ABB 1svr740831r0400 RMS Monitoring Relay 2-Pole

ABB 1SVR740831R0400 CM-ESS.2P Voltage monitoring relay provides RMS-based supervision for DC and AC voltages in a compact single‑phase package, featuring two changeover contacts (2c/o) that can drive alarms or interlocks in control circuits. It monitors the voltage across B–C in the range of 3 to 600 VRMS and is powered from 110–130 V AC, making it compatible with standard 1‑phase mains. The device uses an RMS measuring principle and offers four measurement ranges for threshold selection: 3–30 V, 6–60 V, 30–300 V, and 60–600 VRMS. The two isolated SPDT outputs are rated to 250 V and 4 A, enabling reliable signaling or interlock control in automation, machine protection, and process control applications. This ABB CM-ESS.2P part belongs to ABB’s ERC2 family of voltage-monitor relays, with the 0400 suffix indicating operation on 110–130 V AC.