Furan analysis: a window into transformer insulation health
When cellulose insulation in a transformer degrades, it produces furanic compounds that dissolve in the oil. Measuring these compounds gives us a critical insight into the condition of the cellulose insulation without invasive sampling.
Here’s what each compound tells us:
5-Hydroxymethyl-2-furfural (5HM2F): Often linked to wet insulation or acidic conditions; can convert into other furans, especially 2FAL.
2-Furaldehyde (2FAL): The primary marker of paper aging and cellulose decomposition. Stable, and the best correlator with Degree of Polymerization (DP), an indicator of life expectancy..
2-Furfuryl Alcohol (2FOL): A secondary byproduct of 2FAL degradation, useful for interpreting historical insulation changes.
2-Acetylfuran (2ACF): Indicates severe thermal stress or localized overheating of cellulose insulation.
5-Methyl-2-furaldehyde (5M2F): Points to localized overheating, often suggesting fault conditions beyond generalized aging.
Why it matters:
– Furans form at lower temperatures than CO/CO₂, making them early indicators of degradation.
– Their concentrations correlate with insulation strength and aging.
– Combined with Dissolved Gas Analysis (DGA), furan testing supports a comprehensive view of transformer health and life expectancy.
At MVA, we believe diagnostics like furan testing are the key to identifying problems early, extending the transformer life and preventing unplanned outages.