Correct option is A
· A Buchholz relay is a type of gas-actuated relay used in oil-filled transformers. It is a safety device that detects the presence of gas produced by electrical faults within the transformer.
· The relay is installed in the pipeline between the main tank and the conservator of an oil-cooled transformer. When a fault occurs inside the transformer, such as a short circuit or insulation breakdown, it generates heat and decomposes the transformer oil, producing gas.
· The gas accumulates in the Buchholz relay, causing it to trigger an alarm or trip the transformer circuit, preventing further damage.
· Oil cooled transformers are the primary application for Buchholz relays because these transformers use oil for cooling and insulation. The oil can produce gases when subjected to electrical faults, which the Buchholz relay detects.
