AAA
NA90

PHASE & RESIDUAL OVERCURRENT, PHASE & GROUND DIRECTIONAL, THERMAL IMAGE, PHASE UNDER/OVERVOLTAGE, RESIDUAL OVERVOLTAGE WITH TWO INDEPENDENT RESIDUAL CURRENT INPUTS

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The relay type NA90 can be typically used in radial or meshed MV and LV networks as feeder or power transformer protection:

  • On radial, ring and parallel feeders of any length in solidly grounded, ungrounded, Petersen coil and/or resistance grounded systems.
  • On parallel connected generators and transformer on the same busbar.
  • For ground fault protection on both sides of power MV-LV transformers.

Moreover undervoltage and overvoltage functions are provided.

NA90 - Pro-n ()

Specifications


Key:   standard standard optional optional alternative alternative


Applications

  • Feeder
  • Generator
  • Motor
  • Transformer

Protection functions

  • Pt100 thermometric probes (26)
  • Undervoltage (27)
  • Thermal image (49)
  • Phase overcurrent (50/51)
  • Measured residual overcurrent (50N(1)/51N(1))
  • Measured residual overcurrent (50N(2)/51N(2))
  • Calculated residual overcurrent (50N(Calc)/51N(Calc))
  • Overvoltage (59)
  • Residual overvoltage (59N)
  • Phase directional overcurrent (67)
  • Ground directional overcurrent (67N)
  • High impedance restricted earth fault (87NHIZ)
  • Breaker failure (BF)

Monitoring and control functions

  • CB diagnostic
  • Cold Load Pickup (CLP)
  • CTs monitoring (74CT)
  • Digital Fault recording (DFR)
  • Fault and event logging (SER & SFR)
  • Logic selectivity
  • Multiple setting profiles
  • Programmable Logic Controller
  • Second harmonic restraint
  • Self-test
  • Trip circuit supervision (74TCS)
  • VTs monitoring (74VT)

Hardware

  • 2 binary inputs + 6 output relays + 8 LEDs
  • Auxiliary power supply 110-230 Vac/dc
  • Auxiliary power supply 24-48 Vac/dc
  • Flush, projecting, projecting, rack, with separate MMI
  • Network module with Ethernet FX port (optical fiber)
  • Network module with Ethernet TX port (copper RJ45) + RS485 port
  • Nominal current 1/5 A selectable by DIP-switch
  • RS485 port (unavailable with Ethernet FX port)
  • Standard CT amperometric inputs 1/5 A

Communication

  • Modbus RTU RS232 protocol
  • Modbus RTU RS485 / IEC 870-5-103 / DNP3 protocol
  • Modbus TCP/IP protocol (network board must be provided)