Systems & Electronics

SCK4N – Automatic synchronizing and synchro-check relay

The unit SCK4N belongs to SIGMA-N digital protection line and it performs functions as automatic synchronizing and coupler device (jointly with the CU90N) and as synchro-check relay in high voltage or medium voltage systems.

The user can select one or more of the functional modes listed below:

Voltage check – dead bus LT


Synchro-check PS 25
Synchronizer PA 25

All the functions of the unit are fully programmable by front panel keyboard or through a RS485 serial interface using a personal computer with set-up program; furthermore the relay can be programmed through a remote control and monitoring system.

Operating modes – the SCK4N unit manages the following functional modes:

  • voltage check – dead bus (LT)
  • synchro-check (PS)
  • automatic synchronizer (PA)

It can be selected one or more operating modes; in the last case the selection of the operating mode is done automatically by the relay as function of the measured parameters.

The closing command to the circuit breaker (CB) can be selected as impulsive (to command directly the circuit breaker or a lock-out relay) or continuous to a control unit that manages the CB (parallel enabled).