ABB REF615 HBFFAEAGNBC6BNA11G: A Technical Overview of the Feeder Protection Relay

In the complex ecosystem of an electrical distribution system, protecting medium-voltage feeders is critical for preventing equipment damage and ensuring operational continuity. The ​ABB REF615 HBFFAEAGNBC6BNA11G​ is a highly advanced, numerical protection relay from ABB's renowned RELion® product family. This article provides a comprehensive technical examination of this specific device, decoding its model number, explaining its core protection functions, and detailing the features that make it a cornerstone of modern electrical protection schemes.

Decoding the Model: What does HBFFAEAGNBC6BNA11G mean?

The long suffix ​HBFFAEAGNBC6BNA11G​ is not random; it is a detailed configuration code that specifies the relay's hardware and software options. Decoding it reveals the device's capabilities:

• ​H:​​ Hardware version or case style.
• ​B, F, etc.:​​ These letters typically specify the available protection and control functions enabled (e.g., overcurrent, earth fault).
• ​A, E, A:​​ Often denote the type and rating of the power supply (e.g., 110-250V AC/DC).
• ​G, N, B, C:​​ Usually define the communication options, such as the number of Ethernet ports, support for specific protocols like IEC 61850, and the presence of a rear communication port.
• ​6BNA11G:​​ Specifies the I/O (Input/Output) configuration—the number of binary inputs, output relays, and their specific ratings.

In essence, this full part number describes a fully configured REF615 relay ready for a specific set of application requirements.

Core Protection Functions

The REF615 is designed as a comprehensive feeder protection terminal. Its primary protection functions include:

​1. Overcurrent Protection (50/51/50HS/51HS)​​

This is the fundamental protection for electrical feeders.

• ​Instantaneous Overcurrent (50):​​ Provides immediate tripping for high-magnitude short-circuit currents.
• ​Time-Overcurrent (51):​​ Operates with an inverse time delay for overloads and lower-level faults, allowing for coordination with upstream and downstream devices.
• ​High-Set Instantaneous (50HS):​​ A second, higher-set instantaneous element for very severe faults.
• ​High-Set Time-Overcurrent (51HS):​​ Provides additional flexibility for complex coordination schemes.

​2. Directional Overcurrent Protection (67)​​

In networked systems like ring mains, it is crucial to trip only the breaker closest to the fault. Directional overcurrent protection determines the direction of the fault current, ensuring selective tripping and maintaining power to healthy sections of the network.

​3. Earth-Fault Protection (50N/51N/67N)​​

Detects current leakage to ground, which can be hazardous. It includes both non-directional and directional elements for isolated or compensated neutral systems.

​4. Thermal Overload Protection (49)​​

Models the heating of the protected cable or transformer based on the measured current. It provides an alarm or trip signal before thermal damage occurs, enabling predictive asset management.

Key Technical Features

• ​IEC 61850 Communication:​​ Native support for the ​IEC 61850​ standard allows for seamless integration into modern digital substations, enabling advanced features like GOOSE messaging for high-speed interlocking.
• ​Advanced HMI:​​ A large graphical display and intuitive menu provide local access for commissioning, real-time data monitoring, and event analysis.
• ​Condition Monitoring:​​ The relay provides valuable data on the operating times and number of operations of the circuit breaker, facilitating condition-based maintenance.
• ​Robust Design:​​ Built to withstand the harsh electromagnetic environment of electrical switchgear.

Conclusion

The ​ABB REF615 HBFFAEAGNBC6BNA11G​ is a sophisticated, multi-function protection relay that combines essential feeder protection with modern communication and diagnostic capabilities. Its specific configuration makes it a ready-to-deploy solution for engineers seeking to enhance the safety, reliability, and intelligence of their electrical distribution networks.