Accessories for smart transformers - eDevices

Buchholz relays for smart transformers

Leakage current, arcing, flashovers, loss of insulating liquid, or excessively high flow rates can generate gas inside the transformer oil and affect the transformer performance.

Assure reliable and safe operation of the transformer and a power supply network.

Choose our Buchholz relay type eBR, an evolution of our conventional Buchholz relays. It continuously monitors gas accumulation and oil flow to the conservator from the remote. You will get a reliable product designed to discharge the accumulated gas and detect unexpected oil flow speed and avoid transformer shut down.

The Buchholz relay is equipped with a digital interface for easy connection to smart grid applications and can be integrated into a system through a central control unit. It is compatible with our complete eDevice family, can be connected also to third-party devices, and be part of our modular monitoring ecosystem for transformer diagnostics – MeDICA.

Contact us and get support with the product selection.

Why buy

  • Continuous online monitoring at any time and from the remote
  • Proven technology designed to identify the trip cause immediately enabling the end-user informed decision making
  • Compatibility with other eDevices, and third-party accessories enables the end-user a controlled and gradual digitalization of the transformer and remote asset health monitoring


  • Liquid-filled transformers with or without rubber bag
  • Transformer conservator
  • Transformer tank
  • Suitable for new installations and retrofits
  • Suitable for offshore environment
  • Suitable for tropical climates
  • Part of our MeDICA solution

Additional accessories

Gas sampling device type GSD2

Technical data at a glance

StandardIEC 60076-22-1
Housing and upper part incl. terminal box materialAluminum casting, RAL 7032, powder coated, Offshore model on request (surface tratment, not painted)
InstallationIndoors and outdoors, tropical proof
Nominal pipe diameterDN80
Inspection glassTempered glass with UV filter
Oil temperatireFrom -40 °C to +115 °C
Ambient temperatureFrom -40 °C to +80 °C
Arctic version on demand
SwitchesUp to 4
Max. nominal current2A
Min.switching current10mA/24 V dc
Rated insulation voltage2.5 kV ac 1 min between contacts and earth, 1.0 kV ac 1 min between open contacts
Insulation resistance1000 MΩ/500 V dc
Flap triggering oil flowfrom 1.0 m/s to 23.0 m/s (each ±15%)
Cable gland2 M25 x 1.5
Degree of protectionIP65 in accordance with EN60529 (IP66 available upon request)
Rated voltage24 V dc ±10% polarized
Current consumptionMax 0.5 W
Analog output4-20 mA
Digital outputMODBUS RTU

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