ABB REX521 REX521GHHPSH04G Feeder Protection Relay Unbelievable Prices!

FAQ

Q1: What systems is the ABB REX521 suitable for?
A1: The REX521 is suitable for single busbar systems in radial isolated, solidly earthed, resistance-earthed, and resonant-earthed networks.

Q2: What are the key protection functions of the REX521?
A2: It offers protection functions including three-phase overcurrent, earth fault (directional and non-directional), voltage, phase discontinuity, thermal overload, and motor start-up detection.

Q3: Does the REX521 support directional earth fault protection?
A3: Yes, directional earth fault protection is available in configurations M01, M02, H01 through H08.

Q4: What communication protocols are supported?
A4: The device supports SPA, IEC 103, Modbus, DNP 3.0, and LON protocols through RS-232, RS-485, and fiber optic ports.

Q5: What are the rated input voltage and current values?
A5: Rated current inputs are 0.2 A, 1 A, or 5 A; voltage inputs are configurable from 100 V to 120 V.

Q6: Will the relay retain settings after a power loss?
A6: Yes, the device retains all settings and event records in non-volatile memory after power loss.

Q7: Can the REX521 be used for motor protection?
A7: Yes, configuration H07 is designed specifically for protecting medium and large three-phase motors.

Q8: What is the ingress protection (IP) rating of the unit?
A8: The front side is rated IP54, and the rear terminal area is rated IP20, suitable for industrial installations.