ABB REF543CM129AAA A Feeder Terminal

The ABB REF543CM129AAA A is a member of the ABB REF 543 series of numerical feeder terminals, designed for protection, control, measurement and supervision of overhead lines and cable feeders in medium voltage distribution networks. As a compact and fully programmable IED (Intelligent Electronic Device), it integrates multiple protection functions into a single unit, reducing panel space and wiring complexity while increasing reliability.

Protection Functions

The REF543CM129AAA A offers comprehensive protection for radial and loop feeders. Standard protection elements include three-phase overcurrent (50/51), directional overcurrent (67), sensitive earth fault (50N/51N), and directional earth fault (67N). It also supports undervoltage (27), overvoltage (59), and frequency elements (81). For networks requiring autoreclosing, the terminal includes a multi-shot autorecloser (79) with programmable sequences and check for synchronism or dead line/dead bus conditions. All protection stages are independently configurable with definite time or inverse time characteristics (IEC, IEEE, user-defined curves).

Control and Monitoring

Beyond protection, the REF543 acts as a local control unit for circuit breakers and disconnectors. It features a programmable logic matrix for interlocking and automation tasks. The integrated disturbance recorder captures up to 120 seconds of fault data, enabling detailed post-fault analysis. Measured values (I, U, P, Q, f, cosφ) are displayed locally on the LCD and transmitted via communication links. The unit also includes breaker condition monitoring, trip circuit supervision, and event logging.

Communication and Integration

The REF543CM129AAA A supports multiple communication protocols for seamless integration into substation automation systems. Standard rear communication ports provide options for IEC 61850, IEC 60870-5-103, Modbus RTU, and DNP3.0. It also supports time synchronization via IRIG-B or SNTP. The device can be accessed locally via the front panel HMI or remotely via the protocol gateway. The REF543 is fully compatible with ABB’s MicroSCADA and Network Manager systems.

Technical Specifications

• Measuring inputs: 4 current inputs (1/5 A) and 4 voltage inputs (100-230 V AC).

• Binary I/O: Up to 12 binary inputs and 8 output relays, expandable via I/O modules.

• Power supply: 80-265 V DC or 100-240 V AC.

• Housing: 19" rack or flush mount case, IP54 front.

• Self-supervision: Continuous hardware/software monitoring with watchdog output.

Typical Applications

The REF543CM129AAA A is used in utility substations, industrial power distribution, and commercial complexes. It is particularly suited for feeder protection in secondary distribution networks where space is limited. The model CM129AAA A variant includes a specific I/O configuration optimized for directional earth fault applications and fast communication. With its robust design and compliance with IEC 60255 and IEEE standards, the REF543 ensures reliable operation in harsh environments.

By combining protection, control, and communication in one device, the ABB REF543 feeder terminal helps utilities improve network reliability, reduce outage times, and simplify asset management.