized.
Since the oil does not come in contact with the atmosphere’s air in this transformers type, minimal maintenance will be required to it compared with the conservator type as it does not require its oil to be changed.