What does dissolved gas analysis reveal about transformer faults?

DGA reveals whether faults are thermal, electrical, or a mix. Elevated ethylene can suggest high temperature overheating, acetylene is often associated with arcing, and hydrogen can be linked to partial discharge or low energy faults. Carbon monoxide and dioxide indicate paper insulation aging and thermal stress. Interpreting absolute values plus trending helps identify developing faults early, prioritize inspections, and decide whether to reduce load, dry out, or plan an outage.