About us

The company EMB GmbH provides more than 50 years experience in producing Buchholz relays, monitoring relays and other protection devices for liquidcooled and liquid insulated appliances. It ranks among the most distinguished manufacturers of this type equipment.

Our staff of highly-qualified engineers and experienced skilled workers help ensure we produce top-quality, high-precision equipment. The casings are machined on modern CNC-controlled machine tools. All products are subjected to a final inspection, when all functions are checked using special test equipment.

Profound experience and expertise are a sound basis for high product quality. Extensive references from reputed tap changers and transformer manufacturers as well as other users are proof of the high qualitative level of the products.

The company is certified to DIN EN ISO 9001:2015 and approved for AEO F.

Products and services

  • Transformer protection relay (Buchholz principle) - Buchholz relay
  • Buchholz relay NM series
  • Monitoring relay for tap changers
  • Air cell failure relais
  • Additional devices for Buchholz relays
  • Breathing boxes for transformers
  • Further transformer accessories
SMART Buchholz Relay

Buchholz relay with extended functions by means of sensors: Capacitive sensor-NM Series - For analogue measuring of gas accumulation - Reliable & continuous monitoring of Buchholz gases for early fault detection Moisture sensor - Constant monitoring of humidity in oil - For early detection & preventive measuring - Output of measured values via analogue & digital signals Temperature sensor - For continuous oil temperature monitoring - Available separately or combined with humidity sensor

Further reading

Monitoring Relay for Tap Changers

The monitoring relay for tap changers, also known as the protection relay for tap changers or oil flow relay, is a monitoring device for insulating liquid-filled tap changers with conservators. It protects the tap changer and the transformer from damage. The monitoring relay responds to excessive oil flow in the direction of the conservator and generates a signal disconnecting
the tap changer and the transformer immediately from voltage supply.

Further reading

Breathing Buffer Box G3B

Ageing of the transformer's insulation system is accelerated by oxygen dissolved in oil. With open-type transformers oxygen consumed is replenished from the atmosphere. This longtime effect has negative implications. The breathing buffer box (G3B) inserted in the transformer's breathing line upstream of the dessicant layer is deemed to solve this problem. This ensures hermetical sealing of the transformer.

Further reading

Otto-Von-Guericke-Allee 12
39179 Barleben

Phone: +49 39203 79-0
Internet: www.emb-online.de
E-mail: Send message

News & Innovations

Buchholz Gas Tester BGT 4.2
• Measuring and analysis of Buchholz gas directly on site
• Detection & analysis of H2, CO, CO2, C2H2, CH4+
• Enables to decide about the continuous operation of the transformer
• Easy handling via touch display
• Incl. Buchholz gas sampler BGS
Further reading
Gas relay for Transformers CF 38 (Type 80)
The gas relay can be used both on open-type transformers and hermetically sealed transformers.
On open-type transformers with conservator the gas relay of type 80 can be used both as an air cell failure relay monitoring the hydro-type compensator (rubber sack) in the conservator, and as a gas relay on the cover of the transformer.
On hermetically sealed transformers without nitrogen cushion the gas relay serves to monitor potential gas collection.
For normal operation the gas relay must be filled completely with oil. Due to its boyant force the float is positioned in the upper limit position.
When due to any event gases are formed, these are collected in the gas relay causing the float to move downwards. This operates a switching contact (magnet contact tube) and produces a signal.
Gas accumulation is visible on the inspection glass.
Further reading

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