The insulation level of the Dry type transformer is divided according to the heat resistance of the insulation material used.
The insulation level is mainly divided into the following levels:
1. Class A insulation
The materials of the Dry type transformer with Class A insulation are mainly impregnated organic materials such as paper and cotton yarn. The allowable working temperature is 105℃. Under normal operation, the Dry type transformer with this insulation level can work stably for a long time within this temperature range, and the insulation performance will not drop rapidly due to excessive temperature. However, once this temperature is exceeded, the life of the insulation material will be sharply shortened, which may cause transformer failure.
2. Class E insulation
The insulation material used in the Dry type transformer with Class E insulation has a slightly higher heat resistance than Class A. The allowable working temperature is 120℃. This type of transformer has certain applications in some occasions with relatively high temperature requirements. Its insulation material has been specially treated to maintain good insulation performance at higher temperatures, but it also needs to strictly control the working temperature to avoid over-temperature operation.
3. Class B insulation
The Dry type transformer with Class B insulation can work for a long time at a temperature of 130℃. The quality and performance of its insulation materials are further improved, and it can withstand higher temperatures. In some special industrial environments, such as high-temperature workshops, B-class insulation Dry type transformers may have more advantages. However, in order to ensure the safe and stable operation of the transformer, effective heat dissipation measures are still needed to prevent the temperature from being too high.
4. F-class insulation
F-class insulation is a higher level of insulation. The allowable operating temperature is 155℃. This insulation level Dry type transformer usually uses high-performance insulation materials, such as special resins. It has good heat resistance and insulation performance and can work in relatively harsh environments. In some occasions where transformer reliability is required to be high, such as important power facilities, large industrial enterprises, etc., F-class insulation Dry type transformers are widely used.
5. H-class insulation
H-class insulation Dry type transformers are currently the highest heat-resistant one. The allowable operating temperature is as high as 180℃ or above. It uses special high-temperature resistant insulation materials, which can maintain stable insulation performance in extremely high temperature environments. Transformers of this insulation level are usually used in some special high-temperature industrial fields or occasions with extremely high reliability requirements.
In short, the insulation level classification of Dry type transformer is crucial for its application in different environments. When selecting a Dry type transformer, it is necessary to reasonably select the appropriate insulation level based on factors such as the temperature requirements and reliability requirements of the actual working environment to ensure the safe, stable and efficient operation of the transformer.
