Dry-type transformers are skilled in the maintenance and maintenance of dry-type transformers. For dry-type transformers, various basic methods and methods of maintenance and maintenance of dry-type transformers must be continuously enhanced. Common maintenance of dry-type transformers The basic steps of maintenance and repair must be continuously improved, and the basic methods and methods to achieve dry-type transformer maintenance and maintenance must be carried out. For the manufacturer, it is necessary to have specialized technical personnel to operate, as well as frequency and time. Operation, therefore, the basic method of dry-type transformer maintenance and maintenance is as follows:

When repairing and maintaining dry-type transformers, check whether the grounding of the dry-type transformer is good, whether the ground wire is corroded, and should be replaced if the corrosion is serious; tighten the lead terminals, pins, grounding screws, and connection bus screws; be sure to clean and dry during maintenance. Check whether the fire-fighting facilities and ventilation system are in good condition for dust around the transformer and on its accessories. Is there any problem with the cooling fan and the temperature controller? Disconnect the grounding switch on the high-voltage side, lock the high-voltage switch section, and measure the insulation resistance with a 2500V shaker. Compared with the measured value of the dry-type transformer before leaving the factory, the insulation resistance should not be lower than 70% of the original data when leaving the factory. Whether there are any tools left in the transformer room and the dry-type transformer, evacuate the site, and the electrician shall make a detailed record of the maintenance and trial operation of the dry-type transformer.

Precautions for maintenance of dry-type transformers:

1. Prevent the dry-type transformer from overloading operation: If it is overloaded for a long time, it will cause the coil to heat up and cause the insulation to gradually age. When the dry-type transformer is in operation, its coil and iron core produce copper loss and iron loss, and these losses become heat energy, which causes the temperature of the iron core and coil of the dry-type transformer to rise. If the temperature exceeds the allowable value for a long time, the insulation will gradually lose its mechanical elasticity and cause the insulation to age.

2. Check the breather and refuel it regularly if it is short of oil. Monitoring the upper oil temperature during dry-type transformer operation cannot guarantee the safe operation of the dry-type transformer. It is also necessary to monitor the temperature difference between the upper oil temperature and the cooling air-that is, the temperature rise. The difference between the temperature of the dry-type transformer and the temperature of the surrounding air is called the temperature rise of the dry-type transformer

3. Reasonable capacity During normal operation, the electrical load of the dry-type transformer should be about 75-90% of the rated capacity of the dry-type transformer.

4. Overload Overload is divided into two situations: normal overload and accident overload. Normal overload is caused by the increase in user power consumption under normal power supply conditions. It will increase the temperature of the dry-type transformer, leading to accelerated aging of the dry-type transformer's insulation and reduced service life. Therefore, under normal circumstances, overload operation is not allowed. In special circumstances, dry-type transformers can be overloaded for a short period of time, but they must not exceed 30% of the rated load in winter and 15% of the rated load in summer. In addition, the overload capacity of the dry-type transformer should be determined according to the temperature rise of the dry-type transformer and the manufacturer's regulations. When an accident occurs in the power system or user substation, in order to ensure continuous power supply to important equipment, the dry-type transformer is allowed to operate under short-term overload, that is, accident overload. When the accident overload occurs, the temperature of the coil will exceed the allowable value, so the insulation In terms of aging faster than normal conditions. However, there are few chances of accidental overload. In general, dry-type transformers are under-load operation, so short-term overload can damage the insulation of dry-type transformers. The time and multiple of the accident overload shall be implemented according to the manufacturer's regulations.