ABB REF610C11HCNN – Compact Feeder Protection Relay for MV/LV Distribution

The ABB REF610C11HCNN is part of ABB’s proven REF610 family, typically used for non-directional overcurrent and earth-fault protection on feeders, incomers, and transformer secondaries. It fits well in retrofit scenarios where you want reliable protection, clear indications, and straightforward settings without overcomplicating your panel. From my experience, it’s a practical choice for medium-voltage switchgear modernization and as a like-for-like spare in plants that standardize on ABB’s 600-series relays.

Company’s Order Placement Process and Guarantees

• Warranty: 365 days
• Lead time: 1 week if in stock; no more than 1 month at the latest
• Payment: 50% advance payment, full payment prior to delivery
• Express delivery options: FedEx, UPS, DHL

Key Features

• Feeder overcurrent and earth-fault protection – Typically includes 50/51 and 50N/51N functions for fast and inverse-time protection on MV/LV feeders.
• Thermal overload (49) and CB supervision – Helps protect equipment and monitor breaker health in many cases where load profiles fluctuate.
• Selectable 1 A / 5 A CT inputs – Eases retrofit into existing switchgear; you might notice how it reduces CT adaptation work.
• Event and disturbance records – Captures trip/events so maintenance teams can validate protection operations quickly.
• Self-supervision and watchdog output – Relay health monitoring that maintenance teams often appreciate during periodic checks.
• Clear front-panel indications – LEDs and a menu-driven interface for quick diagnostics on the door.
• Communication-ready – SPA-bus via RS-485 is common; certain builds support fiber converters or utility protocols for SCADA tie-in.

Technical Specifications

Where it fits best

Typical use cases include feeder protection on 6–35 kV switchgear, transformer LV side protection, and industrial distribution boards where a stable, non-directional overcurrent/earth-fault scheme is sufficient. One thing I appreciate is how quickly a maintenance team can replace a legacy unit with the REF610 form factor and reuse existing wiring with minimal rework.

A maintenance lead from a steel plant summed it up well: “We swapped two legacy relays for REF610 units in a day. Settings were straightforward, and our SCADA saw the status right away through the SPA link.”

Related or Supporting Products

• ABB REF615 – Newer generation feeder protection with IEC 61850, more functions, and enhanced cybersecurity; a common modernization path from REF610.
• ABB REF601 – Compact alternative where only basic non-directional OC/EF protection is required.
• ABB SPA‑ZC series – Fiber‑optic/RS‑485 converters for SPA‑bus when galvanic isolation or long runs are needed.
• ABB RTXP test plugs – For safe secondary injection, isolation, and functional testing during commissioning and maintenance.
• Matching CTs (1 A / 5 A) – Use appropriately rated protection‑class CTs for correct time‑current characteristics.

Installation & Maintenance

• Panel and wiring – Install in a clean, vibration‑limited switchgear compartment with adequate door depth. Maintain clearances for heat dissipation and cable bend radius. Use shielded twisted pair for RS‑485 and segregate from power cables.
• Auxiliary supply and grounding – Verify the auxiliary voltage matches the unit label; bond the relay case/terminal earth to the switchgear ground bar. In most cases, CT secondaries must be earthed at one point only.
• Commissioning – Secondary‑inject 3I and Io, validate pickup and time‑dial settings, trip logic, and binary I/O mapping. You might notice tests go faster with a test plug and a template checklist.
• Protection settings – Apply coordination studies (definite/inverse curves) versus upstream/downstream devices. Revisit cold‑load pickup and inrush behavior on transformer feeders.
• Routine maintenance – Annually verify event recorder time sync, clean front panel, back up settings, and check firmware revision if applicable. Inspect terminations and check CB trip circuit continuity.
• Safety – De‑energize control circuits where possible, short CTs before disconnection, lockout/tagout per site procedure, and use suitable PPE.

Quality & Certifications

• Conforms to typical protection relay standards (e.g., IEC 60255 series for measurement and protection).
• CE-marked; RoHS compliance applies to many builds in this series.
• Manufacturer’s warranty policy generally 12 months; our supply is covered by a 365‑day warranty as stated above.