Description
Product Overview
The ABB REL551 1MRK002480-AE is a microprocessor-based line differential protection terminal from ABB’s 500-series protection platform, designed for the protection, control, and monitoring of overhead lines and power cables. The ABB REL551 1MRK002480-AE combines phase-segregated current differential protection with additional protection, control, measurement, and recording functions, providing a dedicated solution for distribution, subtransmission, and transmission networks. Its architecture is particularly suited to applications where fast and selective fault clearance is required.
The REL551 1MRK002480-AE compares current information from the protected line ends and incorporates CT saturation stabilization and transmission-delay compensation. It supports transfer-trip functions and different communication arrangements, including multiplexed connections, direct fiber, and pilot-wire interfaces depending on configuration. Additional functions include overcurrent protection, breaker-failure protection, current-circuit supervision, autoreclosing, and single- or multi-pole tripping.
For power-utility and industrial substations, the ABB REL551 1MRK002480-AE can integrate protection information with station automation and supervisory systems through serial communication interfaces such as SPA and IEC 60870-5-103, while LON communication can support control-related functions. Its event, disturbance, and trip-value recording capabilities provide valuable information for fault investigation and maintenance of critical power assets.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | REL551 1MRK002480-AE |
| Manufacturer | ABB |
| Product Family | ABB 500-Series Protection |
| Product Type | Line Differential Protection Terminal / Numerical Protection Relay |
| Primary Application | Overhead Line and Cable Protection |
| Main Protection | Phase-Segregated Line Differential Protection |
| Additional Protection | Overcurrent, Ground/Residual Current, Breaker Failure |
| Tripping | Single-, Two-, and/or Three-Pole Tripping |
| Control Functions | Autoreclosing, Command Control |
| Communication | SPA / IEC 60870-5-103, LON; remote-end protection communication depending on configuration |
| Remote Communication | Multiplexed, dedicated fiber, or galvanic channel depending on configuration |
| Monitoring | Event Recorder, Disturbance Recorder, Trip Value Recorder |
| Measurement Accuracy | Up to 0.25% for specified measured line-current/frequency values |
| Installation | Substation protection/control panel |
| Hardware Architecture | Flexible / expandable protection terminal |
Exact auxiliary supply, CT/VT input ratings, binary I/O configuration, communication hardware, and mounting details depend on the specific ordering configuration. Some third-party listings contain conflicting specifications, so the complete order code and original ABB documentation should be used when selecting a replacement.
Main Features and Advantages
High-speed line differential protection
The REL551 1MRK002480-AE is primarily designed for differential protection of electrical lines. Phase-segregated current differential measurement evaluates both magnitude and phase angle, allowing faults within the protected zone to be identified rapidly and selectively. This helps minimize unnecessary disconnection of healthy portions of the power network.
Enhanced stability during CT saturation
The protection algorithm incorporates CT saturation detection to improve differential protection stability during demanding fault conditions. This is important because inaccurate CT reproduction during high-current faults can otherwise create unwanted differential operating conditions.
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REL551
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Flexible communication architecture
The relay supports multiple remote-end communication arrangements, including multiplexed channels, dedicated fiber, and galvanic connections depending on the hardware configuration. Continuous compensation of transmission delay allows the protection scheme to accommodate communication paths where signal delay must be considered.
Integrated backup and control functions
In addition to differential protection, the terminal provides phase and residual-current functions, breaker-failure protection, current-circuit supervision, autoreclosing, and configurable tripping logic. This multifunctional approach reduces the need for separate protection devices in many line-protection schemes.
Comprehensive disturbance analysis
Built-in event, disturbance, and trip-value recording provides engineers with useful information after a fault. Recorded measurements and binary status information can help determine fault behavior, verify relay operation, and support maintenance investigations.
Flexible engineering and configuration
The platform provides extensive configurable logic using internal gates, timers, and connections between functions, binary inputs, and outputs. This makes the 1MRK002480-AE adaptable to different protection philosophies and substation architectures.
Application Fields
The ABB 1MRK002480-AE is primarily intended for protection of overhead transmission and subtransmission lines, as well as suitable power-cable applications. In utility substations, it can be applied to incoming and outgoing lines where rapid differential fault detection is required. The terminal’s selective protection philosophy helps isolate only the affected circuit while maintaining availability of healthy network sections.
In power-generation facilities, the relay can protect high-voltage connections between generators, substations, and transmission networks. Its differential protection, breaker-failure logic, autoreclosing, and remote-end communication capabilities can be incorporated into coordinated protection schemes for critical grid connections.
The 1MRK002480-AE is also applicable to industrial substations in oil and gas, chemical processing, metallurgy, mining, and large manufacturing plants. These facilities frequently operate medium- and high-voltage distribution networks where a line fault can cause significant production disruption. Integrating the relay with station automation and SCADA infrastructure allows protection events, measurements, and alarms to be incorporated into centralized operational monitoring.
For cable and overhead-line installations with challenging communication or network configurations, the relay’s configurable remote-end communication options provide additional engineering flexibility. It can also support maintenance and post-fault analysis through event and disturbance recording, making it useful for long-term operation of legacy power-protection systems.
Related Products
- REL561 1MRK002496-AC – Closely related ABB line-protection terminal from the same broader 500-series platform, offering enhanced line protection functionality and suitable for transmission applications.
- RED521 1MRK002003-BA – ABB line differential protection terminal designed for high-speed differential protection of electrical power lines.
- 1MRK002480-AG – Related configuration reported with different communication options; verify the complete order code before considering substitution.
- – Other configurations provide different hardware, I/O, communication, and application options within the same line-protection platform.
- REC670 1MRK002814-AC – ABB protection and control IED used for substation control and automation functions, complementing dedicated line-protection equipment.
- REF610 – ABB feeder protection relay designed for feeder, motor, transformer, and distribution protection applications rather than dedicated line differential protection.
- RET670 1MRK002816-AC – ABB transformer protection and control IED suitable for transformer protection within power-generation and substation architectures.
- REG670 – ABB generator protection and control IED designed for generator-related protection applications.
- REL650 Series – Later ABB Relion-family line protection platform providing modern numerical protection and communication capabilities for transmission and subtransmission applications.
- REX521 – ABB multifunctional protection relay family used in earlier distribution and industrial protection installations, providing an alternative for legacy protection architectures.
