What standards govern transformer oil quality in utility grids?

Transformer oil quality is governed by international standards such as IEC 60296, IEEE C57.106, and ASTM D3487. These standards define requirements for new and in-service oils, including dielectric strength, acidity, moisture limits, oxidation stability, and contaminant levels. Utilities rely on these standards to ensure compatibility, safety, and consistent performance across grid assets while meeting regulatory and environmental requirements.