ABB RED670 1MRK004810-AB Line Differential Protection

Overview

The RED670 (1MRK004810-AB) is an advanced Intelligent Electronic Device (IED) within the ABB Relion 670 series, specifically optimized for high-speed line differential protection. It serves as a mechanical necessity for protecting critical transmission and distribution infrastructure by providing phase-segregated fault detection. 

Technical Specifications

• Manufacturer: ABB

• Model/ID: RED670

• Part Number: 1MRK004810-AB

• Product Series: Relion 670

• Primary Function: High-speed, phase-segregated line differential protection

• Backup Protection: 5-zone Distance Protection, Directional Overcurrent

• Earth Fault Protection: Sensitive Earth Fault (SEF) for high-resistance detection

• Communication Interface: Support for IEEE C37.94 (fiber optic) and IEC 61850

• Network Redundancy: PRP (Parallel Redundancy Protocol) and HSR (High-availability Seamless Redundancy)

• Application: Two-ended and multi-ended lines (transformer in-zone support)

• Operating Temperature: -25°C to +55°C

Key Functional Characteristics

High-Speed Differential Protection

The RED670 1MRK004810-AB utilizes a sophisticated phase-segregated differential principle. It continuously monitors the current vectors at all ends of the line and calculates the differential current. If the vector sum exceeds the threshold, the relay issues a trip command. This method provides absolute selectivity, ensuring that the relay only trips for internal faults while remaining completely stable during external through-faults or heavy load swings.

Integrated Multi-Zone Backup

To ensure the line remains protected even if the communication link between terminals is interrupted, the 1MRK004810-AB includes a full-featured distance protection scheme. It provides up to five zones of protection with high-speed under-impedance detection. Combined with directional overcurrent and sensitive earth fault (SEF) logic, this creates a layered defense capable of detecting high-resistance ground faults that standard protection might overlook.

Digital Substation Readiness

This IED is built for the modern utility network. It natively supports IEC 61850 Edition 1 and 2, facilitating horizontal communication (GOOSE) for fast interlocking and vertical communication to SCADA. For line-to-line communication, it utilizes the C37.94 standard over optical fiber, ensuring low-latency data exchange that is immune to electromagnetic interference (EMI) from the high-voltage environment.