ABB RED670 – High‑speed Line Differential Protection for Transmission Lines and Cables

The ABB RED670 is a Relion 670 series line differential protection and control IED designed for high‑voltage and sub‑transmission corridors. It delivers sub‑cycle fault clearance, rock‑solid stability during external faults, and dependable performance over long fiber or telecom channels. From my experience, it’s typically selected when utilities want dependable current differential protection with strong backup functions and modern IEC 61850 interoperability.

Typical applications include single‑ or multi‑terminal overhead lines and cables, parallel circuits, and mixed overhead/cable sections. You might notice that it shines where CT saturation, charging current, or weak-end infeeds can trip up simpler schemes.

• Phase‑segregated current differential – High‑speed, stabilized algorithm with adaptive restraint for CT saturation and through‑fault stability.

• Flexible channel options – Works over direct fiber or digital telecom links; redundancy is typically supported for main/backup differential channels.

• Robust backup protection – Distance (as backup), overcurrent, earth‑fault, switch‑on‑to‑fault, power swing blocking, and autoreclose options in many cases.

• IEC 61850 Ed.1/Ed.2 – GOOSE messaging, station bus integration, and engineering via standard SCL, easing substation interoperability.

• Time synchronization – SNTP and IRIG‑B commonly supported; precise time stamping for disturbance records and event logs.

• Redundant Ethernet networking – PRP/HSR support is typically available to eliminate single points of failure in the station LAN.

• Powerful recording – Disturbance recorder, sequence of events, and fault locator help operators validate protection behavior quickly.

• Configurable I/O and logic – Scalable CT/VT inputs (1 A / 5 A; 100/110 V), binary I/O, and programmable logic for scheme customization.

• Built for harsh environments – Wide operating temperature, EMC-hardened design, and 4U case suitable for panel or 19‑inch rack mounting.

- Transmission and sub‑transmission overhead lines (single or multi‑terminal)
   - Underground and mixed OHL/cable circuits where charging current compensation matters
   - Parallel lines with mutual coupling, weak‑infeed terminals, and long line sections
   - Grid interties, industrial utility feeders, and renewable evacuation corridors

“On our 220 kV mixed line, RED670’s differential stayed stable through heavy external faults while giving us dependable tripping on internal faults. Commissioning was quicker than we expected.” — Protection Engineer, utility customer

• Reliability under real‑world conditions – Stabilized differential logic copes with CT saturation, evolving faults, and load variations.

• Interoperability – IEC 61850 with GOOSE streamlines bay‑level schemes and reduces copper wiring; multi‑vendor stations are easier to engineer.

• Channel flexibility – Use direct fiber for greenfield sites or reuse existing telecom bearers; dual channels help meet N‑1 availability goals.

• Lifecycle economy – Modular I/O and firmware updates typically extend service life; disturbance records cut fault analysis time and site visits.

• Grid support features – Power swing blocking, weak‑end infeed logic, and autoreclose reduce nuisance trips and speed system restoration.

• Panel/cabinet – Mount in a clean, ventilated control cabinet (19″ rack or flush panel). Maintain ambient within the specified temperature range.

• Wiring – Use shielded twisted pairs for binary I/O where appropriate; segregate CT/VT circuits; ensure solid protective earthing and cable screen terminations.

• Differential channel – For fiber links, verify optical budget and connector quality; for telecom bearers, confirm latency and symmetry meet scheme requirements.

• Time sync – Provide reliable SNTP or IRIG‑B; align the entire bay to avoid conflicting time stamps in disturbance records.

• Commissioning – Primary/secondary injection to validate pickup, restraint, and slope; test weak‑end infeed logic and SOTF before energization.

• Routine care – Back up settings and IED CID/SCD files, clean connectors, review event/fault records after operations, and apply approved firmware updates during planned outages.

• Safety – Never work on CT circuits while energized; prove isolation; follow lock‑out/tag‑out and arc‑flash practices.

• Conforms to IEC 61850 for substation communication; type tested per IEC 60255 series for protection relays.

• CE marking and RoHS compliance typically applicable; regional approvals may vary by delivery country.

• Manufacturer warranty commonly 12 months from delivery, extendable with service agreements (project‑specific).

• Backed by global service and spare strategy for Relion 670 series, which in many cases simplifies long‑term support.

• Redundant power supply module (for higher availability in critical bays)

• Fiber interface kits and patch panels for direct channel connections

• Time synchronization accessories (IRIG‑B distribution or network time sources)

• Pre‑terminated harnesses and test switches to speed FAT/SAT and maintenance

If you share your line configuration (number of terminals, channel type, CT ratios, expected charging current, and desired backup schemes), I can propose a RED670 variant and I/O build that fits without over‑specifying. In many cases, a dual‑channel build with PRP networking hits the right balance of speed and availability.