Feeder protection

Protection and control panels that can be installed to the risers of the MV section and HV user line of primary substations. The devices can also be installed to MV nodes and primary substations operated with neutral to ground or very low neutral resistance in foreign countries. To supplement the protection functions, the system includes the following functions: breaker failure (BF), CT monitoring (74CT), VT monitoring (74VT), trip circuit monitoring (74TCS), Synchrocheck relay, EAC (Equilibratore Automatico di Carico)/ALB (Automatic Load Balancer) protection, programmable logic controller (PLC) and automatic reclosing (79). The system can be calibrated, programmed and its logs and values read with a PC running the Thy-Visor software, or via Ethernet; all the above operations are also available via the front panel keypad (MMI).


Standard Protective & control elements
  • SynchroCheck
  • Maximum Residual Overcurrent
  • Calculated Residual Overcurrent
  • Overvoltage
  • Residual Overvoltage
  • CT Supervision
  • VT Supervision
  • Remote TRIP
  • Direct undervoltage
  • Negative sequence overcurrent
  • Phase overcurrent side H and side L
  • Automatic Recloser
  • Breaker Failure
  • Trip Circuit Supervision
  • Directional active overpower
  • Phase Directional Overcurrent (Voltmetric Permission)
  • Ground directional overcurrent
  • Automatic Load Balancer


  • One Ethernet local RJ45 port for communication with ThyVisor setup software
  • One Fibre Optic Ethernet port dedicated to IEC 61850