Siemens SIRIUS 3UG4513-1BR20 Analog Monitoring Relay is a phase‑failure and phase‑sequence monitor for 3‑phase power systems, including undervoltage detection with a fixed 20% asymmetry threshold. It operates on 3 x 160–690 V AC at 50–60 Hz, features a fixed 5% hysteresis, and provides an adjustable delay time of 0–20 seconds. The unit offers two changeover contacts (DPDT) on screw terminals for DIN‑rail mounting, is IP20 protected, and belongs to the SIRIUS 3UG4 family, with 3UG5514-1BR20 listed as the preferred successor.
