Qualitrol STB000 Main Tank and LTC Smart Transformer Dehydrating Breather

Remove moisture from entering oil-filed transformers or LTC conservators

As a transformer operates, oil expansion and contraction cause a transformer to breathe in humidity from the atmosphere that may age a transformer’s bladder, oil, and insulation system over time. This unnecessary aging to the transformer reduces the overall life of the asset making it difficult to provide reliable power leading. This can lead to additional costs for transformer maintenance or even premature transformer failure.

The Qualitrol STB000 Smart Transformer Breather removes moisture from the air that enters oil-filled transformers or Load Tap Changers (LTC) conservators. Moisture is trapped in silica gel desiccant located within the dehydrating breather.  The Qualitrol STB000 is automated to regenerate the silica gel desiccant at a user-selectable time interval using either of the industry’s leading technology – Parts Per Million (PPM) or Relative Humidity (RH) thresholds.

Unnecessary truck rolls or substation maintenance is avoided due to the Qualitrol STB000 Smart Transformer Breather’s internal heather unit that drives out moisture on the transformer exhale cycle allowing the silica gel to regenerate.

Even the smallest amounts of moisture in a power transformer can have varying degrees of problems ranging from limited output to failure.  The Qualitrol STB000 represents real cost savings, in addition to customization and easy install.


  • Reduce maintenance costs with learned transformer breathing patterns and self-regenerating desiccant
  • Universal algorithm determines the best regeneration style based on the breathing pattern of the transformer. The STB000 automatically shifts to a time-based regeneration if it is installed on a tank that does not breathe, such as LTC application, eliminating the need to carry two models in your inventory
  • All units have standard C5M coating and carry a 5-year warranty
  • Multiple communication options including 4-20 mA, RS-485 MODBUS and local USB port provide allow for trending of moisture readings and regeneration cycles
  • New test button option allows for an easy diagnostic check of breather functions in the field
  • External LED indication gives current status of unit including active regeneration
  • Oil desiccant size of 30,000 liters/8,000 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

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The Qualitrol STB series smart transformer dehydrating 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, relative humidity (RH) or PPM thresholds. Regenerating the silica gel automatically reduces unnecessary breather maintenance costs over time. Alarms and digital communications allow for remote monitoring of moisture levels and breather status. Recommended for use on Medium/Large Transformers with a voltage of 1.38kV and above.

Compare to Similar Products


Traditional Breather in the Marketplace

Utilizes silica gel to dry atmospheric air as the transformer breathes

Low initial cost of ownership, but the associated maintenance costs outweigh this over time

No alarming capability or failure detection available, must rely on human interaction to maintain and service

Reoccuring desiccant disposal costs may apply if silica gel containing cobalt is used

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Other Smart Breathers in the Marketplace

Do not utilize color changing desiccants (Color changing silica gels allow the user to have a secondary visual indication of regeneration)

Some do not utilize a pressure sensor and solenoid valve technology to detect breathing shifts within the transformer (This prevents liquid water from being drawn into the transformer accidentally)

May not have additional smart breather options for harsh environmental conditions

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Qualitrol STB000 main tank LTC smart breather power transformers moisture

Qualitrol STB000 Main Tank and LTC Smart Transformer Dehydrating Breather

No need for unnecessary maintenance or replacing silica gel in the field

Alarming and failure detection capability; no need to rely on human interaction

Utilizes a color changing silica gel as a secondary indication that regeneration took place giving peace of mind

Detects inhale and exhale phases to prevent excess moisture from being drawn into the transformer

Learn More
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