ABB Protection Relay REX 521

Trigger methods: digital input, overcurrent/overvoltage threshold, manual or communication trigger.

Power Quality Monitoring

PQ 3Inf: Current Harmonics (THD/TDD), supports 1-13 harmonics, with an accuracy of ± 1% (1-10 times).

PQ 3Unf: Voltage harmonics, compliant with EN 50160 standard, accuracy ± 0.3% (1-10 times).

Control and Interface

digital input

8 programmable inputs, supporting inversion and pre delay (0-1000ms).

The functions include: reset, blocking, disturbance triggering, main tripping, and 16 other functions.

communication interface

Supports Modbus and DNP 3.0 protocols, with optional CANopen and Ethernet interfaces (requiring module expansion).

Environment and Certification

Working temperature: -25 ° C -+70 ° C (non condensing).

Protection level: IP40 (front panel), IP20 (back).

Certification: Compliant with standards such as IEC 61850 and EN 61000-6-2, suitable for industrial grade electromagnetic compatibility environments.

Product advantages

High reliability and safety

Compliant with IEC 61850 standard, supports redundant design, and adapts to industrial electromagnetic compatibility environment (-25 ℃~+70 ℃ working temperature).

Built in trip circuit supervision (TCS1) and circuit breaker wear calculation (CB wear 1) enhance equipment status monitoring capability.

Usability and Configurability

Visualize configuration through HMI or Relay Setting Tool, support batch import/export of parameters, and reduce debugging time.

Standard configuration presets typical scenario parameters to reduce the difficulty of project implementation.

Typical application scenario parameters

Outgoing feeder: Basic B01, 3I>Starting current 1.2 x In, operating time 0.5s; Io>Starting current 5% In

Motor protection: High H07, thermal overload time constant of 10 minutes, starting current of 6 x In, starting time of 15 seconds

Busbar segmenter: High H03, 3I>>Starting current 2.0 x In, synchronous check voltage difference ≤ 5% Un

Incoming feeder: High H08, 3U>starting voltage 1.15 x Un, operating time 60s; 3U<starting voltage 0.85 x Un