Oil-immersed transformer failure analysis

Transformers in operation failures are common windings, bushings and tap and core, fuel tank and other accessories for failure.
  1, winding fault
  There are inter-turn short circuit, winding ground, phase short circuit, disconnection and other open solder joints.
  2, casing failure
Transformer bushing fouling, in fog or rain caused flashover, high voltage side of the transformer single phase, or phase short circuit.
  3, severe leaks
Transformer oil leakage severe or continuous operation on broken constantly spill resulting from the oil level gauge has been to see the oil level, you should immediately disable the transformer to trap and refueling, causing oil leakage due to a  power transformers weld cracking or seal parts fail, run by vibration force collision damage and other serious and tank corrosion.
  4, tap failure
Common fault partakers tap is bad or wrong position, the contact surface melting and burning and white discharge or sub connector contact discharge.
  5, the over-voltage power transformers  by the fault
Operation of the transformer to lightning strikes, due to the high potential of lightning, will cause the alternating voltage is external over-voltage, when some parameters of the power system changes, causes the electromagnetic oscillation, will cause internal over-voltage  circuit breakers , the two class overvoltage damage caused by the transformer primary winding insulation breakdown is mostly caused transformer fault.
  6, the core of the fault
  Largely because of the failure of the core legs of the core or the core of the mandrel screw clamp screw caused by damage to the insulation.
  7, oil leakage phenomenon
The oil transformer oil is too low, the sleeve tap leads and exposed to air, the insulation level will be greatly reduced, so easily cause the breakdown discharge