The 3UG3013-1BL60: The relay monitors three-phase voltage in the range 180…260 V AC, 50/60 Hz. That means it is sized for nominal 230 V line-to-line systems with undervoltage detection; it will not work on 400 V supplies without a step-down transformer. The two changeover contacts (CO) give one normally-open and one normally-closed set per contact, suitable for signalling an alarm or tripping a downstream contactor. Screw terminals accept standard panel wiring.
Three-phase voltage monitoring relays like this one are installed in motor control centres, pump panels, and conveyor systems to protect equipment from phase loss, undervoltage, or phase sequence reversal. The reference code K per DIN EN 81346-2 confirms its role as a monitoring/control device in industrial schematics.