Voltage Monitoring Relay

Protection of 3 Phase devices against Over voltage, Under voltage, Single Phasing, Reverse Phasing & Unbalance Supply are one of the major issues in electrical systems. For safe running of 3-phase devices, special protections that keep a continuous watch on supply conditions are very essential. The major cause of maximum load burn-out is overloading which occurs due to Unbalance Supply, Single Phasing & Reverse Phasing conditions. VMR-3P detects such Conditions & protect the load from burn out.

VMR-3P offer above protections along with 3 digit display showing. R-Y, Y-B, B-R voltages in scanning mode with precise accuracy. low/high voltage tripping to ensure trouble free running of 3-phase Loads.

Features :

  • Voltage protection along with digital voltage readout
  • Wide range of supply variation
  • Unit will also work if any one phase is present
  • Protection against Under voltage
  • Indications for Low voltage, High Voltage, SPP & Relay ON
  • Message Display for SPP, Reverse Phasing
  • Protection against Over voltage
  • Phase unbalance protection
  • Reverse Phasing Protection can be able to bypass through settings
  • Single Phasing & Reverse Phasing protection
  • No separate auxiliary supply required
  • All the set points settable by keys


  • Supply voltage: 3 Phase 415 VAC, 50 Hz (R, Y, B & N) (No auxiliary supply)
  • Output Contacts: Two changeover (C-NO), Rating 5A at 230VAC
  • Trip Time delay: Trip time less than 100msec for SPP, Reverse Phasing & Over Voltage
  • On Delay: Selectable by keys from 1 to 60 sec
  • Voltage trip setting:
  • Lower Limit is 340 for under voltage (Resolution of 1 Volt)
  • Upper Limit is 460 Volts for OV (resolution of 1 V)
  • Reset Mode: Auto reset
  • Operating Temperature range: -5 C to 60 deg. C
  • Mounting: DIN rail
  • Base mounting dimensions: 55 (W) x 65 (L) x 125 (D) mm