Conservator Transformers types 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.
The dimensions of the expansion tanks are designed based on the calculations of how much would the oil level expand due to the increase of the temperature.
Since these transformers are exposed to the atmosphere, the oil pressure will change due to thermal effects. So to ensure the pressure stability, air moisture will be filtered from the air by means of the silica gel (air dryer) found on the transformer’s tank.
When the transformer starts to operate and depending on its load and the air exchange caused by the temperature rise, the silica gel starts to lose its feature over time and causes the oil to moisten and its structure to deteriorate. For this reason, maintenance such as changing the silica gel in certain periods and measuring the voltage by taking samples from the oil should be done.