This guide describes the ABB REU 610 voltage protection relay, a digital relay used for over‑voltage, under‑voltage, residual‑over‑voltage and phase‑sequence protection in substations and industrial switchgear. It explains the relay’s measurement capabilities, disturbance and event recorders, trip‑circuit supervision, self‑supervision, and I/O options.
The document also provides information on communication protocol support (IEC 61850, IEC 60870‑5‑103, Modbus, Profibus, DNP), technical specifications such as dimensions, power supply types, and mounting methods, as well as accessories, tools, and a terminal diagram for installation and configuration.