The REA system is a fast and flexible arc fault protection system for air-insulated low voltage and medium voltage switchgears. A fast and selective arc fault protection system is a natural constituent of modern switchgear panels and a safety and security investment for older switchgear panels to protect human lives and prevent or reduce material damage
The function of the REA arc fault protection system is based on detecting the intense light of an electric arc alone or on a detection of light and simultaneous phase or neutral overcurrent. On detection of an arc fault, the REA arc fault protection system delivers trip commands in less than 2.5 ms to all circuit breakers that feed the fault zone. Furthermore, the operation indicators of the REA arc fault protection system help localizing faults by selectively guiding the maintenance staff to the fault zone that was identified by the arc fault protection system.