ABB REX521GHHPSH51G Protection relay

ABB  REX521GHHPSH51G

A specific model of the REX 521 series within ABB’s Relion® product family, it is specifically designed to provide comprehensive and reliable primary protection for medium and large power transformers. It integrates advanced differential protection algorithms and multiple backup protection functions in a compact unit.

Key Features & Characteristics

1. Primary Protection: Transformer Differential Protection

   • Core Principle: Detects internal transformer faults by comparing the magnitude and phase of currents on the high-voltage and low-voltage sides. This is the most sensitive and rapid primary protection for transformers.

   • Advanced Characteristics:

     • Percentage Restraint Characteristic: Reliably distinguishes between internal fault currents and external events (like through-faults) or inrush currents, preventing false operation.

     • Inrush Current Restraint: Identifies transformer magnetizing inrush current during energization (typically through 2nd harmonic analysis) and blocks the differential protection to prevent unnecessary tripping.

     • CT Circuit Supervision: Detects breaks in the Current Transformer circuits and issues an alarm or blocks the protection.

2. Comprehensive Backup Protection Functions

   • In addition to the main differential protection, the unit integrates various backup protections, creating a complete solution that often eliminates the need for separate relays. Common backup functions include:

     • Overcurrent protection (Definite Time, Inverse Time)

     • Earth-Fault (Ground) protection

     • Overvoltage/Undervoltage protection

     • Overfrequency/Underfrequency protection

     • Thermal overload protection (for the transformer)

3. Control, Monitoring & Communication

   • Measurement & Metering: Real-time monitoring of electrical parameters like current, voltage, power, power factor, and energy.

   • Event Recording: A time-tagged event logger records all operations, alarms, and fault events.

   • Fault Disturbance Recording: Captures current and voltage waveforms before, during, and after a fault for detailed analysis.

   • Communication Capabilities:

     • Typically equipped with multiple communication interfaces, such as RS485.

     • Supports standard industrial protocols like IEC 61850 (for digital substations), Modbus, IEC 60870-5-103, etc., enabling easy integration into Substation Automation Systems (SAS).

4. User-Friendly Operation

   • Front Panel: Features a large graphical LCD display and navigation keys for local data viewing, setting modification, and control.

   • Configuration Software: Dedicated ABB software tools (like PCM600 or the earlier CAP 501) allow for easy parameter setting, logic configuration, and data analysis.

Model Code Breakdown

• REX 521: Product series name.

• G: Stands for “Generation,” indicating the hardware platform.

• HH: Indicates the current input configuration for both the High-Voltage and Low-Voltage sides. It signifies the relay can accept inputs from CTs on both sides of the transformer.

• P: Indicates the unit is equipped with a Printer interface.

• S: Indicates the unit is equipped with a Serial communication interface (e.g., RS485).

• H51: This is a specific Hardware/Software version code defining the exact protection functions and firmware version included in this model.

• G: Typically indicates the enclosure color or other physical characteristics.

Typical Applications

• Main substations in industrial plants and mines

• Integrated power distribution systems in commercial buildings

• Step-up transformers in renewable power plants (e.g., wind, solar)

• Medium and small-sized substations in the utility power sector

Sales of the brand:

ABB、EPRO、GE、FOXBORO、Schneider、Rexroth、Honeywell、Bently、YASKAWA other global DCS system and PLC system, servo system of famous industrial brand.

☀️Tara(Sales Director)

📞Tel: + 86-13806028623

📮Whatsapp:+86-13806028623

💬Email: ydf8801@163.com

🏚️Ship to you via DHL/TNT/UPS/EMS/Fedex

🥇Product Condition: One-year warranty

requently Asked Questions:
1. How long does it take to receive the goods?
We have stock in stock and can accept same-day payment and delivery!

2. What payment methods do you accept?
There are many methods (T/T…) for you to choose from, and you can choose whatever you want.

3. Is there after-sales service?
Of course, if our products are brand new, they have a one-year warranty!

4. What courier services do you accept? We offer SF Express, DHL, and other international express delivery options.

5. How can I contact you?

You can contact me 24/7 via WeChat, Skype, WhatsApp, LINE, and my email!

Company Profile

Xingchuang Ronghe (Fuzhou) Electric Co., Ltd. is a company specializing in the sales and technical services of spare parts for the world’s top industrial automation systems. With our profound industry experience and stable supply channels, we provide domestic and foreign customers with original, authentic, complete models, and fast-delivered precision spare parts solutions. We are your reliable partner in ensuring production continuity and stability.

We specialize in distributing the following core brands and product lines:

ABB

•  Process Control: ABB DCS process control system full range of components.
• ABB FreeLance AC800F power modules: SA801F/SA811F/SD802F/SD812F, EI811F/ABB EI812F/ABB EI813F, etc.
• ABB S800 analog I/O modules: AI801/AI810/AI825/AO801/AO845/AO895
• ABB S800 digital I/O modules: DI801/DI810/DO801/DO810

Bently Nevada
3500 Module Mainboards: 3500/42, 3500/45, 3500/40, 3500/50, etc.
(CPU Modules): 3200/32, 3500/25
3500 Module Minimum Cards: 128229-01, 128229-01, 133442-01, 125800-01, 167699-02, etc.
Extension Cables: 330850-50-05 (for preamplifier), 330730-040-00-00, 330103-00-06-10-02-00, etc.

EPRO

•  MMS6000 TSI System: MMS6110/MMS6210/MMS6220 series monitoring modules.
  Sensors: Proximitor sensors CON011, CON021, CON031, etc

GE

• PLC Systems: IC693, IC695, and IC697 Series Modules.
• Drives and Protection: GE DRIVE SYSTEMS Series Inverters, SR Integrated Protection Frame Series.

Rexroth

• Drives and Motors: Full range of Rexroth servo drives and controllers; models include: servo motor 2AD160B-B0350R2-BS03-D2V1, MSK040C-0600-NN-M1-UP1-NSNN, etc.
• Rexroth communication boards and amplifier boards: MTS-P01.2-D2-B1-E1-NN-NN-FWEP, VT-VPCD-1-1X/V0/1-0-1, VT5006-17B, etc.

Siemens

· Process Instruments and Controllers: Siemens MOORE series, common models include: QLCDM024DCBAN, 39ACM24BEN, 39AC12T4V1, 16114-171, etc.
· Automation Systems: Full range of SIMATIC S5 PLCs, SIMATIC S7-400 CPU modules and expansion modules, Simatic C7 systems, and various Siemens touch screens.