Moisture is one of the biggest threats to the reliability and lifespan of oil-immersed transformers. To ensure high insulation performance and prevent premature failures, vacuum drying is a critical process during transformer manufacturing and maintenance.
Why Is Vacuum Drying Necessary?
Transformer insulation systems consist of cellulose-based paper and insulating oil, both of which are highly sensitive to moisture. Excess moisture can lead to:
- Reduced Dielectric Strength – Moisture lowers the insulating ability of oil and paper, increasing the risk of electrical breakdown.
- Accelerated Aging – Water speeds up the degradation of insulation materials, shortening the transformer's lifespan.
- Gas Formation – Moisture contributes to the formation of gas bubbles, which can trigger protective relays and cause operational issues.
How Does Vacuum Drying Work?
During manufacturing and servicing, transformer windings and core materials undergo a vacuum drying process to remove absorbed moisture. This is done by:
- Placing the Active Parts in a Vacuum Chamber – The transformer core and windings are subjected to low-pressure conditions, which force moisture out of the insulation materials.
- Gradual Heating – Controlled heating helps release moisture trapped in the cellulose insulation.
- Final Oil Filling Under Vacuum – Once dried, the transformer is filled with high-purity insulating oil under vacuum to prevent moisture reabsorption.
Key Benefits of Vacuum Drying
✅ Improved Insulation Performance – Ensures oil and paper maintain high dielectric strength.
✅ Extended Transformer Lifespan – Reduces aging effects caused by water contamination.
✅ Enhanced Reliability – Minimizes failure risks, ensuring stable transformer operation.
At Jiangsu Ryan Electric, we employ advanced vacuum drying technology to guarantee high-quality oil-immersed transformers with superior insulation performance and long-term reliability.
Looking for high-performance transformers? Contact us today!
