Sigma F+E 3 2.0 is a combined short-circuit and earth fault indicator. Due to the measuring principle the earth fault indication is suitable for low-impedance, solidly and isolated earthed neutral networks.

The current is measured via three single-phase current sensors. This allows phase-selective fault detection and indication.

There are two response criteria for short-circuit detection, fixed response values with response delay or auto-adjustment based on load current.

If the current for the selected response criterion – fixed value or self-adjustment – is exceeded, the fault-affected phase will be indicated by a bright flashing LED and remote contact will be activated. A double  flashing LED signals a second fault that has occurred within the reset time, e. g. by an automatic reclose attempt and the remote contact will be reactivated.

Two additional LEDs display the fault type. The red LED I>> signals a short-circuit, the yellow LED IE> signals an earth fault. The L1, L2 and L3 indication fields display the fault-affected phase. In addition, phase-selective (L1, L2, L3) or group-selective (I>>, IE>, I>> and IE>) remote signalling is possible.

For testing and commissioning purposes, the trip current values can be reduced to 10 A without changing the DIP switch settings.

Sigma F+E 3 2.0 AC/DC

This version can be connected to auxiliary supply. If the auxiliary power drops out in the event of a fault, the LED indicator can operate using a back-up capacitor for up to 8 hours.

Equipment set includes:

• 1 display unit
• 3 single-phase current sensors