Systems & Electronics

ING4N – Digital multifunction generator protection relay

The multifunction protection relay ING4N belongs to SIGMAN digital protection line and it performs functions as generator protection relay against overloads, shortcircuits, stator earth fault, negative sequence currents and overheating (thermal overload). The user can select one or more of the functions listed in the table below:


Phase overcurrent

50 – 51

Earth fault overcurrent (stator 95%) 64S – 51N
Negative sequence overcurrent
– unbalanced loads
Thermal overload 49

About the line current it is possible to select three-phase or two-phase connection.

All the functions of the relay 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.

Thresholds – the ING4N relay manages the following thresholds:

  • 2 line overcurrent thresholds
  • 2 earth-fault overcurrent thresholds
  • 2 negative sequence overcurrent thresholds
  • 2 thermal overload thresholds

Earch definite time threshold delay can be combined with an additional timer controlled by the digital inputs. The trip of the relay is shown by LEDs and by a message on the display.