SIEMENS 3UG4512-1AR20 Phase Failure Relay

The Siemens 3UG4512-1AR20 is a compact, analog-setting 3-phase line monitoring relay. It is designed to continuously monitor a 3-phase electrical supply system to protect electric motors, machinery, and industrial plants against critical power supply faults.

Technical Specifications

• Manufacturer: Siemens

• Product Series: SIRIUS 3UG4

• Part Number / MPN: 3UG4512-1AR20

• Product Function: 3-Phase line monitoring relay

• Monitored Parameters: * Phase failure (detects loss of a phase)

  • Phase sequence (detects incorrect rotation direction)

• Voltage Range (Three-Phase AC): 3 x 160V AC to 690V AC

• Frequency Rating: 50 / 60 Hz

• Power Supply: Self-powered (draws operating voltage directly from the monitored 3-phase network)

• Output Contact Configuration: 1 Changeover contact (CO) / SPDT

• Contact Electrical Parameters: 3A at 250V AC / 400V AC (AC-15)

• Reset Method: Auto-Reset (automatically restores the circuit once the phase conditions return to normal)

• Connection Type: Heavy-duty screw terminals

• Mounting Type: DIN rail mounting (Snap-on 35mm)

• Status Indicators: Integrated LED display for immediate status diagnosis

• Dimensions (W x H x D): 22.5 mm x 83 mm x 91 mm

• Enclosure Protection Rating: IP20

• Ambient Operating Temperature: -25 Degree C to +60 Degree C