Transforming Reliability at Vardhman Group
with Online Transformer Dryout & OLTC Filtration
Proud to share a compelling case study from Vardhman Group of Industries, showcasing the adoption of the Online Transformer Dryout System (TDS) and OLTC filtration process for their critical power transformer way back in the year 2008. The textile industry faces steep costs and downtime risks from transformer failures, especially during moisture entrapment, which typically mandates lengthy shutdowns and costly traditional dehydration procedures.
By implementing the online dryout system, Vardhman achieved continuous operation while improving vital transformer health markers and they took the wise decision of installing Online Transformer Dryout System and Online OLTC Filtration System in their various plants across India
Oil Quality Boost
Water Content reduced from 28 ppm to well under permissible limits of less than 10ppm.
Breakdown Voltage (BDV) increased from 28 kV to a robust 52 kV.
Other key indicators such as interfacial tension, flash point, and specific resistance returned to healthy levels, with tan delta and sludge contents minimized—all without requiring oil replacement.
Insulation Resistance (IR) & Polarization Index (PI) Recovery.
IR and PI values, which dropped significantly after 10 years in service, saw dramatic improvement. HV-E went from a post-oil-change low of 410 MΩ to a remarkable 1275 MΩ, LV-E from 400 MΩ to 1250 MΩ, and HV-LV from 540 MΩ to 2250 MΩ post online TDS treatment. PI values, initially in the “Questionable” range (1.12–1.3), rebounded to “Good” (>2.0) classification.
Oil Quality Boost
Water Content reduced from 28 ppm to well under permissible limits of less than 10ppm.
Breakdown Voltage (BDV) increased from 28 kV to a robust 52 kV.
Other key indicators such as interfacial tension, flash point, and specific resistance returned to healthy levels, with tan delta and sludge contents minimized—all without requiring oil replacement.
Insulation Resistance (IR) & Polarization Index (PI) Recovery.
IR and PI values, which dropped significantly after 10 years in service, saw dramatic improvement. HV-E went from a post-oil-change low of 410 MΩ to a remarkable 1275 MΩ, LV-E from 400 MΩ to 1250 MΩ, and HV-LV from 540 MΩ to 2250 MΩ post online TDS treatment. PI values, initially in the “Questionable” range (1.12–1.3), rebounded to “Good” (>2.0) classification.
Operational Benefits
No need for shutdown online process meant production losses were averted (potentially could touch up to Rs. 50 Lacs for offline dryouts).
Minimal cartridge consumption demonstrates sustainable, cost-effective maintenance.
Preventive care now keeps the entire transformer fleet in excellent shape, extending lifespan and reliability.
This case exemplifies how modern transformer maintenance online dryout, continuous oil conditioning, real-time diagnostics can eliminate deep-seated moisture, restore dielectric integrity, and dramatically extend asset life.
Few site pictures are enclosed related to connections of Online Transformer Dryout System and Online OLTC filtration system with main tank and OLTC tank for easy understanding.
