ABB REF 542plus  Protective diagnostic controller REF542plus 

• Real-time multifunction protections and switchgear controls: - protections - fault locator - measurements - controls - monitoring and diagnosis - power quality functions - communication - self diagnosis 

• Task separation for implemented protections and control scheme modifications 

• Flexible installation variations due to separated HMI and base unit 

• Large multilingual LCD display for singleline diagram, text messages and menu texts 

• Calculated primary quantities include: - maximum and mean currents in the settable monitoring period 0-30 min - sum of interrupted currents - operating time - number of switching cycles 

• Spring charging time supervision 

• Trip coil supervision 

• Binary input and output modules to interface with external processes 

• Analog input module for primary current and voltage signals: - analog transformers - non-inductive sensors 

• Life Cycle Traceability 

• Optional analog input module 4-20 mA

• Optional analog output module 0(4)-20 mA 

• Optional communication module for the substation automation system 

• Ethernet interface for embedded web server 

• Optional optical input port for time synchronization

 • Part of the ABB Distribution Automation system

Analog inputs 

REF 542plus feeder terminal is designed for connecting to non-conventional current and voltage sensors as well as to instrument transformers. At most 8 analog input channels are available. Due to their linear characteristic, modern current and voltage sensors provide greater accuracy and reliability in signal measurements. Compared to instrument transformers, the new non-inductive sensors have the following advantages: 

• higher linearity 

• high accuracy 

• compact dimensions 

• wide dynamic range 

• easy integration in the panels. 

The current sensor is based on the Rogowsky coil principle and consists of a single airwounded coil. Due to the lack of an iron core, the saturation effects of conventional current transformers do not exist anymore. Current sensors are thus well suited for the deployment of distance and differential protection functions. The voltage sensor is based on the resistive divider principle. Therefore, the voltage sensor is linear throughout the whole measuring range. The output signal is a voltage, directly proportional to the primary voltage. 

Binary inputs and outputs 

The REF 542plus unit acquires the primary objects status with auxiliary contacts, which are read by binary inputs, and sends commands using binary outputs. Several signals coming from other components are also monitored. Among others, the following operations are implemented using binary inputs and outputs: 

• primary objects control and interlocking in the switchgear

 • primary objects status acquisition (for example circuit breaker in opened/closed position) 

• circuit breaker spring supervision (when applicable). Binary inputs are isolated by opto-couplers. Binary outputs can be implemented either with mechanical relays or with static (semiconductor) devices. In a switchgear with directly driven motors, static power outputs are usually required.

 Life Cycle Traceability 

This feature will enable the management of the whole product life cycle, from the ordering until the refurbishment phase, by using a software structure within the ABB organization to automatically collect, store and retreive the relevant data, e.g. hardware module composition, software version etc. Therefore the firmware of each REF 542plus terminal is extended for detection of changes in the hardware composition or in the firmware. Due to the existing history record, technical support and services as well as repairs can be provided by ABB within the shortest possible time. 

Interfacing a station automation system 

An optional communication module can be provided for interfacing a station automation system. The four different protocols available for the REF 542plus make possible to interface any kind of station automation system, both from ABB or from third parties. The following typical functions are possible:

 • primary objects status monitoring 

• primary objects control 

• protections parameterization 

• measurements, alarms end events acquisition 

• fault recorder data acquisition. The available protocols are: 

• SPA • ABB LON according to LON Application Guide (LAG) 1.4 definitions 

• MODBUS RTU 

• MODBUS TCP

 • IEC 60870-5-103 with the extensions for control functions according to VDEW (Vereinigung Deutscher Elektrizitätswerke = Association of German Utilities) 

• IEC 61850-8-1 (only vertical communication)