Motor protection

The relay type NM20 can be used for protection of large size motors in MV systems. For any grounded systems (solidly grounded, ungrounded or Petersen coil and/or resistance grounded) the protection can be used on feeders of any lenght.


Standard Protective & control elements
  • Under Voltage
  • Positive Sequence Undervoltage
  • Directional active overpower
  • Under Current
  • Directional reactive underpower
  • Loss of Field
  • Negative sequence overcurrent Motor/Generator
  • Phase reversal
  • Thermal Image Motor/Generator
  • Phase overcurrent side H and side L
  • Maximum Residual Overcurrent
  • Locked Rotor
  • Minimum Power Factor
  • Overvoltage
  • Negative sequence overvoltage
  • Maximum number of startings (Restart inhibition)
  • Ground directional overcurrent
  • Over frequency
  • Under frequency
  • Breaker Failure
  • CT Supervision
  • VT Supervision
  • Trip Circuit Supervision
SW Pack optional configuration
  • Thermal with Pt100 Probes