BUCHHOLZ RELAY | TRANSFORMER FAULT PROTECTION | EMB
Gas operated relay for transformer fault detection. It works by sensing gas buildup from insulation breakdown or arcing, and monitoring oil flow during severe faults. Depending on the situation, it either triggers an alarm minor fault or trips the transformer major fault.
About the product
Buchholz Relays
The Buchholz relay was developed in 1921 by Max Buchholz, Oberrat (senior councillor) at Preußische Elektrizitäts-A.G. (Prussian electricity company) in Kassel. Since that time it has been an important protection and monitoring device for insulating liquid filled transformers with conservator and choke coils. It also allows separate monitoring of oil-filled bushings or cable terminal boxes. It is mounted in the cooling cycle of the device to be protected and responds to faults such as gas generation, loss of as well as high flow rates of the insulating liquid.For transformers with hermetical closure by means of a hydro-type compensator (rubber sack) in the conservator, the Buchholz relay can be used also as monitoring device (air cell failure relay) of the hydro-type compensator.
The Buchholz relay is suitable for open-air as well as indoor installations.
General
The type diversity of the Buchholz relay is tailored to norms and standards as well as to special customer demands. The type of relay to be used depends on the nominal rating and construction features of the device to be protected. Our range of products permits optimum adaptation to actual requirements.Elektromotoren und Gerätebau GmbH (EMB GmbH) provides more than 70 years experience in producing Buchholz relays and other protective devices for liquid-cooled and liquid-insulated devices. It ranks today among the most distinguished manufacturers of this type of equipment.
EMB Buchholz relays are in compliance with EN 50216-2 as well as IEC 60076-22-1 and are known for their easy operation, high reliability and extremely long life. The functionality of the EMB Buchholz relays is given by using all conventional insulating liquids. The functionality in combination with new insulating fluids will be tested in close cooperation with the manufacturers.
EMB has been certified according to: DIN EN ISO 9001:2015, AEO F, Known Consignor (Airfreight Security) and EAC. Further certifications have been awarded by well-known independent test laboratories such as TÜV Rheinland and TZO.
Technical Data
The technical data listed in table named below are applicable to all Buchholz relays in standard version manufactured by EMB. EMB Buchholz relays are in compliance with DIN EN 50216-2 as well as IEC 60076-22-1.| Parameter | Data | Notes |
|---|---|---|
| Voltage | AC 5 V - max. 250 V DC 5 V - max. 250 V | |
| Current | AC 0,01 A - max. 6 A DC 0,01 A - max. 6 A | Cos φ > 0,5 L/R < 40 ms |
| Switching capacity | AC max. 1500 VA DC max. 1250 W | |
| Dielectric strength | AC 2500 V AC 2000 V (NO-contact, NC-contact) AC 1000 V (CO-contact) | Between electric circuit and earth Between open contacts |
Temperature range:
| - 40 °C to +55 °C - 40 °F to +131 °F | Climatic testing acc. to DIN EN 60068-2-78: 2002-09 Others on request |
Temperature range:
| - 40 °C to +115 °C - 40 °F to +239 °F Till +135 °C requires type code 21 | |
Temperature range:
| 1 mm²/s to 1100 mm²/s | |
| Insulating liquid | Mineral oil | Others on request |
| Resistance against vibration | Vibration: 2-200 Hz, 2 g Shock: 25 g, 6 ms | Acc. to class 4M6 following DIN EN 60721-3-4 |
| Resistance to pressure | 0,25 MPa | |
| Resistance to vacuum | < 2,5 kPa | |
| Insensitivity to magnetic fields | 25 mT | Static magnetic field of any direction and polarity |
Switching system:
Response time of damper | Magnet contact tube Held by magnets < 0,1 s | |
Response of switching system in case of:
| 200 cm³ to 300 cm³ Min. 0,65 to max. 3,00 m/s ± 15 % | Others on request For possible data see Ordering Data/Type code Others on request |
| Cable gland | M20x1,5; M25x1,5 | Others on request |
| Nominal installation position | 0° to 5° | Ascending towards conservator |
| IP code | IP 56 | Others on request |
| Casing colour | Two-component texture paint | On polyurethane basis |
