Maintenance Tip: Extending the Service Life of Oil-immersed Transformers in Humid Climates

The environment always has a significant impact on electrical appliances, either major or minor. A humid environment has a greater influence on oil-type transformers, mainly due to the infiltration of moisture. Water accelerates the deterioration of the oil inside the oil-type transformer, weakens cellulose insulation materials, and speeds up the formation of corrosive sludge, thereby significantly shortening the service life of the oil-type transformer. Therefore, maintaining the lifespan of the oil-type transformer is very important.
1. Moisture-proof measures are very important:
(1) Sealing integrity: Staff should regularly inspect gaskets, welds, and bushings. No matter how minor the leakage is, it must be repaired in time to ensure that the oil reservoir is well sealed.
(2) Breathing system: Regular maintenance of desiccant respirators is required. If the color of the silica gel changes significantly, such as exceeding 25% turning pink, it should be replaced immediately. In extremely humid environments, consider using double-chamber respirators or continuous air dryers to ensure a dry indoor environment. Check the sealing of air vents and pressure release devices.
(3) Oil quality management: Conduct oil sample collection and testing according to IEC 60422 or equivalent standards on a regular basis. Monitor key parameters: moisture content, dielectric strength, acidity, and interfacial tension. If moisture or dissolved gases exceed the limit, immediately treat the oil quality through vacuum degassing and filtration.
(4) Temperature control: Ensure the normal operation of the cooling system. Prevent the top oil temperature from being too high, as this will accelerate the migration of moisture and oil aging.
(5) Load monitoring: Avoid long-term overloading, especially in high-temperature and high-humidity environments, which will increase the insulation pressure and increase the solubility of moisture in hot oil.
(6) Cleaning and inspection: Keep the transformer exterior clean to prevent the accumulation of dirt and impede heat dissipation. A power-off operation can be performed to check for signs of moisture, corrosion, or sludge in the internal components of the transformer.
(7) Anti-corrosion protection: Maintain the paint and grounding facilities of the transformer tank to prevent external corrosion from intensifying due to humidity.
By strictly controlling humidity through measures such as sealing, advanced breathing systems, and strict oil management, and supplemented by comprehensive proactive maintenance, operators can significantly reduce the adverse effects of humidity. This rigorous approach can protect the insulation integrity of the transformer and prevent premature aging.