Month: July 2025

Features

• A protection, control, and monitoring IED with extensive functional library and configuration

possibilities and expandable hardware design to meet specific user requirements

• For overhead lines and cables

• For transformer feeders

• For single and/or three phase tripping

• High impedance differential protection for tee-feeders

• Phase-segregated line differential protection with up to six stabilized inputs for up to five line terminals with:

– Charging current compensation

– Separate inputs for each CT in double breaker, ring and one and a half breaker

installations for improved through fault stability

– Suitable for multiplexed, route switched, as well as dedicated fibre, communication networks using C37.94 protocol

– Power transformers can be included in the protected zone

– Transfer of up to eight binary signals

– Time synchronization with the echo-method or built-in GPS

• Full scheme phase-to-phase and phase-to-earth distance protection with up to three zones:

– All types of scheme communication

– Load encroachment feature

Entry-level numerical relay for distribution networks

REF601 is a dedicated feeder protection and control relay intended for the protection and 

control of utility and industrial power systems in primary and secondary distribution networks. 

The relay provides an optimized composition of protection, monitoring and control functionality in one unit, with the best performance and usability in its class.

Besides the conventional current transformer interface based variant, the relay also supports a variant based on Rogowski current sensors’ analog interface. 

This helps to obtain a compact medium voltage switchgear equipment size reduc­tion with improved performance and standardization.

Scope

Main protection for overhead lines and cable feeders in solidly earthed, resistance-earthed or isolated networks

Inrush current stabilization function for distribution transformers

Product benefits

Compact, flexible and simple to handle

Speedy commissioning through selective test function for protection functions, binary signals and communication features

Easily configurable binary inputs and outputs

Extensive self-supervision of the relay hardware and software

Enhanced safety with usage of sensors variant / detachable terminals with CT shorting facility

Press fit mounting arrangement facilitates easy and fast installation

Product features

Overcurrent, earth-fault, phase-discontinuity, negative-phase sequence and thermal-overload protections, 

inrush current detection, circuit-breaker control, reclosing and measurement

Preconfigured functionality facilitates easy and fast commissioning

Universal power supply 24-265 V AC/DC

Configurable binary inputs/outputs using local HMI or communication interface

Specific variant with site selectable CT selection (1 or 5A), Boolean logic and timers

Site selectable Modbus and IEC 60870-5-103 protocols