Distribution transformers typically include a protective device known as a Buchholz relay. The Buchholz relay is an oil and gas actuated relay that is installed between the transformer tank and the conservator. It is designed to detect and provide protection against internal faults in the transformer.
The Buchholz relay operates based on the principle of gas accumulation and oil flow within the transformer. It detects the presence of gas or oil flow abnormalities, which can indicate faults such as internal short circuits, insulation breakdown, or overheating. When such faults occur, the resulting gas or oil flow activates the relay, which in turn initiates an alarm or triggers a trip signal to disconnect the transformer from the network.
The Buchholz relay is an important safety feature in distribution transformers, helping to prevent further damage and ensuring the protection of both the transformer and the electrical system it is connected to.
