ALSTOM MFAC14K1AA0001A Feeder Protection Relay

Overview

The MFAC14K1AA0001A monitors three-phase currents and residual current to detect phase faults and earth faults. It features definite time and inverse time overcurrent characteristics (IEC/ANSI curves) and includes a sensitive earth fault element for high-resistance ground faults. The relay also offers optional autoreclose functionality for overhead line applications. With its small footprint and user-friendly interface, it is easy to install and operate.

Key Features

• Phase Overcurrent (50/51): Three-phase overcurrent with independent pickup and time delay settings.

• Earth Fault (50N/51N): Sensitive residual current measurement for ground fault detection.

• Definite/Inverse Time Curves: Selectable IEC or ANSI curves for coordination.

• Autoreclose (79): Optional multi-shot reclosing for overhead feeders.

• Measurement: Phase currents, residual current, demand current.

• User Interface: Local LCD display (2x16 characters) and keypad.

• Digital I/O: 4 digital inputs, 3 output relays (standard).

• Communication: RS485 with Modbus RTU protocol.

• Event Recorder: 50 time-stamped events.

Technical Specifications

• Nominal Current: 1 A or 5 A (selectable via CT ratio).

• Auxiliary Supply: 24-250 VDC / 100-240 VAC.

• Current Inputs: 0-20 A RMS continuous, 100 A for 1 s.

• Overcurrent Accuracy: ±2% of setting.

• Time Delay Accuracy: ±2% or ±20 ms.

• Output Contacts: 3 form-C, rated 8A / 250 VAC.

• Digital Inputs: 4, 24-250 VDC.

• Operating Temperature: -25°C to +70°C.

• Enclosure: Panel mount, 96 x 96 mm.

• Certifications: IEC 60255, CE.

Applications

The MFAC14K1AA0001A is well-suited for a variety of feeder protection applications:

• Radial distribution feeders in utilities.

• Industrial plant incoming and outgoing feeders.

• Transformer primary and secondary protection.

• Motor feeder protection (with coordination).

• Capacitor bank protection (with overcurrent).

Configuration and Integration

The relay is configured using front panel pushbuttons or via the Modbus communication port using ALSTOM's setting software. It supports multiple setting groups, allowing adaptation to different system configurations. The autoreclose function, if enabled, can be programmed with up to four shots and dead time settings. The relay's compact size allows easy retrofitting into existing panels. Integration with SCADA is straightforward via Modbus RTU.

In summary, the ALSTOM MFAC14K1AA0001A feeder protection relay delivers essential protection functions in a cost-effective package, ensuring reliable operation of distribution networks.