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.
Specifications
Key: 
standard 
optional 
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)