Analog monitoring relay phase sequence monitoring 3 x 420...690 V AC 50...60 Hz 1 changeover contact screw connection Analog adjustable mains monitoring relay SIRIUS 3UG4 for monitoring phase sequence, phase failure and asymmetry and/or undervoltage, e.g. in mobile systems such as air conditioning compressors, refrigerated containers, construction site compressors or cranes. Worldwide use through international validation. Different variants enable application-specific product selection. Less space required in the control cabinet thanks to a narrow width. All versions with removable connection terminals. In addition to screw connection technology, the devices are also available with spring-loaded connections for a quick, maintenance-free and vibration-proof connection. Variants with a wide voltage range without auxiliary voltage can be used in all networks in the world. The comprehensive range of accessories, such as device identification plates, insertion tabs and cover caps, is the same for all relays. SIRIUS relays - a program for all situations.