Transformer Buchholz Relay

Transformer buchholz relay

A transformer buchholz relay is a protective device that is installed in oil-immersed transformers to detect and prevent faults that may occur within the transformer. The buchholz relay operates on the principle of gas detection and is named after its inventor, Max Buchholz.

The buchholz relay is located in the pipeline between the transformer's main tank and its conservator tank. It is designed to detect the presence of gases, such as hydrogen and methane, that are generated by the decomposition of the transformer oil due to electrical faults, overheating or mechanical stresses. When these gases are detected, the buchholz relay sends a signal to the transformer protection system, which can initiate an alarm or trip the transformer.

The buchholz relay consists of a gas chamber that is connected to the transformer tank by two pipes, one from the top and the other from the bottom. A float switch, which is located inside the gas chamber, is used to detect the level of oil in the transformer. If the level drops below a certain point, the float switch will activate the buchholz relay.

The buchholz relay is an important protection device for transformers as it provides early detection of faults that could cause serious damage or even complete failure of the transformer. By detecting gas accumulation, the buchholz relay can prevent further damage and allow for timely repairs or maintenance.