The Key Role of DGA (Dissolved Gas Analysis) in Transformer Health Testing

When it comes to high-value electrical assets like transformers, early fault detection can mean the difference between a simple repair and a catastrophic failure. That is where DGA testing comes in - a powerful diagnostic tool that helps identify internal faults in transformers before they escalate.

Gas Indicators:

H₂ (Hydrogen): Partial discharges / corona

CH₄ (Methane): Low-temp oil overheating (150–300°C)

C₂H₄ (Ethylene): Moderate overheating (300–400°C)

C₂H₂ (Acetylene): High-temp arcing (>500°C) – most alarming

CO (Carbon Monoxide): Cellulose insulation overheating

CO₂ (Carbon Dioxide): Slow paper degradation

Why This Matters for Asset Managers and Engineers

Preventive Maintenance: Detect issues early and avoid forced outages.

Root Cause Analysis: Different gases point to different fault types.

Life Extension: Monitor insulation aging and optimize loading.

Safety & Reliability: Stay ahead of catastrophic failures.

Pro Tip

It is not just about individual gases. The ratios between gases, their rate of increase, and absolute concentrations help pinpoint whether the issue is electrical, thermal, or incipient.