A Monitoring Relay serves as a protective control device that processes input signals, continuously monitors them, and triggers an alarm when a predetermined threshold is met. Altech Voltage Monitoring Relays present a range of features tailored for voltage oversight across different systems. The AMR-AP3U690V2D model is specifically engineered for 3-phase systems and boasts a compact industrial design. In contrast, the AMR-EP1M230V1 is intended for 1-phase systems, providing functionalities such as undervoltage detection, window monitoring, and supply voltage alignment with the measured voltage. The AMR-EP1F480277V1D, also designed for 3-phase systems, offers monitoring capabilities for undervoltage, phase sequence, phase failure, and asymmetry, along with a supply voltage that corresponds to the measuring voltage.