Sigma 2.0

Short-circuit detection from 3 single-phase current sensors

The Sigma 2.0 is a phase-selective short-circuit indicator. It is designed to detect, display and remotely indicate short-circuits in medium voltage distribution networks.

The current is measured via three single-phase current sensors. By using the new sensors retrofit to more advanced indicator series is possible at any time – without changing the sensors.

There are two response criteria for short-circuit detection, fixed response value 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.

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

Sigma 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
  • Phase-selective fault indication
  • „„Trip current values: load-dependent self-adjustment or fixed values
  • „„Single and double flash mode for operation in radial and ring networks
  • „„With auxiliary supply and capacitor storage available in AC/DC version

Your advantages

  • No false trips due to harmonics
  • „„Highly visible LED fault indication
  • „„Retrofit ready for earth and short-circuit indicators with monitoring/control and fault direction function

Technical specifications

Earth fault detection methods

Earth short-circuit

Low-impedance/short-term low-impedance earthed ---
Isolated earthed -
Resonant earthed -
Earth short-circuit trip current -
Response delay earth short-circuit -
Trip current transient method -
Trip current active current cos ɸ -
Response delay active current cos ɸ -
Trip current reactive current sin ɸ -
Response delay reactive current sin ɸ -
Trip current permanent earth fault -
Response delay permanent earth fault -
Trip current pulse detection -
Short-circuit trip current

200, 300, 400, 600, 800, 1,000, 2,000 A, self-adjustment

Response delay short-circuit

40, 80 ms

Indication

Short-circuit: 3 red LEDs (L1, L2, L3)

Relay contacts 1
Remote contact

Potential-free permanent or momentary contact (>1 s)

Contact capacity: 230 V AC/1 A/62,5 VA max.

220 V DC/1 A/60 W max.

RS485/Modbus-RTU -
USB port -
Binary inputs -
Ethernet interface -
Manual reset ---
Remote reset ---
Automatic time reset ---
Reset via interface -
Reset on current restoration -
Reset on voltage restoration -
Reset on restoration of auxiliary supply -
Reset via Explorer Software -
Internal power supply

Long-life lithium cell, active flashing time >900 h, shelf life ≥20 years

AC/DC version: back-up capacitor, max. 8 h

External auxiliary supply AC/DC version: 24 – 230 V AC/DC
CT powered ---
Housing

Polycarbonate, IP40

Temperature range -30 to +70 °C
Cable diameter -
  1. Highly visible, phase-selective LED fault indication
  2. Setting via DIP switch behind front panel
  3. Test/Reset button
  4. Connection of remote contacts
  5. Push‐in clamps for quick installation
Produktfinder Product finder Kontakt Contact