What are protection of power transformer?

Answer Posted / sakthi

Internal
Winding Phase-Phase,
Phase-Ground faults
Differential (87T), over current (51, 51N)
Restricted ground fault protection
(87RGF)
Winding inter-turn
faults
Differential (87T), Buchholz relay,
Core insulation failure,
shorted laminations
Differential (87T), Buchholz relay,
sudden pressure relay
Tank faults Differential (87T), Buchholz relay and
tank-ground protection
Overfluxing Volts/Hz (24)
External
Overloads Thermal (49)
Overvoltage Overvoltage (59)
Overfluxing Volts/Hz (24)
External system short
circuits
Time overcurrent (51, 51G),
Instantaneous overcurrent (50, 50G)

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