BRR - Bladder Rupture Relays

BRR – Bladder Rupture Relays combined with Pronal STP flexible separators are intelligent systems able to detect any liquid that is unusually present in the protective liquid storage bladder (oil in case of leakage or a connection / condensation defect linked to a dryer issue).

It’s composed an optical sensor installed in the bladder through the flange during assembly or a maintenance operation, and a connection unit that connects the sensor to the external control relay installed in the transformer’s electric switchboard. Equipped with two LEDs, the latter allows full-time visual monitoring. The red LED indicates an anomaly while the other is green in normal situations.



  • Full-time visual monitoring
  • Quick leak detection
  • Installation during assembly


  • Failures anticipation
  • System protection
  • Intelligent alarm


  • Compatible with Pronal products
  • Optical liquid detection
  • Transformer connectivity

Detailed information

  • Kit contents:
    • 1 optical sensor with a 5 m cable
    • 1 connection unit
    • 1 outside control relay with LEDs
  • Temperature resistance: -20°/+100°C

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Our design department employs the best project leaders and designers and will be pleased to develop and create a tailor-made product specially for your unique project.


Composition / Advice

Installation advice
Install permanently with an STP bladder or use it on a one-off basis for on-site checks during maintenance work.

Standards / regulations

Standardized control unit IP20, standardized sensor IP67.


Fact Sheets / Business Guides
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1 optical sensor with a 5 m cable
1 connection unit
1 control relay with LEDs