Moisture and condensation in dry-type transformers
In the severe cold and humid air temperature and the conditions of the area, if the dry-type transformer suddenly stops running, it is necessary to check whether there are abnormal wet and cold conditions. If so, be sure to remove the frost on the surface to avoid thermal breakdown of the insulation. To ensure that everything does not endanger the insulation windings of the transformer. If the insulation resistance is not less than 2MΩ / 1000V, the transformer can run normally. The heat generated by the operation of the transformer will return to all normal insulation resistors. Under all normal practical operating standards. The temperature of the transformer itself is higher than its surrounding operating temperature, so it is not easy to reduce the insulation resistor.
Dry-type transformers are often damaged during the entire process of application. There are many reasons for dry-type transformers to burn out. Therefore, when your dry-type transformers are burned out, pay attention to analysis. If there is burning out, how to carry out a better development to grasp the burning out of dry-type transformers, so that the dry-type transformers will be more protective and the characteristics will be more improved. What are the reasons for the dry-type transformer burnout? Let's analyze it carefully with the net editor:
1. The end of the dry-type transformer is damaged, and the other wire cakes are not damaged. The dry-type transformer end insulation is usually a weaker area. The two pie cakes in front of the end of the 10kV class electromagnetic coil should be insulated. . Let ’s see if the design scheme is useful. ZTELEC is a well-known manufacturer of rectifier dry-type transformers. It should not be easy to have any problems.
2. If production and operation are all normal, then the repair of the power grid was an induced reason. Turning off the power to the dry-type transformer and connecting it to the power supply caused the actual operation to be overvoltage ?
3. It is very likely (but it is very likely) that the over-voltage caused by the actual operation will cause the end insulation to thermally break down, resulting in a short-circuit fault between turns or pie, and the end of the electromagnetic coil will be damaged.
4. The general standard for the pressure test of dry transformers is slightly lower than that of oil transformers because it is operated indoors. Some electric power bureaus also stipulate that dry change and oil change have the same pressure test level. 10kV dry transformer, DC withstand voltage test is 28kV, oil transformer is 35kV. Look at the factory nameplate is 28kV. See the factory nameplate. This dry-type transformer is a dry-type transformer in the plateau, and the insulation should be improved.