Solutions   for   Protecting   andManaging   the   Electrical   Network

NP.M 800

Asynchronous motor protection relay

NPM800 protects MV and high power LV motors. This multi-function relay supervises motor current during all its operating modes: starting, normal operation and reacceleration. The good operating of the circuit breaker and its trip circuits are also supervised.
As well as the usual protection functions, NP800 relays provide monitoring, measurement and recording of the electrical quantities of the network. The relays can be set locally, using either the keypad and display or the RS232 port, or remotely using the RS485 port. Setting, reading, measurement and recording are all available locally or remotely.


  • Thermal start authorisation [5]
  • Thermal overload [49]
  • Too long start [48]
  • Locked rotor [51LR]
  • Phase to phase short-circuit [50]
  • Limitation of number of starts [66]
  • Unbalance, Reversal and Loss of Phase [46]
  • Earth fault [51N]
  • Minimum of Load - Unpriming [37I]
  • Latching of the output contacts [86]
  • Trip circuit supervision of the breaker [74TC]
  • Breaker failure [50BF] [50N_BF]


  • Configuration and parameter setting by local MMI or off-line / on-line PC
  • Measurement of electrical quantities:
    – Instantaneous, integrated and maximum values of phase and earth currents
  • 2 setting groups, locally or remotely selectable by digital input or by the communication channel
  • Self-diagnosis: Memories, output relays, A/D converters, auxiliary supply, cycles of execution of software, hardware failure
  • NP.M 800: 3+1 assignable output units / 4 assignable digital inputs (option: additional card with 4 assignable output relays and 4 assignable digital inputs)
  • Event recording: 250 locally recorded events, 200 saved in case of loss of auxiliary supply
  • Disturbance recording according to Comtrade┬« format: storage of 4 recordings of 52 periods
  • Optional Communication by Modbus┬« RS 485 or Ethernet by Modbus/TCP


  Device Doc. Type Lang. Ref. Index
NPM800 Leaflet EN A540 G
NPM800 First Handling Guide EN A344 G
NPM800 User Manual EN A343 H
NPM800 Connection/Definition Diagram EN / FR S38024 G