REX521BBHGLB01C

Description

Product Overview

The ABB REX521BBHGLB01C is a highperformance feeder and motor protection relay that belongs to ABB’s renowned REX521 series of mediumvoltage protection devices. Designed as a compact, modular unit, the ABB REX521BBHGLB01C integrates measurement, monitoring, and basic control functions to safeguard distribution networks, transformers, generators, and large threephase motors. Core protection algorithms include threephase overcurrent, directional and nondirectional groundfault, thermal overload, phasebreak, and harmonicdistortion monitoring, while its builtin measurement suite provides accurate current, voltage, frequency, and power data for conditionbased diagnostics. The relay supports a wide range of communication standards such as IEC 608705103, LON, SPA, Modbus and DNP3.0, enabling seamless integration into SCADA, DMS and IEC 61850based automation systems. Positioned as a versatile, costeffective solution for mediumvoltage (typically 10 kV–36 kV) networks, the ABB REX521BBHGLB01C delivers reliable protection, realtime data acquisition, and userfriendly operation, making it a key component in modern powersystem automation.

Technical Specifications

REX521BBHGLB01C

Main Features and Advantages

The ABB REX521BBHGLC01C combines advanced digital protection algorithms with a robust hardware platform, delivering fast fault detection and selective tripping that minimizes outage time. Its multiprocessor architecture ensures high reliability and redundancy, while the builtin selfdiagnosis continuously monitors internal health and alerts operators to potential failures before they affect the system. The relay’s user interface features a clear LCD display and intuitive keypad, supporting multilingual operation (including Chinese), which simplifies configuration and onsite troubleshooting. Communication flexibility is a standout advantage: the ABB REX521BBHGLB01C can interface with legacy fieldbuses (IEC 608705103, LON, SPA) as well as modern Ethernetbased protocols (Modbus, DNP3.0, IEC 61850), enabling seamless integration into existing SCADA or DMS environments. Its compact DINrailmountable design reduces panel space requirements, and the modular construction allows easy replacement or upgrade of individual functional blocks. Additionally, the relay records pre and postfault waveforms, providing valuable data for postevent analysis and facilitating rootcause investigations.

Application Field

The ABB REX521BBHGLB01C is ideally suited for mediumvoltage distribution networks where reliable feeder protection is critical, such as municipal substations, industrial parks, and large commercial complexes. It excels in protecting feeder lines that connect to various grounding schemes (solid, resonant, resistancegrounded) and is equally effective for safeguarding mediumsize threephase induction motors in pumping stations, compressors, and manufacturing equipment. In power generation facilities, the relay can be deployed on transformer secondary circuits and generator excitations to provide comprehensive protection and realtime monitoring. Its harmonicdistortion measurement capability makes it valuable for powerquality assessment in sensitive industrial processes, while the builtin breakercontrol outputs enable automated reclosing and loadshedding strategies. By delivering precise fault discrimination and extensive diagnostic data, the ABB REX521BBHGLB01C helps utilities and plant operators improve system reliability, reduce maintenance costs, and comply with stringent grid codes.

Related Products

ABB REX521GBHPLB01G – a variant optimized for gasinsulated switchgear applications.
ABB REX521GHHPSH51G – a highspeed protection module for critical feeder sections.
ABB RET670 – a digital relay family offering extended differential protection functions.
ABB RED521 – a universal terminal unit that can be paired with the ABB REX521BBHGLB01C for expanded I/O.
ABB REL551 – a linedifferential protection relay that complements feeder protection schemes.

REX521BBHGLB01C

Installation and Maintenance

Preinstallation preparation: Verify that the installation environment meets the temperature range of –25 °C to +55 °C, ensure a clean, dustfree panel, and confirm that the DINrail dimensions accommodate the 148.8 mm × 265.9 mm × 235 mm footprint of the ABB REX521BBHGLB01C. Perform a thorough inspection of CT/PT connections, secure the power supply wiring (24 V DC), and configure the communication interface (IEC 608705103, Modbus, etc.) before mounting.

Maintenance recommendations: Conduct periodic selfdiagnosis checks via the LCD interface, update firmware to the latest ABB release, and review recorded fault waveforms after each event. Clean the relay’s enclosure to prevent dust accumulation, verify the integrity of CT/PT secondary circuits, and replace any worn terminal blocks. Keep a spare ABB REX521BBHGLB01C on hand for rapid field replacement to minimize downtime.

Product Guarantee

ABB stands behind the ABB REX521BBHGLB01C with a comprehensive quality guarantee, offering a standard twoyear warranty that covers manufacturing defects and includes free firmware upgrades throughout the warranty period. Technical support is available 24 × 7 via ABB’s global service network, providing onsite assistance, remote diagnostics, and training resources to ensure optimal performance. The robust design, rigorous testing, and ABB’s longstanding reputation in powersystem protection give customers confidence that the ABB REX521BBHGLB01C will deliver reliable, highquality service throughout its operational life.