Transformer protection
Protection of busbars and transformers

This mechanical relay is located in the oil line (figure 11) which connects the transformer tank to the oil receiver. It is sensitive to any gas or oil movement. If this movement is slight, it closes a Buchholz alarm contact. In addition, a tripping command is given by another contact which closes in the event of significant movement. This relay is the only device that can detect ignitions between transformer windings that produce a gas release. All transformers and chokes in oil are equipped with this type of relay.