Description
Product Core Brief
- Model: REA101-AAA
- Brand: ABB
- Core Function: Arc protection relay central unit for fast detection and isolation of arc-flash faults in medium- and low-voltage switchgear.
- Product Type: Arc Protection Relay / Arc Fault Protection Main Module
- Key Specs: Fiber-optic arc detection | ≤2.5 ms trip time | Dual light + overcurrent criteria | 2× HSO IGBT outputs | CBFP support | Expandable with REA103/REA105/REA107
- Condition: New Original / New Surplus
Product Introduction
The ABB REA101-AAA is the central unit of the ABB REA arc fault protection system. It is designed for air-insulated low- and medium-voltage switchgear, where it detects arc-flash faults through fiber-optic sensors and, when configured, combines light detection with overcurrent supervision to reduce nuisance tripping.
Upon arc-fault detection, the REA101-AAA issues trip commands to downstream circuit breakers in less than 2.5 ms, helping limit equipment damage, reduce arc energy, and improve personnel safety. It can operate standalone or together with additional REA101 units and REA103, REA105, or REA107 extension modules. This makes it suitable for replacement, spare-parts stocking, and system expansion in existing REA arc protection installations.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Product Name | REA101-AAA Arc Protection Relay |
| Brand | ABB |
| Product Type | Arc Fault Protection Central Unit |
| Rated / Operating Voltage | 110/120/220/240 V AC or 110/125/220/250 V DC reported |
| Trip Time | ≤2.5 ms from arc detection to trip signal |
| Detection Method | Fiber-optic arc-flash detection; optional overcurrent supervision |
| Outputs | 2× high-speed isolated IGBT outputs; 1× heavy-duty relay output |
| Extension Support | Up to 10 extension modules via 2× RJ45 ports; REA103/REA105/REA107 supported |
| Communication | RS-485 Modbus RTU; optical links for central-unit signaling |
| Protection / Self-Monitoring | Sensor loop, supply voltage, and cabling supervision; IRF monitoring |
| Typical Applications | MV/LV switchgear, substations, industrial distribution, petrochemical, metallurgy, power plants |
| Condition Available | New Original / New Surplus |
Note: Public sources confirm REA101-AAA as an ABB arc protection relay central unit. Some listed values such as IP rating, dimensions, weight, operating temperature, and exact auxiliary voltage range vary across sources. Always verify the installed nameplate, firmware, DIP/switch settings, and system wiring before replacement.
Quality Control Process
Each REA101-AAA unit is inspected for housing condition, terminal blocks, optical connectors, RJ45 ports, DIN-rail/panel mounting points, and nameplate data. Where test conditions allow, auxiliary power, LED indicators, optical interfaces, and output circuits are checked to confirm basic readiness. The unit is packed with anti-static and shock-resistant protection to prevent damage to optical ports, terminals, and PCB assemblies during transit.
Replacement Pitfall Guide
❗ Confirm the full model code. REA101-AAA must match the existing central unit. Other REA variants or extension modules are not direct replacements for the main unit.
❗ Check auxiliary supply voltage. The relay supports wide-range AC/DC auxiliary supplies, but the installed setting and wiring must match the site power source.
❗ Verify arc detection mode. The unit can trip on light only or on light plus overcurrent. Changing the criterion without reviewing the protection scheme may cause nuisance trips or delayed operation.
❗ Review extension module configuration. REA103, REA105, and REA107 modules serve different roles. Port A/B activation, sensor type, and link topology must match the original design.
❗ Record DIP switches and wiring before removal. Trip logic, overcurrent thresholds, communication mode, and output assignment are set locally. Photograph switch positions, terminal wiring, fiber routing, and LED status before replacement.
Compatibility Matrix & Benchmarks
| Original Model | Replacement / Related Model | Compatibility Level | Migration Notes |
|---|---|---|---|
| ABB | ABB | Direct | Same central unit; verify auxiliary supply, switches, and firmware |
| ABB | ABB REA103 | Extension | Adds fiber-optic sensor inputs; not a standalone replacement for REA101 |
| ABB | ABB REA105 | Extension | Provides HSO outputs and inter-unit linking; not a direct REA101 replacement |
| ABB | ABB REA107 | Extension | Adds lens-type sensor inputs; requires REA101 central unit |
Benchmarks
- Platform: ABB REA arc fault protection system.
- Typical use: fast arc-flash protection for MV/LV switchgear, busbar compartments, cable compartments, and feeder sections.
- Key advantage: sub-2.5 ms trip response with fiber-optic detection and optional overcurrent supervision.
