Product Description

Overview

The REF543 feeder terminal from ABB is a multifunctional relay designed for advanced protection, control, measurement, and monitoring of medium-voltage electrical networks. It integrates comprehensive protection features with programmable logic control (PLC) capabilities, enabling automation and interlocking functions within substations. Suitable for single busbar, double busbar, and duplex systems, the REF543 supports various network types, including isolated, resonant-earthed, and partially earthed configurations.

Protection and Control Capabilities

The REF543 combines extensive protection functions with high-performance control:

Current and Voltage Protection

• Three-stage overcurrent (non-directional and directional)

• Earth-fault protection and residual overvoltage detection

• Under/overfrequency protection

• Phase sequence and phase loss detection

Motor and Equipment Protection

• Thermal overload protection for medium-sized three-phase asynchronous motors

• Short-circuit fault location for cables and network feeders

• Shunt capacitor bank monitoring and reactive power management

Control and Automation

• Local and remote control of up to 14 switching devices (circuit breakers, disconnectors)

• Embedded PLC functions based on IEC 61131-3 standard for automation sequences

• Reduces hardwiring requirements using integrated LON bus and programmable logic

Measurement and Monitoring

• Three-phase current, voltage, neutral current, frequency, and power factor measurement

• Active and reactive power monitoring

• Total Harmonic Distortion (THD) monitoring up to the 13th harmonic

• Detection of voltage sags, swells, and interruptions

• Transient recorder with 16 analog channels and 16 digital signals for post-fault analysis

Connectivity and Communication

• Supports multiple communication standards: SPA Bus, LON Bus, IEC 60870-5-103, IEC 61850 (via SPA-ZC 400 adapter), Profibus DPV1 (via SPA-ZC 302), DNP 3.0, Modbus

• Compatible with conventional transformers and modern sensors, including Rogowski coils and voltage dividers

• Optical communication minimizes disturbance and accelerates relay-to-relay data exchange

Technical Specifications

Applications

• Medium-voltage feeder protection for overhead lines and cable networks

• Motor protection and control for medium-sized three-phase motors

• Shunt capacitor bank management and reactive power compensation

• Substation automation and bay-level control

FAQ

Q: Can the REF543 be used in partially earthed networks?
A: Yes, the relay supports isolated, resonant-earthed, and partially earthed systems.

Q: Does it support PLC logic programming?
A: Yes, it has embedded PLC functions compliant with IEC 61131-3.

Q: Which communication protocols are supported?
A: SPA Bus, LON Bus, IEC 60870-5-103, IEC 61850 (via SPA-ZC 400), Profibus DPV1, DNP 3.0, and Modbus.

Q: Is it suitable for capacitor bank control?
A: Yes, it manages monitoring, switching, and reactive power compensation for capacitor banks.