1. Temperature control system

　　The safe operation and service life of dry-type transformers depend largely on the safety and reliability of transformer windings. The winding temperature exceeds the insulation tolerance temperature, and the insulation is damaged, which is one of the main reasons for the dry-type transformer to failure to work normally. Therefore, it is very important to monitor the operating temperature of the transformer and its alarm control.

　　2. Shell

　　According to the characteristics of the use environment and protection requirements, different shells can be selected for dry-type transformers. Usually, IP20 protective shell is used to prevent solid foreign objects with a diameter greater than 12mm and small animals such as rats, snakes, cats, and sparrows from entering and causing vicious failures such as short-circuit power failures. If the transformer must be installed outdoors, an IP23 protective case can be selected. In addition to the above-mentioned IP20 protection function, it can also prevent water from dripping within an angle of 60° from the vertical line. However, the IP23 shell will reduce the cooling capacity of the transformer, and attention should be paid to the reduction of its operating capacity when selecting it.

　　3. Cooling method

　　Dry-type transformer cooling methods are divided into natural air cooling and forced air cooling. When naturally air-cooled, the transformer can operate continuously for a long time at the rated capacity. When forced air cooling, the output capacity of the transformer can be increased by 50%, which is suitable for intermittent overload operation or emergency accident overload operation. Due to the large increase in load loss and impedance voltage during overload, it is in a non-economic operating state, so it should not be operated continuously for a long time.

　　4. Overload capacity

　　The overload capacity of a dry-type transformer is related to the ambient temperature, the load before overload, the insulation and heat dissipation of the transformer, and the heating time constant.