ABB RET620 Transformer Protection and Control Relay

The ABB RET620 is a high-performance protection and control relay designed specifically for power transformers and generator-transformer units. Part of the Relion® 620 series, it delivers a comprehensive set of functionalities for protection, control, measurement, and monitoring in substations and industrial distribution systems.

Key Features and Capabilities

• All-in-One Functionality
Integrates protection, control, measurement, and monitoring in a single compact device—streamlining system design and simplifying operation.

• Advanced Transformer Protection
Supports two-winding transformer protection with fast and secure differential protection featuring inrush restraint. Includes a range of protection features such as:

• High/low impedance restricted earth fault protection

• Overcurrent and undervoltage protection

• Overexcitation and thermal overload protection

• Automatic Voltage Regulation (AVR)
Optional AVR function supports on-load tap changer control.

• Arc Flash Protection
Available with optional integrated arc protection for enhanced safety.

• Flexible System Integration
Suitable for a wide range of transformer configurations (Y-Δ), with one or two circuit breakers, across single or double busbar systems.

• Extensive Communication Support
Supports multiple communication protocols for seamless integration into substation automation systems:

• IEC 61850 (Editions 1 and 2), including HSR/PRP redundancy, GOOSE messaging, and Sampled Values (IEC 61850-9-2)

• Modbus®

• DNP3

• IEC 60870-5-103

• Time synchronization via IEEE 1588 v2 PTP and other methods

• Intuitive User Interface
Equipped with a large LCD display and user-editable single-line diagrams. Operable via both local panel and web-based HMI.

• Pluggable Design
Facilitates easy installation, maintenance, and testing.

• Scalable I/O Options
Expandable I/O capacity through connection with ABB’s RIO600 remote I/O units.

• Configurable and Ready-to-Use
Ships with pre-engineered configurations and can be quickly tailored using ABB’s functional configuration tools.

Typical Applications

• Power Transformers (Two-Winding)
Provides comprehensive protection, including differential and thermal overload functions.

• Generator-Transformer Units
Safeguards the transformer component in generator-transformer assemblies.

• Industrial Distribution Systems
Delivers reliable transformer protection in demanding industrial environments.