What are the main standards for transformer oil quality?

The main standards for transformer oil quality include ASTM D3487, which specifies the requirements for mineral insulating oils used in transformers, and IEC 60296, which outlines the specifications for unused insulating liquids for transformers and switchgear. Additionally, IEEE C57.106 provides guidelines for the maintenance and testing of transformer oils. These standards ensure the oil’s electrical, thermal, and chemical properties meet operational safety and performance criteria.