BR / BS / C1 / NF / OR / BG — Buchholz gas relays DN25–DN80, R1 relay, GSD2 gas sampler
COMEM C1, BS, BR, NF, OR and BG are Buchholz gas relays DN25–DN80 to IEC 60076-22-1 for protecting oil-filled transformers and reactors against internal faults. The range is complemented by the R1 relay for hermetically sealed transformers and the GSD2 gas sampler.
- Standard
- IEC 60076-22-1
- Nominal bore
- DN25, DN50, DN80 (up to DN100 according to the brochure) or thread G 1½
- Contacts
- up to 6; 2 A; min. 10 mA / 24 V DC (gold-plated for lower currents)
- Flow settings
- 1.0–3.0 m/s (±15 %)
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
A Buchholz gas relay is installed in the oil pipe between the tank and the conservator of an oil-filled transformer or reactor. During turn-to-turn faults, partial discharges, overheating or arcing, gas is released from the oil and collects in the upper part of the relay. A small accumulation gives an alarm signal. A sharp oil surge towards the conservator, typical of a serious fault, deflects the flap, and the relay issues an immediate trip command.
The COMEM range includes C1, BS, BR, NF, OR and BG relays with nominal bores DN25, DN50 and DN80, up to DN100 according to the brochure, or with a G 1½ threaded connection. The alarm gas volume is 100–230 or 200–300 ml depending on the type, with up to 4 or up to 6 contacts. Separate versions are produced with testing of alarm and trip contacts from ground level, with flap latching and manual reset, for on-load tap changers and for railway traction (BR25).
The R1 relay with a DN25 bore is fitted on hermetically sealed transformers and used to detect rupture of the rubber bag in the conservator. It gives an alarm at 75–100 ml of gas and a trip at 190–250 ml. The GSD2 gas sampler brings the gas from the relay down to ground level, so the sample is taken without climbing to the relay.
Oil flow velocity settings range from 1.0 to 3.0 m/s with a tolerance of ±15 %. The contacts withstand a maximum current of 2 A, the minimum switching current is 10 mA at 24 V DC, and gold-plated contacts are available for lower currents. The dielectric strength is 2.5 kV AC for 1 min between contacts and earth and 1.0 kV between open contacts. The housing is cast aluminium alloy, the inspection window is tempered glass with a UV filter.
Oil temperature is from −40 to +120 °C, ambient from −40 to +80 °C, lower values on request. The degree of protection is IP65 (IP66 on request), vibration resistance 4M4 or 4M6. Corrosion protection is C4-M, C5-M for tropical climates and CX for offshore. The relays comply with IEC 60076-22-1 and are suitable for power, distribution, hermetically sealed and traction transformers, on-load tap changers, seismic areas, new installations and replacement during repairs.
Technical specifications
| Standard | IEC 60076-22-1 |
|---|---|
| Nominal bore | DN25, DN50, DN80 (up to DN100 according to the brochure) or thread G 1½ |
| Contacts | up to 6; 2 A; min. 10 mA / 24 V DC (gold-plated for lower currents) |
| Flow settings | 1.0–3.0 m/s (±15 %) |
| Gas for alarm | 100–230 or 200–300 ml |
| Insulation | 2.5 kV AC 1 min contacts–earth; 1.0 kV between open contacts |
| Oil temperature | −40…+120 °C |
| Degree of protection | IP65 (IP66 on request) |
| Vibration | 4M4 (4M6 on request) |
| Corrosion protection | C4-M; C5-M; CX |
Replacement for
transformer protection relays РЗТ-25, РЗТ-50, РЗТ-80 (Buchholz gas relays DN25/DN50/DN80), РГЧЗ-66, BF-80/Q
selected by purpose and main parameters, please confirm with our manager
Request a price and lead time
BR / BS / C1 / NF / OR / BG — Buchholz gas relays DN25–DN80, R1 relay, GSD2 gas sampler. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8536 49 00 00 |
|---|---|
| HS, 6 digits | 8536 49 |
| CN (EU) | 8536 49 00 |
| HTSUS (USA) | 8536 49 00 80 |
| China customs tariff | 8536 49 00 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
What can replace РЗТ-80?
COMEM relays with a DN80 bore are selected as a replacement according to the application, oil pipe diameter, flow setting and number of contacts. Agree the final choice with the manager.
What oil flow settings are available?
Settings from 1.0 to 3.0 m/s with a tolerance of ±15 %.
Are there relays for hermetically sealed transformers?
Yes, the R1 relay with a DN25 bore gives an alarm at 75–100 ml of gas and a trip at 190–250 ml. It is also used to detect rupture of the rubber bag in the conservator.
CIS originals replaced by this item
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