The ABB RED670 is indeed a robust line differential protection relay, designed to ensure reliable protection for various components within power transmission and distribution systems. Here are some technical specifications and features:

Technical Specifications

• Rated Voltage: Up to 765 kV
• Rated Current: Up to 5,000 A
• Protection Accuracy: 0.2%
• Operating Time: Less than 2 ms for main protection

Key Features

• High-speed main protection for internal faults
• Restricted earth fault (REF) protection
• Second harmonic restraint (SHR)
• Out-of-step protection
• Breaker failure protection
• Self-test and diagnostic functions
• Event and fault records
• Communication interfaces: IEC 61850, Ethernet, RS-232