Transformer oil: The Core Guarantee for the Efficient and Stable Operation of Power Equipment

Product Series and Characteristics

Synthetic Transformer Oil

• Tergarf1 (ISO viscosity grade 25): Formulated with hydro-treated naphtha base oils and oxidation inhibitor, it effectively controls the formation of sludge and deposits, significantly extending the service life. It has a high dielectric strength and low power factor, providing outstanding insulating properties, which can effectively prevent arc and corona discharge and ensure the electrical insulation safety inside the transformer. Specially developed for oil-immersed transformers, capacitors, tap changers, and circuit breakers, it fully complies with the requirements of ANSI/ASTM D3487 – 09. Its kinematic viscosity at 40°C is 9.652 mm²/S, pour point is -25°C, and flash point is 140°C. It is suitable for power equipment with extremely high requirements for insulating performance, such as the main transformers in large power plants and the key transformers in ultra-high voltage transmission systems, ensuring the safe and efficient transmission of electricity in high-voltage environments.
• Tergarf2 (ISO Viscosity Grade 45): Also based on an advanced formula, it has excellent oxidation resistance, which can effectively resist oxidation and delay oil aging. It performs outstandingly in low-temperature environments with a pour point as low as -45°C, ensuring that the transformer oil can still maintain good fluidity in cold regions or low-temperature working conditions and normally perform insulation and heat dissipation functions. Its high insulating performance and stable chemical properties make it widely used in various oil-immersed power equipment, including distribution transformers and industrial transformers. Its kinematic viscosity at 40°C is 9.606 mm²/S, and flash point is 135°C. It can meet the needs of transformers of different voltage levels and operating environments, providing reliable support for the stable operation of the power system.

Transformer Oil Selection Guide

Selection Based on Transformer Type

• Power Transformer: Power transformers are responsible for voltage transformation and power transmission and usually operate under high-voltage and large-capacity working conditions. For such transformers, transformer oil with excellent insulating performance, strong oxidation resistance, and good heat dissipation performance should be preferred. Tergarf1 synthetic transformer oil is an ideal choice. Its high dielectric strength and excellent oxidation resistance can ensure long-term stable operation in a high-voltage environment, effectively prevent insulation aging and breakdown, and ensure the safety and reliability of power transmission. For example, in a large power plant, using Tergarf1 transformer oil in the main transformer can maintain stable electrical performance under high-load operation conditions, reduce maintenance times, and extend the service life.
• Distribution Transformer: Distribution transformers are mainly used for power distribution, with relatively low voltage levels but are widely distributed and in large numbers. When selecting oil for distribution transformers, comprehensive consideration should be given to cost, heat dissipation performance, and operational stability. Tergarf2 synthetic transformer oil, due to its good low-temperature fluidity and moderate viscosity, can quickly dissipate heat at different ambient temperatures, ensuring the normal operation of the transformer. At the same time, its stable performance and relatively low cost make it very suitable for distribution transformers in urban power distribution networks, such as transformers in community substations and Factory power distribution rooms, ensuring reliable power supply for surrounding users.
• Special Transformers (such as Rectifier Transformers, Electric Furnace Transformers, etc.): Special transformers have specific requirements for transformer oil due to their special working principles and application scenarios. Rectifier transformers may require transformer oil to have good anti-harmonic ability to deal with the harmonic interference generated during the rectification process; electric furnace transformers require transformer oil to maintain stable performance in a high-temperature environment. In response to these special needs, we can provide customized transformer oil solutions. According to the specific working conditions and technical requirements of special transformers, we can formulate the most suitable transformer oil products to ensure the efficient and safe operation of special transformers under special working conditions.

Consideration of Voltage Level Factors

• High Voltage (110 kV and above): High-voltage transformers have extremely high requirements for insulating performance and need to use transformer oil with high insulating strength, extremely low dielectric loss, and excellent oxidation resistance. Tergarf1 synthetic transformer oil performs outstandingly in this regard. Its high insulating strength can withstand the long-term action of high-voltage electric fields, effectively prevent insulation breakdown; the extremely low dielectric loss factor can reduce energy loss inside the transformer and improve power transmission efficiency; and the excellent oxidation resistance ensures that the transformer oil maintains good electrical and chemical properties during long-term operation, reducing maintenance and replacement frequencies and ensuring the stable operation of the high-voltage power system.
• Medium Voltage (35 kV – 110 kV): Medium-voltage transformer oil should focus on heat dissipation performance and economy while ensuring insulating performance. The moderate viscosity of Tergarf2 synthetic transformer oil helps to form a good convective circulation inside the transformer, effectively taking away the heat generated during operation and preventing the transformer from overheating. At the same time, its reasonable cost control makes it a high-quality choice for medium-voltage transformers. It can not only meet the operating requirements of medium-voltage power equipment but also reduce operating costs to a certain extent and improve economic benefits.
• Low Voltage (below 35 kV): Low-voltage transformer oil focuses more on heat dissipation performance and cost-effectiveness. Selecting transformer oil with good thermal conductivity and lower cost can improve the operating efficiency of the transformer and reduce energy consumption. We provide a variety of economical and reliable low-voltage transformer oil products. These products can meet the heat dissipation needs of transformers in low-voltage distribution systems, ensure that the transformers operate within the normal working temperature range, extend the service life of the equipment, and save costs for users.

Combination with Operating Environment Characteristics

• Outdoor Environment: Outdoor transformers face complex and changeable climatic conditions, such as large temperature variations, strong ultraviolet radiation, and fluctuating humidity. Therefore, the transformer oil needs to have excellent weather resistance, oxidation resistance, and low-temperature fluidity. Both Tergarf1 and Tergarf2 synthetic transformer oils are added with special additives, which can effectively resist the damage of ultraviolet rays to the oil quality, delay the oxidation process, and maintain good fluidity in low-temperature environments, ensuring the stable operation of the transformer in harsh outdoor conditions and ensuring the continuity of power supply. For example, in substations in mountainous or remote areas, using our transformer oil in outdoor transformers can adapt to the harsh natural environment and reduce the risk of failures caused by environmental factors.
• Indoor Environment: The operating environment of indoor transformers is relatively stable, but attention still needs to be paid to heat dissipation and long-term stability. Selecting transformer oil with good heat dissipation performance and anti-aging performance, such as Tergarf2 synthetic transformer oil, can ensure the long-term stable operation of the transformer indoors. Its stable chemical properties and good heat dissipation ability help maintain the temperature balance inside the transformer, reduce failures caused by oil quality deterioration, and provide reliable power support for indoor electrical equipment.
• Humid Environment: In a humid environment, moisture is prone to enter the transformer oil, affecting its insulating performance. At this time, transformer oil with excellent anti-emulsification performance should be selected, which can quickly separate the moisture mixed in the oil and maintain stable insulating performance. Our transformer oil products are specially formulated and have excellent anti-emulsification ability in humid environments, ensuring the safe operation of the transformer in humid environments (such as substations near rivers, seas, or in humid areas), effectively preventing insulation failures caused by moisture.
• High-Temperature Environment (such as near heat sources or in high-temperature areas): For transformers operating in a high-temperature environment, the transformer oil must have good thermal stability and heat dissipation performance. Our high-temperature transformer oil has a high flash point and boiling point, can maintain stable performance at high temperatures, effectively dissipate heat, and prevent the transformer from overheating and being damaged. For example, in transformers in steel mills, smelters, and other high-temperature environments, using our high-temperature transformer oil can ensure the normal operation of the transformer under harsh high-temperature conditions and ensure the continuity and stability of the production process.

Key Points for Transformer Oil Use and Maintenance

Usage Points

• Storage: Transformer oil should be stored in a dedicated warehouse that is dry, cool, and well-ventilated, strictly avoiding direct sunlight and high-temperature environments to prevent the oil from oxidizing and deteriorating. The storage container must be tightly sealed to prevent the entry of moisture, impurities, and air. Different brands, models, and batches of transformer oil should be stored separately and clearly labeled to prevent confusion. During storage, the appearance, color, and transparency of the oil should be regularly checked. If any abnormality is found, such as darkening of the color, turbidity, or precipitation, the oil quality should be tested in a timely manner.
• Filling: Before filling the transformer oil, it is essential to ensure that the inside of the transformer is clean without impurities, moisture, and oil stains. Use special filling equipment and tools and strictly follow the oil level and filling amount specified by the transformer Manufacturer to avoid overfilling or underfilling. The filling process should be slow and steady to prevent the generation of bubbles, ensuring that the transformer oil can evenly and fully fill all the spaces inside the transformer and form a good insulating and heat dissipation medium. After filling, let the transformer stand for a while to allow the bubbles to escape completely, and then carefully check whether the oil level is within the normal range.

Maintenance Points

• Regular Inspection of Oil Quality: The transformer oil should be regularly and comprehensively tested, and the test items include electrical properties (such as insulation strength, dielectric loss factor, volume resistivity, etc.), physical and chemical properties (such as flash point, pour point, viscosity, acid value, moisture content, impurity content, etc.), and dissolved gas analysis in the oil (such as hydrogen, methane, ethane, ethylene, acetylene, carbon monoxide, carbon dioxide, etc.). According to the operating status, importance, and operating environment of the transformer, generally, a test should be carried out every 3 months of operation. If it is found that the oil quality indicators exceed the specified range, such as a decrease in insulation strength, an increase in acid value, or excessive moisture content, corresponding measures must be taken in a timely manner, such as oil treatment or replacement of the transformer oil.
• Oil Filtration and Dehydration Treatment: During the operation of the transformer, impurities and moisture will inevitably enter the transformer oil, affecting its performance. Regular oil filtration and dehydration treatment are key measures to maintain good performance of the transformer oil. The oil filtration equipment should be selected with appropriate precision and capacity according to the actual needs to ensure the effective removal of tiny impurities in the oil. Dehydration treatment can be carried out using advanced equipment such as vacuum oil purifiers to reduce the moisture in the oil to below the specified standard. According to the operating environment and oil quality change situation, generally, oil filtration and dehydration treatment should be carried out every 2 years or when the oil quality indicators deteriorate to restore the performance of the transformer oil and extend its service life.
• Prevention of Contamination: During the operation and maintenance of the transformer, great attention should be paid to preventing the contamination of the transformer oil. Keep the surrounding environment of the transformer clean and hygienic to prevent dust, debris, and other substances from entering the transformer tank. Regularly check the seals of the transformer. Once any damage or aging is found, they should be replaced immediately to prevent external contaminants from entering. During transformer maintenance or repair work, be sure to use clean tools and materials to avoid bringing impurities into the transformer oil. In addition, strictly prevent the mixing of different types and quality standards of transformer oil to avoid affecting the performance of the oil and endangering the safe operation of the transformer.

Actual Application Case

Packages 208L, 200L, 18L