Q. What is function of Buchholz relay?

Answer

Typically, a Buchholz relay will include a pair of contact points. Both are designed to function differently in the case of an internal fault: one for moderate gas accumulations and the other for massive oil displacement. The former triggers an alert, whereas the latter is often hardwired to the breaker trip relay. The contacts on a Buchholz relay often come in pairs. The former triggers an alarm, whereas the latter is often hardwired to the breaker trip relay. Every transformer with a conservator should have Buchholz protection built in. In the event of a small failure within the transformer, fault currents generate heat. The oil in the transformer is decomposed by the generated heat, leading to the release of gas bubbles.