What are the specifications for transformer insulating oil?

Transformer insulating oil specifications typically include properties such as dielectric strength, viscosity, moisture content, acidity, flash point, and interfacial tension. Dielectric strength should be high to prevent electrical breakdown, generally exceeding 30 kV per cm. Viscosity is crucial for proper circulation and should range around 10-20 cSt at 40°C. Moisture content must be minimal, usually less than 10 ppm, while acidity (neutralization number) should be below 0.1 mg KOH/g to prevent corrosion. The flash point generally needs to be above 140°C to ensure safety, and interfacial tension should stay around 30-45 mN/m to identify contamination. Adhering to these transformer insulating oil specifications is essential for optimal performance and longevity of transformer systems.