Oil immersed Transformer in the operation of the common faults are winding, casing and tap switches and iron core, fuel tank and other accessories failure.
Winding fault
There are inter-turn short circuit, winding ground, phase short circuit, broken wire and joint welding.
Casing failure
Transformer casing fouling, in the fog or light rain caused by pollution, so that the transformer high-voltage side of the single-phase ground or phase short circuit.
Serious leakage
Transformer operation Leakage oil is continuously or continuously spilled from the break so that the oil level gauge has not seen the oil level. At this time, the transformer should be deactivated for leak and refueling, causing the transformer to leak oil. There is weld cracking or sealing Pieces of failure, the operation by the shock of the external impact of oil tank serious corrosion and damage.
Tapping switch
Common faults are caused by poor contact or position of the on-load tap-changer, contact surface melting and burns, and inter-phase contact discharge or tap discharge.
Overvoltage
When the transformer in the running is struck by lightning, due to the high potential of the lightning, it will cause the overvoltage of the transformer. When some parameters of the power system change, due to the electromagnetic oscillation, the internal voltage of the transformer will be caused. Overvoltage caused by the transformer damage is mostly winding the main insulation breakdown, resulting in transformer failure.
Iron core
Most of the core failure is caused by damage to the insulation of the clamping screw of the core stud or the core of the core.
Leakage of oil
The oil level of the transformer oil is too low, so that the casing lead and the tap switch are exposed to the air. The insulation level will be greatly reduced, so it will cause the breakdown discharge.
Related links：
Oil-immersed Transformer (S11,13; SZ11,13; SFZ11,13)
