SIEMENS 3UG4512-1AR20 Monitoring Relay

Product Description

SIEMENS 3UG4512-1AR20 is a SIRIUS Line Monitoring Relay (Phase Monitoring Relay) designed for monitoring three-phase electrical systems. It detects phase failure and phase sequence errors and provides a relay output signal for protecting motors, machines, and electrical equipment.

Specifications

• Brand: SIEMENS
• Model: 3UG4512-1AR20
• Series: SIRIUS 3UG4
• Product Type: Monitoring Relay / Phase Monitoring Relay
• Function:
  • Phase failure monitoring
  • Phase sequence monitoring
• Measured Voltage Range: 3 × 160…690 V AC
• Frequency: 50…60 Hz
• Number of Monitoring Functions: 2 functions
• Output Contact: 1 × Changeover contact (SPDT)
• Contact Rating:
  • AC-15: 3 A at 250/400 V AC
  • DC-13: 1 A at 24 V DC
• Display: LED status indication
• Mounting: DIN rail mounting
• Connection: Screw terminals
• Protection Rating: IP20
• Operating Temperature: -20…+65 °C
• Weight: Approx. 119 g

Advantages & Features

• Protects motors and equipment from phase failure faults
• Detects incorrect phase sequence before equipment startup
• Improves electrical system safety and reliability
• Compact DIN rail design saves control cabinet space
• LED indication simplifies troubleshooting
• Suitable for industrial automation and motor control systems
• Reliable relay switching for alarm and control circuits

Applications

• Motor protection systems
• Industrial control cabinets
• Pumps and fans
• Conveyor systems
• Machine automation equipment
• Power distribution monitoring
• Three-phase electrical equipment protection

Notes

• Confirm the monitored voltage range before installation
• Check phase wiring sequence carefully
• Ensure correct relay output wiring
• Not designed for direct motor switching; use with contactors or control circuits
• Verify compatibility before replacing older monitoring relays
• Siemens has listed this model as phased out, with 3UG5512-1AR20 as a preferred successor.