ABB's Relion® 615 series medium-voltage protection relays

ABB's Relion® 615 series is a leading product in the medium-voltage protection and control sector, gaining widespread recognition globally for its compactness, rich functionality, robust communications capabilities (especially IEC 61850 compliance), and excellent price-performance ratio. With a variety of base function models (REM, REF, RET, etc.) and a wide range of suffix configurations (E, G, H, etc.), it flexibly meets the protection, control, and monitoring needs of a wide range of applications, from medium-voltage feeders and transformers to motors and capacitors. The unified PCM600 tool significantly simplifies engineering and maintenance.

The ABB Relion® 615 series is a compact, versatile, and cost-effective line of protection relays designed by ABB for medium-voltage power grids (typically 1 kV to 52 kV). It is part of ABB's broader Relion® product family and REx 6xx technology platform, providing comprehensive protection, control, measurement, and monitoring capabilities for critical assets such as feeders, transformers, motors, and capacitors in applications such as distribution systems, industrial facilities, renewable energy (such as wind power and photovoltaics), and infrastructure.

Common Model List (Base Model + Common Suffix Description)

Relion 615 model numbers generally follow the naming convention of <Function Code>615<Hardware Version>_<Special Features/Certifications>:

REM615: Line Protection Relay

Core Functions: Distance protection, overcurrent protection, ground fault protection, autoreclosing, etc.

Common Models:

REM615E_G

REM615E_H

REM615E_L (may indicate a specific housing or terminal configuration)

REM615E_S (may indicate a specific feature set or certification)

REF615: Feeder Protection Relay

Core Functions: Comprehensive overcurrent protection (phase, zero sequence, negative sequence), ground fault protection, thermal overload protection, voltage protection, frequency protection, circuit breaker failure protection, etc. This is one of the most versatile models.

Common Models:

REF615E_G

REF615E_H

REF615E_L

REF615E_S

REF615F_G (F may indicate a newer hardware version or feature)

REB615: Busbar Protection Relay

Core Function: Busbar differential protection based on logic or low-impedance principles (usually requires multiple units).

Common Models:

REB615E_G

REB615E_H

REC615: Capacitor Bank Protection Relay

Core Function: Protection designed for capacitor banks, such as unbalance protection (voltage and current), overcurrent protection, overvoltage protection, and undervoltage protection.

Common Models:

REC615E_G

REC615E_H

RET615: Transformer Protection Relay

Core Functions: Differential protection, backup overcurrent protection (with selectable direction), ground fault protection, thermal overload protection, on-load tap changer control, etc.

Common Models:

RET615E_G

RET615E_H

REQ615: Automatic Backup Power Supply Enable Device

Core Function: Automatically switches busbar sectionalizers or incoming line circuit breakers to ensure power supply continuity.

Common Models:

REQ615E_G

REQ615E_H

Suffix Description (Common)

E: Indicates the hardware platform or generation to which the model belongs. E is the most common and widely used platform in the Relion 615 series, offering improved performance and enhanced functionality compared to the earlier D platform.

G: Typically indicates compliance with global standards and extensive certifications (e.g., UL, CE, IEC), making it suitable for international markets.

H: Typically indicates a higher-density I/O module configuration, providing more DI/DO points.

L/S: May indicate a specific housing type (e.g., more compact), terminal block configuration, or a simplified feature set for a specific market. Please refer to the specific model's data sheet for the exact meaning.

F: (Seen on some newer models, such as the REF615F) May indicate a feature-enhanced or updated version based on the E platform.