Functional Description

The ABB REA101-AAA is the main processing unit of the ABB REA 101 arc protection system. It is designed to detect dangerous arc faults in electrical switchgear and issue extremely fast trip commands to circuit breakers to reduce equipment damage and improve personnel safety.

The relay detects:

Arc flash light through fiber-optic sensors
Arc fault conditions combined with overcurrent measurement
Fault location through sensor loop monitoring

When an arc fault is detected, the REA101-AAA can send a breaker trip command in less than 2.5 ms, helping minimize arc energy release.

Key Features
Feature Description
Arc Detection Fiber-optic light detection
Overcurrent Supervision Three low-burden current inputs
Trip Outputs High-speed semiconductor trip outputs + relay output
Sensor Connection Plastic fiber sensor interface
Extension Support REA103 / REA105 / REA107 modules
Diagnostics Continuous system monitoring
Application LV/MV air-insulated switchgear

Technical Specifications
Power Supply
Parameter Specification
Auxiliary Voltage 110–240 VAC
DC Supply Range 110–250 VDC
Frequency 50/60 Hz
Power Consumption Approx. 9 W standby / 12 W operating

Arc Sensor Interface
Parameter Specification
Sensor Type Fiber-optic loop sensors
Maximum Fiber Length Up to 60 m (depending on splice configuration)
Fiber Operating Temperature -35°C to +80°C
Optical Link Plastic fiber / glass fiber versions available

Expansion Modules

The REA101-AAA can be expanded with additional ABB REA modules:

Module Function
REA103-AA Extends arc sensor coverage
REA105-AA Additional trip outputs and overcurrent link
REA107-AA Supports lens-type arc sensors

Typical Applications

The REA101-AAA is commonly installed in:

Medium-voltage switchgear
Low-voltage switchboards
Motor control centers (MCC)
Power distribution panels
Industrial substations

Industries include:

Power generation
Oil & gas
Mining
Metals processing
Chemical plants
Manufacturing facilities
Protection Benefits

The ABB REA system provides:

Fast arc fault interruption
Reduced arc flash energy
Reduced equipment damage
Improved operator safety
Faster fault localization during maintenance

Maintenance & Replacement Notes

When replacing an REA101-AAA, verify:

Exact type code: REA101-AAA
Auxiliary supply voltage (110–240 VAC / 110–250 VDC)
Fiber sensor type (plastic vs. glass fiber)
Existing REA extension modules
Trip circuit wiring configuration
Switchgear protection coordination settings

The replacement unit should be commissioned and trip-tested before returning the switchgear to service.

Recommended other models：