Sigma 2.0 / Sigma F+E 2.0 / F+E 3 2.0 — non-directional short-circuit and earth fault indicators for MV switchgear
Sigma 2.0, Sigma F+E 2.0 and Sigma F+E 3 2.0 are non-directional short-circuit and earth fault indicators for medium-voltage switchgear cubicles. Short-circuit setting 200–2000 A or self-adjustment by load current, earth fault 20–160 A. The devices are installed in radial and ring cable networks.
- SC setting I>>
- 200, 300, 400, 600, 800, 1000, 2000 A or self-adjustment (IB<100 A → 400 A; IB>100 A → 4×IB)
- SC delay
- 40 or 80 ms
- Earth fault setting IE> (F+E)
- 20, 40, 60, 80, 100, 120, 160 A; delay 80/160 ms
- Accuracy
- ±5 % (0–630 A), ±10 % (>630 A)
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The series shows a fault without determining its direction. Sigma 2.0 works as a per-phase short-circuit indicator. Sigma F+E 2.0 and Sigma F+E 3 2.0 detect both short circuits and earth faults, and the earth fault measuring principle suits networks with a low-impedance earthed, solidly earthed or isolated neutral. Current is measured by three single-phase sensors, so a fault is determined and displayed for each phase. These same sensors can later be kept when changing over to indicators with a directional function and monitoring.
For short circuits, one of two criteria is chosen. The first provides a fixed setting with a delay of 40 or 80 ms. The second works with self-adjustment by load current: at a current up to 100 A the setting equals 400 A, and at a higher current it is four times the load current. Earth fault settings have a delay of 80 or 160 ms. The operating tolerance is ±5 % up to 630 A and ±10 % above. Higher harmonics do not cause false operations.
When the current exceeds the setting, the LED of the corresponding phase flashes and the remote signalling contact closes. Repeated excitation within the reset time, for example during auto-reclosing, is shown by the device with a double flash, which in radial and ring networks makes it easier to reconstruct the course of the fault. Sigma F+E 3 2.0 has separate LEDs I>> for short circuits and IE> for earth faults, and its remote signalling is per phase (L1, L2, L3) or group. For tests and commissioning, the settings are temporarily lowered to 10 A without moving the DIP switches.
The basic versions are powered from current transformers and a lithium cell with a service life of at least 20 years. AC/DC variants have an auxiliary power input of 24–230 V, and if it disappears during a fault, a capacitor maintains the indication for up to 8 h. Settings are made by DIP switches behind the front panel, reset by a button, remotely or by time after 1, 2, 4 or 8 h. Push-in terminals, polycarbonate housing IP40, operating temperature −40…+70 °C. The delivery includes the device and three phase current sensors, and a wall-mounted housing and a remote signal lamp are offered as accessories.
Technical specifications
| SC setting I>> | 200, 300, 400, 600, 800, 1000, 2000 A or self-adjustment (IB<100 A → 400 A; IB>100 A → 4×IB) |
|---|---|
| SC delay | 40 or 80 ms |
| Earth fault setting IE> (F+E) | 20, 40, 60, 80, 100, 120, 160 A; delay 80/160 ms |
| Accuracy | ±5 % (0–630 A), ±10 % (>630 A) |
| Signalling | 1 (Sigma 2.0) or 2 (F+E 2.0) relays; F+E 3 — per phase/group |
| Time reset | 1, 2, 4 or 8 h |
| Power supply | from CT + lithium cell ≥ 20 years; AC/DC variant 24–230 V with a capacitor for 8 h |
| Housing | polycarbonate IP40, −40…+70 °C |
Request a price and lead time
Sigma 2.0 / Sigma F+E 2.0 / F+E 3 2.0 — non-directional short-circuit and earth fault indicators for MV switchgear. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 9030 33 70 00 |
|---|---|
| HS, 6 digits | 9030 33 |
| CN (EU) | 9030 33 70 |
| HTSUS (USA) | 9030 33 38 00 |
| China customs tariff | 9030 33 90 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
For which neutral modes is Sigma F+E 2.0 suitable?
The earth fault detection principle suits networks with a low-impedance earthed, solidly earthed or isolated neutral. Earth fault settings are 20–160 A.
How does short-circuit setting self-adjustment work?
At a load current up to 100 A the setting is 400 A. At a higher load the device takes four times the load current.
How long does the indication last without auxiliary power?
In the AC/DC variant a capacitor maintains the indication for up to 8 h. The basic versions have a lithium cell with a service life of at least 20 years.
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