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).
Up to 2 external RIO modules DMRIS0 can be supplied.
Compliant to ENEL DMI 900016 and GSTP101 and to cyber security standards.



  • Calculated Residual Overcurrent - 50N/51N (Comp)
  • Phase overcurrent side H and side L - 50/51
  • Residual Overvoltage - 59N
  • SynchroCheck - 25
  • Remote TRIP
  • VT Supervision - 74VT
  • Overvoltage - 59
  • Automatic Recloser - 79
  • Breaker Failure - BF
  • CT Supervision - 74CT
  • Directional active overpower - 32P
  • Direct undervoltage - 27CC
  • Ground directional overcurrent - 67N
  • Maximum Residual Overcurrent - 50N/51N
  • Negative sequence overcurrent - 46
  • Phase Directional Overcurrent (Voltmetric Permission) - 67
  • Trip Circuit Supervision - 74TCS
  • Automatic Load Balancer


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


DMC3S Manual RO
Cyber Security Manual DMC3S_ Portuguese
DMRIS0 Manual
DMRIS0 Manual RO
Manual DMC900A3S0 
DMC3S Installation Guide RO