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Transformer inspection
1) Daily inspection of transformer
(i) Oil temperature and oil level should be normal, without oil seepage or leakage;
(ii) Bushing should be free of cracks, oil stains, or discharge marks;
(ii) Sound should be normal;
(iv) Cooler should feel similar to the touch, fan should operate normally, oil flow and gas relay should work normally;
(v) Desiccant should be intact, adsorbent should be dry;
(vi) Lead connectors, cables, and busbars should show no signs of heating;
(vii) Pressure release device, safety airway and explosion-proof membrane should be intact;
(viii) There should be no gas in the gas relay;
(ix) All control boxes and secondary control boxes should be tightly closed and free of moisture;
(x) The doors, windows and lighting of the transformer room should be intact, the room should not leak, and the temperature should be normal
(2) The transformer should be inspected regularly, and the following inspection contents should be added:
(i) There is no abnormal heating of the shell and the edge of the box;
(ii) All parts are well grounded;
(iii) Various signs should be complete and obvious;
(iv) All protective devices should be safe and in good condition;
(v) The temperature gauge should indicate normally;
(vi) Fire-fighting facilities should be complete and intact;
(vii) The oil storage tank and oil drainage facilities should be kept in good condition;
3) Special inspections should be carried out on the transformer in the following cases, and the number of inspections should be increased:
(1) New equipment or overhauled transformers within 72 hours of commissioning;
(2) When there are serious defects;
(3) Sudden weather changes (strong winds, heavy fog, heavy snow and hail, cold waves, etc.);
(4) Thunderstorm season, especially after thunderstorms;
(5) When the transformer is running under emergency load.
(6) Transformers put into operation for the first time after overhaul must be inspected every 2 hours in the first 8 hours after being put into operation; for transformers running under overload, inspections should be strengthened.
3. Operation and shutdown of transformers
1) Before operation, the duty officer shall confirm that the transformer and its protective devices are in good condition; there are no foreign objects on the outside, the temporary grounding wire has been removed, the tap changer is in the correct position, and the valves are in the correct position.
2) The charging of the transformer should be operated by a circuit breaker on the power supply side with a protective device; when shutting down, the load side should be shut down first, and then the power supply side.
3) For newly put into use transformers, the impact closing number should be 3 to 5 times; for transformers after replacing the winding, the impact closing number is 3 times.
