Distribution transformers
Expansion tank transformer
Since transformers with expansion tanks are open to the atmosphere, the changing oil pressure due to thermal effects and air exchange is ensured by dehumidifying the air thanks to the slicagel in the tank.
Manufactured in power range 25-2500 kVA, high voltage range from 2 kV to 40.5 kV, three or single phase, oil, natural cooling (ONAN), no-load tap changer or automatic tap under load. modifier, for external and internal use.
The dimensions of the expansion tanks of the transformers are designed as a result of calculations to contain the expansion of the oil, which increases with temperature.
Since the transformer with the expansion tank is open to the atmosphere, the oil pressure changes due to the thermal effect, and thanks to the slikajel (air dryer) in the transformer tank, air humidity is removed and air exchange is ensured.
A commissioned expansion tank transformer (transformer with expansion tank) loses its slicagel property over time due to air exchange caused by temperature differences depending on the load, causing oil wetting and structural deterioration. For this reason, maintenance work such as changing the slicagel and measuring the breaking stress by taking oil samples should be carried out at certain intervals.
Hermetic transformer
Since the oil in hermetic transformers is not in contact with the atmosphere, it does not require oil changes and periodic maintenance, as in transformers with expansion tanks.
Manufactured in power range 25-2500 kVA, high voltage range from 2 kV to 40.5 kV, three or single phase, oil, natural cooling (ONAN), with off-load tap changer or automatic tap under load. modifier, for external and internal use.
The hermetic transformer is produced by adjusting the pressure in the factory environment in special vacuum chambers so that there is no air gap and it does not come into contact with the atmosphere. Therefore, because there is no moisture in the boiler, deterioration caused by oxidation in the oil is minimized.
Hermetic transformers (hermetic type transformers) have a lower height than transformers with expansion tanks.
Since the oil in hermetic transformers is not in contact with the atmosphere, it does not require oil changes and periodic maintenance, as in transformers with expansion tanks.