Answer / pradhyumn

Buchholz relay is installed between the pipe connecting the
main tank & conservator. It indicates about the incipient
(initial) faults like insulation failure, core heating, and
fall in oil level due to leakage joints.
During initial faults when oil in the main tank decompose,
hydrogen gas is produced as result whose volume is more
than 70%, so this gas as result of being lighter tries to
escape to the conservator which is at the top, but gets
caught in the buchholz relay, where when determined amt. of
gas is accumulated, it gives the alarm of gas surge.

During major faults when enormous amount of gas is
released, this causes the oil surge which enters the
buchholz relay & thus due to this oil surge the causes the
circuit to trip as this being the major fault.

* Used in oil and gas surge protection.(plz. forgive
spelling mistakes.)

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