REU610

Overview

The ABB REU610 is a voltage protection relay designed to monitor and protect electrical systems by measuring phase-to-phase and residual voltages.

Inputs

• Energizing Inputs: Four total; three for phase-to-phase voltages, one for residual voltage

• Digital Inputs: Two standard digital inputs, plus three optional digital inputs controlled by external voltage

• Voltage Measurement: Mainly phase-to-phase; can measure phase-to-earth but does not convert it to phase-to-phase

Outputs

• Power Output Contacts: Three (PO1, PO2, PO3)

• Signal Output Contacts: Two standard (SO1, SO2) and three optional (SO3, SO4, SO5)

Front Panel

• Display: Alphanumeric 2 × 16 characters LCD with backlight and automatic contrast control

• Indicator LEDs: Three fixed-function LEDs (green, yellow, red) and eight programmable red LEDs

• HMI Buttons: Four arrow keys plus clear/cancel and enter buttons for menu navigation and setting adjustments

• Communication Port: Optically isolated serial port with indicator LED

---