Product Core Brief

• Model: ABB REJ603 REJ603BB401NN31E
• Brand: ABB
• Series: Relion 600 (REJ603 platform)
• Core Function: Feeder protection for MV distribution networks
• Product Type: Self-powered numerical protection relay (IED)
• Key Specs: CT self-powered operation | 1 A / 5 A inputs | IEC 60870-5-103 (variant dependent)
• Condition: New Original (New Surplus)

Key Technical Specifications

• Product Type: Self-powered feeder protection relay (IED)
• Platform: ABB Relion® REJ603 series
• Power Supply Concept:
  • Self-powered via CT energy harvesting (no external auxiliary supply required in basic configurations)
  • Optional auxiliary supply variants exist depending on order code
• Order Code: REJ603BB401NN31E (hardware + I/O + application configuration variant)
• Protection Functions:
  • 3-stage overcurrent protection (50/51)
  • Earth fault protection (50N/51N)
  • Thermal overload (49)
  • Transformer inrush restraint (variant dependent)
  • Circuit breaker failure protection (optional function set)
• Current Inputs:
  • 1 A / 5 A CT selectable
  • Wide dynamic range for distribution feeder applications
• Binary Inputs/Outputs:
  • 1–2 binary inputs (variant dependent)
  • 1–2 trip outputs (configurable relay contacts)
• Communication Interfaces:
  • IEC 60870-5-103 (common in REJ603 deployments)
  • Modbus RTU (optional variant dependent)
  • Some configurations support IEC 61850 gateway integration externally
• Event & Fault Recording:
  • Event log storage (limited memory, protection-focused)
  • Fault indication via LEDs + relay status output
• Protection Characteristics:
  • IEC 60255 inverse time curves (IDMT)
  • Definite time (DT) selectable stages
• Mechanical & Environmental:
  • Operating temperature: -25°C to +55°C
  • Storage temperature: -40°C to +70°C
  • Mounting: Panel / RMU integration format
  • Compact switchgear-friendly enclosure
• Compliance:
  • IEC 60255 series
  • CE marking (variant dependent certification batch)

Product Introduction

ABB REJ603 REJ603BB401NN31E is a self-powered feeder protection relay designed for secondary distribution networks, typically installed in RMUs, compact substations, and industrial MV feeders. It operates without an external auxiliary supply by harvesting energy from CT secondary current during fault and load conditions.

The relay provides essential protection functions including overcurrent, earth fault, and thermal overload, using IEC 60255-based time-current characteristics. The BB401NN31E configuration defines a specific hardware build with defined I/O mapping and communication options for distribution automation applications. This variant is commonly used in legacy ABB feeder protection schemes where simplicity, autonomy, and fast tripping are prioritized over full IEC 61850 substation integration.