What It Assesses
Dielectric losses under the defined test conditions.
Tan Delta measures dielectric losses in the oil. Increased losses may be associated with moisture, contamination or ageing by-products. It is most useful when considered with resistivity, moisture and historical trends.
Dielectric losses under the defined test conditions.
Tan Delta measures dielectric losses and is useful with moisture, resistivity and historical trends.
Review the stated method, units, sample condition, companion tests and historical trend before making a condition judgement.
No single test result should be used as a universal diagnosis. Final maintenance, operational and safety decisions remain with the asset owner and qualified engineering personnel.
Provide the transformer details, sample count, reason for testing and any previous report reference so the exact scope and sample volume can be confirmed.