What does the presence of furan in transformer oil indicate?

The presence of furan in transformer oil indicates the degradation of the paper insulation within the transformer. Furan compounds are byproducts formed as the cellulose insulation material breaks down due to elevated temperatures and moisture over time. Monitoring furan levels in transformer oil is crucial for assessing the health of the insulation system, as increased concentrations can signal deterioration and potential failure of the transformer. Regular testing for furan in transformer oil helps in proactive maintenance and can extend the operational life of the transformer by enabling timely interventions.