Phase monitoring relay with LCD and five-function flexibility
The Siemens 3UG4615-1CR20 is a SIRIUS network monitoring relay that watches three-phase AC supplies for undervoltage, overvoltage, phase loss, phase sequence, and asymmetry — five functions in one 22.5 mm-wide housing. The LCD display shows the measured voltage and fault type, so a field tech can read the trip cause without a meter. Rated for 160 to 690 V AC at 50 or 60 Hz, it covers the common low-voltage distribution range from 208 V to 600 V without needing a separate PT. The output relay switches 3 A at 250 V or 400 V AC, enough to signal a PLC input or drop out a contactor coil directly. Asymmetry detection is built in — it monitors voltage imbalance indirectly through the voltage limit thresholds, so a failing motor winding or a loose connection on one phase will trip the relay before the motor overheats.
Mounting and environment — fits any panel orientation
IP20 finger-safe terminals accept 2 x 14 to 20 AWG solid or stranded wire.