ABB REX 521 Technical Reference Manual, General

Protection Relay

REX 521

Technical Reference Manual, General

Protection Relay

Technical Reference Manual, General

REX 521

1MRS 751108-MUM

Issued: 27.06.2001

Version: F/10.08.2004

Contents

1. About this manual .....................................................................6

1.1. Copyrights .....................................................................................6

1.2. Trademarks ...................................................................................6

1.3. General .........................................................................................6

1.4. Abbreviations ................................................................................7

1.5. Related documents .......................................................................7

1.6. Document revisions .......................................................................8

1.7. Safety information .........................................................................8

2. Introduction ...............................................................................9

2.1. General .........................................................................................9

2.2. Application ...................................................................................10

2.3. Hardware versions ......................................................................12

3. Requirements ..........................................................................13

4. Technical description .............................................................14

4.1. Functional description .................................................................14

4.1.1. Parametrization ................................................................14

4.1.1.1. Local parametrization .........................................14

4.1.1.2. External parametrization ....................................14

4.1.1.3. Relay Setting Tool view ......................................15

4.1.1.4. Graphical I/O Setting Tool ..................................16

4.1.1.5. Factory settings ..................................................16

4.1.2. Non-volatile memory ........................................................17

4.1.3. Real-time clock ................................................................17

4.1.4. Auxiliary voltage ...............................................................18

4.1.4.1. Power supply versions .......................................18

4.1.4.2. Low auxiliary voltage indication ..........................18

4.1.5. Overtemperature indication ..............................................19

4.1.6. Analog channels ..............................................................19

4.1.6.1. Scaling the rated values of the protected unit

for analog channels 19

4.1.6.2. Technical data of the measuring devices ...........20

4.1.6.3. Calculated analog channels ...............................22

4.1.6.4. Select Io .............................................................22

4.1.6.5. Rated frequency .................................................22

4.1.7. Digital inputs ....................................................................22

4.1.7.1. Filtering of digital inputs .....................................22

4.1.7.2. Inversion of digital inputs ....................................23

4.1.8. Outputs ............................................................................23

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Technical Reference Manual, General

REX 521

4.1.8.1. High-speed power output (HSPO) .....................24

4.1.8.2. Single-pole power outputs (PO) .........................24

4.1.8.3. Signalling outputs (SO) ......................................25

4.1.9. Testing inputs and outputs ..............................................25

4.1.10.Trip-circuit supervision .....................................................26

4.1.11.Self-supervision ...............................................................28

4.1.11.1.Fault indication ..................................................29

4.1.11.2.Fault indication texts ..........................................30

4.1.12.Serial communication ......................................................31

4.1.12.1.Optical communication port on the rear panel ...32

4.1.12.2.Isolated RS-485 connection on the rear panel ..32

4.1.12.3.Front panel optical connection for a PC .............33

4.1.12.4.The service pin located on the rear panel ..........33

4.1.12.5.SPA bus .............................................................33

4.1.12.6.LON bus ............................................................35

4.1.12.7.IEC 60870-5-103 bus ........................................37

4.1.12.8.Modbus bus .......................................................37

4.1.12.9.DNP 3.0 Bus ......................................................39

4.1.13.Time synchronization .......................................................39

4.1.14.Display panel (HMI) .........................................................40

4.1.15.Indication LEDs ...............................................................41

4.1.16. Alarm LEDs ....................................................................41

4.1.16.1.Special features of alarm LEDs .........................41

4.1.16.2.Writing signal names on alarm LED label ..........42

4.2. Design description ......................................................................44

4.2.1. Technical data ........................................44

4.2.2. Terminal diagram of REX 521: Basic ...............................48

4.2.3. Terminal diagram of REX 521: Medium ...........................49

4.2.4. Terminal diagram of REX 521: High ................................50

4.2.4.1. Terminal diagram of H08 configuration ..............51

4.2.5. Terminal diagram of REX 521: Sensor ............................52

4.2.6. Terminal connections ......................................................53

5. Service ..................................................................................... 56

6. Ordering information ............................................................. 57

7. Revision history of REX 521 .................................................. 58

7.1. Revision identification .................................................................58

7.2. Changes and additions to earlier released revision C ................58

7.3. Configuration, setting, and SA system tools ...............................58

8. Index ........................................................................................ 59

9. Appendix A: IEC 60870-5-103 bus ........................................ 63

9.1. Functions supported by REX 521 ...............................................63

Protection Relay

Technical Reference Manual, General

REX 521

5

9.2. General principle of application data mapping ............................63

9.3. Principle of the protection functions mapping .............................64

9.4. Class 2 data ................................................................................64

9.5. Default mappings ........................................................................65

10.Appendix B: Parameters visible only in the relay ...............71

11.Appendix C: Parameters which cause reset ........................72

12.Appendix D: Parameters which require test mode .............74

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1MRS 751108-MUM

Protection Relay

Technical Reference Manual, General

REX 521

1. About this manual

1.1. Copyrights

The information in this document is subject to change without notice and should not

be construed as a commitment by ABB Oy. ABB Oy assumes no responsibility for

any errors that may appear in this document.

In no event shall ABB Oy be liable for direct, indirect, special, incidental or

consequential damages of any nature or kind arising from the use of this document,

nor shall ABB Oy be liable for incidental or consequential damages arising from use

of any software or hardware described in this document.

This document and parts thereof must not be reproduced or copied without written

permission from ABB Oy, and the contents thereof must not be imparted to a third

party nor used for any unauthorized purpose.

The software or hardware described in this document is furnished under a license

and may be used, copied, or disclosed only in accordance with the terms of such

license.

1.2. Trademarks

Brand and product names mentioned in this document are trademarks or registered

trademarks of their respective companies.

1.3. General

This document provides a general description of the protection relay REX 521

Revision E. For more information about the earlier revisions, refer to section

“Revision history of REX 521” on page 57.

For detailed information about the separate functions, see REX 521 Technical

Reference Manual, Standard Configurations (see “Related documents” on page 7).

1MRS 751108-MUM

REX 521

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Protection Relay

Technical Reference Manual, General

1.4. Abbreviations

1.5. Related documents

Manuals for REX 521

Parameter and event lists for REX 521

ASCII American Standard Code for Information Interchange

CRC Cyclic Redundancy Check

CT Current transformer

DI Digital Input

HMI Human-machine interface

HSPO High-speed power output

IRF Internal relay fault

LCD Liquid crystal display

MMI Man-machine interface

NC Normally closed

NO Normally open

PO Power output

RS Rogowski sensor

RTC Real-time clock

RTU Remote Terminal Unit

SA Substation automation

SO Signalling output

TCS Trip-circuit supervision

VD Voltage divider

VT Voltage transformer

• Technical Reference Manual, Standard Configurations 1MRS751802-MUM

• Operator’s Manual 1MRS 751107-MUM

• Installation Manual 1MRS 750526-MUM

• Technical Descriptions of Functions (CD-ROM) 1MRS750889-MCD

• Modbus Remote Communication Protocol for REX 521,

Technical Description 1MRS755017

• DNP 3.0 Remote Communication Protocol for REF 54_

and REX 521, Technical Description

1MRS755260

• Parameter List for REX 521 1MRS751999-RTI

• Event List for REX 521 1MRS752000-RTI

• General Parameters for REX 521 1MRS752156-RTI

• Interoperability List for REX 521 1MRS752157-RTI

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1MRS 751108-MUM

Protection Relay

Technical Reference Manual, General

REX 521

Tool-specific manuals

1.6. Document revisions

1.7. Safety information

• CAP505 Installation and Commissioning Manual 1MRS751273-MEN

• CAP505 Operator’s Manual 1MRS751709-MEN

• CAP505 Protocol Mapping Tool Operator’s Manual 1MRS755277

• Tools for Relays and Terminals, User’s Guide 1MRS752008-MUM

• CAP 501 Installation and Commissioning Manual 1MRS751270-MEN

• CAP 501 Operator’s Manual 1MRS751271-MUM

Version Date History

E 22.6.2004 - Manual updated to include DNP 3.0

- Fig. 4.1.1.4.-1 updated

- Fig. 4.1.12.8.-1 updated

- Cable type updated in Table 4.2.1-9

- Fig. 6.-1 updated

- Section 7. updated

- Table 9.5.-1 updated

F 10.8.2004 - Table in 2.2. updated

Dangerous voltages can occur on the connectors, even though the

auxiliary voltage has been disconnected.

National and local electrical safety regulations must always be

followed.

The device contains components which are sensitive to electrostatic

discharge. Unnecessary touching of electronic components must

therefore be avoided.

The frame of the device has to be carefully earthed.

Only a competent electrician is allowed to carry out the electrical

installation.

Non-observance can result in death, personal injury or substantial

property damage.

Breaking the sealing tape on the upper handle of the device will result

in loss of warranty and proper operation will no longer be guaranteed.

When the plug-in unit has been detached from the case, do not touch

the inside of the case. The relay case internals may contain high

voltage potential and touching these may cause personal injury.

!

1MRS 751108-MUM

REX 521

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Protection Relay

Technical Reference Manual, General

2. Introduction

2.1. General

The protection relay REX 521 is designed for protection, control, measuring, and

supervision in medium voltage networks. Typical applications include incoming and

outgoing feeders as well as substation protection. The protection relay is provided

with energizing inputs for conventional current and voltage transformers. Also a

hardware version with inputs for current and voltage sensors is available.

The protection relay is based on a multiprocessor environment. The HMI

1

(Human-

Machine Interface) including an LCD (Liquid Crystal Display) with different views

makes the local use easy and informs the user via indication messages. Modern

technology is applied both in hardware and software solutions.

The REX 521 is part of the substation automation concept for Distribution

Automation and extends the functionality and flexibility of the concept further.

Fig. 2.1.-1 REX 521 protection relay

1. HMI is referred to as MMI (man-machine interface) in the relay and in the Relay

Setting Tool.

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Technical Reference Manual, General

REX 521

2.2. Application

The REX 521 is designed for protection of incoming and outgoing feeders in

medium voltage distribution substations. Further, the relay can, for example, be

applied to back-up protection of power transformers and back-up for high voltage

line protection relays.

HW versions Basic Medium High/Sensor

Standard configurations

B01

B02

M01

M02

H01

1

H02

H03

H04

H05

H06

H07

H08

6

Function

blocks

FB name

(in CD-ROM)

IEEE

device

number

Protection functions

3I> NOC3Low 51 xxx x xxxxxxx

3I>> NOC3High 50/51 xxx x xxxxxxx

3I>>> NOC3Inst 50/51 x x x x x x x x x x

Io> NEF1Low 51N x x

x

2

xxx

Io>> NEF1High 50N/51N x x

x

2

xxx

Io>>> NEF1Inst 50N x x

x

2

xx

Io>->

3

DEF2Low 67N/51N x xxxxx x

Io>>->

3

DEF2High 67N x xxxxx x

Io>>>->

3

DEF2Inst 67N x xxxxx

3I>-> DOC6Low 67 x

x

4

x

3I>>-> DOC6High 67 x

x

4

3U> OV3Low 59 xxxx

3U>> OV3High 59 x x x x

3U< UV3Low 27 x x x x

3U<< UV3High 27 x x x x

3I2f> Inrush3 68 xxx xxxxxx x

Iub> CUB3Low 46 xxx xxxxx

3Ith> TOL3Cab 49F xxx xxxxx

O->I AR5Func 79 x xxxxx

Uo> ROV1Low 59N x x x

Uo>> ROV1High 59N x x x

Uo>>> ROV1Inst 59N x x x

f1 Freq1St1 81U/81O x x x x

f2 Freq1St2 81U/81O x

SYNC1 SCVCSt1 25 x x

Is2t n< MotStart 48, 14, 66 x

3I() PREV3 46R x

I2> NPS3Low 46 x

I2>> NPS3High 46 x

3I< NUC3St1 37 x

FUSEF FuseFail 60 x

3Ithdev> Tol3Dev 49M x x x

U1<U1U2> PSV3St1 27, 47, 59 x

1MRS 751108-MUM

REX 521

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Protection Relay

Technical Reference Manual, General

For more information, see REX 521 Technical Reference Manual, Standard

Configurations (see “Related documents” on page 7).

Control functions

I<->O CB1COCB1 xxx xxxxxxxxx

I<->O IND1COIND1 xxx xxxxxxxxx

I<->O IND2COIND2 xxx xxxxxxxxx

I<->O IND3 COIND3

x

5

I<->O POSCOLOCAT xxx xxxxxxxxx

ALARM1-8MMIALAR1-8 xxx xxxxxxxxx

Measurement functions

3I MECU3A xxx xxxxxxxxx

Io MECU1A xxx xxxxxxxxx

Uo MEVO1A x xxxxxxxxx

DREC MEDREC xxx xxxxxxxxx

3U MEVO3A xxxxxxxx

3U_B MEVO3B x

f MEFR1 xxxxxxxx

PQE MEPE7 xxxxxxxx

AI1 MEAI1 x

Condition monitoring functions

CB wear CMBWEAR1 xxx xxxxxxxxx

TCS1 CMTCS1 xxx xxxxxxxxx

MCS 3I CMCU3 xxx xxxxxxxxx

MCS 3U CMVO3 xxxxxxxx

TIME1 CMTIME1 x

Power quality monitoring functions

PQ 3Inf PQCU3H xxx xxxxxxxxx

PQ 3Unf PQVO3H xxxxxxxx

Standard functions

SWGRP xxx xxxxxxxxx

1. H01 available only with sensor version of REX 521

2. Configured fixedly to the I

0

(1/5 A) channel or Ios if selected

3. Can be used as Io>, Io>> and Io>>> or Uo>, Uo>> and Uo>>> function block with some limitations

4. 3I>-> and 3I>>-> cannot be set to operate as 3I>, 3I>> or 3I>>>

5. Motor status indication

6. H08 available only with VT version of REX 521. VTs are used to measure phase-to-earth voltages.

Calculated phase-to-phase voltages shown by 3U_B

Note! Calculated Uo (Uos) used in Sensor versions of H01 and H03 configurations.

Calculated Io (Ios) also available in H01-H05, H08 configurations

HW versions (Continued) Basic Medium High/Sensor

Standard configurations

B01

B02

M01

M02

H01

1

H02

H03

H04

H05

H06

H07

H08

6

Function

blocks

FB name

(in CD-ROM)

IEEE

device

number

12

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Protection Relay

Technical Reference Manual, General

REX 521

2.3. Hardware versions

Table 2.3.-1 Hardware versions of REX 521

Relay type REX 521

Version name Basic Medium High Sensor

REX521xBxxx

REX521xMxxx

REX521xHxxx

REX521xSxxx

Transformer modules (MIM)

1111

Transformers

• Current transformers 1/5 A 4 4 4 1

• Current transformers 0.2/1 A 1 1 1

• Voltage transformers 100 V 1 4 1

Sensor channels

• Current sensor inputs 3

• Voltage sensor inputs 3

Main CPU modules

1111

CPU_SP (SPA/ IEC/MODBUS plastic)

CPU_SG (SPA/ IEC/MODBUS glass)

CPU_LP (SPA/ IEC/ LON/MODBUS plastic)

CPU_LG (SPA/ IEC/ LON/MODBUS glass)

Power supply modules

1111

PS_87H (DItresh.=80 VDC)

PS_87L (DItresh.=18 VDC)

Display module

1111

2 x 16 character display

Digital inputs

9

High-speed power outputs

1

Power outputs (PO)

3

Signalling outputs (SO)

2

IRF outputs

1

Trip-circuit supervision (TCS)

1

1MRS 751108-MUM

REX 521

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Protection Relay

Technical Reference Manual, General

3. Requirements

If the environmental conditions differ from those specified in section “Technical

data” on page 44, as to temperature and humidity, or if the environmental conditions

around the protection relay contain chemically active gases or dust, the relay should

be visually inspected in association with the secondary testing. The visual inspection

should focus on:

• Signs of mechanical damage to the relay case and terminals.

• Signs of corrosion on terminals or on the case.

• For information about the maintenance of relays, refer to section “Service” on

page 55.

Protection relays are measuring instruments and should be handled with

care and protected against moisture and mechanical stress, especially

during transport.

!

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REX 521

4. Technical description

4.1. Functional description

4.1.1. Parametrization

To ensure that a protection function block protects the feeder in the desired manner,

the default values of parameters must be checked and set before taking the function

block into use.

The parameters can be set either locally over the HMI or externally via the serial

communication using Relay Setting Tool. See “Serial communication” on page 31.

4.1.1.1. Local parametrization

The parameter to be changed is entered by navigating in the menu structure. For

detailed instructions, see Operator’s Manual (see “Related documents” on page 7).

4.1.1.2. External parametrization

The Relay Setting Tool and/or Graphical I/O Setting Tool is used for external

parametrization of the protection relay. The parameters can be set by using a PC and

downloaded to the protection relay over a communication port. The menu structure

of the setting tool, including views relating to parametrization and settings, is the

same as the menu structure of the protection relay

1

. The use of the tool is instructed

in Tools for Relays and Terminals, User’s Guide (see “Related documents” on

page 7).

1. A few parameters are visible only in the relay, see the list on page 70.

1MRS 751108-MUM

REX 521

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Protection Relay

Technical Reference Manual, General

RSTmain.tif

Fig. 4.1.1.2.-1 Main dialog box of the Relay Setting Tool

4.1.1.3. Relay Setting Tool view

To improve usability, a REX 521 specific pull-down menu, View, with three views

has been created to the Relay Setting Tool.

views.tif

Fig. 4.1.1.3.-1 Relay Setting Tool views

The Settings view includes the parameters for setting of all the function blocks. The

Configuration view includes signalling and hardware related settings. The

parameters in the Configuration view are advised to be set during commissioning

and service because some of the parameters cause resetting of the device. See

“Appendix C: Parameters which cause reset” on page 71 for a list of these

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Technical Reference Manual, General

REX 521

parameters. In that case the disturbance recorder DREC will be cleared. Measured

values and registered data, for example current, digital input states, can be uploaded

by means of the Measurements & Registered Data view.

When uploading or downloading parameters with Relay Setting Tool by

using the option All, it covers only the parameters of the selected view

(that is, Settings, Configuration, or Measurements & Registered

Data).

4.1.1.4. Graphical I/O Setting Tool

To make the external relay parametrization even easier, a REX 521 specific

Graphical I/O Setting Tool has been added to the Relay Setting Tool. The Graphical

I/O Setting Tool offers a user-friendly environment for better visualization and

makes it easier to get a complete overview of the settings.

The tool is used for setting input switchgroups, output switchgroups, and Alarm

LED switchgroups. Using this tool is instructed in Tools for Relays and Terminals

User's Guide (see “Related documents” on page 7).

graphical setting tool.tif

Fig. 4.1.1.4.-1 Graphical I/O Setting Tool

4.1.1.5. Factory settings

The factory settings for the relay can be restored by selecting “Activate” from HMI

path Configuration\General\Software\Factory settings. After

this, the relay will reset itself immediately and start with the factory-set parameter

values.

!

1MRS 751108-MUM

REX 521

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Technical Reference Manual, General

When starting again, the relay display shows the text

:WARNING EEPROM -> FLASH

on the display. This means that the calibration parameters have been read from the

MIM card and copied to the non-volatile memory of the CPU card. After ten

seconds, the relay will reset itself again, and takes the correct calibration parameters

into use.

4.1.2. Non-volatile memory

The protection relay is equipped with a non-volatile memory for preserving

important data during auxiliary supply breaks. For example, when a setting value is

changed, the new value is stored in the memory at the moment of sending it to the

relay, without additional store commands. The memory does not need batteries, and

a lifelong service is guaranteed.

Following data is stored in the non-volatile memory:

• Setting values

• Display state

• Lockout state

• Recorded values

1

• Last 50 events

When the relay is restarted, the LED indication and text displayed before the

auxiliary supply break are restored on the display. More information about the alarm

LEDs can be found in section “Alarm LEDs” on page 41.

Recorded values are stored from start, trip and other important events. After an

auxiliary power break, time and date and fault currents for the three last events can

be viewed by navigating to the “Recorded values” section of the function block that

caused an indication.

The last 50 events that occurred before the auxiliary power supply break can be

viewed in the HMI event buffer. Time and date for the events are also restored.

4.1.3. Real-time clock

The real-time clock (RTC) is used for time stamping of events. It is also running

during auxiliary power breaks. When the supply is re-established, the relay sets the

right time and new events are stamped accordingly.

The protection relay is provided with a 1-week capacitor back-up protection

2

that

enables the internal clock to keep time in case of an auxiliary power failure.

The unnecessary restoring of factory settings should be avoided because

all the parameter settings that are written earlier to the relay will be lost,

that is, overwritten with the default values. During normal use this can

cause a protection function to trip when the settings are suddenly changed.

!

1. Because the storing of the recorded values is a background task, it might be affected

by a sudden auxiliary power failure.

2. Capacitor ageing may decrease the back-up time.

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4.1.4. Auxiliary voltage

For its operation, the protection relay requires a secured auxiliary voltage supply.

The protection relay’s internal power supply module forms the voltages required by

the protection relay electronics. The power supply module is a galvanically isolated

(flyback-type) DC/DC converter. A green LED indicator on the front panel is lit

when the power supply module is in operation.

4.1.4.1. Power supply versions

There are two basic versions of power supply modules available for REX 521

protection relays: type PS_87H and type PS_87L.

The input voltage range of the power supply module is marked on the front panel of

the REX 521 unit. The power supply version is specified by a letter in the order

number of the protection relay (refer to section “Ordering information” on page 56).

The voltage range of the digital inputs is tied to the selected power supply. If a power

supply version with the higher rated input voltage is selected, the protection relays

will be delivered with digital inputs that also have the higher rated input voltage. The

digital input, DI9, on the CPU module has also lower rated input voltage.

The auxiliary voltages of power supply modules and the corresponding rated input

voltages of digital inputs are:

For further technical data of the power supply, see Table 4.2.1-2 on page 44.

4.1.4.2. Low auxiliary voltage indication

The relay is provided with a low auxiliary voltage indication feature. The power

supply module issues an internal alarm signal when a drop in the power supply

voltage is detected. The alarm signal is activated if the power supply voltage falls

about 10% below the lowest rated DC input voltage of the power supply module, see

the table below:

The indication of a low auxiliary voltage (ACFail) can be seen as an event via serial

communication.

Power supply module

Rated input voltage

of power supply

Rated input voltage

of digital inputs

PS_87H 110/120/220/240 V AC

or 110/125/220 V DC

DI1...DI8: 110/125/220 V DC

DI9: 24/48/60/110/125/220 V DC

PS_87L 24/48/60 V DC DI1...DI9: 24/48/60/110/125/220 V DC

Rated input voltage Low indication level

PS_87H

• Rated input voltage 110/125/ 220 V DC 99 V DC

• Rated input voltage 110/120/220/ 240 V AC 88 V AC

PS_87L

• Rated input voltage 24/48/60 V DC 21.6 V DC

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4.1.5. Overtemperature indication

The REX protection relay includes an internal temperature supervision function.

The CPU module issues an internal alarm signal when overtemperature has been

detected inside the relay enclosure. The alarm signal will be activated once the

temperature inside the relay enclosure increases approximately to +78

o

C. The

overtemperature indication can be seen on the HMI or as an event via serial

communication. The relay will go to the IRF (internal relay fault) state. See

Table 4.1.11.2-1, “Fault indications,” on page 30.

4.1.6. Analog channels

The protection relay measures the analog signals needed for protection, measuring,

etc. via galvanically separated matching transformers. In addition, current sensors

(Rogowski coil) and voltage dividers developed by ABB can be used with REX 521.

The different versions of REX 521 are provided with the following matching

transformers and sensor inputs:

A letter in the order number specifies whether the protection relay is equipped with

basic, medium, high or sensor measuring input modules. (Refer to section “Ordering

information” on page 56).

4.1.6.1. Scaling the rated values of the protected unit for analog

channels

A separate scaling factor can be set for each analog channel. The factors enable

differences between the ratings of the protected unit and those of the measuring

device (CTs, VTs etc.) The setting value 1.00 means that the rated value of the

protected unit is exactly the same as that of the measuring device.

When scaling factors are used, it should be noted that they affect the

operation accuracy of the relay. The accuracies stated in the description of

each function block (in the CD-ROM Technical Descriptions of Functions)

only apply with the default values of the scaling factors. For example, a high

factor affects the operation of sensitive protection functions such as the

directional earth fault protection. To ensure the proper operation of the

function blocks, it must be checked that the analog scales (pu scales) of the

phase currents I

L1

, I

L2

, and I

L3

, and correspondingly, the analog scales of the

phase-to-phase voltages U

12

, U

23

, and U

31

or phase-to-earth voltages U

1

,

U

2

,

and U

3

are identical.

Version Matching transformers Sensor inputs

Basic CT1, CT2, CT3, CT4 -

Medium CT1, CT2, CT3, CT4, CT5, VT1 -

High CT1, CT2, CT3, CT4, CT5, VT1, VT2, VT3, VT4 -

Sensor CT4, CT5, VT1 RS1, RS2, RS3, VD1, VD2, VD3

!

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The scaling factor is calculated channel by channel as follows:

Scaling factor = I

nmd

/ I

np,

where

Example:

The scaling factors for the analog channels can be set via the HMI of the protection

relay or with the Relay Setting Tool. The HMI path for the scaling factors is:

Configuration\Protected unit\IL1: scaling, IL2:

scaling...

4.1.6.2. Technical data of the measuring devices

The technical data of the measuring devices is set using the Relay Setting Tool or

via HMI. The set values (Configuration\Meas.devices\) will affect the

measurements carried out by REX 521.

Values to be set for a current transformer:

• rated primary current (1...6000 A) of the current transformer

• rated secondary current (5 A, 2 A, 1 A, 0.2 A) of the current transformer

• rated current (5 A, 1 A, 0.2 A) of the current measuring input (= rated current of

the matching transformer of the protection relay)

• amplitude correction factor (0.9000...1.1000) of the current transformer at rated

current

• correction parameter for the phase displacement error of the current transformer

at rated current (-5.00°...0.00°)

• amplitude correction factor of the current transformer at a signal level of 1% of

the rated current (0.9000...1.1000)

• correction parameter for the phase displacement error of the current transformer

at a signal level of 1% of the rated current (-10.00°...0.00°)

Values to be set for a voltage transformer:

• rated voltage of primary voltage transformer (0.100...440.000 kV)

• rated voltage of voltage input (same as the secondary rated voltage of the primary

voltage transformer connected to the voltage input, 100 V, 110 V, 115 V, 120 V)

• amplitude correction factor of the primary voltage transformer voltage at rated

voltage (0.9000...1.1000)

• correction parameter for the primary transformer phase displacement error at

rated voltage (-2.00°...2.00°)

I

nmd

Rated primary current [A] of the measuring device

I

np

Rated primary current [A] of the protected unit connected to the

channel

Rated primary current of current trafo = 500 A: I

nmd

= 500 A

Rated current of the protected unit = 250 A: I

np

= 250 A

Scaling factor for current channels: 500 A / 250 A = 2.00

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ABB REX 521 Technical Reference Manual, General

ABB REX 521 Technical Reference Manual, General

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