How To Judge The Fault From The Sound Of Dry-type Transformer

1. Noise when phase is missing

When Dry Type Transformer is phase missing, if the second phase is not connected, there is still no sound when the second phase is sent, and there is a sound when the third phase is sent; if the third phase is not connected, the sound does not change, and it is the same as when the two phases are connected. There are roughly three reasons for phase loss:

① One phase of the power supply is missing;

② One phase of the transformer high-voltage fuse is blown;

③ The transformer is transported carelessly, and the high-voltage lead is thin, causing vibration and wire breakage (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 emit a loud "chirp" sound, and in severe cases, the high-voltage fuse will be blown; if the tap changer has poor contact, it will produce a slight "squeak" spark discharge sound, and once the load increases, it may burn the contacts of the tap changer. In this case, it is necessary to shut down the power supply and repair it in time.

3. Foreign objects dropped in and the through-core screw is loose

When the through-core screw of the transformer clamping the core is loose, there are nut parts left on the core or small metal objects fall into the transformer, the transformer will emit a "ding-dong" knocking sound or a "whoosh..." blowing sound and a "squeaky" sound like a magnet sucking a small gasket, while the voltage, current and temperature of the transformer are normal. This kind of situation generally does not affect the normal operation of the transformer and can be handled when the power is off.

4. Dirty and cracked high-voltage bushing of the transformer

When the high-voltage bushing of the transformer is dirty, the surface enamel falls off or cracks, surface flashover will occur, and a "hissing" or "chi chi" sound will be heard, and sparks can be seen at night. ?

5. The core grounding of the transformer is broken

When the core grounding of the transformer is broken, the transformer will produce a slight discharge sound of "beeping".

6. Internal discharge

When power is supplied, a crisp "crackling" sound is heard, which is the sound of the conductive lead discharging through the air to the transformer shell; if a dull "crackling" sound is heard through the liquid, it is the sound of the conductor discharging through the transformer oil surface to the shell. If the insulation distance is insufficient, the power should be shut down for inspection, and the insulation should be strengthened or an insulating partition should be added.

7. External line disconnection or short circuit

When the line is disconnected at the connection point or T-junction of the conductor, it is connected and disconnected when the wind blows, and arc or sparks occur when in contact. At this time, the transformer makes a "chi wa ji wa" sound like a frog; when the low-voltage line is grounded or a short circuit occurs, the transformer makes a "booming" sound; if the short circuit point is close, the transformer will make a roar like a tiger. ?

8. Transformer overload

When the transformer is seriously overloaded, it will make a low "buzzing" sound like a heavy-loaded aircraft.

9. Voltage is too high

When the power supply voltage is too high, the transformer will be overexcited, and the noise will increase and become sharper.

10. Winding short circuit

When the transformer winding is short-circuited between layers or turns and burns out, the transformer will make a "gurgling" sound like boiling water.