ABB REB670 SR91C790 | Busbar Protection Relay

🔧 Product Overview

The ABB REB670 is a high-performance busbar protection relay designed for fast and selective protection of medium- to extra-high-voltage busbar systems. It is part of ABB’s Relion 670 series and is intended for applications where dependable fault detection and rapid fault clearance are essential.

The listed unit is configured as a REB670 busbar protection relay with the SR91C790 designation, 50/60 Hz operation, and a high-voltage DC auxiliary supply. The listed configuration also specifies a 1 A current rating. The exact ordering code should always be matched against the protection scheme and the relay nameplate before replacement.

⚙️ Key Features

• ABB Relion 670 series busbar protection platform
• Designed for selective busbar fault protection
• Suitable for phase-to-phase and phase-to-ground fault detection
• Supports multi-zone protection arrangements
• 50/60 Hz system frequency
• 90–250 VDC auxiliary supply range for the applicable configuration
• 1 A current-input rating as listed
• Advanced protection and control functionality
• Suitable for new installations and retrofit projects
• Communication and system-integration functions depend on the selected hardware and configuration
• Suitable for substations, switchyards, industrial power systems, and utility applications

 

📋 Product Datasheet

Parameter	Specification
Brand	ABB
Model	REB670
Ordering Configuration	REB670*1.1-A31X03-C07C11-B1X0-EE-KB-B-A1A1-EAEAE-X-XD
Product Type	Busbar Protection Relay
Series	Relion 670
Designation	SR91C790
Rated Frequency	50/60 Hz
Current Rating	1 A
Auxiliary Supply	90–250 VDC
Listed Relay Voltage	220–250 VDC
Condition	Used
Weight	Approx. 16.38 kg
Country of Origin	India, according to the listing
Application	Busbar Protection / Substation Protection
Protection Architecture	Multi-zone busbar protection
Mounting	Panel / control cabinet installation, configuration dependent

The listing identifies the unit as used and gives an approximate weight of 16.38 kg.

 

⚡ Operating Function

The REB670 operates as a dedicated protection IED for busbar systems. Its primary task is to distinguish between faults inside the protected busbar zone and faults occurring outside that zone.

During a busbar fault, the relay processes current measurements from the connected CT circuits and determines whether the fault belongs to the protected zone. When the protection criteria are satisfied, the relay can issue trip commands to the appropriate circuit breakers.

For larger substations, the protection arrangement can be divided into multiple zones. This allows the system to isolate the affected section while keeping healthy parts of the switchgear energized.

ABB describes the REB670 as a solution for selective, reliable and fast clearance of internal phase-to-phase and phase-to-ground busbar faults.

 

🛠️ Installation & Maintenance

Before installation, confirm the complete ordering code rather than relying only on the basic REB670 model number. The configuration shown on the nameplate determines the available protection functions, I/O arrangement, communication options, current-input configuration and auxiliary supply.

Recommended checks include:

1. Verify the complete relay ordering code and hardware revision.
2. Confirm the auxiliary DC supply before energizing the relay.
3. Check CT wiring, polarity, ratios and grounding.
4. Verify the busbar protection zones in the protection configuration.
5. Check binary inputs and trip outputs during commissioning.
6. Review communication settings if the relay is connected to a substation automation network.
7. Perform secondary injection and protection-function testing before placing the relay into service.
8. Record existing settings before modifying an installed relay.
9. Keep ventilation openings and cabinet areas clean and free from excessive dust.
10. For a replacement unit, compare firmware, configuration files and hardware options with the original device.

The REB670 documentation specifies an operating ambient range of approximately -25°C to +55°C for the referenced version.

 

🔍 Maintenance Tips

For an installed REB670, periodic inspection should focus on the protection circuit rather than simply checking whether the front panel powers up.

Pay particular attention to CT circuit continuity, trip-circuit supervision, DC auxiliary supply quality, event records, communication status and protection settings. Any abnormal alarm or self-supervision indication should be investigated before the relay is returned to normal service.

For a used replacement unit, it is especially important to verify the hardware configuration and protection settings before connecting it to an energized system.

 

❓ Common Questions

Q: What is the ABB REB670 used for?
A: It is a dedicated busbar protection relay used to detect and selectively clear faults within protected busbar zones.

Q: Is the REB670 suitable for 50 Hz and 60 Hz systems?
A: Yes. The listed unit is specified for 50/60 Hz operation.

Q: What auxiliary supply does this configuration use?
A: The applicable REB670 configuration supports a 90–250 VDC auxiliary supply range. The listing identifies 220–250 VDC for the relay voltage specification.

Q: Is this relay a general-purpose overcurrent relay?
A: No. REB670 is specifically designed around busbar protection applications and associated protection schemes.

Q: Can I replace another REB670 directly with this unit?
A: Not automatically. The complete ordering code, hardware options, current-input rating, firmware, communication configuration and protection settings should be compared before replacement.

Q: What should be checked before purchasing a used REB670?
A: Check the nameplate, complete ordering code, hardware condition, display and keypad condition, terminal blocks, auxiliary supply range, firmware/configuration, and available test records.

 

🔄 Recommended ABB Models

1. ABB REB650 — Busbar Protection IED
2. ABB REL670 — Line Distance Protection Relay
3. ABB RED670 — Differential Protection Relay
4. ABB RET670 — Transformer Protection Relay
5. ABB REG670 — Generator Protection Relay
6. ABB REC670 — Bay Control Unit
7. ABB REF615 — Feeder Protection and Control Relay
8. ABB RET615 — Transformer Protection and Control Relay
9. ABB REF620 — Feeder Protection Relay
10. ABB REM615 — Motor Protection and Control Relay

 

🏭 Application Summary

The ABB REB670 is intended for protection-critical electrical systems where a busbar fault must be identified and isolated quickly. Typical applications include utility substations, industrial substations, power generation facilities, transmission switchyards and high-voltage distribution systems.

Its main advantage is the ability to provide fast and selective busbar protection while supporting complex protection arrangements and integration into modern substation automation systems. For replacement projects, however, the exact configuration is more important than the basic REB670 model name. Matching the full ordering code and existing protection scheme is the safest approach.