A Buchholz relay is used for

A Buchholz relay is used for

Right Answer is:

Protection of a transformer against all internal faults.


When a fault occurs inside the transformer tank, gas is usually generated, slowly for an incipient fault and violently for heavy faults. Most of the short circuits are developed by impulse breakdown [insulation failure] between adjacent turns at the end turns of the winding. The heat produced by the high local current causes the transformer oil to decompose and produce gas which can be made used to detect the winding faults.

Buchholz relay is the simplest form of protection which is commonly used in all transformers provided with the conservator. It will act (or) close the breaker circuit, whenever there is a sudden rise of oil pressure inside the transformer or there is more gas collection. So, this device will only sense the internal fault of transformers.

Scroll to Top