Product Overview

The ABB REU615 is a high-performance Voltage Protection and Control Intelligent Electronic Device (IED) belonging to ABB’s Relion® 615 Series protection relay family. It is specifically designed for voltage protection, synchronization, monitoring, and control applications in medium-voltage and industrial power distribution networks. The relay provides a flexible solution for protecting electrical systems against abnormal voltage conditions while improving grid reliability and operational efficiency.

The ABB REU615 is commonly used in substations, power plants, renewable energy facilities, and industrial electrical networks where accurate voltage monitoring and advanced protection functions are required. It combines protection algorithms, measurement functions, communication capabilities, and programmable logic into a compact device, making it suitable for modern digital substation applications.

As part of ABB’s Relion 615 product family, the REU615 follows ABB’s modular design philosophy and supports flexible configuration through ABB PCM600 engineering software. The relay can be adapted for different application requirements by selecting suitable protection functions, communication options, and input/output configurations.

The device is especially valuable in systems where voltage stability is critical. It helps detect undervoltage, overvoltage, frequency-related abnormalities, and power quality issues, allowing operators to take corrective actions quickly and maintain stable electrical operation.

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Product Specifications

Parameter	Description
Manufacturer	ABB
Product Family	Relion® 615 Series
Model	REU615
Product Type	Voltage Protection and Control Relay
Application	Medium-voltage voltage protection systems
Protection Functions	Overvoltage, undervoltage, frequency protection, synchronization
Rated Frequency	50/60 Hz
Current Inputs	1 A / 5 A
Voltage Inputs	60–210 V AC
Auxiliary Supply	AC and DC power supply options
Communication	IEC 61850 and other protocols depending on configuration
Installation Type	Panel mounting / switchgear installation
Dimensions	Approx. 177 mm × 177 mm × 201 mm
Weight	Approx. 4.1 kg
Engineering Tool	ABB PCM600

 

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Functional Description

The primary function of the ABB REU615 Voltage Protection Relay is to continuously monitor electrical voltage conditions and provide protective control actions when abnormal situations occur.

The relay receives voltage measurement signals from voltage transformers (VTs) installed in the electrical network. Using advanced digital processing technology, it analyzes voltage values, frequency conditions, and system status to determine whether protection actions are required.

The REU615 can perform functions such as:

• Overvoltage protection
• Undervoltage protection
• Residual voltage protection
• Frequency supervision
• Voltage-based automation
• Synchronism checking
• Circuit breaker control
• Event recording
• Disturbance recording

By detecting abnormal voltage conditions at an early stage, the relay helps prevent equipment damage and improves the reliability of electrical distribution systems.

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Protection Functions and Operating Performance

Overvoltage and Undervoltage Protection

One of the core functions of the ABB REU615 is voltage level monitoring.

Electrical systems may experience abnormal voltage conditions due to:

• Grid disturbances
• Equipment failures
• Generator operation problems
• Load changes
• Network switching operations

The REU615 continuously evaluates voltage levels and can initiate alarms or trip commands when voltage exceeds or falls below configured limits.

This protection helps safeguard:

• Transformers
• Motors
• Generators
• Distribution equipment
• Sensitive electrical loads

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Frequency Protection and Monitoring

The REU615 also supports frequency-related protection applications.

Frequency deviations may indicate problems such as:

• Generator imbalance
• Grid instability
• Power supply disturbances

By monitoring frequency conditions, the relay helps maintain system stability and supports power management applications.

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Human Machine Interface

The front panel provides a convenient interface for local operation and maintenance.

Operators can access:

• Relay status information
• Alarm messages
• Measurement values
• Event records
• Protection settings

This simplifies commissioning and troubleshooting activities.

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Main Features and Advantages

High Reliability Voltage Protection

The ABB REU615 provides dependable protection for medium-voltage electrical networks.

Its advantages include:

• Fast fault detection
• Accurate measurement
• Flexible protection configuration
• Continuous system monitoring

Reliable voltage protection helps improve electrical system availability and reduce unexpected shutdowns.

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Flexible Application Configuration

The relay supports multiple application configurations that can be adjusted according to project requirements.

Through ABB PCM600 engineering software, users can customize:

• Protection logic
• Input/output mapping
• Communication settings
• Control functions

This flexibility makes the REU615 suitable for different power system architectures.

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Advanced Diagnostic Capability

The REU615 includes self-monitoring and diagnostic functions.

Diagnostic features help maintenance teams:

• Identify faults quickly
• Monitor relay health
• Analyze system events
• Reduce troubleshooting time

This improves maintenance efficiency and supports preventive maintenance strategies.

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Industrial Electrical Networks

Large industrial facilities depend on reliable electrical protection systems.

Typical applications include:

• Manufacturing plants
• Petrochemical facilities
• Mining operations
• Heavy industrial systems

The relay helps protect electrical equipment from harmful voltage conditions.

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Installation and Maintenance

Installation Guidelines

Before installing the ABB REU615, engineers should confirm:

• Correct protection application
• Proper VT wiring
• Suitable auxiliary power supply
• Correct communication configuration
• Appropriate panel mounting conditions

Accurate wiring and configuration are essential for reliable protection operation.

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Maintenance Recommendations

Regular maintenance ensures long-term relay performance.

Recommended maintenance activities include:

• Checking relay self-diagnostic status
• Reviewing event records
• Testing protection functions
• Inspecting terminal connections
• Verifying communication operation

Protection relay testing should be performed according to electrical standards and site maintenance procedures.

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Product Value and Supply Information

The ABB REU615 Voltage Protection and Control Relay is an advanced solution for medium-voltage electrical protection applications. With flexible configuration, intelligent monitoring functions, reliable voltage protection, and modern communication capability, it provides strong support for digital power system automation.

For customers maintaining ABB Relion 615 series installations, the REU615 is an important spare and replacement component that helps maintain stable operation of substations, industrial power networks, and energy systems.