Alpha M | Alpha E
Short-circuit indicator
The Alpha is designed to detect, display, and remotely indicate short-circuit faults in medium voltage distribution networks. The indication is tripped by a short-circuit current and remains active until the device is reset. If a new device is connected to the CTs that are already installed in the switchgear, the Alpha must be factory-calibrated to match the existing CTs.
Product features
- Adjustable trip currents
- Flag-type indication (black / red)
- Remote signal
Phase-selective short-circuit indication
Simple setting options for trip current, reset time and relay function
Test/reset function
Your added value
- Durable (Alpha M)
- Remote reset also possible (Alpha E)
Terminal strip
Technical data
| Alpha M | Alpha E | |
|---|---|
| Short-circuit indicator | ✅ |
| Earth fault detection method | Earth short-circuit |
| I>> short-circuit trip current | 400, 600, 800, 1.000 A |
| tI>> Response delay | 100 ms, no excitation under 20 ms |
| Accuracy | ±15 % |
| Display | 3 bistable display elements (black / red) for L1, L2, L3 |
| Remote signaling / communication | 1 relay contact |
| Remote contact | Potential-free permanent or momentary contact (>100 ms)Contact capacity: 230 V AC / 1 A / 62.5 VA max.;220 V DC / 1 A / 60 W max. |
| Reset | Alpha M:
|
| Supply | |
| CT powered | ✅ |
| Internal power supply | Alpha M: – Alpha E: Long-life lithium cell, service life ≥20 years |
| Housing | Polycarbonate, IP40 |
| Temperature range | -30 °C to +70 °C |
All important documents for the device
Do you need additional information about our device? In our download area you will find all relevant documents such as brochures and product catalogs, technical reports, operating instructions and dimensional drawings (login required). Simply click on the download area to obtain the documents you require.
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Other short-circuit and earth fault indicators
ComPass A 2.0
- Load current monitoring
- Detection of earth faults and short circuits for NOSPE/ KNOSPE networks
- Error display without direction indication
ComPass B
- Highly accurate monitoring
- Detection of earth faults and short circuits for all networks
- Remote signaling via RS485 / Modbus interface
ComPass B 2.0
- Highly accurate monitoring
- Detection of earth faults and short circuits for all networks
- Error direction display
ComPass Bs 2.0
- Fault direction indicator with monitoring
- Detection of earth faults and short circuits for all networks
- Switching ComPass Bs 2.0 for controlling a switch-disconnector or circuit-breaker remotely