What type of transformer oil is recommended for ABB transformers?

ABB transformers typically require insulating oil that meets the transformer’s nameplate or manual specification, commonly an IEC compliant mineral oil or approved alternative fluids such as esters for specific designs. The recommended oil type depends on bushing design, sealing system, cooling class, and temperature limits. Utilities should follow ABB documentation and ensure the oil meets required standards and compatibility constraints, verified by certificates and acceptance testing.