ABB REX521GHHPSH07G

Product Description

The ABB REX521GHHPSH07G is a sophisticated numerical protection relay from ABB’s renowned REX521 series, designed for feeder protection, motor protection, and control applications in medium voltage and low voltage power distribution systems. This unit combines advanced protection functions, measurement capabilities, and control logic within a compact, panel-mounted enclosure. As a member of the ABB REX521 product family, the ABB REX521GHHPSH07G offers programmable logic, extensive communication options, and user-friendly local interface, making it a versatile solution for industrial and utility power networks. It is recognized as a reliable OEM component for safeguarding critical electrical infrastructure and enabling intelligent substation automation.

Product Parameters

• Model: ABB REX521GHHPSH07G

• Type: Numerical Protection Relay / Feeder Protection Terminal

• Protection Functions: Overcurrent, earth fault, thermal overload, circuit breaker failure protection, and optional voltage-based functions depending on configuration

• Current Inputs: Typically 5A or 1A CT secondary inputs (configurable)

• Voltage Inputs: Optional voltage measurement capabilities for directional protection and power metering

• Control Capability: Integrated circuit breaker control with position indication and trip/close commands

• Communication Protocols: Supports IEC 60870-5-103, Modbus RTU, Profibus DP (via optional module), and SPA bus protocols

• Local Interface: Large graphical LCD display with backlight, keypad for local programming and monitoring

• Programmable Logic: Configurable logic using ABB’s built-in function block programming (Parametrizable Logic)

• Power Supply: Wide-range auxiliary power supply, typically 24-250V DC or 48-230V AC

• Mounting: Flush panel mount with rear terminals for wiring

Advantages and Features

The ABB REX521GHHPSH07G offers a comprehensive set of features that distinguish it as a versatile protection solution:

• Integrated Protection and Control: The ABB REX521GHHPSH07G combines protective relaying with circuit breaker control, eliminating the need for separate control switches and indicating instruments. This integration simplifies panel design and reduces overall system complexity.

• Flexible Protection Configuration: This unit supports a wide range of protection functions, including directional overcurrent, earth fault, and thermal overload protection. The ABB REX521GHHPSH07G can be customized to suit various applications, from simple feeder protection to complex motor protection schemes.

• User-Friendly Interface: The large graphical LCD display provides clear visualization of measured values, event logs, and fault records. Local programming via the keypad allows for rapid configuration changes without requiring external software, making the ABB REX521GHHPSH07G accessible to field technicians.

• Event Logging and Disturbance Recording: The relay features comprehensive event logging and fault recording capabilities, storing up to 200 events and multiple fault records. This functionality is invaluable for post-fault analysis and system optimization.

• Wide Communication Flexibility: With multiple supported communication protocols, the ABB REX521GHHPSH07G integrates seamlessly into existing substation automation systems, SCADA networks, and industrial control systems. The ability to add Profibus DP or other modules extends its connectivity options.

• Robust Build Quality: Designed for demanding electrical environments, the ABB REX521GHHPSH07G features robust insulation, high immunity to electromagnetic interference, and a wide operating temperature range, ensuring reliable performance in harsh substation conditions.

Application Cases

The ABB REX521GHHPSH07G is deployed across various sectors where reliable power protection is essential:

• Industrial Power Distribution: Used in manufacturing facilities as feeder protection for medium voltage switchgear. The ABB REX521GHHPSH07G monitors incoming and outgoing feeders, providing overcurrent and earth fault protection while communicating with plant SCADA systems for real-time power management.

• Motor Protection in Heavy Industry: Deployed in mining and metals processing plants to protect large motors driving crushers, mills, and conveyors. The thermal overload and start-up supervision functions of the ABB REX521GHHPSH07G prevent damage from prolonged starting times or excessive cycling.

• Utility Substations: Installed in primary and secondary distribution substations for feeder protection and network monitoring. The directional protection capabilities of the ABB REX521GHHPSH07G enable selective fault clearing in radial or looped network configurations.

• Renewable Energy Installations: Used in solar farms and wind power plants to protect medium voltage collection systems and interconnection points. The ABB REX521GHHPSH07G provides voltage and frequency protection essential for grid code compliance in renewable applications.

Comparison with Competing Products

When compared to alternative protection relays from other manufacturers or newer ABB platforms, the ABB REX521GHHPSH07G holds specific advantages:

• Legacy Compatibility: The ABB REX521GHHPSH07G is part of the widely installed REX521 series, making it a direct drop-in replacement for existing installations. Unlike newer relay platforms that may require panel modifications or complete rewiring, this unit maintains form, fit, and function compatibility with existing switchgear designs.

• Integrated Control Logic: While many competing relays offer protection functions but require external PLCs for logic and control, the ABB REX521GHHPSH07G features built-in programmable logic (Parametrizable Logic). This allows simple interlocking, auto-reclosing schemes, and alarm handling to be implemented within the relay itself, reducing hardware costs.

• User Interface Quality: Competitor relays in this class often feature smaller LCD screens with limited graphical capability. The ABB REX521GHHPSH07G provides a larger graphical display with detailed single-line diagram representations, improving operator situational awareness at the panel level.

• Protocol Versatility: Many protection relays support only one or two communication protocols. The ABB REX521GHHPSH07G offers multiple native protocol options, providing greater flexibility for integration into existing systems without requiring protocol converters, which can add points of failure.

• Reliability Track Record: The REX521 series, including the ABB REX521GHHPSH07G, has established a strong reputation for long-term reliability in the field. For facilities seeking to maintain proven equipment rather than migrate to new platforms with unknown long-term performance, this unit represents a trusted choice.

Selection Suggestions and Precautions

When selecting and configuring the ABB REX521GHHPSH07G, consider the following guidelines:

• Verify Protection Requirements: The ABB REX521GHHPSH07G configuration includes specific protection function sets. Confirm that the unit’s hardware and firmware version supports the required protection elements for your application, such as directional overcurrent, voltage protection, or dedicated motor protection functions.

• CT and PT Sizing: Ensure that the current transformer (CT) and voltage transformer (PT) secondary ratings match the relay’s input specifications. The ABB REX521GHHPSH07G typically accepts 5A or 1A CT secondaries; incorrect CT selection will result in inaccurate measurement and protection misoperation.

• Auxiliary Power Supply Compatibility: Verify that the auxiliary power supply voltage matches the available station battery or AC supply. The ABB REX521GHHPSH07G supports a wide range, but applying incorrect voltage can damage the internal power supply module.

• Communication Network Planning: Determine the required communication protocol before installation. The ABB REX521GHHPSH07G may require optional communication modules for certain protocols such as Profibus DP. Plan the network architecture and addressing to ensure seamless integration with SCADA or DCS systems.

• Firmware Version Consistency: When replacing an existing unit or adding to an existing system, confirm that the firmware version of the ABB REX521GHHPSH07G is compatible with the configuration files and communication settings used elsewhere. Firmware mismatches can cause interoperability issues.

• Parameter Backup: Before decommissioning an existing relay, extract and save all protection settings, logic configurations, and communication parameters. This data can be downloaded into the replacement ABB REX521GHHPSH07G using ABB’s configuration software, significantly reducing commissioning time.

• Testing and Commissioning: After installation, perform comprehensive protection testing using secondary injection test equipment. Verify that all protection elements operate correctly, trip outputs function as intended, and communication with the host system is established. Document all test results for regulatory compliance and future reference.

• Handling and Storage: Store the ABB REX521GHHPSH07G in a clean, dry environment before installation. Observe electrostatic discharge (ESD) precautions during handling to prevent damage to sensitive electronic components.