- Highly visible, phase-selective LED fault indication
- Setting via DIP switch behind front panel
- Test/Reset button
- Connection of remote contacts
- Push‐in clamps for quick installation
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
- 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
|Earth fault detection methods|
|Low-impedance/short-term low-impedance earthed||---|
|Short-circuit trip current|
200, 300, 400, 600, 800, 1,000, 2,000 A, self-adjustment
|Response delay short-circuit|
40, 80 ms
Short-circuit: 3 red LEDs (L1, L2, L3)
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.
|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|
|Temperature range||-30 to +70 °C|
Set of Devices
Order no. 37-1111-101
Sigma 2.0 AC/DC
Order no. 37-1121-101
Phase current sensor
For new installations on bushings
For all indicators with relay contacts
External signal lamp, 3 LEDs, 5 m connection cable
Order no. 49-0702-005
External signal lamp, 3 LEDs, bicolour red/green, 3 m connection cable
Order no. 49-0706-001
External signal lamp, 1 LED, bicolour red/green, 2 m connection cable
Order no. 49-0704-001
Wall-mounted housing, bottom cable entry
Order no. 49-9001-001