Maintenance Methods And Steps Of Dry-type Transformers:

1. Before the maintenance of the dry-type transformer, put in the backup transformer, disconnect the low-voltage side circuit breaker of the dry-type transformer for maintenance, remove the operating insurance that controls the power supply, and hang the "No closing" sign at the switch handle.
2. Disconnect the circuit breaker on the high-voltage side of the dry-type transformer, close the grounding switch, fully discharge the dry-type transformer, lock the high-voltage cabinet, and hang the "No Closing" sign at the switch handle.
3. The maintenance of dry-type transformers, first clean the insulator and shell, secondly check whether the shell, gasket and porcelain casing are ruptured, discharge marks or whether the rubber pad is aging, whether the cable and busbar are deformed, and the broken should be replaced.
4. Check whether the contact surface of the busbar is kept clean, and the contact surface should be removed from the oxide layer and coated with electric compound grease.
5. Check whether the grounding of the dry-type transformer is good, whether the ground wire is corroded, and the corrosion should be replaced if the corrosion is serious.
6. Tighten the lead terminal, pin, grounding screw, connecting busbar screw, if there is loose, remove the screw, or file the contact surface with a fine flat file, or replace the spring washer and screw until the contact is good.
7. Clean the dust around the dry-type transformer and accessories, and check whether the fire fighting facilities and ventilation system are good.
8. Disconnect the grounding switch on the high-voltage side, lock the high-voltage switch joint, and use a 2500V shake meter to measure the insulation resistance. Compared with the measured value of the transformer before leaving the factory, the insulation resistance should not be less than 70% of the original data at the time of delivery, and if it is unqualified, it should be reported to the company in time.
9. Close the grounding switch on the high voltage side again and let the dry-type transformer be discharged.
10. Check whether there are any tools left in the dry-type transformer chamber and dry-type transformer, and evacuate the site.
11. Connect the low-voltage side circuit breaker to control the power operation insurance, and re-hang the "no closing" sign plate to prevent the reverse transmission of power to the transformer.