High Voltage Transformer Maintenance

1) High voltage maintenance personnel must be licensed. Those who without a license has no right to operate.
2) When the power outages are required, the authorities should report to the competent department for approval and shall be notified to the user.
3) The insulation oil should be detected once a year in the outdoor oil immersed transformer, and the oil immersed transformer in the room should detect the insulating oil once every two years.

(2) The operation sequence of transformer switching: the load side is stopped first and the power side is stopped after. The power supply is in reverse order with the above operation.

1) Send electricity from the power side to the load side by step, if there is a fault, it is convenient to make sure the range and make timely judgment and treatmen so as to avoid the spreading of the fault.
2) In the case of multiple power supply, first stop load side can prevent the transformer from recharging. If the power side is stopped first, the fault may cause the misoperation of the protection device.

(3) Patrol inspection: According to the requirements of the substation safety operation regulation, the operators on duty should inspect 5 times of each substation apart from patrolling for inspection on turn. Inspection items are as followed.

1) Whether the temperature and sound of the transformer are normal, whether there is odor, discoloration, overheating or smoking. The upper oil temperature of the oil immersed transformer shall not exceed 95 degrees according to the regulations of the manufacturer. The allowable temperature rise is 55 degrees. In order to prevent deterioration of the transformer oil too fast, the upper oil temperature should not exceed 85 degrees.
2) Keep the porcelain bottle, casing and magnetic surfaces clean and check if there is a crack and electric discharge. The oil level of the oil immersed transformer should be in accordance with the standard, the color is normal and there is no oil leakage.
3) Whether the fan operation sound and temperature controller of the dry transformer are normal.
4) Whether the transformer is in good contact with the connection of the wiring place of high, low voltage and grounding, and whether there is a discoloration.