Transformer oil, as the "insulation guardian" of power equipment, plays a crucial role in equipment lifespan and power grid safety. However, industry surveys show that over 30% of transformer failures are related to improper oil selection. Many companies fall into the trap of "prioritizing low prices" and "mixing different oil types," leading to premature equipment aging, short circuits, and even fire accidents. This practical guide helps companies make accurate selections and avoid risks.
Pitfall 1: Prioritizing low prices and neglecting standard compliance. Some companies use non-standard, low-priced oil to cut costs. These oils have insufficient breakdown voltage (below 30kV, while the national standard for new oil requires ≥35kV) and excessive moisture content, easily leading to insulation breakdown. Correct approach: Prioritize checking if the product meets the GB2536 national standard, focusing on key indicators such as breakdown voltage, dielectric loss factor, and acid value. Request third-party test reports if necessary.
Pitfall 2: Randomly mixing different oil types and ignoring base oil differences. Mixing transformer oils with different base oils can damage insulation performance. There have been cases where a short circuit occurred in the coil just one hour after adding oil due to incompatibility between the new and old oil types. Correct approach: Adhere to "same type, same standard" selection. If supplementary oil is needed, conduct compatibility tests beforehand; thoroughly clean the oil tank when changing oil types.
Pitfall 3: Ignoring ambient temperature and selecting the wrong grade. Southern companies mistakenly using DB-45 oil (suitable for -45℃ severe cold regions) will increase procurement costs by 30%. Northern companies using DB-10 oil will experience cooling failure due to solidification in winter. Correct approach: Match the grade to the lowest ambient temperature. Use DB-10 for normal temperature regions, DB-25 for temperate regions, and DB-45 for severe cold regions.
Pitfall 4: Mismatching equipment grade and overlooking special scenarios. Using ordinary mineral oil in high-voltage equipment (220kV and above) can easily cause failures due to impurities. Not using high-flashpoint oil in densely populated areas poses safety hazards. Correct approach: Prioritize hydrotreated refined oil for high-voltage equipment. For environmentally sensitive applications, consider vegetable insulating oil. For fire-prone areas, use synthetic insulating oils such as silicone oil.
Industry experts warn that equipment selection should consider three core factors: equipment voltage, ambient temperature, and application requirements. Blindly following trends should be avoided. Establishing a comprehensive "selection-testing-maintenance" management system is crucial to ensure that transformer oil effectively provides protection and safeguards the stable operation of the power system.
