What does routine oil transformer maintenance include?

Routine maintenance includes visual inspection for leaks, checking oil level and temperatures, inspecting bushings, radiators, fans, pumps, and breathers or nitrogen systems. The silica gel breather is examined for moisture saturation and replaced as needed. Oil sampling is performed for BDV, moisture, acidity, interfacial tension, tan delta, and DGA to detect developing faults. Tap changers and protection devices are checked per schedule. Findings drive corrective actions such as gasket replacement, dehydration, filtration, or regeneration to maintain dielectric and thermal performance.