NT10 – BIASED DIFFERENTIAL FOR TWO WINDING TRANSFORMERS

The differential current relay type NT10 is intended for the protection of two-winding power transformers, auto-transformers, generator- transformer units and short lines.
No matching CTs are required.

NT10 - Pro-n ()

Specifications

Key:   standard standard optional optional alternative alternative

Applications

  • Transformer

Protection functions

  • Pt100 thermometric probes (26)
  • Phase undercurrent (37)
  • Negative sequence overcurrent (46)
  • Thermal image (49)
  • Phase overcurrent (50/51)
  • Residual overcurrent (50N/51N)
  • Low impedance restricted ground fault (64REF)
  • High impedance restricted earth fault (87NHIZ)
  • Biased differential for transformer (87T)
  • 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)

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

  • IEC 61850 Protocol
  • Modbus RTU RS232 protocol
  • Modbus RTU RS485 / IEC 870-5-103 / DNP3 protocol
  • Modbus TCP/IP protocol (network board must be provided)