Dry type transformer can be continuously operated with a uniform temperature rise of 150 K at the difference between an ambient temperature of approximately 40°C and a sought-after 30°C. Under higher environmental conditions, many local regulations must use 50°C as the ambient temperature. Therefore, a temperature rise of 140°C and a sought-after difference of 30°C can be used in these systems. Because of the high temperature resistance of the insulation system and the choice of cooling space compared with the low temperature additional transformer of the same capacity, it is smaller in weight and more compact. On the bottom line, each time the transformer specifications of this kind of heat-resistant grade are improved, about 10% to 15% can be selected. For example, 500 kVA transformer of C class (220°C) can be 15% smaller than a H class (180°C) transformer, and 30% smaller than a F class (155°C) transformer.
Generally, the insulation grades of three phase medium voltage dry-type transformers are divided into F grade, H grade (180℃) to C grade (220℃).
When users plan to purchase transformers, they will choose suppliers who can provide them with the necessary and best solutions. This generally includes a reliable transformer with the required electrical performance specifications, environmental and fire protection ratings, supplied at an excellent value. The user generally does not delineate the insulation system, because the insulation system is regarded as a complete part of the equipment, and the manufacturer will use it to produce the best products necessary for the user. However, if users want to get the most appropriate transformer they need, they should know all the options available, their technical benefits, and the benefits and shortcomings of these solutions during operation.
In many environments, large specifications can be obtained and certain benefits can be obtained by selecting the weight. The commonly used solution is to receive C 220 ℃ insulation system for transformers operating under F or H. This option allows users to have very compact equipment, which can provide great mobility, including higher overload skills, lower energy consumption, and many practical benefits brought across the country. . This dry-type transformer is particularly advantageous in areas with high load addition and extreme environmental and climatic conditions.
Varelen Electric Co., Ltd