Smart Transformer Breather

Main Tank and LTC Smart Transformer Breather


  • The transformer bladder, oil, and insulation system can degrade over time due to excess moisture in the atmosphere. This degradation may result in aging of the asset or reducing the overall life and performance. With multiple communication options, Qualitrol’s Smart Breather can provide a wide range of monitoring solutions for any application.


  • Reduce maintenance costs with learned transformer breathing patterns and self-regenerating desiccant.
  • Color changing silica gel desiccant allows for a visual confirmation of breather regeneration.
  • Multiple communication options including 4-20 mA, RS-485 MODBUS and local USB port provide for a variety of monitoring solutions for any application.
  • Front mounted indication LED lights of green, amber, and red indicate breather status and alarm capabilities.
  • Oil desiccant size of 136,000 liters/36,000 gallons.


  • Polar models offer additional internal heaters to withstand harsh temperatures down to -60 °C.
  • Offshore Xtreme™ models contain material sets specially engineered to adapt to life in harsh marine environments.
  • Multiple mounting options available for new or retrofit installation.
  • Includes a solenoid valve that closes during the regeneration process to ensure moisture is not wicked into the transformer accidentally.


  • The Qualitrol STB series smart transformer breather removes moisture from air entering oil-filled transformers or LTC conservators. 
  • The breather is automated to regenerate the silica gel desiccant at a user selectable time interval or relative humidity (RH) threshold.
  • Alarming capability and communications reduce unnecessary breather maintenance costs over time. The silica gel may be regenerated many times without replacement due to internal heaters inside the unit that drive off accumulated water on a transformer exhale cycle. 

Recommended for use on Medium/Large Transformers with a voltage range of 138 kV-345+ kV. 



Smart breather for transformer

stb-200-4 series