Transformer oil, as an essential insulating and cooling medium in transformers, plays a crucial role in the normal operation of transformers. To ensure the performance and longevity of transformers, different types of transformer oils have been developed to meet various application needs.
Ⅰ. What are the Classifications of Transformer Oil?
1、Mineral Oil:
Mineral oil is the most common type of transformer oil. Refined from crude oil, it has good insulation and thermal conductivity properties. Based on different processing techniques, mineral oil can be divided into the following types:
– Paraffin-based Oil: This oil has a high wax content, resulting in poorer fluidity. However, its oxidation stability is good, making it suitable for high-temperature environments.
– Naphthenic Oil: This oil has low wax content, providing better low-temperature fluidity, though its oxidation stability is slightly inferior to paraffin-based oil. It is commonly used in medium and low-temperature environments.
– Mixed-base Oil: This oil is a blend of paraffin-based oil and naphthenic oil in certain proportions. It retains the high-temperature stability of paraffin-based oil and the low-temperature fluidity of naphthenic oil, making it widely applicable.
2、Synthetic Oil:
Synthetic oil, prepared by chemical synthesis methods, has better high-temperature resistance and oxidation stability but is relatively more expensive. Common synthetic oils include:
– Silicone Oil: It has excellent thermal and chemical stability, making it suitable for high-temperature and special environments, but it is more costly.
– Ester Oil: It is biodegradable and environmentally friendly, suitable for applications with high environmental requirements.
3、Vegetable Oil:
Vegetable oil is a new type of environmentally friendly transformer oil, mainly made from natural vegetable oils. It has good biodegradability and environmental performance, suitable for places requiring high environmental friendliness. The downside is its higher cost, and its long-term stability needs further verification.
4、Specialty Oils:
Some specialty oils have been developed to meet specific application needs, such as:
– Fire-resistant Oil: Mainly used in places with high fire safety requirements, such as high-rise buildings and subways, due to its good fire resistance.
– High-voltage Oil: Suitable for high-voltage transformers, offering excellent electrical insulation and pressure resistance.
5、Type 1 and Type 2 Oils:
Another classification method for transformer oils is Type 1 and Type 2、Type 1 oil does not contain antioxidants, while Type 2 oil contains oxidation inhibitors.
Ⅱ. What is the Difference Between Type 1 and Type 2 Transformer Oil?
Type 1 and Type 2 transformer oils are two common classifications, differing in performance and application range.
1、Type 1 Transformer Oil: Also known as standard transformer oil, it is mainly used in general power transformers and distribution equipment. Its characteristics include:
– Good insulation performance: Effectively prevents current flow within the transformer, ensuring normal operation.
– Excellent thermal conductivity: Quickly dissipates heat generated during transformer operation, preventing equipment overheating.
– Lower cost: Relatively simple production process, suitable for most conventional transformers. Suitable scenarios: General power transformers and distribution equipment, used in environments with no high requirements.
2、Type 2 Transformer Oil: Also known as antioxidant transformer oil, it enhances oxidation resistance on the basis of Type 1 oil. Its characteristics include:
– Excellent oxidation resistance: Less prone to oxidation at high temperatures, extending service life and reducing maintenance frequency.
– Higher thermal stability: Maintains stable physical and chemical properties in high-temperature environments, less likely to produce deposits.
– Better electrical insulation: Maintains good electrical insulation in high-temperature and high-pressure environments. Suitable scenarios: High-voltage transformers, large power transformers, and transformers operating in high-temperature environments.
In summary, Type 1 oil does not contain antioxidants, while Type 2 oil contains oxidation inhibitors, which help delay the aging process of the transformer oil. Considering oxidation, it is more recommended to use Type 2 transformer oil to extend the service life of the transformer and maintain its stable performance.
Yueqing Yirui Electric Co Ltd (SUNPOLE) is committed to providing you with outstanding transformer products, especially our high-quality transformer oil. SUNPOLE transformer oil is refined using the most advanced technology, featuring excellent insulation performance and superior cooling effect, ensuring your transformer maintains stable and efficient operation under various conditions. Whether facing high temperatures, humidity, or other harsh environments, SUNPOLE transformer oil offers lasting protection and reliability. Choose SUNPOLE transformers for peace of mind and trust, providing the most robust guarantee for your power equipment.
Ⅲ. How Often Should Transformer Oil be Tested?
To ensure the normal operation and prolong the service life of transformers, regularly testing the transformer oil quality is very necessary.
1、New Transformers
For new transformers, perform the first oil quality test within three months of commissioning to ensure there is no contamination or damage to the oil during transportation and installation. Conduct another test within the first six months of operation to monitor initial oil quality changes.
2、Normal Operation Transformers
During normal operation, generally test the transformer oil annually. This frequency applies to transformers with relatively stable loads and good environmental conditions. For transformers operating under conditions with frequent load changes or harsh environments (e.g., high temperature, high humidity, severely polluted areas), test every six months.
2、Aging Transformers
For transformers in operation for 5 years or more, increase the inspection frequency. Additionally, conduct a furan test every two years. The furan test evaluates the aging degree of the transformer’s internal solid insulation materials (usually paper or cardboard) by detecting the furan compounds in the transformer oil. This test is crucial for monitoring the transformer’s condition and evaluating its service life.
SUNPOLE provides professional transformer oil and insulation oil analysis and testing services. SUNPOLE has extensive industry experience in oil sampling, oil testing, and data interpretation. If the analysis results show poor oil quality, SUNPOLE can also provide necessary oil treatment services to restore the oil to its best condition. The specific transformer oil testing methods vary by region. For more information, please send an email to our mailbox.
Ⅳ. How to Take an Oil Sample from a Transformer?
Sampling oil from a transformer is a professional skill typically performed by power system maintenance personnel or technical professionals. To ensure the accuracy and representativeness of the sample, it must be done according to standard procedures. Here are the detailed steps and precautions for sampling oil from a transformer.
1、Required Tools and Materials
– Sampling Bottles: Clean, dry, and well-sealed sampling bottles, usually made of glass or special plastic.
– Sampling Valve: A valve specifically used for sampling on the transformer.
– Clean Towels or Cloths: Used to wipe the sampling valve and surrounding areas.
– Gloves: To prevent direct contact with transformer oil.
– Labels: To mark the sampling time, location, and other relevant information.
– Oil Handling Equipment: Such as necessary filters, funnels, etc.
2、Steps for Sampling Oil:
Step 1: Preparation:
– Confirm Sampling Location: Generally, the sampling is done from the bottom valve of the transformer, as the oil sample here is more representative.
– Clean the Sampling Valve: Wipe the sampling valve and surrounding areas with a clean towel or cloth to ensure there are no contaminants.
Step 2: Initial Oil Discharge:
– Open the sampling valve and discharge a small amount of oil (about 200-500 milliliters) into a waste oil container to clear any impurities and sediment from the sampling pipeline.
Step 3: Formal Sampling:
– Use a clean sampling bottle to collect the oil. Slowly open the sampling valve, ensuring the oil flows into the sampling bottle at an even rate to avoid air bubbles.
– The sampling amount is generally 500 milliliters to 1 liter, depending on the testing requirements.
Step 4: Post-Sampling Handling:
– After sampling, close the sampling valve to ensure no oil leaks and clean the valve and surrounding areas again.
– Immediately seal the sampling bottle to prevent contamination.
– Label the sample with the sampling date, time, transformer number, sampling location, and other necessary information.
Step 5: Send for Testing:
– Ensure the sampling bottle is well-sealed to prevent leaks and contamination, and promptly send it to a qualified testing institution for analysis.
Oil sampling is a process that requires professional skills and safety precautions. Incorrect sampling methods can affect the accuracy of the test results and even lead to safety incidents. Therefore, it is recommended that experienced professionals perform the operation.
