ABB REL551 1MRK002480-AE

Description

Detailed parameter table

ABB REL551 1MRK002480-AE

Product introduction

The REL551 1MRK002480-AE is a compact numerical protective relay from ABB, designed to provide reliable protection for low to medium-voltage distribution networks and industrial electrical systems. As part of ABB’s Relion® family, REL551 1MRK002480-AE focuses on essential overcurrent and earth fault protection, making it an ideal solution for applications where simplicity and cost-effectiveness are prioritized without compromising safety.

Engineered for ease of use, REL551 1MRK002480-AE delivers core protection functions with straightforward configuration via front-panel buttons or software. Its compact design allows installation in space-constrained cabinets, while compatibility with standard communication protocols ensures integration with legacy SCADA systems. Whether deployed in commercial buildings, small industrial facilities, or rural distribution networks, REL551 1MRK002480-AE acts as a vigilant guardian, detecting faults quickly to minimize damage and ensure continuity of power supply.

Core advantages and technical highlights

Simplified operation and configuration: REL551 1MRK002480-AE features an intuitive interface with a 4-digit display and membrane keypad, allowing technicians to set parameters like pickup currents and time delays without specialized software. For example, adjusting the earth fault sensitivity in a retail building’s distribution panel can be completed in minutes via the front panel, reducing commissioning time compared to software-dependent models like REL561 1MRK002496-AC. This simplicity makes it ideal for facilities with limited technical resources.

Cost-effective protection: Focused on essential functions, REL551 1MRK002480-AE delivers reliable overcurrent and earth fault protection at a lower price point than advanced relays. It omits complex features like IEC 61850 support, making it a practical choice for applications where basic protection suffices—such as protecting lighting circuits in a shopping mall or pumps in a small agricultural irrigation system. This balance of performance and cost makes it a popular choice for retrofitting older installations.

Legacy system compatibility: With native support for Modbus RTU and IEC 60870-5-103, REL551 1MRK002480-AE integrates seamlessly with older SCADA and control systems common in industrial facilities built before 2010. In a textile mill with a legacy PLC, this compatibility allows the relay to transmit fault alerts to the existing monitoring system without expensive network upgrades, extending the lifespan of the facility’s automation infrastructure.

Robust performance in moderate environments: REL551 1MRK002480-AE operates reliably in temperatures from -20°C to 65°C, with an IP42 front panel rating that resists dust and dripping water—suitable for indoor applications like factory control rooms or utility substations. While it lacks the extreme temperature tolerance of REL561 1MRK002496-AC, it provides sufficient durability for most non-harsh environments, such as schools, hospitals, and office complexes.

Typical application scenarios

In a regional hospital’s electrical distribution system, REL551 1MRK002480-AE protects critical circuits feeding operating rooms and life support equipment. The relay’s overcurrent protection detects overloads in HVAC systems, while earth fault monitoring prevents electrical hazards in patient care areas. Its compact size fits into the hospital’s existing control cabinets, and Modbus RTU integration allows the facility’s BMS (Building Management System) to log fault events, ensuring compliance with safety regulations. During a minor overload from a malfunctioning MRI cooling pump, REL551 1MRK002480-AE issues an alarm before tripping, allowing maintenance to address the issue without disrupting patient care.

In a rural electrical cooperative’s 11 kV distribution network, REL551 1MRK002480-AE safeguards feeder lines serving remote farms and villages. The relay’s earth fault protection quickly isolates faults caused by storm-damaged poles or animal contact, minimizing outage duration. Its simple configuration via front-panel buttons allows cooperative technicians—who may lack specialized software—to adjust settings during seasonal load changes (e.g., higher demand for irrigation pumps in summer). The IP42 rating ensures reliable operation in outdoor kiosks, even during rainstorms.

ABB REL551 1MRK002480-AE

Related model recommendations

ABB REL561 1MRK002496-AC: A higher-featured relay with IEC 61850 support, suitable for upgrading from REL551 1MRK002480-AE in complex systems.

ABB SPACOM S100: A communication converter that enhances REL551 1MRK002480-AE’s connectivity to modern SCADA systems.

ABB CT500: Compact current transformers optimized for use with REL551 1MRK002480-AE in low-voltage applications.

ABB 3BHB003688R0101: A power module providing stable 24 V DC to REL551 1MRK002480-AE in control cabinets.

ABB PCM600: Software for advanced configuration and monitoring of REL551 1MRK002480-AE (optional).

ABB TB850: A surge arrester that protects REL551 1MRK002480-AE from transient voltage spikes in rural networks.

Installation, commissioning and maintenance instructions

Installation preparation: Mount REL551 1MRK002480-AE in a flush panel cutout (112 mm × 112 mm), securing with the provided screws torqued to 1.2 Nm. Connect current transformers to the relay’s input terminals, ensuring phase alignment (A→A, B→B, C→C). Wire the 110-240 V AC/DC power supply using 0.75 mm² cable, protected by a 1 A fuse. For Modbus communication, use shielded twisted-pair cable (0.5 mm²) with the shield grounded at the relay end. Set the current input (1 A/5 A) and frequency (50/60 Hz) via DIP switches before powering on. Disconnect all power sources during installation.

Maintenance suggestions: Inspect REL551 1MRK002480-AE quarterly for loose connections, dust, and LED status (power: green, trip: red). Clean the front panel with a dry cloth; avoid water or solvents. Verify protection settings semi-annually using the front-panel display or PCM600 software, ensuring they match the latest system requirements. Test trip functionality annually by injecting test currents with a relay tester, confirming response times within 60 ms for short circuits. Check Modbus communication monthly by verifying data transmission to the SCADA system. If the relay displays persistent faults, reset to factory settings before replacing—use only ABB-certified units for replacements.

Service and guarantee commitment

REL551 1MRK002480-AE is backed by a 4-year warranty from installation, covering manufacturing defects and ensuring compliance with published specifications. ABB’s technical support team provides weekday response within 12 hours for troubleshooting, with guidance available via phone or email.

The warranty includes access to user manuals, configuration guides, and firmware updates. Extended service contracts offer bi-annual maintenance checks, including calibration verification and function testing, to maximize reliability in critical applications. ABB’s commitment to quality ensures REL551 1MRK002480-AE delivers consistent performance as a cost-effective protective solution for electrical systems.