The relay type NA80 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.
Moreover undervoltage, overvoltage and automatic reclosing functions are provided.
The NA80 relay can be can be provided with circuits for input phase current suitable for traditional CTs and VTs, or combined ThySensor devices.

Applications
• Feeder
• Generator
• Motor
• Transformer
Protection functions
• Pt100 thermometric probes (26)
• Undervoltage (27)
• Thermal image (49)
• Phase overcurrent (50/51)
• Residual overcurrent (50N/51N)
• Overvoltage (59)
• Residual overvoltage (59N)
• Phase directional overcurrent (67)
• Ground directional overcurrent (67N)
• Automatic reclosing (79)
• 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
• ThySensor amperometric & voltmetric inputs
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)