Systems & Electronics

The multifunction protection relay IDG8N belongs to SIGMA-N digital protection line and it performs function as three-poles percentage biased generator differential protection relay and/or selective earth fault protection relay.

The user can select one or more of the functions listed in the table below:

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 IDG8N relay manages the following thresholds:

• 1 differential percentage biased threshold (two branches)
• 1 absolute value differential threshold
• 1 earth-fault differential percentage biased threshold (two branches)
• 1 absolute value earth-fault differential threshold

All the thresholds are definite time and each of them 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.