ABB REA107-AA System-Ready Arc Protection Relay for REA107 Architecture

ABB REA107-AA System-Ready Arc Protection Relay for REA107 Architecture

In modern industrial power distribution and protection architectures, the integrity of the entire control system depends on the precise coordination of every protection layer. The ABB REA107-AA arc protection relay is engineered not as a standalone device, but as a contextually integrated component within the broader REA107 system architecture — designed to operate in seamless coordination with upstream circuit breakers, downstream feeder protection relays, substation automation controllers, and communication gateways that together form a complete, layered protection scheme.

Arc flash incidents represent one of the most severe hazards in medium-voltage switchgear environments. The REA107-AA addresses this risk at the system level by providing ultra-fast arc detection and tripping signals that interact directly with the control layer — including ABB REF615, REF630, and REM615 feeder protection relays — ensuring that fault isolation occurs within milliseconds, well before thermal and pressure damage can propagate across the busbar or adjacent panels. This speed of response is only achievable when the arc protection relay is properly integrated into the system’s I/O layer and communication backbone.

Within a layered automation architecture, the REA107-AA occupies a critical position at the protection and safety layer, interfacing with the substation control unit (SCU) or bay control unit (BCU) via hardwired binary I/O or optical fiber sensor loops. Its tripping output connects directly to the circuit breaker’s shunt trip coil, bypassing slower SCADA or DCS command paths to guarantee deterministic fault clearance. This architecture ensures that even in the event of communication network degradation, the arc protection function remains fully operational — a key requirement for IEC 61850-compliant substation designs.

The REA107-AA is designed for installation within ABB UniGear, SafeRing, or ZS1 medium-voltage switchgear panels, where it monitors arc light sensors positioned at the busbar compartment, cable compartment, and circuit breaker compartment. When integrated with the REA101 or REA103 sensor units and the REA107 central unit, the system forms a complete arc protection loop capable of covering entire switchgear lineups with zone-selective interlocking. This modular, scalable architecture allows engineers to expand protection coverage without replacing the central relay — simply adding sensor units as the switchgear lineup grows.

From a system engineering perspective, the REA107-AA supports both current-based and light-based arc detection, providing a dual-criterion tripping logic that minimizes nuisance trips while maintaining the fastest possible fault clearance time. This dual-criterion approach is particularly valuable in environments where ambient light interference or high-frequency switching transients could otherwise trigger false alarms — such as in steel mills, petrochemical plants, water treatment facilities, and mining substations where the REA107 series is widely deployed.

Long-term maintenance efficiency is a core design principle of the REA107 architecture. The REA107-AA’s self-supervision function continuously monitors the integrity of the sensor loop, the relay output contacts, and the internal power supply — generating alarm signals that can be routed to the substation HMI or SCADA system via the ABB COM600 or COM610 substation gateway. This proactive fault detection capability reduces unplanned downtime and supports predictive maintenance strategies, which are increasingly mandated in critical infrastructure applications.

For projects requiring redundant protection architectures, the REA107-AA can be deployed in parallel with a secondary arc protection relay, with the two units sharing sensor inputs and providing independent tripping paths to the circuit breaker. This redundancy design is consistent with IEC 61511 functional safety requirements for SIL-rated protection systems in process industries. The relay’s compact DIN-rail or panel-mount form factor facilitates installation in space-constrained control cabinets alongside ABB SACE Emax2 or Tmax XT series circuit breakers and ABB S800 I/O modules.

All units supplied by ZYPLC are covered by a 12-Month Warranty, with stock available for immediate dispatch to support both planned project timelines and emergency replacement requirements. Our engineering team provides pre-sales technical consultation on system architecture compatibility, sensor loop configuration, and integration with existing ABB protection relay platforms.

Architecture Specification Table

Coordinated Control System Design

The REA107-AA achieves its full protective potential only when deployed as part of a coordinated system architecture. In a typical medium-voltage substation, the relay operates alongside the ABB REF615 feeder protection relay, which provides overcurrent, earth fault, and distance protection for the outgoing feeders, while the REA107-AA handles the arc flash protection layer independently — ensuring that arc fault clearance is not delayed by the REF615’s time-graded overcurrent settings.

The central unit communicates alarm and trip status to the ABB COM600 substation gateway, which aggregates protection relay data from the entire switchgear lineup and forwards it to the SCADA system via IEC 61850 GOOSE messaging or Modbus TCP. This integration allows operators at the ABB CP600 or CP635 HMI panel to monitor arc protection status in real time, acknowledge alarms, and review event logs without requiring physical access to the switchgear room.

Power supply stability for the REA107-AA and associated protection relays is maintained by the ABB UNO-PS/1AC/24DC/100W DIN rail power supply, which provides regulated 24 V DC auxiliary power with built-in overvoltage and short-circuit protection. In redundant architectures, a secondary power supply unit is connected in parallel via a diode ORing module, ensuring that auxiliary power is maintained even during a single power supply failure.

The sensor loop connecting the REA107-AA to the REA101 point sensor units and REA103 arc sensor units is routed through the busbar, cable, and circuit breaker compartments of the switchgear. Each sensor unit detects arc light in its compartment and transmits a signal to the REA107-AA central unit via the optical fiber loop. The central unit evaluates the sensor signals against the overcurrent criterion from the ABB CT (current transformer) secondary circuits and issues a trip command to the ABB Emax2 or Tmax XT circuit breaker shunt trip coil within milliseconds of arc inception.

For installations requiring zone-selective interlocking, the REA107-AA interfaces with the ABB REX640 protection and control relay, which manages the interlocking logic between multiple protection zones and ensures that only the faulted zone is isolated — minimizing the impact of arc flash events on healthy sections of the switchgear lineup. This zone-selective architecture is particularly important in large industrial substations with multiple bus sections and tie breakers.

Application in Layered Automation Systems

The REA107-AA is deployed across a wide range of industrial sectors where medium-voltage switchgear protection is critical to operational continuity and personnel safety. In manufacturing and automotive assembly plants, the relay protects the main incoming switchgear that supplies power to robotic welding lines, CNC machining centers, and conveyor systems — where an unprotected arc flash event could cause catastrophic damage to production equipment and extended downtime.

In power generation and utility substations, the REA107-AA is integrated into the protection scheme for generator switchgear, transformer feeders, and bus coupler panels. Its ultra-fast tripping capability is essential in these applications, where the high fault current levels associated with large generators and transformers can cause severe busbar damage within a few milliseconds of arc inception. The relay’s IEC 61850 compatibility ensures seamless integration with the substation automation system.

In petrochemical and oil refinery facilities, the REA107-AA is installed in hazardous area substations where arc flash protection must comply with IEC 61511 functional safety requirements. The relay’s dual-criterion tripping logic and self-supervision function provide the diagnostic coverage required for SIL 2 protection functions, supporting the facility’s overall safety instrumented system (SIS) architecture.

In water treatment and pumping stations, the relay protects the medium-voltage motor control centers (MCCs) that supply large submersible pumps and aerators. Its compact form factor and DIN-rail mounting make it suitable for installation in the space-constrained control rooms typical of water infrastructure projects. In mining and mineral processing operations, the REA107-AA is deployed in underground and surface substations where rapid arc fault clearance is essential to prevent fire and explosion hazards in confined spaces.

Architecture Engineering FAQ

Q1: Is the REA107-AA compatible with non-ABB switchgear and protection relay platforms?
The REA107-AA is designed primarily for integration within ABB switchgear families including UniGear, SafeRing, and ZS1. However, its hardwired binary I/O interface for tripping output and sensor loop connection is electrically compatible with third-party circuit breakers and switchgear panels, provided that the auxiliary supply voltage and contact ratings are matched. For IEC 61850 communication integration with non-ABB substation automation systems, the relay’s output signals can be routed through a compatible IEC 61850 gateway. ZYPLC’s engineering team can advise on specific compatibility requirements for your project architecture.

Q2: What is the recommended maintenance schedule for the REA107-AA in a continuous-process industrial environment?
ABB recommends annual functional testing of the arc protection relay, including verification of sensor loop continuity, tripping output contact resistance, and auxiliary supply voltage levels. The REA107-AA’s built-in self-supervision function provides continuous monitoring between scheduled maintenance intervals, generating alarms for any detected faults in the sensor loop or relay output circuits. All units supplied by ZYPLC include a 12-Month Warranty covering manufacturing defects and component failures, with technical support available for installation, commissioning, and troubleshooting throughout the warranty period.

Q3: How does the REA107-AA support system expansion when additional switchgear panels are added to an existing lineup?
The REA107 architecture is designed for modular expansion. Additional REA101 point sensors or REA103 arc sensors can be added to the existing sensor loop without replacing the REA107-AA central unit, up to the maximum sensor loop capacity specified in the system documentation. For larger switchgear lineups requiring multiple protection zones, additional REA107-AA central units can be deployed with zone-selective interlocking configured between units. This scalable architecture protects the initial investment in the central unit while allowing the protection system to grow with the switchgear installation. ZYPLC maintains stock of REA107 series components to support both new installations and expansion projects with short lead times.

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