Category: ABB

Self-supervision and test function 

The relay’s built-in self-supervision system continuously monitors the state of the relay hardware and the operation of the relay software. 

Any fault or malfunction detected will signal an alert for the operator. 

A permanent relay fault will block the protection functions of the relay to prevent incorrect relay operation. 

The relays support a built-in test mode which enables the user to test the relay HMI and binary outputs.

Trip-circuit monitoring

The trip-circuit monitoring continuously monitors the availability and operability of the trip circuit. 

It provides open-circuit monitoring both when the circuit breaker is in its closed and in its open position. 

It also detects loss of circuit-breaker control voltage.

Access control 

To protect from unauthorized access and to maintain the integrity of information, the relays are armed with a three level, 

role-based user authentication system with individual passwords for operator, engineer and administrator levels. 

There are two alternative password protection options. 

The default is a combination of different navigation keys. 

The alternative is an alpha-numeric password. 

The user can select the password option based on their requirement.

Event log 

To collect sequence of events (SoE) information, the relays 

incorporate non-volatile memory with a storage capacity of 100 

events with associated time stamps and a resolution of 1 ms. 

The event log includes trip circuit monitoring status, protection 

operation status, binary I/O status and relay fault code. 

The event logs are stored sequentially, the most recent being first and so on. 

The non-volatile memory retains its data in the event of temporary auxiliary supply loss. 

The event log facilitates detailed post-fault analysis of feeder faults and disturbances. 

The SoE information can be accessed locally via the user interface on the relay front panel or remotely 

via the communication interface of the relay. 

​Recorded data

The relays store fault records of analog values for the last five trip events in non-volatile memory. 

The fault recording is triggered by the trip signal of a protection function. 

Each fault record includes the current values for three phases and ground current along with a time stamp. 

These records enable the user to analyze the five most recent power system events. 

The relays record the number of phase and ground fault trip events into dedicated trip counters. 

These trip counters cannot be reset by the user and are stored in non-volatile memory. 

The recorded information can be accessed locally via the user interface on the relay front

panel and can be uploaded for subsequent fault analysis. 

Optimized for limited space

With their compact size and unique technical features, the 

REF601 and REJ601 are ideal for retrofits, compact switchgear 

and switchgear with limited space. These relays have a small 

mounting depth and do not have any loose mounting accessories. 

Uniquely, the REF601 and REJ601 use a press-fit mounting 

arrangement, suitable for quick and easy installation on switchgear

Control 

The REF601 features control of one circuit breaker with dedicated push-buttons and guidance on local HMI for opening and closing. 

It includes two dedicated outputs for breaker control. 

The breaker control is also possible through optional MODBUS RTU or IEC 60870-5-103 communication.

Measurement 

All versions of the relay continuously measure phase currents 

and ground current. Ground current can be measured using an 

external zero sequence current transformer or can be calculated internally.

During operation, the default view of display shows the highest 

loaded phase current in primary terms (Amps) and the ground current. 

The values measured can be accessed locally via the 

user interface on the relay or remotely via the communication interface of the relay. 

These relays continuously measure negative sequence current, 

thermal level and counter values if these functions are supported as per application configurations.

Application 

The REF601 and REJ601 are protection relays aimed at protection and control of incoming and outgoing feeders in MV distribution substations. 

They can be applied for short-circuit, overcurrent and ground-fault protection of 

overhead lines and cable feeders of distribution and sub-distribution networks.

The inrush current stabilization function allows the relays to be 

used as the main protection for distribution transformers.

The relay with application configuration B offers non-directional 

overcurrent and ground-fault protection. The residual current for 

the ground-fault protection is derived from the phase currents. 

When applicable, core-balance current transformers can be 

used for measuring the residual current, especially when sensitive ground-fault protection is required.

The application configuration C adds thermal overload protection for feeders, cables and transformers, phase discontinuity 

protection and circuit breaker failure protection.

The application configuration D provides the highest functionality with incorporation of negative 

phase sequence protection and a multi-shot auto-recloser function making the relay suitable for overhead line feeders.

Protection functions 

The REF601 and REJ601 offer three-stage overcurrent and twostage ground-fault protection functions. 

The transformer inrush detector function is incorporated to prevent unwanted tripping due to energizing of transformers.

The REF601 and REJ601 offer three-stage overcurrent and 

two-stage ground fault protection functions. 

The low-set stages for overcurrent and ground fault protection are equipped with 

selectable characteristics – Definite Time (DT) and Inverse Definite Minimum Time (IDMT). 

The relays feature standard IDMT characteristics according IEC 61255-3 – Normal Inverse, Very 

Inverse, Extremely Inverse, Long-time Inverse. 

They also feature characteristics according to ANSI C37.112 – Moderate Inverse, 

Normal Inverse, Very Inverse, and Extremely Inverse. 

The relays also have a special characteristic RI Inverse (RI) for better coordination with the rest of the network. 

Additionally the relays also support two setting groups.

The REF601 and REJ601 also offer thermal overload protection for feeders, cables and transformers. 

Other protections include negative phase sequence protection, phase discontinuity 

protection and circuit breaker failure protection. 

The relays also have an auto-recloser option for overhead line feeders.

Description 

The REF601 is a dedicated feeder protection and control relay. 

The REJ601 is an overcurrent protection relay without breaker control. 

These relays are intended for the protection of utility 

substations and industrial power systems within primary and 

secondary distribution networks. They are members of ABB’s 

Relion® product family and part of its 605 series.

These relays, provide an optimized composition of protection, 

monitoring and control functionality in one unit, with the best 

performance usability in its class and are based on ABB’s indepth knowledge of protection and numerical technology

Relay functions

The REF601 and REJ601 can be pre-configured which facilitates easy and fast commissioning of switchgear. 

To emphasize the simplicity of using these relays, only application specific parameters need to be set within the relay’s intended area of application. 

The standard signal configuration can be altered by LHMI (local human-machine interface).

Basic Functions

Self Supervision

The IED is provided with an extensive self-supervision system which continuously 

supervises the software and the electronics. It handles run-time fault situations and 

informs the user about an existing fault via the LHMI and the communication. 

When in an IED internal fault is detected, the green Ready LED ceases to glow and the 

self-supervision output contact is activated. Internal fault indications have the highest 

priority on the LHMI. None of the other LHMI indications can override the internal fault 

indication. An indication about the fault is also shown as a message on the LHMI. 

The text IRF with an additional text message, a code is shown to indicate the fault type. 

The user can try to eliminate the fault by restarting the IED. 

If the fault is still found, the IED stays in internal fault mode. 

All other output contacts are released and locked for the internal fault. 

The IED continues to perform internal tests during the fault situation.

If an internal fault disappears, the green Ready LED starts glowing and the IED 

returns to the normal service state. The fault indication message remains on the LCD until manually cleared.

The self-supervision signal output operates on the closed circuit principle.

Under normal conditions the relay is energized and the contact gap 5-6 in connector XK2 is closed.

If the auxiliary power supply fail or an internal fault is detected, the contact gap 5-6 is opened.

Overview

REF601 CEI overview

REF601 is a dedicated feeder protection relay, intended for the protection, measurement and supervision of utility substations and industrial power systems.

Engineered from the ground up, the relay is inspired by and is compatible with the Rogowski coil sensor for current measurement. 

The new feeder protection relay is designed to unleash the advantages of current sensors for protection and control in medium voltage applications.

The REF601 features compact size and ease of use. 

The features include:

. Sensor input for phase current 

. External CBCT input for earth current 

. Three-stage overcurrent protection 

. Two-stage earth-fault protection 

. Magnetizing inrush detection 

. Control of circuit breaker 

. Local and remote control 

. Five event logs 

 . Two fault records of analogue value 

. Non-resettable trip counter 

. On-line measurements 

. Comprehensive local HMI 

. Universal auxiliary supply rating 

. Circuit breaker or panel mounting 

. Optional Modbus communication 

. Non-volatile memory 

. Access control 

. Self-supervision 

. Built-in test functionality

Introduction

This manual

This manual contains application and functionality descriptions and connection

diagrams, input and output signals, setting parameters and technical data. The

manual can be used as a technical reference during the engineering phase,

installation and commissioning phase, and during normal service. The manual

can also be used when calculating settings. Instructions on how to operate the IED

during normal service once it has been commissioned and it can be used to fi nd

out how to handle disturbances or how to view calculated and measured network

data in order to determine the cause of a fault

Intended Audience

This manual addresses system engineers, installation and commissioning personnel, 

who use technical data during engineering, installation and commissioning, and

in normal service. system engineer must have a thorough knowledge of protection

systems, protection equipment, protection functions and the confi gured functional

logics in the IEDs. The installation and commissioning personnel must have a basic

knowledge in handling electronic equipment.

This manual addresses Protection and control engineer responsible for planning, preengineering and engineering. 

The protection and control engineer must be experienced

in electrical power engineering and have knowledge of related technology, such as

communication and protocols.

The manual also addresses the operator, who operates the IED on a daily basis. The

operator must be trained in and have a basic knowledge of how to operate protection

equipment. The manual contains terms and expressions commonly used to describe

this kind of equipment.

Principle of Operation

REF601 has earth fault protection with low set and high set module.

Earth fault modules operate the protection as soon as fault current exceeds the set value of current.

It supports both DMT and IDMT timing while highset supports to DMT timings.

As the fault current exceeds the set value, trip time counting is started and start LED on front panel of relay glows ON.

If fault current falls down below the drop-off value of set current for 40 ms before trip time gets complete,

start LED will be turned off and trip count will become zero.

Trip time will start from zero next time when the fault current exceeds the set value again.

After a healthy trip, Start LED will be turned off and again

if fault current exceeds threshold, start LED will be turned ON again.

In case of healthy fault generation, after trip time get elapsed relay generates the trip

command which operates the Trip relay contacts as per user selected configuration.

Two LED indications on front plate of relay i.e.

Trip (common trip indication) and Trip Io and one signaling contact (XK2.1 –XK2.2) will

also be generated for user as Trip indication.