ABB Entrelec DLM911 Voltage Monitoring Module

ABB Entrelec DLM911 Voltage Monitor is a three‑phase voltage monitoring relay designed for 400–480 VAC three‑phase power systems. It continuously checks the three phase voltages against setpoints to detect undervoltage, overvoltage, and phase loss, providing a safe, automatic signal through its SPDT output contacts to trip a contactor or alert downstream equipment when abnormal conditions are detected. The module’s outputs are rated up to 10 A resistive, enabling control of standard industrial loads, and it includes LED indicators to show status at a glance. The DLM911 supports both delta and wye configurations, accommodating common electrical distribution arrangements, and is designed for compact installation in control panels. Typical trip delay ranges reported in catalogs span from 2 to 20 seconds, allowing brief voltage disturbances to pass without unnecessary tripping. The product has appeared in ABB Entrelec literature as a DLM911 three‑phase voltage monitor for 400–480 VAC service, and catalog entries from third‑party suppliers identify the unit; some sources note that ABB has discontinued the model. Used in industrial automation for protecting motors, conveyors, pumps, and other three‑phase equipment, the DLM911 provides a straightforward, dedicated solution to monitor supply quality without modifying the primary control circuitry.