Technology is of Online Dryout process for drying out wet transformer in energized conditions by monitoring the percentage of Moisture in the insulation to its Dry Weight. PTss-Velcon TDS equipment is fitted with TIMES (Transformer Insulation Moisture Estimation System) which automatically estimates the %M/DWi (%Moisture to Dry Weight of insulation) and triggers itself for self removal of moisture in Transformers. It uses Specialized cartridges for maintaining the %M/DWi to acceptable levels. This equipment is capable of being safely fitted, operated and moved between transformers/reactors under energized conditions and is being installed upto 764 KV Class Transformers. Process will not deteriorate any of the Oil characteristics before and after the process.


PTss-TDS is basically designed to operate on an energized Transformer to remove moisture from it. The moisture is removed by circulation of Oil through TDS which has special type of absorptive cartridges which absorb and remove moisture from the oil. This process does not employ any heating or vacuum process of oil thereby retaining the original virgin characteristics of the oil. Process does not remove Oxidation inhibitors or fault gases. Equipment estimates the %M/Dwi (Percentage of Moisture to Dry Wt of Insulation) and automatically triggers itself for operation and is safe for unattended operation.



TDS comes in various flow capacities from 120 LPH to 2400 LPH and can be sized based on the requirements of the transformer oil capacity. Variable Flow option is available. Based on the selection chart customers can choose the equipment.

TDS5FV4X – Transformer Dryout System with 120-1200 LPH(Variable Flow) and 4 Cartridges
TDS9FV8X – Transformer Dryout System with 240-2400 LPH(Variable Flow) and 8 Cartridges.

Power Requirements

3 Phase, 415 Volts, 50 Hz 5.0 Hp 3.7

Dimension and Weight of equipment

TDS5FV4X : 1270 x 800 x 1730 mm Weight: 650 Kgs Equipment (Nett) and 900 Kgs (gross) packed with accessories.
TDS9FV8X : 1600 x 800 x 1716 mm Weight: 800 Kgs Equipment (Nett) and 1000 Kgs (gross) packed with accessories.

Communication Details

External interfaces provided on TDS include Ethernet ( RJ45 ) for SCADA over OPC Server / RS 485 / Modbus RTU and ASCII