Description
Product Overview
The ABB REL561 1MRK002496-AC is a microprocessor-based line protection terminal designed for high-voltage and extra-high-voltage transmission-line protection applications. It belongs to ABB’s REL561 protection platform and combines high-speed protection functions with measurement, control, disturbance recording, and communication capabilities. Available technical references identify the REL561 1MRK002496-AC as a line differential and distance protection terminal, making it suitable for critical transmission networks where rapid fault detection and selective isolation are essential.
The ABB REL561 1MRK002496-AC is centered on phase-segregated line differential protection and distance protection, allowing internal line faults to be identified through current comparison while providing impedance-based backup protection. The protection terminal can exchange synchronized protection information with the remote end of a protected line and incorporates functions for fault recording and system supervision. This architecture makes the REL561 1MRK002496-AC suitable for substations and transmission systems requiring dependable primary and backup protection in a single intelligent electronic device.
Within modern power automation architectures, the REL561 1MRK002496-AC can operate alongside substation control systems, SCADA platforms, station communication networks, circuit breakers, CT/VT equipment, and supervisory systems. Its combination of protection and monitoring functions helps reduce the number of separate devices required while providing operators with detailed information for fault analysis, maintenance, and grid operation.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | REL561 1MRK002496-AC |
| Manufacturer | ABB |
| Product Family | REL561 Protection Terminal |
| Product Type | Line Differential and Distance Protection Relay |
| Primary Application | Transmission Line Protection |
| Protection Functions | Line Differential, Distance, Overcurrent, Ground-Fault Protection |
| System Frequency | 45–65 Hz |
| Protection Architecture | Microprocessor-based digital protection |
| Differential Communication | Dedicated digital communication channel |
| Measurement | Three-phase current and voltage measurement |
| Fault Recording | Disturbance and sequence-of-events recording |
| Communication | Protection and station communication interfaces; configuration dependent |
| Installation | Substation protection/control panel |
| Typical System | HV/EHV transmission and distribution networks |
| Application Environment | Electrical substation / power utility environment |
Exact I/O configuration, communication interfaces, CT/VT input ratings, auxiliary supply, terminal arrangement, and option codes are configuration-dependent. The 1MRK002496-AC designation should therefore be matched against the original nameplate and applicable ABB documentation before replacement.
Main Features and Advantages
High-speed line differential protection
The REL561 1MRK002496-AC is designed to provide selective protection for transmission lines by comparing electrical quantities at the two ends of the protected circuit. Differential protection is particularly effective for identifying faults within the protected zone and can initiate rapid circuit-breaker tripping to limit equipment damage and maintain grid stability. Published references describe phase-segregated differential protection with fast operating performance.
REL561
Integrated distance protection
Distance protection provides an additional protection layer based on the apparent impedance between the relay location and the fault. This allows the relay to provide primary or backup protection depending on the protection scheme and engineering configuration. Combining differential and distance functions in one terminal is valuable for transmission networks where dependable redundancy is required.
Multifunctional protection and monitoring
In addition to line protection, the REL561 platform can incorporate overcurrent and ground-fault protection, measurement, control, disturbance recording, and event monitoring. This multifunctional architecture provides operators and protection engineers with more complete information when analyzing abnormal network conditions.
Fault recording and diagnostics
The terminal can capture disturbance information and sequence-of-events data for post-fault analysis. Such information is valuable for determining fault location, verifying relay operation, investigating breaker performance, and improving protection coordination.
Designed for critical power networks
The ABB REL561 1MRK002496-AC is intended for applications where protection response, selectivity, and availability are critical. It is therefore more appropriately regarded as a dedicated power-system protection IED rather than a conventional PLC or general-purpose industrial relay.
Integration with substation automation
Communication capability allows protection information, measurements, alarms, and status information to be incorporated into broader substation automation and SCADA architectures. This supports centralized monitoring and facilitates maintenance of transmission assets.
Application Fields
The ABB REL561 1MRK002496-AC is primarily intended for transmission-line protection in electrical power systems. In high-voltage and extra-high-voltage substations, it can provide primary line differential protection together with distance and other backup protection functions. This combination is valuable on critical transmission corridors where a fault must be isolated quickly without unnecessarily disconnecting healthy sections of the network.
In power-generation facilities, the relay can be applied to generator step-up transformer outgoing lines and high-voltage transmission connections. It can exchange protection information with remote substations while providing local measurements, fault records, and protection indications to plant operators and engineers.
Utility transmission and distribution networks can use the REL561 1MRK002496-AC for overhead lines, cable circuits, and interconnected grid sections. Its distance protection function can provide backup protection when communication-assisted differential protection is unavailable or when the protection coordination strategy requires independent impedance-based protection.
The terminal is also relevant to renewable-energy substations, including wind and solar power plants, where collector systems and grid-interconnection lines require selective protection. Hydroelectric stations, industrial captive-power networks, and large metallurgical facilities with high-voltage interconnections can similarly benefit from dedicated line protection.
For substation automation, the relay can work alongside SCADA, RTU, PLC, circuit-breaker control, disturbance-recording, and station communication systems. Its combination of protection, measurement, event recording, and communication functions makes it suitable for both new installations and maintenance or replacement projects involving established ABB protection architectures.
Related Products
- REL561 1MRK002496-AE – Related REL561 configuration; useful as a same-family comparison or potential replacement candidate, subject to complete hardware and configuration verification.
- REL561 1MRK002496-AD – Another REL561 variant with different configuration options; intended for compatible line-protection applications.
- REL561 1MRK002497-AC – Related REL561 part-number variant for line protection applications, with configuration differences that should be checked before substitution.
- REL561 1MRK002498-AC – Additional REL561 configuration within the same protection platform, suitable for applications requiring corresponding hardware/configuration options.
- REL551 1MRK002480-AE – Earlier/related ABB REL-series protection product; useful when maintaining legacy ABB line-protection installations.
- RED521 1MRK002003-BA – ABB line differential protection product designed for high-speed protection of electrical power networks.
- REC670 1MRK002814-AC – ABB substation control and protection IED used for station automation and control functions, complementing dedicated line-protection equipment.
- REG670 – ABB generator protection and control IED, intended for generator-related protection rather than transmission-line differential protection.
- RET670 1MRK002816-AC – ABB transformer protection and control relay, suitable for transformer protection applications within the same broader Relion/ABB protection ecosystem.
- REF620C_F – ABB feeder protection and control platform, better suited to feeder-level protection and automation than the transmission-line-focused REL561.
