Overview

The ABB REJ603BB401NN31E Protection Relay is a self‑powered feeder protection relay, part of ABB's Relion® 600 series. This relay is specifically engineered for secondary distribution networks, where reliable fault protection is critical. It is powered directly from the current transformers (CTs) connected to the feeder, eliminating the need for an external auxiliary power supply, making it perfect for installations with limited or unavailable auxiliary voltage sources.

The REJ603 offers selective short-circuit and earth-fault protection, ensuring quick fault detection and tripping to safeguard both equipment and personnel. Its compact design and ease of installation make it well-suited for use in ring main units (RMUs), compact substations, and distribution automation projects.

Technical Data

Typical Applications

• Ring Main Units (RMUs): Ideal for compact substations requiring self-powered protection.

• Secondary Distribution Networks: Reliable fault detection without the need for auxiliary power.

• Industrial Plants: Protects feeders in chemical, paper, textile, and steel industries.

• Power Utilities: Perfect for distribution automation projects where auxiliary voltage sources are limited.

• Retrofit Projects: Replaces legacy feeder protection relays with modern ABB solutions.

FAQ

Q1: What is the ABB REJ603BB401NN31E used for?
A1: It provides selective short-circuit and earth-fault protection for medium-voltage distribution networks.

Q2: Does the REJ603 require an auxiliary power supply?
A2: No, it is self-powered via current transformers, making it ideal for installations where auxiliary voltage is unavailable.

Q3: What industries typically use the REJ603 relay?
A3: It is widely used in power utilities, industrial plants, and compact substations.

Q4: How reliable is the ABB REJ603?
A4: The REJ603 stores up to 100 fault records and operates independently of external power, ensuring dependable long-term protection.