What contaminants degrade oil in transformers and how are they removed?

Common contaminants include moisture, oxygen, sludge, acids, solid particles, and gases produced by electrical faults. Moisture reduces dielectric strength, while acids and sludge impair cooling and accelerate insulation aging. These contaminants are removed through vacuum dehydration, filtration, oil regeneration systems, and breather maintenance. Regular oil testing helps identify contamination early and guides corrective maintenance actions to protect transformer health.