The 3EST000214-134 is part of ALSTOM’s MiCOM series of numerical relays, known for their flexibility and performance. This particular model is a comprehensive feeder protection unit, integrating multiple protection functions in a compact housing. It is suitable for radial and ring main systems, and can be used with or without voltage inputs for directional control.
Protection Functions: Definite time and inverse time overcurrent (50/51), directional overcurrent (67), earth fault (50N/51N/67N), sensitive earth fault (50SEF/51SEF), and breaker failure (50BF).
Measurement: Phase and residual currents, voltage (optional), frequency, power, energy, power factor.
Directional Element: Voltage polarized or current polarized, with memory function for close-in faults.
Inputs/Outputs: 4 current inputs (1 A or 5 A), 4 voltage inputs (optional), 6 digital inputs, 5 output relays.
Communication: RS485 Modbus RTU, optional Ethernet IEC 61850 or Profibus DP.
Event & Fault Recording: Up to 256 events, 20 fault records with oscillography (up to 10 cycles).
Display: Alphanumeric LCD with backlit, showing real-time values and settings.
Auxiliary Supply: 48-250 V DC / 100-240 V AC,<8 W.
Current Inputs: 1 A or 5 A rated, continuous 4x rated, dynamic range 0.1-40 A.
Frequency Range: 50/60 Hz (selectable).
Accuracy: ±2% for protection, ±0.5% for metering.
Operating Temperature: -25°C to +70°C.
Dimensions: 177 x 266 x 210 mm (flush mounting).
Protection Class: IP52 front, IP20 rear.

The relay continuously samples current and voltage waveforms. Protection elements operate based on user-selectable curves (IEC, ANSI, or custom). Directional elements use either voltage or current polarization to determine fault direction, with adjustable characteristic angles. The relay includes auto-reclosure logic (up to 4 shots) and setting groups (4 groups) for different network configurations. All measured values and statuses are available via communication for SCADA integration.
Feeder protection in distribution substations (up to 36 kV).
Industrial plant incoming feeders and bus-ties.
Backup protection for transformers and lines.
Protection of capacitor banks and reactors.
Settings can be adjusted via front keypad or using MiCOM S1 software. The software enables offline setting preparation, real-time monitoring, and disturbance analysis. Communication protocols support DNP3, IEC 60870-5-103, and Modbus. The relay also supports time synchronization via IRIG-B or SNTP.
CE, UL, and C-Tick marked.
Complies with IEC 60255 series and IEEE C37.90.
Designed for use in substations per IEC 61000-6-5.
Note: This document is for technical reference; refer to the official ALSTOM 3EST000214-134 manual for detailed engineering data.



