Home Products Protection Relays DRAGON SERIESRMI D Motor protection and control

RMI D Motor protection and control

RMI D is a powerful Protection and Control IED for large (> 2 MW) asynchronous and synchronous Motors. It is also suitable for medium (from 0.5 to 2 MW) and small sized (from 0.1 to 0.5 MW) motors, where directional earth fault, voltage and frequency functions are necessary.

RMI D can be used also as a basic generator protection unit.

The protection is suitable for all types of current transformers -iron-core and linearized (Rogowski coil).



Relay protection functions***

  • Optional motor differential protection
  • Starting time supervision
  • Number of starts limitation
  • Stalled Rotor Protection function
  • Loss of load protection
  • Cooling failure protection
  • Loss of field/Under excitation
  • Over excitation
  • Four stages directional/non-directional definite time/instantaneous overcurrent protection
  • Directional/non-directional Inverse time overcurrent protection with 12 inverse time characteristics
  • Four stages directional/non-directional definite time/instantaneous ground fault protection
  • Directional/non-directional Inverse time ground fault protection with 12 inverse time characteristics
  • Definite time undercurrent protection
  • Negative Sequence overcurrent protection
  • Phase discontinuity detection
  • Three stages definite time over voltage protection
  • Three stages definite time under voltage protection
  • Two stages negative sequence over voltage protection
  • Directional overpower protection
  • Directional underpower protection
  • Three stages neutral voltage displacement
  • Four stages definite time over frequency protection
  • Four stages definite time under frequency protection
  • Four stages definite time rate of change of frequency protection
  • Thermal overload protection
  • Arc protection
  • Fuse failure monitoring
  • Voltage balance protection
  • Breaker failure protection
  • Clockwise and anticlockwise phase rotation function
  • Trip circuits supervision
  • Current circuits supervision functions
  • Circuit breaker life time monitoring 

 *** All relay protection functions meet all ANSI and IEC standards' requirements.

Automation and remote control functions

Disturbance (Fault) Recorder

  • Sampling rate – 1 kHz/2 kHz
  • User defined trigger conditions and records duration
  • Recording mode -overwrite (ring buffer) or saturate
  • Each sample consists of instantaneous values of all analog and digital values
  • File format – COMTRADE

 Data Logger

  • Sampling rate – 50 Hz  / 10 Hz  / 1 Hz
  • User defined trigger conditions, records duration and values
  • The function could be enabled or disabled
  • Recording mode -overwrite (ring buffer)
  • Each sample contains RMS values of all selected analog values
  • File format – COMTRADE

Event Recorder

  • Up to 1000 records
  • Each event consists of information about the event’s type, some additional data (such as pick-up current, voltage, the time elapsed and so on) and the time stamp of the event (year, month, day, hour, minute, second, millisecond)
  • Recording mode – overwrite


  • SCADA communication - IEC 61850, IEC 60870-5-103, IEC 60870-5-104, MODBUS RTU/TCP
  • Configuration tool - ROCON MMI protocol
  • Web-based interface - HTTP
  • Time synchronization - PTP (IEEE 1588), NTP / SNTP, IRIG-B or PPS
  • File system access – FTP

Configuration, setting and administration

  • Web server


  • Optional extension with I/O modules.