The main difference between light and heavy gas protection lies in the relay's setting values: light gas protection only issues an alarm signal without tripping, while heavy gas protection directly initiates a trip. The zero-sequence voltage equals the vector sum of. Gas Relay The role of: The gas relay is the primary protective device for internal faults in oil-immersed transformers; it is installed on the connecting pipe between the transformer tank and the oil conservator. When an internal fault in the transformer causes the insulating oil to decompose and. The Buchholz relay provides early warning and protection against incipient (minor) internal faults that, if left undetected, can develop into serious faults and cause transformer failure or explosion. Unlike electrical protection relays that rely on current and voltage measurements, the Buchholz. For transformers with a capacity of 0. 4 MVA and above, primary voltage of 10 kV or below, and delta-star winding connections, two-phase three-relay overcurrent protection may be used. To further enhance the sensitivity of gas relays for the heavy gas alarm, this paper takes the BF type double float gas relay as the research object and proposes a new method for heavy gas setting, which is based on the internal oil flow acceleration characteristics of the gas relay. It is named after its inventor, the German engineer Max Buchholz, who developed the relay in 1921.
