The Sigma F+E 3 2.0 is a combined short-circuit and earth fault indicator. Due to the measuring principle, the earth fault indicator is suitable for networks with low-resistance, rigidly earthed or insulated neutral point treatment. The Sigma 2.0 series measures current via three single-phase current sensors. This enables phase-selective fault detection and display. For short-circuit excitation, you can choose between two excitation criteria – fixed response values with response delay or self-adjustment depending on the operating current. If the current of the selected response criterion – fixed response value or self-adjustment – is exceeded, the LED of the relevant phase flashes and the remote signaling contact is activated. If a second excitation occurs within the reset time, e.g. due to automatic reclosing, this is signaled by a double flashing display and the remote signalling contact is activated again. The red LED I >> indicates a short circuit, the yellow LED IE> indicates an earth fault, while the display fields L1, L2 and L3 indicate the fault phase-selectively. In addition, the Sigma R+D 3 2.0 has a phase-selective (L1, L2, L3) or group-selective (I >>, IE>, I>> and IE>) Remote signaling. For testing and commissioning purposes, the current response values can be reduced to 10 A without changing the DIP switch settings.

The Sigma F+E 3 2.0 AC/DC variant also offers an auxiliary voltage connection. If the auxiliary voltage fails in the event of a fault, the LED display can be operated with capacitor support for up to 8 hours.