How to judge the fault from the sound of dry-type transformer
1. The sound when phase is missing
When a phase loss occurs in the transformer, if the second phase is blocked, there will still be no sound when the second phase is supplied, and there will be a sound only when the third phase is supplied. If the third phase is blocked, the sound will not change, just like the two-phase condition. There are generally three reasons for phase loss:
①The power supply is missing one phase;
②The high-voltage fuse of the transformer has blown one phase;
③ Due to careless transportation of the transformer and the thin high-voltage lead, the transformer was vibrated and disconnected (but not grounded).
2. The voltage regulating tap-changer is not in place or has poor contact.
When the transformer is put into operation, if the tap changer is not in place, it will make a loud "chirp" sound, which may cause the high-voltage fuse to blow in serious cases; if the tap changer has poor contact, a slight "squeak" spark discharge sound will be produced. , once the load increases, it is possible to burn out the contacts of the tap changer. In this case, the power should be cut off and repaired in time.
3. Falling foreign objects and loosening of the threaded screw
When the core screw of the transformer clamps the iron core is loose, there are nut parts left on the iron core, or small metal objects fall into the transformer, the transformer will make a "dinging, clanging" knocking sound or a "whooshing..." blowing sound. There is also a "squeaking" sound like a magnet attracting a small gasket, but the voltage, current and temperature of the transformer are normal. This type of situation directly affects the normal operation of the transformer and requires a power outage for processing.
4. The high-voltage bushing of the transformer is dirty and cracked
When the high-voltage bushing of the transformer is dirty and the surface enamel is peeled off or cracked, surface flashover will occur, and a "hissing" or "chipping" sound will be heard, and sparks can be seen at night. ˆ
5. The core of the transformer is grounded and disconnected
When the core of the transformer is grounded and disconnected, the transformer will produce a slight discharge sound of "beeping, beeping, beeping".
6. Internal discharge
If you hear a crisp "crackling" sound when power is being transmitted, it is the discharge sound of the conductive lead passing through the air to the transformer shell; if you hear a dull "crackling" sound passing through the liquid, it means the conductor is facing the shell through the transformer oil. The sound of discharge. If the insulation distance is insufficient, the power should be cut off to check the hoisting core, and the insulation should be strengthened or insulation partitions should be added.
7. The external circuit is disconnected or short-circuited
When the line is disconnected at the connection point of the wire or the T-connection, is connected and disconnected when the wind blows, and arc or spark occurs during contact, then the transformer will make a "chirp, chirp, chirp" sound like a frog; when the voltage is low When the line is grounded or a short-circuit accident occurs, the transformer will make a "booming" sound; if the short-circuit point is close, the transformer will make a roaring sound like a tiger. ˆ
8. Transformer overload
When the transformer is severely overloaded, it will emit a low "buzzing" sound like a heavily loaded aircraft.
9. The voltage is too high
When the power supply voltage is too high, the transformer will be over-excited and the sound will become louder and sharper.
10. Short circuit in winding
When the transformer winding is burned out due to an inter-layer or inter-turn short circuit, the transformer will make a "gurgling" sound of boiling water.