What is the function of the Conservator in a Transformer

The Conservator is a cylindrical component of the transformer. The conservator is located at the top of the transformer. The Conservator is designed to act as a reservoir for the transformer oil. The level of the oil in the transformer can rise and fall due to temperature. The increase of temperature can be caused either by a rise in ambient temperature or due to increased load on the transformer.

An increase in temperature causes the oil in the transformer to expand. The conservator provides space for this expansion of the oil. The oil level indicator in the conservator needs to be monitored to ensure that the level of oil does not fall below the alarm limit.

As the level of oil rises and falls inside the conservator, air enters and leaves the chamber. The air may carry moisture which may cause the oil to deteriorate. Breathers filled with silica gels are provided to separate moisture from the aspirated air.

The silica gel is blue when it is dry. It turns pink when it is saturated with moisture
after which it needs to be replaced.