Assessing Transformer Paper Insulation Health by Detecting Aging Markers in Oil.
Furan Analysis of transformer oil is performed to assess the extent of degradation of the paper (cellulose) insulation within the transformer. As the paper ages or undergoes thermal and oxidative stress, it breaks down and releases furanic compounds into the oil. Measuring these compounds provides a reliable, non-intrusive indicator of insulation health, allowing for early detection of aging or faults, timely maintenance planning, and prevention of transformer failure.
Furan Analysis is a test that detects and measures furanic compounds in transformer oil to assess the degradation of paper insulation inside the transformer.
It is important because furan compounds are reliable markers of paper insulation aging—high levels can warn of serious insulation deterioration and impending transformer failure.ial.
Typically, five furanic derivatives are detected, but 2-furfural (2-FAL) is most commonly monitored, as it is the most stable and abundant by-product of cellulose breakdown.
Furan Analysis is recommended every two years for transformers in service for five years or more, or more frequently if accelerated aging or fault conditions are suspected.
Low furan levels (<100 ppb) suggest healthy insulation; intermediate levels (100–250 ppb) indicate early aging; high levels (>250/2,500 ppb) point to substantial degradation and increased failure risk.
Furan Analysis is non-invasive, provides early warning of paper insulation breakdown, supports predictive maintenance, and helps extend transformer service life.
Can Furan Analysis predict the remaining life of a transformer?
While not precise alone, furan analysis trends—combined with other diagnostics such as Degree of Polymerization (DP) tests—help estimate remaining insulation life and guide maintenance planning.