What does ethane presence indicate in transformer oil?

The presence of ethane in transformer oil typically indicates the early stages of thermal degradation of the insulation materials within the transformer. Ethane is a byproduct of the breakdown of hydrocarbons, suggesting that the oil is undergoing thermal stress or that the insulation is deteriorating. Monitoring ethane levels can help in assessing the condition of the transformer and in predicting potential failures, allowing for timely maintenance actions.