ABB REX521GHHGSH51G Feeder Protection Relay

Description

Technical Specifications

General Specifications

• Product Family: ABB Relion® Legacy Series (Discontinued since 2012)
• Application: Medium‑voltage feeder protection, motor protection, substation backup protection
• Mounting: Panel‑mounted, compact design for standard switchgear integration
• Operating Voltage: 110/220 V AC/DC (configurable)
• Operating Temperature: -25°C to +55°C; Storage Temperature: -40°C to +85°C
• Ingress Protection: IP54 (front panel)
• Input Compatibility: Supports conventional current transformers (CTs) and voltage transformers (VTs); sensor‑input hardware version available

Measurement & Protection Inputs

• Current Inputs: 3‑phase current inputs (5 A or 1 A nominal, programmable)
• Voltage Inputs: 3‑phase voltage inputs for voltage, frequency, and power measurement
• Analog Inputs: 2 configurable analog inputs (4–20 mA) for auxiliary monitoring
• Digital Inputs: 10 programmable digital inputs for status signals and control commands

Communication Interfaces

• Ethernet: 2×10/100 Mbps RJ45 ports
• Serial: RS‑485 port supporting Modbus RTU
• Supported Protocols: IEC 61850 Edition 2 (MMS + GOOSE), Modbus TCP/RTU, DNP3.0 (optional)
• Time Synchronization: SNTP, IRIG‑B for accurate event time‑stamping

Output & Control

• Digital Outputs: 6 configurable relay outputs for circuit breaker control, alarms, and interlocking
• Control Functions: Circuit breaker trip/close, programmable logic control (PLC), autoreclosing
• Protection Response Time: Fast overcurrent and earth‑fault tripping (< 30 ms) for rapid fault isolation

Measurement Accuracy

• Current/Voltage: ±0.5% of rated value
• Power/Energy: ±1.0% (compliant with IEC 62053‑22 Class 0.5S)
• Frequency: ±0.01 Hz

Key Features

Comprehensive Protection Functions

• Overcurrent Protection: Three‑stage non‑directional/directional overcurrent (3I>, 3I>>, 3I>>>) with IDMT (inverse definite minimum time) or DT (definite time) characteristics.
• Earth‑Fault Protection: Non‑directional/directional earth‑fault (Io>, Io>>, Io>>>) and high‑impedance fault (HIF) detection, compatible with isolated, resonant, solidly earthed, and resistively earthed networks.
• Voltage & Frequency Protection: Overvoltage, undervoltage, overfrequency, and underfrequency protection to safeguard against grid anomalies.
• Motor‑Specific Protection: Thermal overload, start‑up supervision, phase sequence, and stall protection for medium/large AC motors.
• Backup Protection Functions: Provides backup protection for power transformers and high‑voltage line protection relays.
• Autoreclosing: Programmable 3‑shot autoreclosing for automatic fault recovery on temporary faults.
• Breaker Failure Protection: Integrated breaker failure detection to ensure backup tripping in case of primary breaker malfunction.

Advanced Measurement & Monitoring

• Precision Metering: Real‑time measurement of phase currents, voltages, active/reactive power, energy, power factor, frequency, and harmonic distortion (THD/TDD).
• Disturbance Recording: High‑resolution oscillography and event logging with pre‑trigger capability for detailed post‑fault analysis.
• Continuous Supervision: Monitors breaker status, tap positions, and auxiliary analog signals (e.g., pressure, temperature).

Flexible Control & Logic

• Programmable Logic Controller (PLC): Customizable logic for interlocking, synchrocheck, load shedding, and custom control sequences.
• Synchrocheck Function: Ensures safe paralleling of feeders and transformers by verifying voltage, frequency, and phase angle matching.
• Local/Remote Control: Supports local HMI operation and remote control via communication networks.

Robust Communication & Integration

• IEC 61850 Compliance: Full support for digital substation communication standards, enabling seamless integration with SCADA systems and other IEDs.
• Multiple Protocol Support: Compatibility with Modbus and DNP3.0 for integration with legacy and modern automation systems.
• Redundant Communication: Dual Ethernet ports for enhanced communication reliability.

User‑Friendly Design

• Pre‑Configured Templates: Standard application configurations for quick setup and commissioning in various network types.
• Local HMI: Intuitive interface for local monitoring, parameter setting, and fault diagnostics.
• Easy Maintenance: Compact, modular design for straightforward installation, testing, and replacement.

Application Scenarios

• Medium‑Voltage Utility Distribution Networks: Primary protection for incoming and outgoing feeders in radial, looped, and meshed MV distribution systems.
• Industrial Power Systems: Feeder and motor protection in manufacturing plants, refineries, chemical facilities, and large industrial complexes.
• Motor Control Centers (MCCs): Dedicated protection for medium and large three‑phase AC motors in circuit‑breaker‑controlled drive applications.
• Substation Backup Protection: Backup protection for power transformers and high‑voltage transmission line protection relays.
• Isolated/Resonant Earthed Networks: Optimized protection for MV networks with isolated neutral, resonant (Petersen coil) earthing, solid earthing, and resistive earthing configurations.
• Single‑Busbar Substations: Ideal for single‑busbar switchgear solutions, providing comprehensive protection with a single circuit breaker.