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.
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)
