Technical Overview

The RED615 is a high-performance digital relay engineered for phase-segregated, two-end line differential protection. As part of the ABB Relion 615 series, it is purpose-built for the protection, control, and measurement of overhead lines and cable feeders. Its architecture is optimized for diverse network topologies, including radial, looped, and meshed configurations, providing absolute selectivity in fault detection.

The unit incorporates a withdrawable plug-in design, allowing for rapid installation and streamlined maintenance procedures without disturbing the case wiring. For local interfacing, the RED615 features a large graphical display capable of presenting customized Single Line Diagrams (SLDs), accessible both on-site and via a secure web-based HMI.

Technical Specifications and Capabilities

• Protection Functions: Core 87L phase-segregated differential protection supplemented by directional/non-directional overcurrent (50/51) and earth-fault (50N/51N) safeguards.

• Secondary Protection: Integrated thermal overload and advanced fault location for precision short-circuit and earth-fault diagnostics.

• Communication Interfacing: Dedicated fiber-optic or galvanic pilot wire links support in-zone transformer compensation and remote end synchronization.

• Protocols: Native support for IEC 61850 Editions 1 and 2, including GOOSE messaging, HSR/PRP redundancy, and IEC 61850-9-2 LE sampled values.

• Synchronization: IEEE 1588 V2 Precision Time Protocol for microsecond-level accuracy across distributed networks.

• Legacy Connectivity: Compatible with Modbus and DNP3 protocols.

• Physical Interface: Rugged ring-type terminals for high-vibration industrial environments.

• Weight and Origin: Approximately 1000g, manufactured in Sweden.

Application Environments

The RED615 is specifically deployed in utility substations and industrial power distribution systems. It is the preferred choice for critical feeders where high-speed fault clearance and high sensitivity are required to maintain system stability. The support for in-zone transformers allows it to protect feeders that include power transformers without requiring additional differential units.