Jessica Mitchell

A transformer dielectric strength test is conducted using a transformer oil bdv tester, which is designed to assess the breakdown voltage of insulating fluids in transformers. The process involves taking a sample of the transformer oil and placing it in a test cell, where two electrodes are immersed in the oil. The tester then applies a gradually increasing AC voltage to the electrodes until a dielectric breakdown occurs. The maximum voltage reached before the oil breaks down is recorded as the breakdown voltage, which is a critical measure of the oil’s insulating properties. It is essential to perform this test in accordance with relevant standards and conditions, such as temperature and cleanliness, to ensure accurate and reliable results. Proper calibration of the transformer oil bdv tester is also necessary for consistent outcomes.

The normal oil temperature in a transformer typically ranges between 60°C to 80°C (140°F to 176°F) during operation. However, some transformers may have slightly higher acceptable temperature limits, potentially reaching up to 95°C (203°F) under normal conditions. It’s crucial to monitor the oil temperature consistently to ensure the transformer operates efficiently and to prevent any overheating, as elevated temperatures can lead to accelerated aging of the insulating oil and components. Regular maintenance and oil analysis can help maintain the optimal conditions for the oil tank transformer, ensuring its longevity and performance.

The primary difference between a cast resin transformer and an oil transformer lies in their cooling and insulation methods:

Cast Resin Transformer: Uses solid epoxy resin for insulation. The windings are encapsulated in resin, which provides electrical insulation and protects against moisture, dust, and corrosive environments. These transformers are typically air-cooled and are often used in indoor or environmentally sensitive areas where fire risk is a concern. They require less maintenance than oil transformers and are more fire-resistant but may have lower cooling efficiency.
Oil Transformer: Uses insulating oil to both cool and insulate the internal components. The oil circulates within the transformer, dissipating heat and providing excellent insulation properties. Oil transformers are typically used in high-voltage applications and can handle larger loads due to their effective cooling capabilities. However, they require regular maintenance to monitor oil quality and prevent leaks, and there is a potential fire risk associated with the oil.
Both types of transformers have their specific advantages and are selected based on the application, environment, and specific requirements.

The oil capacity of a 2500 kVA transformer is approximately 1500 to 1800 liters, depending on the design, cooling requirements, and specifications from the manufacturer.