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Service Manual

Types KCGG 141, 241, 341Overcurrent Relays

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Service Manual


HANDLING OF ELECTRONIC EQUIPMENT

A person's normal movements can easily generate electrostatic potentials of several thousand volts.Discharge of these voltages into semiconductor devices when handling electronic circuits can causeserious damage, which often may not be immediately apparent but the reliability of the circuit will havebeen reduced.

The electronic circuits of ALSTOM T&D Protection & Control Ltd products are immune to the relevant levelsof electrostatic discharge when housed in their cases. Do not expose them to the risk of damage bywithdrawing modules unnecessarily.

Each module incorporates the highest practicable protection for its semiconductor devices. However, if itbecomes necessary to withdraw a module, the following precautions should be taken to preserve the highreliability and long life for which the equipment has been designed and manufactured.

1. Before removing a module, ensure that you are at the same electrostatic potential as the equipmentby touching the case.

2. Handle the module by its front-plate, frame, or edges of the printed circuit board.Avoid touching the electronic components, printed circuit track or connectors.

3. Do not pass the module to any person without first ensuring that you are both at the sameelectrostatic potential. Shaking hands achieves equipotential.

4. Place the module on an antistatic surface, or on a conducting surface which is at the samepotential as yourself.

5. Store or transport the module in a conductive bag.

More information on safe working procedures for all electronic equipment can be found in BS5783 andIEC 60147-0F.

If you are making measurements on the internal electronic circuitry of an equipment in service, it is

preferable that you are earthed to the case with a conductive wrist strap.Wrist straps should have a resistance to ground between 500k 10M ohms. If a wrist strap is notavailable, you should maintain regular contact with the case to prevent the build up of static.Instrumentation which may be used for making measurements should be earthed to the case wheneverpossible.

ALSTOM T&D Protection & Control Ltd strongly recommends that detailed investigations on the electroniccircuitry, or modification work, should be carried out in a Special Handling Area such as described inBS5783 or IEC 60147-0F.

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SAFETY SECTION

This Safety Section should be read before commencing any work on

the equipment.

Health and safety

The information in the Safety Section of the product documentation is intended toensure that products are properly installed and handled in order to maintain themin a safe condition. It is assumed that everyone who will be associated with theequipment will be familiar with the contents of the Safety Section.

Explanation of symbols and labels

The meaning of symbols and labels which may be used on the equipment or in theproduct documentation, is given below.

Caution:refer to product documentation Caution:risk of electric shock

Protective/safety *earth terminal

Functional *earth terminal.Note: this symbol may also be used for a protective/safety earth terminal if that terminal is part of aterminal block or sub-assembly eg. power supply.

*Note:The term earth used throughout the product documentation is the directequivalent of the North American term ground.

Installing, Commissioning and ServicingEquipment connections

Personnel undertaking installation, commissioning or servicing work on thisequipment should be aware of the correct working procedures to ensure safety.The product documentation should be consulted before installing, commissioning orservicing the equipment.

Terminals exposed during installation, commissioning and maintenance maypresent a hazardous voltage unless the equipment is electrically isolated.

If there is unlocked access to the rear of the equipment, care should be taken by allpersonnel to avoid electric shock or energy hazards.

Voltage and current connections should be made using insulated crimpterminations to ensure that terminal block insulation requirements are maintainedfor safety. To ensure that wires are correctly terminated, the correct crimp terminaland tool for the wire size should be used.

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Before energising the equipment it must be earthed using the protective earthterminal, or the appropriate termination of the supply plug in the case of plugconnected equipment. Omitting or disconnecting the equipment earth may cause a

safety hazard.The recommended minimum earth wire size is 2.5 mm2, unless otherwise stated inthe technical data section of the product documentation.

Before energising the equipment, the following should be checked:

Voltage rating and polarity;

CT circuit rating and integrity of connections;

Protective fuse rating;

Integrity of earth connection (where applicable)

Equipment operating conditions

The equipment should be operated within the specified electrical andenvironmental limits.

Current transformer circuits

Do not open the secondary circuit of a live CT since the high voltage producedmay be lethal to personnel and could damage insulation.

External resistors

Where external resistors are fitted to relays, these may present a risk of electric

shock or burns, if touched.Battery replacement

Where internal batteries are fitted they should be replaced with the recommendedtype and be installed with the correct polarity, to avoid possible damage to theequipment.

Insulation and dielectric strength testing

Insulation testing may leave capacitors charged up to a hazardous voltage. At theend of each part of the test, the voltage should be gradually reduced to zero, todischarge capacitors, before the test leads are disconnected.

Insertion of modules and pcb cards

These must not be inserted into or withdrawn from equipment whilst it is energised,since this may result in damage.

Fibre optic communication

Where fibre optic communication devices are fitted, these should not be vieweddirectly. Optical power meters should be used to determine the operation or signallevel of the device.

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Older ProductsElectrical adjustments

Equipments which require direct physical adjustments to their operating mechanismto change current or voltage settings, should have the electrical power removedbefore making the change, to avoid any risk of electric shock.

Mechanical adjustments

The electrical power to the relay contacts should be removed before checking anymechanical settings, to avoid any risk of electric shock.

Draw out case relays

Removal of the cover on equipment incorporating electromechanical operatingelements, may expose hazardous live parts such as relay contacts.

Insertion and withdrawal of extender cardsWhen using an extender card, this should not be inserted or withdrawn from theequipment whilst it is energised. This is to avoid possible shock or damagehazards. Hazardous live voltages may be accessible on the extender card.

Insertion and withdrawal of heavy current test plugs

When using a heavy current test plug, CT shorting links must be in place beforeinsertion or removal, to avoid potentially lethal voltages.

Decommissioning and DisposalDecommissioning: The auxiliary supply circuit in the relay may include

capacitors across the supply or to earth. To avoid electricshock or energy hazards, after completely isolating thesupplies to the relay (both poles of any dc supply), thecapacitors should be safely discharged via the externalterminals prior to decommissioning.

Disposal: It is recommended that incineration and disposal to watercourses is avoided. The product should be disposed of in asafe manner. Any products containing batteries should havethem removed before disposal, taking precautions to avoid

short circuits. Particular regulations within the country ofoperation, may apply to the disposal of lithium batteries.

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Technical SpecificationsProtective fuse rating

The recommended maximum rating of the external protective fuse for thisequipment is 16A, Red Spot type or equivalent, unless otherwise stated in thetechnical data section of the product documentation.

Insulation class: IEC 601010-1: 1990/A2: 1995 This equipment requires aClass I protective (safety) earthEN 61010-1: 1993/A2: 1995 connection to ensure userClass I safety.

Installation IEC 601010-1: 1990/A2: 1995 Distribution level, fixedCategory Category III installation. Equipment in(Overvoltage): EN 61010-1: 1993/A2: 1995 this category is qualification

Category III tested at 5kV peak,1.2/50s, 500, 0.5J,between all supply circuitsand earth and also betweenindependent circuits.

Environment: IEC 601010-1:1990/A2: 1995 Compliance is demonstratedPollution degree 2 by reference to genericEN 61010-1: 1993/A2: 1995 safety standards.Pollution degree 2

Product safety: 73/23/EEC Compliance with theEuropean Commission LowVoltage Directive.

EN 61010-1: 1993/A2: 1995 Compliance is demonstratedEN 60950: 1992/A11: 1997 by reference to generic

safety standards.

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SERVICE MANUAL R8557BKCGG 141, 241, 341 Contents

CHAPTER 1. INTRODUCTION

CHAPTER 2 HANDLING AND INSTALLATION

CHAPTER 3 RELAY DESCRIPTION

CHAPTER 4 APPLICATION OF PROTECTION FUNCTIONS

CHAPTER 5 MEASUREMENT AND RECORDS

CHAPTER 6 SERIAL COMMUNICATIONS

CHAPTER 7 TECHNICAL DATA

CHAPTER 8 COMMISSIONING

APPENDIX 1 RELAY CHARACTERISTIC CURVES

APPENDIX 2 LOGIC DIAGRAMS

APPENDIX 3 CONNECTION DIAGRAMS

APPENDIX 4 COMMISSIONING TEST RECORD

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Service Manual

Chapter 1Introduction

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SERVICE MANUAL R8557BKCGG 141, 241, 341 Chapter 1

Contents

1. USING THE MANUAL 1

2. INTRODUCTION 12.1 KCGG 141 three phase overcurrent and earth fault protection 12.2 KCGG 241 three phase overcurrent and earth fault protection 22.3 KCGG 341 three phase overcurrent and earth fault protection 22.4 Protection features of KCGG 141, KCGG 241 and KCGG 341 relays 22.4.1 Simplified settings configuration 22.5 Features available by model 3

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SERVICE MANUAL R8557BKCGG141, 241, 341 Volume 1

Chapter 1Page 1 of 3

Section 1. USING THE MANUAL

This manual provides a description of the KCGG 141/241/341 overcurrentprotection from K Range Series 2 numerical relays. It is intended to guide the userthrough the application, installation, setting and commissioning of the relays.

The manual has the following format :

Chapter 1. Introduction

An introduction on how to use this manual and a generalintroduction to the relays covered by the manual.

Chapter 2. Handling and Installation

Precautions to be taken when handling electronic equipment.

Chapter 3. Relay DescriptionA detailed description of the features that are common toKCGG 141, 241 and 341 relays

Chapter 4. Application of Protection Functions

An introduction to the applications of the relays and special featuresprovided.

Chapter 5. Measurements and Records

How to customise the measurements and use the recording features.

Section 6. Control Functions and Serial Communications

Hints on using the serial communication feature.

Section 7. Technical Data

Comprehensive details on the ratings, setting ranges andspecifications etc.

Section 8. Commissioning

A guide to commissioning, problem solving and maintenance.

Appendix Appendices include relay characteristic curves, logic diagrams,connection diagrams and commissioning test records.

Section 2. INTRODUCTION

The K Range of numerical relays has been enhanced to include a range of relaysfor three phase overcurrent and earth fault protection with reduced inputs/outputs.The three models covered by this manual are supplied with a fixed configurationthat simplifies their application.

2.1 KCGG 141 three phase overcurrent and earth fault protection

This relay draws power from the substation battery, or a secure AC supply, topower its internal circuits. It will normally be used with shunt tripping

arrangements. It is available either preconfigured with simplified settings(KCGG 141) or customer configurable (KCGG 142 02).

This service manual applies to the KCGG 141 simplified settings relay. The servicemanual R8551 applies to the KCGG 142 02 customer configurable relay.

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This relay can draw the energy necessary to power its internal circuits from the linecurrent transformers and hence can be applied to impose no continuous drain on

the station battery. It is therefore ideal for those situations where the battery is notsupervised. These installations would normally be provided with a battery fortripping the circuit breaker and a shunt trip arrangement would be typical.However, if there is no station battery and the circuit breaker has a suitablysensitive trip mechanism, the capacitor discharge trip feature of this relay may beused to power the trip circuit.

Additionally this relay may be powered from an auxiliary AC supply, such as thelighting supply in the substation, or from the VT on the circuit breaker. Under faultconditions, when this voltage supply may be lost, the relay will be powered fromthe current transformers, but at all other times the voltage supply will power therelay. This will allow settings to be applied, lower earth fault to be detected and

serial communications to be established.


This relay is based on the KCGG 241 and can be used in similar installations. Anadditional electromechanical element is incorporated in this relay so that it may beused in AC Series trip circuits.

2.4 Protection features of KCGG 141, KCGG 241 and KCGG 341 relays

2.4.1 Simplified settings configuration

Two stages of overcurrent protection

Two stages of earth fault protection

Measurement of current and frequency

Fault records for last 5 faults

Event records for the last 50 events

Disturbance record for the last fault

Serial communications

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2.5 Features available by model

Feature KCGG 141 KCGG 241 KCGG 341

simplifiedsettings

Protection

Overcurrent

Earth fault

Measurement

Frequency

Current

Thermal ammeter(s)

Thermal demand(s)

Thermal state

Programmable I/O

Logic inputs 3 3 3

Output relays 4 4 4

Control

Auxiliary timers 1

Remote setting change

Records

Fault records 5 5 5

Event records 50 50 50

Disturbance records 1 1 1

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Service Manual

Chapter 2Handling and Installation

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Contents

1. GENERAL CONSIDERATIONS 1

1.1 Receipt of relays 11.2 Electrostatic discharge (ESD) 1

2. HANDLING OF ELECTRONIC EQUIPMENT 1

3. RELAY MOUNTING 2

4. UNPACKING 2

5. STORAGE 3

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Section 1. GENERAL CONSIDERATIONS

1.1 Receipt of relays

Protective relays, although generally of robust construction, require carefultreatment prior to installation on site. Upon receipt, relays should be examinedimmediately to ensure no damage has been sustained in transit. If damage hasbeen sustained during transit, a claim should be made to the transport contractor,and ALSTOM T&D Protection & Control should be promptly notified.

Relays that are supplied unmounted and not intended for immediate installationshould be returned to their protective polythene bags.

1.2 Electrostatic discharge (ESD)

The relays use components that are sensitive to electrostatic discharges.

The electronic circuits are well protected by the metal case and the internal moduleshould not be withdrawn unnecessarily. When handling the module outside itscase, care should be taken to avoid contact with components and electricalconnections. If removed from the case for storage, the module should be placed inan electrically conducting antistatic bag.

There are no setting adjustments within the module and it is advised that it is notunnecessarily disassembled. Although the printed circuit boards are pluggedtogether, the connectors are a manufacturing aid and not intended for frequentdismantling; in fact considerable effort may be required to separate them.Touching the printed circuit board should be avoided, since complementary metaloxide semiconductors (CMOS) are used, which can be damaged by static

electricity discharged from the body.

Section 2. HANDLING OF ELECTRONIC EQUIPMENT

A persons normal movements can easily generate electrostatic potentials ofseveral thousand volts. Discharge of these voltages into semiconductor deviceswhen handling electronic circuits can cause serious damage, which often may notbe immediately apparent but the reliability of the circuit will have been reduced.

The electronic circuits are completely safe from electrostatic discharge whenhoused in the case. Do not expose them to risk of damage by withdrawingmodules unnecessarily.

Each module incorporates the highest practicable protection for its semiconductordevices. However, if it becomes necessary to withdraw a module, the precautionsshould be taken to preserve the high reliability and long life for which theequipment has been designed and manufactured.

1. Before removing a module, ensure that you are at the same electrostaticpotential as the equipment by touching the case.

2. Handle the module by its frontplate, frame or edges of the printed circuitboard. Avoid touching the electronic components, printed circuit track orconnectors.

3. Do not pass the module to another person without first ensuring you are both atthe same electrostatic potential. Shaking hands achieves equipotential.

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4. Place the module on an antistatic surface, or on a conducting surface which isat the same potential as yourself.

5. Store or transport the module in a conductive bag.

If you are making measurements on the internal electronic circuitry of an equipmentin service, it is preferable that you are earthed to the case with a conductive wriststrap. Wrist straps should have a resistance to ground between 500k 10M.If a wrist strap is not available, you should maintain regular contact with the caseto prevent a build-up of static. Instrumentation which may be used for makingmeasurements should be earthed to the case whenever possible.

More information on safe working procedures for all electronic equipment can befound in BS5783 and IEC 60147-OF. It is strongly recommended that detailedinvestigations on electronic circuitry, or modification work, should be carried out ina Special Handling Area such as described in the above-mentioned BS and IEC

documents.

Section 3. RELAY MOUNTING

Relays are dispatched, either individually, or as part of a panel/rack assembly.If loose relays are to be assembled into a scheme, then construction details can befound in Publication R7012. If an MMLG test block is to be included it should bepositioned at the right hand side of the assembly (viewed from the front).Modules should remain protected by their metal case during assembly into a panelor rack. The design of the relay is such that the fixing holes are accessible withoutremoval of the cover. For individually mounted relays, an outline diagram is

normally supplied showing the panel cut-outs and hole centres. These dimensionswill also be found in Publication R6557.

Section 4. UNPACKING

Care must be taken when unpacking and installing the relays so that none of theparts is damaged, or the settings altered and they must only be handled by skilledpersons. The installation should be clean, dry and reasonably free from dust andexcessive vibration. The site should be well lit to facilitate inspection. Relays thathave been removed from their cases should not be left in situations where they are

exposed to dust or damp. This particularly applies to installations which are beingcarried out at the same time as construction work.

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Section 5. STORAGE

If relays are not to be installed immediately upon receipt they should be stored in a

place free from dust and moisture in their original cartons. Where de-humidifierbags have been included in the packing they should be retained. The action of thede-humidifier crystals will be impaired if the bag has been exposed to ambientconditions and may be restored by gently heating the bag for about an hour, priorto replacing it in the carton.

Dust which collects on a carton may, on subsequent unpacking, find its way intothe relay; in damp conditions the carton and packing may become impregnatedwith moisture and the de-humidifier will lose its efficiency.

Storage temperature 25C to +70C.

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Service Manual

Chapter 3Relay Description

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Contents

1. RELAY DESCRIPTION 1

2. USER INTERFACE 22.1 Frontplate layout 22.2 LED indications 32.3 Keypad 32.4 Liquid crystal display 32.5 Flag display format 3

3. MENU SYSTEM 5

3.1 Default display 53.2 Accessing the menu 63.3 Menu contents 63.4 Menu columns 7

3.5 System data 73.6 Fault records 83.7 Measurements 1 83.8 Measurements 3 83.9 Earth fault 1 93.10 Phase fault 1 93.11 Logic (KCGG 341 menu only) 103.12 Input masks 103.13 Relay masks 103.14 Recorder masks 10

4. ACCESS TO MENU 114.1 Quick guide to menu controls 114.2 Negotiating the menu 124.3 Resetting trip indication 124.4 Clearing fault records 13

5. ACCESS TO SETTINGS 13

5.1 To enter setting mode 135.2 To escape from the setting mode 135.3 Changing setting values 135.4 To accept the new setting 14

5.5 Entering text 146. ACCESS TO ADVANCED SETTINGS 146.1 Changing function links 146.2 Setting communication address 146.3 Setting the relay with a PC or laptop 15

7. ALARM FLAGS 15

8. EXTERNAL CONNECTIONS 16

8.1 Auxiliary powered relays 178.2 Dual powered relays 17

8.3 Powered from current transformers alone 178.4 Special application notes for dual powered relays 188.5 Powered from an auxiliary AC voltage and from current transformers 18

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Contents

8.6 Dead substation protection 198.7 Logic control inputs 198.8 Analogue inputs 20

8.9 Output relays 218.10 Output relay minimum dwell time 218.11 Capacitor discharge tripping 218.12 AC series tripping 228.13 Improving reliability of trip and closing contacts 22

Figure 1. Front plate layout 2

Figure 2. Flag display format 4

Figure 3. Menu format 5

Figure 4. Start up time delay 18Figure 5. Example connection of logic inputs 20

Figure 6. Capacitor discharge trip 21

Figure 7. AC series trip arrangement, KCGG 341 22

Figure 8. Contact reinforcing circuit 23

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SERVICE MANUAL R8557BKCGG 141, 241, 341 Volume 1


Section 1. RELAY DESCRIPTION

The KCGG 141/241/341 relays use numerical techniques to derive protection

and control functions. They have four multiplexed analogue inputs, sampled eighttimes per power frequency cycle. The Fourier derived power frequency componentreturns the rms value of the measured quantity. To ensure optimum performance,frequency tracking is used. The channel that is tracked is chosen on a prioritybasis, a, b, c. Frequency tracking is not employed on the residual current, toensure maximum harmonic rejection. In the absence of a signal to frequency track,the sampling frequency defaults to the rated frequency of the power system.

Four output relays are programmed to respond to a selection of protectionfunctions and three logic inputs are allocated to control functions. The logic inputsare filtered to ensure that induced AC current in the external wiring to these inputsdoes not cause an incorrect response.

The relays are powered from either a DC, or an AC, auxiliary supply which istransformed by a wide ranging DC/DC converter within the relay. This providesthe electronic circuits with regulated and galvanically isolated supply rails.The power supply also provides a regulated and isolated field voltage to energisethe logic inputs.

The dual powered version of the relay draws its energising supply from the currenttransformers in the absence of an auxiliary voltage supply. This makes it suitablefor application where the auxiliary supply is not reliable, or not available. This canbe used in shunt trip, capacitor discharge and AC series trip arrangements.

An interface on the front of the relay allows the user to navigate through the menu

to access data, change settings and reset flags etc. As an alternative the relay canbe connected to a computer via its serial communication port and the menuaccessed on-line. This provides a more friendly and intuitive method of setting therelay, as it allows a whole column of data to be displayed at one time instead ofjust a single menu cell. Computer programs are also available which enablesetting files to be generated off-line and these files can then be down loaded to therelay via the serial port.

In addition to protection and control functions the relays can display all the valuesthat are measured and many additional ones that are calculated. Useful timestamped data for post fault analysis is stored in event records and disturbancerecords. This data is available via a serial communication port for access locally

and/or remotely, with a computer. Remote control actions can also be made andto this end many relays from the K Range have been integrated into SCADAsystems.

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Section 2. USER INTERFACE

The front plate of the relay provides a man machine interface, providing the user

with a means of entering settings to the relay, displaying measured values, faultrecords and alarms. The series 2 relays have additional graphics to assist the user.The area in which the fault flags are displayed is divided up to denote the areaassociated with each phase and there is a marked position for the appropriatephase colours to be marked and for labels to be affixed to denote the use of thethree overcurrent stages and the three auxiliary timers.

F + 0

Relay types

Liquidcrystaldisplay

LED indicators

Ratings

Model number

Serial number

Digit identifiers

Entry keys

Hz

110/125 V

Vn

KCGG141KCGG14101102125

No P967701

-

In 1 A V

110 50/60V

STAGE 2

STAGE 1

STAGE 3

ALARMALARM TRIP

* *

GROUP

CAUX TIMER

EF D

FAULT NoSETTING

3C

AB 89 67 5 4

A B

12 0

HEALTHY

F n _ 2G2 A __ * B __ *

TAU X 1 C * N

Figure 1. Front plate layout

2.1 Frontplate layout

The frontplate of the relay carries a liquid crystal display (LCD) on which data suchas settings and measured values can be viewed. The data is accessed through amenu system. The four keys [F]; [+]; [] and [0] are used to move around the menu,select the data to be accessed and enter settings. Three light emitting diodes LEDsindicate alarm, healthy and trip conditions.

A label at the top corner identifies the relay by both its model number and serialnumber. This information uniquely specifies the product and is required whenmaking any enquiry to the factory about a particular relay. In addition, there is arating label in the bottom corner which gives details of the auxiliary voltage andcurrent ratings. Two handles, one at the top and one at the bottom of thefrontplate, will assist in removing the module from the case.

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2.2 LED indications

The three LEDs provide the following functions:

GREEN LED Indicates the relay is powered up and running. In most cases itfollows the watchdog relay, but dual powered relays are theexception because the watchdog does not operate for loss ofauxiliary supply. Such a condition would be considered a normaloperational condition when the relays are energized from linecurrent transformers alone.

YELLOW LED Indicates alarm conditions that have been detected by the relayduring its self checking routine.

RED LED Indicates a protection trip that has been issued by the relay.

2.3 Keypad

The four keys perform the following functions:[F] - function select/digit select key/next column

[+] - put in setting mode/increment value/accept key/ previous column

[-] - put in setting mode/decrement value/reject key /next column

[0] - reset /escape/change default display key

Note: Only the [F] and [0] keys are accessible when the relay cover is in place.

2.4 Liquid crystal display

The liquid crystal display has two lines, each of sixteen characters. A back-light is

activated, when any key on the frontplate is momentarily pressed and will remainlit until ten minutes after the last key press. This enables the display to be read inall conditions of ambient lighting.

The numbers printed on the frontplate just below the display, identify the individualdigits that are displayed for some of the settings, ie. function links, relay masks etc.Additional text around the display is used to define the areas in which the variousparts of the fault information will be found.

2.5 Flag display format

When the fault flags are displayed, the record number is displayed in the top fourleft-hand digits of the display. Fn, Fn-1, ........Fn-4, to denote the last and

previous fault flags. The unlatched current state of the fault flags can be viewed inmenu cell 0023 in the System Data column, denoted by Fnow.

The two characters after the record number indicate the setting group that was inoperation during the fault. These relays have only one setting group so G1 willbe displayed. When Fnow is displayed, the setting group is that currently active.

The next most important areas are the four each marked by a circle. These circlesare over printed with a letter (A, B, or C) to indicate the phase, or a symbol torepresent an earth fault. Alternatively a coloured disc may be stuck over the circlesto indicate the phases by a colour eg. red, yellow and blue. There are fourcharacters on the display associated with each of these four areas to flagoperation of the start and operation of the three overcurrent stages for that phase.

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Figure 2. Flag display format

Consider the four digits above the circle marked | |. If the relay trips during afault involving phase C then the first digit will be the letter C to indicate the currentexceeded the > threshold and that the protection has started. The next threecharacters are flags for each of the two overcurrent stages (t>, t>>) associated withthat phase (phase C in this example) and an asterisk (*) will be displayed for thestage, or stages that have operated.

Thus: C Would indicate that a current above the > setting had beendetected by the phase C element during the fault(START condition).

C * would indicate the first overcurrent stage (t>) had operated

C _ * would indicate the second stage (t>>) had timed out.

Flag information is similarly provided for the other two phases and for earth faults.

The six characters at the left hand side of the display on the bottom line identify theauxiliary function AUX1. Two printed panels below the display may be used toindicate the function of the auxiliary and the function performed by the main

overcurrent functions. The appropriate pre-printed labels can be affixed in thesetwo areas.

Operation of the thermal element is indicated by the Letter T in the bottom righthand character.

STAGE 2

STAGE 1

STAGE 3

ALARMALARM TRIP

GROUP

CAUX TIMER

EF D

FAULT No

SETTING

3C

AB 89 67 5 4

A B

12 0

HEALTHY

F n _ 2 G 2 A __ * B __ *TAU X 1 C * N

**

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Section 3. MENU SYSTEM

Figure 3. Menu format

Data within the relays is accessed via a menu table. The table is comprised of cells

arranged in rows and columns, like a spreadsheet. A cell may contain text, values,settings or functions. The first cell in a column, the column heading, contains textidentifying the data grouped under it in that column.

3.1 Default display

The configured default display appears on power-up. Whilst the default display isvisible it is possible to scroll through the available options with a momentary pressof the [0] key. The last default display selected by this means will be returnedautomatically 15 minutes after the last key press, but this will not affect the displaythat appears on power-up.

Following a protection trip the display will change automatically from the selected

default display to that for the fault flags for the last fault and the red trip led will belit to draw attention to the fact. Whilst the fault flags are displayed the trip led canbe reset by holding down the [0] for at least one second. The trip LED will be resetand the display will change to the default display that was last selected. The flaginformation will not be lost by this action, it is only cleared from the display andcan still be accessed under FAULT RECORDS.

The display of the trip flags will remain the default display until the trip LED is reset.To return to the default display without waiting for the 15 minute delay to expiremove to a column heading and pressing the [0] key for 1 second.

LONGF

LONGF

LONGF

LONGF

LONGF

F SHORT F SHORT F SHORT F SHORT F SHORT

F1 F2 F3 F4 F5

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3.2 Accessing the menu

To move from the default display the [F] should be pressed momentarily and thedisplay will change to [0000 SYSTEM DATA], the column heading for the first

menu column. The [F] key can now be used with short presses to step down theSystem Data column. Pressing the [F] and [0] keys together and holding for onesecond can be used to step up the menu column to the previous item. A long pressof the [F] key, greater than one second, will display the next column heading.

The only settings that can be changed with the cover in place are those that can bereset either to zero or some preset value. When such a cell is displayed its valuecan be reset by a long press of the [0] key, provided the cell is not passwordprotected. A short press of the [0] key will switch on the back light withoutchanging the display in any way. With just these two keys, the menu can bescanned with the cover in place and reset actions can be effected.

To change any other settings the cover must be removed from the relay to gainaccess to the [+] and [] keys that are used to increment or decrement a value.When a column heading is displayed the [] key will change the display to thenext column and the [+] key will change the display to the previous column, givinga faster selection.

When a cell that can be changed is displayed, the action of pressing either the [+]or [] keys will put the relay in setting mode indicated by a flashing cursor in thedisplay. To escape from the setting mode without making any change, the [0] keyshould be depressed for one second. Section 5.3 gives instructions for changingthe various types of settings.

Configuration settings which can be changed include the selection of time curves,

function links and CT ratios. Individual protection settings and some reset functions,are protected from change when the relay cover is in place.

3.3 Menu contents

Related data and settings are grouped in separate columns of the menu.Each column has a text heading (in capital letters) that identifies the data containedin that column. Each cell may contain text, values, settings and/or a function.The cells are referenced by the column number/row number. For example 0201 iscolumn 02, row 01.When a cell is displayed the four digits at the top left handcorner of the LCD indicate the column number and row number in the menu table.

Those cells that do not provide any useful purpose are not made available in the

factory configuration.

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3.4 Menu columns

Col No Heading Description

00 SYSTEM DATA Settings and data for the system -relay and serial communications.

01 FLT RECORDS Fault records for the last five faults

02 MEASURE 1 Directly measured quantities (V and etc.)

04 MEASURE 3 Calculated (additional)

05 EARTH FLT 1 Earth fault protection settings - Group 1

06 PHASE FLT 1 Phase fault protection settings - Group 1

09 LOGIC Settings for miscellaneous functions usedin the logic

0C RECORDER Settings for the disturbance recorder

Cells that are read only are marked [READ] .

Cells that can be set are marked [SET].

Cells that can be reset are marked [RESET].

3.5 System data

Display Status Description

0000 SYSTEM DATA READ Column heading

0004 Description SET Product description (user programmable text)

0005 Plant SET Plant reference (user programmable text)

0006 Model READ Model number that defines the product

0008 Serial No. READ Serial number - unique number identifyingthe particular product

0009 Freq SET Default sampling frequency - must be set topower system frequency

000A Comms Level READ Indicates the Courier communication levelsupported by the product

000B Rly Address SET Communication address (1 to 255)

0011 Software READ Software reference for the product

0020 Log Status READ Indicates the current status of all the logicinputs

0021 Rly Status READ Indicates the current status of the output relaydrives

0022 Alarms READ Indicates the current state of internal alarms

0 Uncfg READ Error in factory configuration settings

1 Uncalib READ Operating in uncalibrated state

2 Setting READ Error detected in stored settings3 No Service READ Protection out of servive and not functioning

4 No Samples READ No A/D samples but still in service

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5 No Fourier READ Fourier not being performed

6 Test Wdog SET Test watchdog by setting this bit to 1

0023 FnowG1 READ Indicates the current status of the fault flags(These flags are not latched)

3.6 Fault records


0100 FLT RECORDS READ Column heading

0101 Fault No READ Number of fault record displayed - may beselected (Fn; Fn-1;........Fn-4)

0102 Fn G1 READ Flags (latched) indicating the functions thatoperated during the fault

0103 a READ Highest value of current measured inphase A during the fault

0104 b READ Highest value of current measured inphase B during the fault

0105 c READ Highest value of current measured inphase C during the fault

0106 o READ Highest value of residual current measuredduring the fault

0110 Clear=O RESET Press [0] key when this cell is displayed toclear all fault records

3.7 Measurements 1


0200 MEASURE 1 READ Column heading

0201 a READ Measured current in phase A

0202 b READ Measured current in phase B

0203 c READ Measured current in phase C

0204 o READ Measured residual current

020C F READ Measured power system frequency F

3.8 Measurements 3


0400 MEASURE 3 READ Column heading

0404 th A READ Thermal ammeter reading in phase A

0405 th B READ Thermal ammeter reading in phase B

0406 th C READ Thermal ammeter reading in phase C

0407 Thermal SET Thermal state %

040A Pk th A SET Peak thermal ammeter reading in phase A -demand value

040B Pk th B SET Peak thermal ammeter reading in phase B -demand value

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040C Pk th C SET Peak thermal ammeter reading in phase C -demand value

3.9 Earth fault 1


0500 EARTH FLT 1 READ Column heading

0501 EF Links SET Software links that are used to select theavailable optional earth fault functions

0502 CT Ratio SET Overall ratio of the line or neutral CTfeeding the earth fault protection elements

0504 Curve SET Selected characteristic from the definite timeor 10 inverse time options

0505 o> SET Current setting for start output and first earthfault stage

0506 to>/TMS SET Time multiplier setting that will be used witha selected inverse time curve

0507 to>/DT SET Time delay that will be effective when thedefinite time characteristic is selected

0508 toRESET SET Hold time for which the current must remainbelow o> before timer resets to zero

0509 o>> SET Current setting for second earth fault stage

050A to>> SET Time delay for second earth fault stage

3.10 Phase fault 1


0600 PHASE FLT 1 READ Column heading

0601 PF Links SET Software links that are used to select theavailable optional phase fault functions

0602 CT Ratio SET Overall ratio of the line CT feeding thephase fault protection elements

0604 Curve SET Selected characteristic from the definite timeor 10 inverse time options

0605 > SET Current setting for start output and firstovercurrent stage

0606 t>/TMS SET Time multiplier setting that will be used witha selected inverse time curve

0607 t>/DT SET Time delay that will be effective when thedefinite time characteristic is selected

0508 tRESET SET Hold time for which the current must remainbelow > before timer resets to zero

0609 >> SET Current setting for second overcurrent stage

060A t>> SET Time delay for second overcurrent stage

0613 th> Trip SET Thermal current rating (Trip at 1.05 th)

0614 TC SET Setting for thermal time constant

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3.11 Logic (KCGG 341 menu only)


0900 LOGIC READ Column heading0903 tAUX1 SET Auxiliary timer 1 setting

3.12 Input masks

These are pre-configured and do not appear in the menu.

Refer to applications diagrams Figures 1, 2 and 3 for input configurations.

3.13 Relay masks

These are pre-configured and do not appear in the menu.

Refer to applications diagrams Figures 1, 2 and 3 for output configurations.

3.14 Recorder masksIf event or disturbance records are required then the relay must be powered from asecure ac or dc supply. The recorder is pre-configured to trigger on energisation ofthe external trigger input (L2). It is also triggered by the energisation of the STARTrelay output (RL0) in the KCGG 141 and KCGG 241 or by the energisation of theTRIP relay output (RL3) in the KCGG 341.


0C00 RECORDER READ Column heading

0C01 Control SET Control : default value is 'running'

0C02 Capture SET Capture : default value is 'samples'0C03 Post Trigger SET The default setting of the recorder post

trigger is 384 for the KCGG 141 and theKCGG 241 and is 128 for the KCGG 341

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Section 4. ACCESS TO MENU

With the cover in place on the relay access is limited to the [F] and [0] keys. The

Any menu cell can be accessed and its value or text read, but no change can bemade to settings other than resetting the trip indication and the fault records.

4.1 Quick guide to menu controls

Current display Key press Effect of action

Default display [0] long Back-light turns ON no other effect

[0] short Steps through the available default displays

[F] steps down to column heading SYSTEMDATA

[+] Back-light turns ON no other effect[] Back-light turns ON no other effect

Fault flags after a trip [0] short Back-light turns ON no other effect

[F] steps down to column heading SYSTEMDATA without resetting the fault flags

[0] long resets trip LED and returns default display

[+] Back-light turns ON no other effect

[] Back-light turns ON no other effect

Column heading [0] short Back-light turns ON no other effect[0] long Re-establishes password protection

immediately and returns the default display

[F] long move to next column heading

[F] short steps down the menu to the next item inthe column

[] move to next column heading

[+] move to previous column heading

Any menu cell [F] short steps down the menu to the next item in

the column[F] long displays the heading for the next column

[F] + [0] steps back up the menu to the previousitem

[0] short Back-light turns ON no other effect

[0] long Resets the value if the cell is resettable

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Current display Key press Effect of action

Any settable cell [+] or [] Puts the relay in setting mode. The passwordmust first be entered for protected cells

Setting mode [0] Escapes from the setting mode without asetting change

[+] Increments value with increasing rapidity if held

[] Decrements value with increasing rapidityif held

[F] Changes to the confirmation display

[F] If function links, relay or input masks aredisplayed the [F] key will step through themfrom left to right and finally changing to the

confirmation displayConfirmation mode [+] Confirms setting and enters new setting or

text

[] Returns prospective change to check/modify

[0] Escapes from the setting mode without asetting change

The actions shown in the shaded area can only be performed when the cover isremoved.

[F]long - means press F key and hold for longer than 1 second.

[F]short - means press F key and hold for less than 1 second.

[F] - means press the F key length of time does not change the response.

[0]Long - means press the 0 key to perform a reset function when a resettablecell is displayed.

4.2 Negotiating the menu

After being left for some time the relay will show the selected default display.Short presses of the [0] key will step through all the available options. As suppliedthe default will be to display the three phase currents and if no key presses aremade for at least 15 minutes the display will revert to this display.

A short press of the [F] key will change the display to menu cell [0000 SYSTEMDATA], the heading for the first menu column. Long presses of the [F] key will thenstep across the column headings in sequence. When the desired column isreached a short press will move down the column one step at a time. The previouscell can be accessed by pressing the [0] key and the [F] key together and holdingthem down for at least 1 second.

At any point in the menu, a long press of the [F] key will cause the next columnheading to be displayed. When any column heading is displayed a long press ofthe [0] key will return the default display.

4.3 Resetting trip indication

The TRIP LED can be reset when the flags for the last fault are displayed. They aredisplayed automatically in the default display after a trip occurs, or can beselected in the fault record column, menu cell [0102 Fn G1]. The reset is effectedby depressing the [0] key for 1 second whilst this cell is displayed.

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Resetting the fault records as described in the next section will also reset the tripLED indication.

Function link SD5 will be set to 0 for the relays as supplied. The trip LED can only

be manually reset.

4.4 Clearing fault records

The fault records are a group of cells that can be reset and to reset them the lastcell under [FLT RECORDS] must be selected. (This will will be menu cell [0110Clear=0]) and then the [0] key held depressed for at least one second to effect thereset ofall five fault records at the same time. If the records are not cleared, theoldest record will be overwritten by the next new fault record.

Section 5. ACCESS TO SETTINGS

The menu table for the simplified settings KCGG141/241/341 relays has no cellspassword protected. Changes may be made to the protection settings including CTratio, operation time characteristics, current thresholds and time delay settings.

To change these settings the protective front cover has to be removed from therelay. The [+] and [-] keys can then be accessed and these are the keys used toincrement or decrement the settings.

5.1 To enter setting mode

Give the [F] key a momentary press to change from the selected default displayand switch on the back-light; the heading SYSTEM DATA will be displayed.Use the [+] and [-] keys, or a long press of the [F] key, to select the columncontaining the setting, or text that is to be changed. Then with the [F] key stepdown the column until the contents of that cell are displayed. Press the [+] key toput the relay into the setting mode. Setting mode will be indicated by a flashingcursor on the bottom line of the display. If the cell is read-only then the cursor willnot appear and the relay will not be in the setting mode.

5.2 To escape from the setting mode

If at any time you wish to escape from the setting mode without making a changeto the contents of the selected cell: Hold the [0] key depressed for one second, theoriginal setting will be returned and the relay will exit the setting mode.

5.3 Changing setting values

Move through the menu until the cell that is to be edited is displayed. Press the [+]or [] key to put the relay into the setting change mode. A cursor will flash in theextreme left hand position on the bottom line of the display to indicate that therelay is ready to have the setting changed. The value will be incremented in singlesteps by each momentary press of the [+] key, or if the [+] key is held down thevalue will be incremented with increasing rapidity until the key is released.Similarly, the [] key can be used to decrement the value. Follow the instructions inSection 5.4 to exit from the setting change.

Note: When entering a CT RATIO the overall ratio should be entered, ie. a2000/5A CT has an overall ratio of 400:1. With rated current applied the

relay will display 5A when CT RATIO has the default value of 1:1 andwhen the ratio is set to 400:1 the displayed value will be 400 x 5 =2000A.

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5.4 To accept the new setting

Press the [F] key until the confirmation display appears:

Are You Sure?+ = YES = NO .

1.Press the [0] key if you decide not to make any change.

2.Press the [] key if you want to further modify the data before entry.

3.Press the [+] to accept the change. This will terminate the setting mode.

5.5 Entering text

Menu cells [0004 Description] and [0005 Plant Ref] give the relay description andthe plant reference respectively. These two cells have 16 characters on the bottomline that may be changed as required. To do so, first select the menu cell and enter

setting mode by pressing either the [+] or [] key. The cursor will flash in theposition of the extreme left character. Then using the [+] and [] keys select thecharacter to be displayed. The [F] key may then be used to move the cursor to theposition of the next character and so on. Follow the instructions in Section 5.4 toexit from the setting change.

Section 6. ACCESS TO ADVANCED SETTINGS

Settings and text in certain cells of the menu can be changed via the user interface.To do this the cover must be removed from the front of the relay so that the [+] and[] keys can be accessed.

6.1 Changing function links

Select the page heading required and step down to the function links SD Links,EF Links, PF Links, or LOG Links and press either the [+] or [] to put the relayin a setting change mode. A cursor will flash on the bottom line at the extreme leftposition. This is link F; as indicated by the character printed on the frontplateunder the display.

Press the [F] key to step along the row of links, one link at a time, until some textappears on the top line that describes the function of a link. The [+] key willchange the link to a 1 to select the function and the [] key will change it to a0 to deselect it. Follow the instructions in Section 5.4 to accept the new setting

and exit from the setting change, or the instruction in Section 5.2 to escape withoutmaking a change.

Not all links can be set, some being factory selected and locked. The links that arelocked in this way are usually those for functions that are not supported by aparticular relay, when they will be set to 0. Merely moving the cursor past a linkposition does not change it in any way.

6.2 Setting communication address

The communication address will be set to 255, the global address to all relays onthe network, when the relay is first supplied. Reply messages are not issued fromany relay for a global command, because they would all respond at the same time

and result in contention on the bus. Setting the address to 255 will ensure thatwhen first connected to the network they will not interfere with communications onexisting installations. The communication address can be manually set by selecting

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the appropriate cell for the SYSTEM DATA column, entering the setting mode asdescribed in Section 5.1 and then decrementing or incrementing the address. Thenexit setting mode as described in Section 5.4.

6.3 Setting the relay with a PC or laptop

Connection to a personal computer (PC), or lap top, via an K-Bus/RS232 interfaceType KITZ 101 will enable settings to be changed more easily. Software isavailable for the PC that allow on line setting changes in a more user friendly way,with a whole column of data being displayed instead of just single cells. Settingfiles can also be saved to floppy disc and downloaded to other relays of the sametype. There are also programs available to enable settings files to be generatedoff-line, ie. away from the relays that can be later down-loaded as necessary.

The communication connections and available software are covered in theapplications chapter of this manual.

Section 7. ALARM FLAGS

A full list of the alarm flags will be found in Section 3.5 and they are located in cell0022 of the SYSTEM DATA column of the menu. They consist of seven charactersthat may be either 1 or 0 to indicate the set and reset states respectively.The control keys perform for this menu cell in the same way as they do for functionlinks. The cell is selected with the function key [F] and the relay then put in thesetting mode by pressing the [+] key to display the cursor. The cursor will then bestepped through the alarm word from left to right with each press of the [F] keyand text identifying the alarm bit selected will be displayed.

The only alarm flag that can be manually set is bit 6, the watchdog test flag.When this flag is set to 1 the watchdog relay will change state and the greenLED will extinguish.

When any alarm flag is set the alarm LED will be continuously lit.

Note: No control will be possible via the key pad if the Unconfigured alarm israised because the relay will be locked in a non-operative state.

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Section 8. EXTERNAL CONNECTIONS

Standard connection table

Function Terminal Function

Earth terminal 1 2 Not used

Watchdog relay b 3 4 m Watchdog relay(Break contact) 5 6 (Make contact)

48V field voltage [+] 7 8 [] 48V field voltage

Capacitor trip voltage [+] 9 10 [] Capacitor trip voltage

Not used 11 12 Not used

Auxiliary voltage input (+) 13 14 () Auxiliary voltage input

Not used 15 16 Not used

Auxiliary relay coil (+) 17 18 () Auxiliary relay coil

Not used 19 20 - Not used

A phase current In 21 22 Out A phase current

B phase current In 23 24 Out B phase current

C phase current In 25 26 Out C phase current

Neutral current In 27 28 Out Neutral current

Not used 29 30 Output relay 0

31 32Not used 33 34 Output relay 1

35 36

Not used 37 38 Output relay 239 40

Not used 41 42 Output relay 343 44

Not used 45 46 (+) Opto control input L0



Not used 51 52 (-) Common L0/L1/L2

Not used 53 54 K-Bus serial port

Not used 55 56 K-Bus serial port

Key to connection tables

[+] and [] indicate the polarity of the dc output from these terminals.

(+) and () indicate the polarity for the applied dc supply.

All relays have standard Midos terminal blocks to which connections can be madewith either 4mm screws or 4.8mm pre-insulated snap-on connectors.Two connections can be made to each terminal.

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8.1 Auxiliary powered relays

The auxiliary voltage may be DC or AC provided it is within the limiting voltagesfor the particular relay. The voltage range will be found on the frontplate of the

relay; it is marked Vx = (24V to 125V) or (48V to 250V). An ideal supply to usefor testing the relays will be 50V DC or 110V AC because these values fall withinboth of the auxiliary voltage ranges.

The supply should be connected to terminals 13 and 14 only. To avoid anyconfusion it is recommended that the polarity of any applied voltage is kept to theMidos standard:

- for dc supplies the positive lead connected to terminal 13 and the negative toterminal 14.

- for ac supplies the live lead is connected to terminal 13 and the neutral lead toterminal 14.

8.2 Dual powered relays

Dual powered relays derive power from the current transformer circuit and may beused with this power source alone. However, the application of an auxiliary DC orAC voltage will enable lower earth fault settings to be used. It will also enablesettings to be applied and data to be read when the load current is insufficient topower the relay and also allow communications to be maintained at such times.

When powered from the CT circuit alone, the 48V field voltage will be available topower the opto-isolated control inputs when the protection starts up. The phasefault current setting range is limited to the minimum current levels at which thepower requirements of the relay can be maintained, see Technical Data, Section 5.

This model of relay is rated for an auxiliary voltage Vx = (100V to 250V).Note: The capacitance discharge circuit is not isolated from the auxiliary supply

and to prevent the relay from being damaged, no external groundconnection should be made to this circuit.

8.3 Powered from current transformers alone

When powered from the current transformer circuit alone, the minimum current tooperate the relay is that required to establish the power supply rails within therelay. Lowering the design value of this parameter increases the burden on thecurrent transformers and the power dissipated within the relay case. The limits aretherefore a compromise based on these factors:

Minimum current to power the relay for phase faults = 0.4n

Minimum current to power the relay for earth faults = 0.2n

However, a combined three phase and earth/ground fault relay will operate withlower earth/ground fault current settings when the load current in the protectedcircuit is sufficient to power the relay ie. greater than 0.4n. Settings less than0.2n are provided for earth faults, but they must be used with discretion.

When switching onto a fault, the relay will be delayed in operation by the start uptime and this delay will need to be taken into account in any grading exercise.The delay is the time taken by the processor to initialise its registers, read insettings from non-volatile memory and perform self checks. There will be an

additional delay whilst the power supply builds up, but this will be less significantwhen using an inverse time/current characteristic as the power supply delaysimilarly varies with current. The start-up time is not reduced by lowering the timemultiplier setting.

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With prefault load current there will be no start-up time and the relays will operatewithin their normal time settings.

Multiple of minimum current to power the relay

Time(seconds)

0

0.2

1 7 10

0.4

0.6

0.8

70 100

Figure 4. Start up time delay

Note: Where the start-up delay cannot be tolerated it is recommended that therelay is also powered from an auxiliary AC voltage supply so that it can beup and running before a fault occurs. It will also make stored disturbanceand event records more secure, because they are discarded when the relaypowers down.

8.4 Special application notes for dual powered relaysThe KCGG 241/341 relays are fitted with three opto-isolated inputs and four relayoutputs, but at the claimed minimum operating current they cannot all be energisedat the same time. If they are, then the minimum operation current will be increased.However, in applications requiring a dual powered relay it is unlikely that morethan two output relays will be energised at any one time. The following tableshows how the minimum operating current varies with the number of output relays(does not include the watchdog) and inputs that are to be energised at the sametime.

No. of relays energised 2 4

3 opto-inputs energised 1.2 x min 1.3 x min

2 opto-inputs energised 1.1 x min 1.2 x min

min = 0.4n for phase faults and 0.2n for earth/ground faults.

8.5 Powered from an auxiliary AC voltage and from currenttransformers

The addition of an auxiliary AC, or DC, voltage supply to power the relay will:

1. enable the settings to be changed when the protected circuit is de-energised.

2. enable records to be retrieved and control functions to be carried out over thecommunication link.

3. reduce the burden on the line CTs.When using an auxiliary AC voltage, it may be lost during a fault, when powerwill be drawn from the current transformer circuit to maintain the relay in a fully

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operational state. However, if the source of the auxiliary voltage is carefullychosen it is unlikely to be lost completely during earth faults but it may collapse to50% of its rated value. Provided the voltage is still above the minimum required to

power the relay, very low earth fault settings can be successfully applied. In theabsence of the auxiliary voltage the relay is not guaranteed to operate for earthfault currents less than 0.2n.

No alarm is given for loss of the ac auxiliary voltage, unless it is externallymonitored by a separate supervision relay.

8.6 Dead substation protection

The dual powered relays derive power for the electronics and the trip coil of thecircuit breaker from the line current transformers and optionally from an auxiliaryvoltage supply. Applying one of these relays on the incoming feeder to thesubstation will ensure that the substation is still protected in the event of complete

failure of the auxiliary supplies.8.7 Logic control inputs

There are three optically coupled logic control inputs to the relay. They are rated at48V and the power supply within the relay provides an isolated field voltage toenergise them. This arrangement keeps the power consumption of these inputs to aminimum and ensures that they always have a supply to energise them when therelay is operational. This is particularly important for the dual powered relay whenthere is no auxiliary supply voltage available and the relay is energised by thecurrent from the line current transformers.

Software filtering is applied to prevent induced AC signals in the external wiring

causing operation of logic inputs. This is achieved by sampling the logic inputseight times per cycle and five consecutive samples have to indicate that the input isenergised in a positive sense before it is accepted. This ensures that the inputs arerelatively immune to spurious operation from induced ac signals in the wiring.

The capture time is:

12 2.5ms at 50 Hz10.4 2.1ms at 60 Hz.

Note: These inputs will not capture a fleeting contact unless it dwells in the closedstate for a time exceeding the above values.

The opto-isolated logic control inputs (L0, L1, L2) have their common connection on

terminal 52. When they are to be energised from the field voltage terminal 52must be connected to terminal 8, the negative of the field voltage. The logic inputscan then be energised by connecting a volt free contact between the positive of thefield voltage, terminal 7, and the terminal for the appropriate logic input.

The circuit for each opto-isolated input contains a blocking diode to protect it fromany damage that may result from the application of voltage with incorrect polarity.Where the opto-isolated input of more than one relay is to be controlled by thesame contact it will be necessary to connect terminal 7 of each relay together toform a common line. In the example circuit below, contact X operates L1 of relay 1and contact Y operates L0 of relay 1 as well as L0 and L1 of relay 2. L2 is notused on either relay and has no connections made to it.

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L046

L1 48

L2

52

8

48V

Relay 1

7+ +

48V

Relay 2

L0

L1

L2

8

7

Common line

50

X Y

_ _

46

48

52

50

Figure 5. Example connection of logic inputs

The logic inputs can be separated into two isolated groups when it is necessary toenergise some from the station battery. The logic inputs are rated at 48V and it willbe necessary to connect an external resistor in series with the input if the battery isof higher rated voltage. The value of this resistor should be 2400 for everyadditional 10V.

The field voltage is not earthed and has insulation rated for 2kV for 1 minute.Thus if necessary the positive terminal of the field voltage could be connected tothe positive terminal of external battery. Also the two separate groups of logicinputs could be energised from separate batteries.

8.8 Analogue inputs

The relays have four analogue inputs, each fed via an input transducer, a low passfilter and a three range scaling amplifier. The analogue signals are sampled eighttimes per cycle on each channel as the sampling rate tracks the frequency of theinput signal.

The wide setting range provided on the auxiliary powered version of the relays issufficient to enable the 5A version of the relay to operate from either 1A or 5Acurrent transformers and this version of the relay can be used where dual ratedrelays are specified. Alternatively, the wide setting range makes the relay suitablefor use on circuit breakers that may be applied to a wide range of load circuitratings with only one current transformer ratio. For example a circuit breaker ratedat 2000A and fitted with current transformers rated at 2000/10A (or 2000/2A)and relays rated at 5A (or 1A) could be applied to circuits with load ratings from100A to 2000A.

The dual powered relays have a narrower setting range and must be used withcurrent transformers that match their current rating. Thermal dissipation is thelimitation for the upper end of the setting range and the energy required to powerthe relay is the limitation at the lower end. When the relay is powered from anadditional auxiliary voltage source, earth fault settings can be applied below thatat which the relay can derive sufficient power from the CTs. For this reason theearth fault setting range has not been restricted.

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9

10

+

RLY3

Relay

44

42

Trip

8.9 Output relays

Four output relays are provided preconfigured to operate in response to a selectionof the available protection and control functions by the setting the OUTPUT

MASKS.

In addition there is a watchdog relay which has one make and one break contact.Thus it can indicate both healthy and failed conditions. As these contacts aremainly used for alarm purposes, they have a lower rating than the programmableoutputs. The terminal numbers for the output relay contacts are given in the table atthe start of Section 8.

8.10 Output relay minimum dwell time

Outputs from t>, t>>, to> and to>> have a minimum dwell of 100ms. The thermaltrip will have an inherent delay dependent on the selected time constant. Thecontact dwell ensures a positive trip signal is given to the circuit breaker.

All other outputs such as >, >>, o> and o>> have no deliberate dwell timeadded to them. This is because they are either followed by a timer, or used forcontrol purposes which require a faster reset time.

8.11 Capacitor discharge tripping

Dual powered relays may use either of the above methods. In addition, theseparticular relays charge an internal capacitor from the current circuit and also fromthe auxiliary voltage circuit. This capacitor is 680F and it is charged to 50V dc. Itmay be discharged directly into a suitably sensitive trip coil via one of theprogrammable output relays. The minimum energy fed to the trip coil is that fromthe capacitor, but in most cases it will be supplemented by a current from the

auxiliary voltage circuit and/or the current circuit.When energized from current alone the lowest current for which the relay willoperate will be that necessary to start up the power supply. To be able to uselower fault settings an auxiliary supply will be required.

The capacitance discharge circuit is not isolated from the auxiliary supply and toprevent the relay from being damaged, no external ground connection should bemade to this circuit.

Figure 6. Capacitor discharge trip

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8.12 AC series tripping

21

23

RLY3

Relay

10

9

+

44

42

17

18

TrippingRelay

28

25

TC

TC26

27

22

24

TC

a

b

c

n

TolineCTs

Figure 7. AC series trip arrangement, KCGG 341

As an alternative, the trip capacitor in the dual powered relays may be dischargedinto an auxiliary tripping relay. This scheme is supplied as the KCGG 341 relay.This relay will be de-energised in the quiescent state, with its break contacts shortcircuiting the trip coils of the circuit breaker.

The trip coils are connected in series with the current transformer secondary circuitso that, when the auxiliary relay is operated, the full secondary current is divertedthrough the trip coils.

To cover all fault conditions, three trip coils are required.

Note: Withdrawing the KCGG 341 from an energised panel may energise thecircuit breaker trip coils.

8.13 Improving reliability of trip and closing contacts

In the event of the circuit breaker failing to trip, the relay contacts are called uponto break the trip coil current. The majority of protective relays are not rated for thisduty and their contacts may be damaged as a result. This problem can beeliminated if a relay with heavy duty contacts is interposed between the outputcontacts of the protective relay and the circuit breaker trip circuit. Replacing thisrelay can be more economic than the repair costs for the protective relay and theoverall fault clearance time need not be increased as a result. If the interposedrelay is connected as a shunt repeat relay, the protection will trip the circuit

breaker directly and then be backed-up by the contacts of the interposing relay.On breaking, the protective relay will reset first so that the interposing relayperforms the actual circuit interruption.

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Prima

KCGG

Trip coil

CBCG4Blockingdiode

-+

Prima

Similarly the breaking duty of the relay contacts may not be rated for the circuitbreaker closing current and in such cases an interposing relay will be necessary.

Figure 8. Contact reinforcing circuit

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Service Manual

Chapter 4Application of Protection Functions

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Contents

1. CONFIGURATION 1

1.1 Fixed configuration of KCGG 141, 241 and 341 11.1.1 KCGG 141 and KCGG 241 fixed configurations 2

1.1.2 KCGG 341 fixed configuration 21.1.3 First stage overcurrent and earth fault START function 31.1.4 First stage overcurrent and earth fault time delay 31.1.5 First stage overcurrent and earth fault available time delay characteristics 41.1.6 Second stage overcurrent and earth fault time charcteristics 51.2 Relay scheme configuration 51.2.1 Changing the configuration of the relay 51.2.1.1 System data (SD) 51.2.1.2 Earth fault links (EF) 61.2.1.3 Phase fault links (PF) 6

1.2.1.4 Logic links (LOG) 71.2.1.5 Typical use of logic inputs for KCGG 141, 241 71.2.1.6 Typical use of logic inputs for KCGG 341 71.2.1.7 Typical use of output relays for KCGG141, 241 71.2.1.8 Typical use of output relays for KCGG 341 7

2. OVERCURRENT AND EARTH FAULT PROTECTION 8

3. SECOND STAGE OVERCURRENT AND EARTH FAULT LOGIC 8

3.1 Transformer inrush currents 93.2 Sensitivity to harmonics 9

4. GENERAL APPLICATION FEATURES 104.1 Matching the reset time response of an electromechanical relay 104.2 Time graded protection 104.3 Protection against intermittent recurrent faults 104.4 Autoreclose inhibition of instantaneous low set

(KCGG 141 and KCGG 241 only) 11

5. BLOCKED OVERCURRENT PROTECTION 12

5.1 Blocked IDMT overcurrent 125.2 Blocked short time overcurrent 135.3 Protection of busbars on radial system 13

6. RECTIFIER PROTECTION 14

7. HIGH IMPEDANCE DIFFERENTIAL BUSBAR AND RESTRICTEDEARTH FAULT PROTECTION 15

8. THERMAL OVERCURRENT 15

8.1 Thermal state 168.2 Thermal trip and alarm levels 168.3 Operation time 168.4 Thermal memory 178.5 Thermal reset 17

8.6 Application of thermal protection 17

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Contents

Figure 1. Relay logic diagram for KCGG 141 and KCGG 241 configurations. 1

Figure 2. Relay logic diagram for KCGG 341 configuration 3

Figure 3. Available overcurrent characteristics and their settings 8Figure 4. Second stage overcurrent logic 9

Figure 5. Matching electromechanical reset time 10

Figure 6. Intermittent recurrent fault 11

Figure 7. Blocked IDMT overcurrent 12

Figure 8. Blocked overcurrent for busbar protection 13

Figure 9. Protection for silicon rectifiers 14

Figure 10. Matching curve to load and thermal limit of rectifier 14

Figure 11. Thermal alarm and trip logic 16

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Page 1 of 18

Section 1. CONFIGURATION

The configuration of the relay is the interconnection between the various protection

and control elements within the product. With electromechanical relays this wasformed by the internal wiring between the various elements and the external caseterminals. Thus if the configuration was changed the internal connection diagramfor the relay and the external case connection diagram had to be changed, or newones prepared.

With the K Range of numerical relays the configuration is in software. The KCGG141, 241, 341 relays are provided with fixed configurations that will suit themajority of standard overcurrent applications.

More flexibility is provided by the KCGG 142 full functionality relay which hasfurther settings available. The user can then make changes to the internal logic of

the relay by setting software links. Additionally the output relays and logic inputscan be reassigned to different functions. Refer to manual R8551 for informationabout this relay.

1.1 Fixed configuration of KCGG 141, 241 and 341

0B03 to> Stage 1earth fault

Startearth fault

Stage 2earth fault

Blk to>>0A02EF1

Blk t>0A04

0A01 Blk to>

to>>

to>&

&01

to>>0B04

&tB>0B09

tA>0B08

tC>0B0At>

o> Start0B01

o>>

>

> Start0B06

Stage 1overcurrent

Startovercurrent

Blk t>>0A05

& t>>>>

>=1

>=1PF1

01

t>>0B0B Stage 2overcurrent

0A09 EXT. TRIGGER

RLY3

Latch flagsGenerate fault recordCopy to event records Fault record

and flag latchinitiation

o>

SD

LOG

EF1 PF1

Thermalphase element

0B18 th Trip>=1

Thermal trip

PF001

F E D C B A 9 8 7 6 5 4 3 2 1 0

F E D C B A 9 8 7 6 5 4 3 2 1 0 F E D C B A 9 8 7 6 5 4 3 2 1 0 F E D C B A 9 8 7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 07 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

Latch red trip LED

>=1

Figure 1. Relay logic diagram for KCGG 141 and KCGG 241 configurations.

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Page 2 of 18

1.1.1 KCGG 141 and KCGG 241 fixed configurations

This configuration is designed for the more common applications and provides:

8 IDMT characteristics plus definite time for stage 1 (t>/to>) Instantaneous overcurrent for stage 2 (t>>/to>>)

Blocking feature for first overcurrent stage

Blocking feature for second overcurrent stage

Output relays:

RLY0 = START (>/o>)

RLY1 = Phase fault (t>/t>>/th trip)

RLY2 = Earth fault (to>/to>>)

RLY3 = Main shunt trip relay (t>/to>,t>>/to>>,th trip) Logic inputs for:

L0 = Block first stage t>/to>

L1 = Block second stage t>>/to>>

L2 = External trigger

Settings are limited to:

Rated frequency 50Hz or 60HZ

Current settings

Time/current characteristic1.1.2 KCGG 341 fixed configuration

This configuration is designed for the more common applications and provides:

One setting group.

8 IDMT characteristics plus definite time for stage 1 (t>/to>)

Instantaneous overcurrent for stage 2 (t>>/to>>)

Blocking feature for first and second overcurrent stages

Output relays:

RLY0 = Auxiliary timer 1 (AUX 1) RLY1 = Phase fault and thermal trip (t>/t>>/th trip)

RLY2 = Earth fault (to>/to>>)

RLY3 = Main Trip Relay (t>/to>,t>>/to>>,th trip)

Logic inputs for :

L0 = Initiate auxiliary timer 1

L1 = Block t>/to>/t>>/to>>

L2 = External trigger

Internal auxiliary trip relay for AC series trip function

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Page 3 of 18

0B03 to> Stage 1

earth fault

Stage 2earth fault

Blk to>>0A02EF1

Blk t>0A04

0A01 Blk to>

to>>

to>&

&01

to>>0B04

&tB>0B09

tA>0B08

tC>0B0At>

o>>

>

Stage 1overcurrent

Blk t>>0A05

& t>>>>

>=1PF1

01

t>>0B0B Stage 2overcurrent

0A09 EXT. TRIGGER

Fault recordand flag latchinitiation

o>

SD

LOG

EF1 PF1

Thermalphase element

0B18 th Trip>=1

Thermal trip

PF001

F E D C B A 9 8 7 6 5 4 3 2 1 0

F E D C B A 9 8 7 6 5 4 3 2 1 0 F E D C B A 9 8 7 6 5 4 3 2 1 0 F E D C B A 9 8 7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 07 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

7 6 5 4 3 2 1 0

0A0A Aux17 6 5 4 3 2 1 0 tAux1

Aux10B107 6 5 4 3 2 1 0

Time delay forseries trip

Latch flagsGenerate fault recordCopy to event records

Latch red trip LED

>=1

RL3

Figure 2. Relay logic diagram for KCGG 341 configuration

Settings are limited to:

Rated frequency 50Hz or 60HZ

Current settings

Time/current characteristic

The logic diagram and the connection diagram for these relays are to be found atthe back of this manual.

1.1.3 First stage overcurrent and earth fault START function

Available on the KCGG 141/241 relays

As soon as the earth fault o> threshold is exceeded an instantaneous output isavailable from relay RLY0. The phase element also provides a start output fromrelay RLY0 when the current exceeds the > threshold.

1.1.4 First stage overcurrent and earth fault time delay

The first overcurrent and earth fault stage elements (t>/to>) incorporate an integral

time delay after the current threshold measurement. This allows the relay to be timegraded with other similar protective relays, as well as being graded on currentthreshold. When the delay time expires the output relays preconfigured with to>,tA>, tB> and tC> will be energised, causing them to pick-up. The thermal trip will

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Page 4 of 18

energise relay RL3 after the thermal element has timed out. The Relay RLY3 is themain trip relay and is therefore includes all these trip functions.

A delayed reset is provided with the t>/to> time delays and the time set for this

timer determines the duration that the current must remain below the threshold I>/o> before the time delay register is reset to zero. There is an exception to thiswhen the protection trips, because for this condition the time registers t>/to> arereset immediately. For the majority of applications the reset delay could be set tozero. For others a more appropriate setting can be used and some exampleapplications are given later.

1.1.5 First stage overcurrent and earth fault available time delay characteristics

Nine time characteristics are available an

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