Impact of Online Moisture Removal

Sharing a real-life field case study from 2016, demonstrating the effectiveness of PTSS make Online Transformer Dryout Systems implemented at a PGCIL site on a critical EHV asset.

🔧 Asset Details

Make & Year : CGL, 1993
Equipment : 16.67 MVAR, 420 kV Reactor
Oil Volume : 14,730 litres
Operating Temperature: Consistent throughout the entire online drying process

⚙️ Operational Benefits

• Performed completely online with zero interruption to service
• No thermal stress or additional loading on the asset
• Gradual and controlled moisture reduction ensures insulation safety

📊 Achieved Improvement (Baseline → Final)

Moisture in Oil (ppm): 25 ppm → 2 ppm
Relative Saturation (%RS): 17% → 1.2%
Moisture in Solid Insulation: 3.9% → 1.7%
(estimated and displayed with our in-built software)

These results were achieved online, without shutdown, while the reactor remained in service, clearly highlighting the ability of continuous online drying to progressively extract moisture from both oil and solid insulation.

💡 Key Learning

This case study is a strong example of how condition-based online dryout solutions can restore insulation health, improve dielectric margins, and contribute directly to asset life extension and reliability enhancement, especially for aging EHV reactors and transformers.

Continuous moisture control not only reduces the risk of insulation failure but also helps utilities avoid costly outages, emergency maintenance, and premature asset replacement. Online dryout provides a practical and economical approach for maintaining transformer reliability in modern power systems.