What gases are analyzed in DGA and what do they indicate?

In Dissolved Gas Analysis (DGA) for power transformers, key gases analyzed include hydrogen (H2), methane (CH4), ethylene (C2H4), acetylene (C2H2), carbon monoxide (CO), and carbon dioxide (CO2). Each gas indicates specific fault conditions: for example, hydrogen suggests overheating, while acetylene indicates arcing. Methane and ethylene are associated with insulation breakdown, and carbon monoxide can indicate cellulose degradation. Analyzing these gases helps diagnose the health and potential issues within the transformer.