What this relay monitors and how it fits
The Siemens 3UG5618-2CR20 is a digitally adjustable monitoring relay covering phase failure, phase sequence, asymmetry, frequency, overvoltage, and undervoltage on three-phase supplies. It accepts 90–690 V AC across 15–70 Hz, with or without a neutral conductor, and includes phase sequence correction — useful when incoming phase rotation is unpredictable or a motor rotation direction must be enforced without rewiring. The spring-cage design cuts installation time compared to screw clamps and holds reliably under vibration common in panel environments.
RoHS compliance is confirmed effective June 1, 2023.
Mounting and terminal notes
The spring-loaded terminals accept 0.2–2.5 mm² conductors; strip length per typical Siemens spring-cage practice is 8–10 mm. No special tooling needed beyond a screwdriver to depress the cage.