The ABB CM‑PVS.41S is a three‑phase monitoring relay designed to monitor the health of a three‑phase electrical supply. It continuously checks for overvoltage, undervoltage, phase loss, and incorrect phase sequence in three‑phase systems with line‑to‑line voltages within a specific range. When a fault condition is detected, the relay changes the state of its output contacts to signal alarms or to disconnect loads for protection. It is mounted on a DIN rail and typically used in industrial control panels, motor protection systems, and automation circuits to ensure correct and safe operation of three‑phase equipment.