SOLUTION

Transformer oil should not be exposed directly to the atmosphere because it may absorb moisture and dust from the environment and may lose its electrical properties in a very short time. To avoid this from happening, a breather is provided. The function of the breather is to prevent the entry of moist air into the transformer tank after its breath out. Even a small amount of moisture absorbed by the oil reduces the insulating properties of the oil considerably.

The breather is a cylindrical tube containing oil. silica gel or calcium chloride in different chambers. When the pressure inside the tank reduces due to breath out, it is the breather that absorbs moisture from the air entering the conservator. The entering air is to first pass through the oil which filters the moisture and then through the silica get which further dries the air.

The silica gel when dry is blue in color and when it absorbs moisture, its color becomes somewhat pale Pink. Silica gel in the breather is replaced at certain intervals time.