In view of the dry-type transformer in outdoor work, especially in rainy days, there is no moisture-proof countermeasures for the dry-type transformer in outdoor work. The precipitation is very easy to enter the interior of the dry-type transformer, resulting in common faults of the dry-type transformer. So how do you know that there is water in dry-type transformer? How to distinguish the inspection method and solution of water inflow in dry-type transformer:
Inspection method: dry type transformer oil shall be sampled for full moisture test, which shall be less than 50mg / L. The dielectric loss and breakdown field strength test can be checked.
Solution: many oil-water separators must exceed the target value, and rarely can operate, but continuous detection is required.
Specific steps: after the dry-type transformer is filled with oil, it is still for two days, and then release appropriate oil from the bottom (the capacity of the bottom of dry-type transformer body is 100 mm high), and conduct moisture test and chromatography on the released oil. If the oil meets the standard, it can be operated with full oil. If not, put some more and do the experiment until it reaches the standard. Why? Because the density of water is higher than that of oil, the water will sink to the bottom and replace the wet oil.
It is clear that after the dry-type transformer enters the water, it should:
1. Stop operation as soon as possible;
2. Drain the transformer oil completely;
3. Try to air dry the dry-type transformer, very high voltage winding resistance;
4. The new transformer oil can only be filled after it is completely dry;
5. AC withstand voltage test of insulation layer with high voltage grounding megger can only be put into operation after reaching the standard.
The above is about the resolution of dry-type transformer water inflow, dry-type transformer water into this kind of situation will produce dry-type transformer short-circuit fault, resulting in dry-type transformer is burned, fire accidents, can not carry out all normal power consumption, so it is necessary to deal with it immediately.
Service