auto bus transfer scheme in power plants

BUS TRANSFER SYSTEM (BTS) PANEL Microprocessor Based BTS 2000 Fast Bus Transfer System

Instruction Manual Of Standard 2 Breaker Scheme

CONTENTS

Instruction Manual (IM) Detailed Technical Write-Up (DM)

& Datasheets (DS)

AARTECH SOLONICS LIMITED

E-2/57, ARERA COLONY, BHOPAL, 462016 (M.P.)

INDIA TEL/FAX: (91)-(755)-2463593, 4276335

Email: [email protected] WWW: www.aartechsolonics.com

Instruction Manual Bus Transfer System (BTS) Panels

Bus Transfer System (BTS) Panels 1-2 Aartech Solonics Limited

CONFIDENTIAL INFORMATION OF AARTECH SOLONICS LIMITED, BHOPAL, INDIA. THIS MANUAL IS LOANED FOR CONFIDENTIAL USE, SUBJECT TO RETURN ON REQUEST, AND WITH THE MUTUAL UNDERSTANDING THAT IT WILL NOT BE USED IN ANY MANNER DETRIMENTAL TO THE INTEREST OF AARTECH SOLONICS LIMITED. It is not the intention of this manual to cover all details and variations of the use of this equipment, nor does this manual provide data for every possible contingency regarding installation or operation. The availability and design of all features and options are subject to modification without notice. Should further information be required, contact Aartech Solonics Ltd., Bhopal, India.

This document and the accompanying data, documentation, schematics and software Copyright © 2008 Aartech Solonics Ltd.

ALL RIGHTS RESERVED

Copying or distribution of this document and accompanying data, documentation,

schematics and software is prohibited, unless specifically authorized by Aartech Solonics Ltd.

PRINTED IN INDIA

Instruction Manual

1 INTRODUCTION

2 COMPANY PROFILE2.1 ACTIVITIES2.2 MANAGEMENT2.3 ORGANIZATION

3 TECHNICAL WRITE



3.1.12 Online Testing ............................................................................... 3-18 3.1.13 Transfer Analysis ........................................................................... 3-19

3.2 SCHEME DESCRIPTION .............................................................................. 3-19 3.2.1 Single Line Diagrams (SLD) ............................................................. 3-19 3.2.2 Bus Transfer Details ......................................................................... 3-19 3.2.3 Block Logic Diagram ........................................................................ 3-19 3.2.4 BTS 2000 Main Module TB Interface ................................................ 3-20 3.2.5 A.C. Circuit: Supply, Protection and Distribution ............................. 3-20 3.2.6 D.C. Circuit: Supply, Protection and Distribution ............................. 3-21 3.2.7 Control Interface............................................................................... 3-21

3.2.7.1 BTS 2000 Power Supply..............................................................................................................3-21 3.2.7.2 BTS IN/OUT Selection................................................................................................................3-21 3.2.7.3 Closing Supply Control................................................................................................................3-21 3.2.7.4 BTS 2000 Test Transfer / Manual Transfer Interface ................................................................3-22

3.2.8 Unit Bus PT Fuse Failure.................................................................. 3-22 3.2.9 Protective Transfer ........................................................................... 3-22 3.2.10 Permissive Interlocks ..................................................................... 3-22 3.2.11 Breaker NO/NC Contacts............................................................... 3-23 3.2.12 BTS OUT Interlock for Closing Circuit .......................................... 3-23 3.2.13 Breaker Trip/Close Contacts.......................................................... 3-23 3.2.14 Motor Trip Contacts ...................................................................... 3-23 3.2.15 PT Inputs ....................................................................................... 3-24 3.2.16 External Annunciation / Alarm....................................................... 3-24 3.2.17 X-CTB, X-TB1, X-TB2 Interface..................................................... 3-24

3.3 PANEL DESCRIPTION ................................................................................ 3-25 3.3.1 General Arrangement (External View) .............................................. 3-25 3.3.2 Labels ............................................................................................... 3-25 3.3.3 Internal Construction........................................................................ 3-25

3.3.3.1 Construction..................................................................................................................................3-25 3.3.3.2 Panel standard equipments...........................................................................................................3-26 3.3.3.3 Wiring and termination ................................................................................................................3-26 3.3.3.4 Protection ......................................................................................................................................3-26 3.3.3.5 Labels ............................................................................................................................................3-26 3.3.3.6 Earthing .........................................................................................................................................3-26 3.3.3.7 Panel mounting .............................................................................................................................3-26 3.3.3.8 Operation.......................................................................................................................................3-26

3.3.4 Bill of Material (BOM)...................................................................... 3-26 3.3.5 BTS 2000 Main Module Front Panel ................................................. 3-27

3.3.5.1 LED Indications............................................................................................................................3-27 3.3.5.2 LCD Menu Interface.....................................................................................................................3-29 3.3.5.3 RS-232 Data Port..........................................................................................................................3-31 3.3.5.4 Fixed Function Pushbuttons with LED Indications....................................................................3-31 3.3.5.5 Test and Transfer Illuminated Pushbuttons ................................................................................3-32

3.4 SOFTWARE DESCRIPTION.......................................................................... 3-33 3.4.1 Installation........................................................................................ 3-33 3.4.2 Loading the Program ........................................................................ 3-34 3.4.3 Communicating with BTS 2000 ......................................................... 3-34 3.4.4 Software Operation Modes................................................................ 3-35

3.4.4.1 Online Viewing.............................................................................................................................3-35 3.4.4.2 Event Recording with Relay-Replay™.......................................................................................3-36 3.4.4.3 Virtual Test Set Simulation..........................................................................................................3-36

3.4.5 Software Tools : Display Menu ......................................................... 3-37 3.4.5.1 Application Diagram....................................................................................................................3-37 3.4.5.2 Oscillography................................................................................................................................3-37 3.4.5.3 Metering ........................................................................................................................................3-38 3.4.5.4 Targets / LED Indications...........................................................................................................3-39 3.4.5.5 Previous Transfer Log..................................................................................................................3-39 3.4.5.6 Sequence of Events (SOE) Recording.........................................................................................3-40 3.4.5.7 Data Profiler..................................................................................................................................3-40 3.4.5.8 Contact Inputs...............................................................................................................................3-41



3.4.5.9 Contact Outputs ............................................................................................................................3-42 3.4.5.10 Factory Nameplate ...................................................................................................................3-42

3.4.6 Software Settings: Settings Menu....................................................... 3-42 3.4.6.1 File Management ..........................................................................................................................3-43 3.4.6.2 Virtual Test Setup.........................................................................................................................3-43 3.4.6.3 Analog Input Settings...................................................................................................................3-44 3.4.6.4 Breaker Settings............................................................................................................................3-44 3.4.6.5 Transfer Controller Settings.........................................................................................................3-45 3.4.6.6 Transfer Processor Settings..........................................................................................................3-45 3.4.6.7 Admin Settings .............................................................................................................................3-46 3.4.6.8 Scheme Indentification Settings ..................................................................................................3-46

4 INSTALLATION INSTRUCTIONS........................................................... 4-48

4.1 RECEIVING, HANDLING AND STORAGE...................................................... 4-48 4.2 FLOOR PREPARATION AND ERECTION........................................................ 4-48 4.3 INSTRUCTIONS BEFORE ENERGIZING ......................................................... 4-49

5 COMMISSIONING INSTRUCTIONS....................................................... 5-50

5.1 PRE-COMMISSIONING CHECKS.................................................................. 5-50 5.2 COMMISSIONING PROCEDURE ................................................................... 5-50

5.2.1 Cold Trials........................................................................................ 5-50 5.2.2 Spin Down Trials .............................................................................. 5-50 5.2.3 Hot Trials.......................................................................................... 5-50 5.2.4 Trial Procedure................................................................................. 5-51

6 OPERATING INSTRUCTIONS................................................................. 6-53

6.1 OPERATING PROCEDURE........................................................................... 6-53 6.1.1 Operator Interface – BTS Blocked Condition .................................... 6-53 6.1.2 Operator Interface – BTS Not Ready Condition................................. 6-53 6.1.3 Operator Interface – Transfer Mode Combination ............................ 6-53 6.1.4 Operator Interface – Selecting a Transfer Direction.......................... 6-54 6.1.5 Operator Interface – Test Transfer.................................................... 6-54 6.1.6 Operator Interface – Live Transfer.................................................... 6-55

6.2 SAFETY PRECAUTIONS.............................................................................. 6-56 6.3 MAINTENANCE INSTRUCTIONS.................................................................. 6-56 6.4 TROUBLESHOOTING GUIDE ....................................................................... 6-56

6.4.1 ‘BTS 2000 reports a BTS NOT READY condition’............................. 6-56 6.4.2 ‘BTS 2000 reports a BTS BLOCKED condition’................................ 6-57

7 RECOMMENDED SPARES....................................................................... 7-58



1 Introduction This document is an Instruction Manual for the Bus Transfer System (BTS) Panels for STANDARD 2 BREAKER SCHEME. Chapter 1 is an introduction to the contents of this instruction manual. It briefly summarizes the contents of the following chapters. Chapter 2 provides a brief profile of our company, its activities, management and organizational details. Chapter 3 provides a detailed technical write-up of the bus transfer system (BTS) panel and includes the functional description, scheme description, panel description and software description for the auto transfer panels. Chapter 4 provides instructions for the receiving, handling and storage of the panels, and the guidelines to be followed for floor preparation, erection and energizing the panel. Chapter 5 mentions the checks and procedures to be adopted during commissioning of the panel. Chapter 6 mentions the checks and procedures to be adopted during operation of the panel. It also recommends safety precautions and specifies regular maintenance requirements. A troubleshooting guide describes guidelines to handle some of the problems that may be encountered during operation of the panels. Chapter 7 lists the component spares that are recommended for the panels to safeguard restoration in case of a contingency.



2 Company Profile AARTECH SOLONICS LTD., was founded by Mr. Anil A. Raje in the year 1985. After acquiring a plot of land at Mandideep 20 K.M. away from Bhopal city, the factory building was completed and machinery installed with the help of financial assistance from M.P. Financial Corporation. The company started commercial production w.e.f. 1st January’1988. AARTECH was initially incorporated as a Private Limited Company and subsequently in March 1992 converted into a Public Limited Company.

2.1 Activities

The company was established with the view of manufacturing custom-built electrical system as required for power station, receiving stations, sub-stations, distribution networks, process plants and a variety of industries. The company is well established as an “APPLICATION ENGINEERING SPECIALIST” in the field of Electrical Switchgear & Controlgear Engineering and continues to meet the diverse and ever-changing needs of power plants and process industries, using state-of-the-art technologies.

2.2 Management

The company is professionally managed by Board of Directors, drawn from the reputed companies in India and having long experience in their field[s] of activity. A] MR. Anil A. RAJE Qualified Electrical Engineer with 25 years Chairman . of experience in Design/Manufacture of [Full time] Electrical systems and expert application engineer acknowledged in the field. B] MR. Amit A. RAJE Qualified Electrical Engineer with 10 years Managing Director. of experience in Design/Manufacture of [Full time] Electrical systems and expert application engineer acknowledged in the field. C] MR. S. D. KULKARNI Qualified Electrical Engineer with post Director graduate diploma in Industrial Marketing [Full time] having 25 years experience in the fields of Consultancy, Project Management and Marketing in India and abroad. D] MRS. C. A. RAJE Qualified Chemical Technologist with about Director twenty year of working experience in Industry [Full time] from Administration to Finance.



Full time directors take active interest in the affairs of the company and devote time to further the interests of the company activity.

2.3 Organization Details

COMPANY NAME: AARTECH SOLONICS LIMITED REGD. OFFICE: E-2/57, “ASHIRVAD”

ARERA COLONY, BHOPAL-462016 TEL/FAX [0755] 4276335/2463593 UNIT#1: PLOT NO. 35A/36, SECTOR-B, INDUSTRIAL AREA, MANDIDEEP, DIST.-RAISEN [M.P.] TEL. [07480] 233020. UNIT#2: KHASRA NO 311, NEAR HIM COLD STORAGE SECTOR-1, PARWANOO, DIST. SOLAN [H.P.] EMAIL : [email protected] WWW: www.aartechsolonics.com DIRECTORS: MR. A. A. RAJE

CHAIRMAN MR. AMIT A. RAJE

MANAGING DIRECTOR MR. S. D. KULKARNI EXECUTIVE DIRECTOR MRS. C. A. RAJE FINANCE DIRECTOR TECH SUPPORT: MS.SANJEEVANI SHAHAPURKAR

MS.NITISHA TIWARI MS.RUCHIRA BIDKAR



3 Technical Write-Up

3.1 Functional Description

This section describes the features of the numerical two breaker unit-to-station bus transfer scheme.

: 2-Breaker Unit-to-Station Bus Transfer System Configuration

3.1.1 2-Breaker Unit-to-Station Bus Transfer System Configuration

Source 1 has UAT. UAT normally supplying power to the unit board through I/C breaker [UNIT I/C]. Further, the system is designed such that there is a provision for an alternate source of power to the unit board from the station board through normally open unit tie breaker [UNIT TIE] on the unit board and normally closed station tie breaker [STATION TIE] on the station board.

The unit has an independent bus transfer system designated by the designation of the unit board– (BTS-UTS-1) and housed in an independent panel.

The bus transfer system is basically a two breaker bus transfer system operating on the UNIT I/C and the UNIT TIE breaker on the unit board.

3.1.1.1 BTS-UTS-1

The Unit auxiliary transformer (UAT) is connected through a normally closed (NC) UNIT I/C breaker to the unit board, Similarly, station board is connected through a normally closed (NC) STATION TIE breaker and normally open (NO) UNIT TIE breaker to the unit board. BTS-UTS-1 bus transfer system thus relates to unit board and operates (trip & close) on the respective UNIT I/C, UNIT TIE breakers. Under certain breaker failure



conditions, the system also sends trip command to the normally closed (NC) STATION TIE breaker.

3.1.2 BTS 2000 Bus Transfer System

The bus transfer systems are each based on Aartech’s Microprocessor based BTS 2000 Fast Bus Transfer System. BTS 2000 is an advanced, fully integrated fast bus transfer system. It has powerful, state-of-the-art features, to provide fast and safe bus transfer operations in an intelligent manner. The hardware used is an Edison Idea PLUS relay platform, which is a microprocessor controlled relay platform for power system protection, monitoring, and control. It is designed to the standards for robust, high-performance industrial computer systems. The software environment, ProView provides an integrated environment for the configuration and operation of the Edison Idea PLUS relay platform, as well as a complete programming system for developing power system applications.

3.1.3 Bus Transfer Directions

Bus transfers can take place in a 2-breaker bus configuration in several directions. Each bus transfer direction uniquely identifies the transfer bus, the old source feeding the bus prior to transfer, and the new source which will feed the bus after the transfer. The old source breaker (tripping breaker) and the new source breaker (closing breaker) are thus uniquely identified along with the identity of the transfer bus PT, the old source PT and the new source PT inputs. This information is used to determine the monitoring and supervision of various system dynamics during bus transfer. The bus transfer direction for a given bus transfer is determined by several factors. For manual transfers, the bus transfer direction is automatically selected based on the current bus configuration. For protective / auto transfers the bus transfer direction is selected automatically based on pre-fed software settings. Different transfer directions are selectively enabled for different transfer initiation criteria using pre-fed software settings.

UNIT I/C ONUNIT TIE OFF

UNIT I/C OFFUNIT TIE ON

TRANSFER BUS

OLD (TRIPPING)SOURCE

NEW (CLOSING)SOURCE

PT BKR PT BKR PT

CHOICE: MANUAL/

PROTECTIVE/ AUTO

UNIT BUS UNIT I/C

TRANSFER DIRECTION

UNIT => STN UNIT I/C LINE PTUNIT TIEUNIT TIE

LINE PT

MANUAL / PROTECTIVE /

AUTO

UNIT BUS UNIT TIESTN => UNIT UNIT TIE LINE PT UNIT I/CUNIT I/C

LINE PT MANUAL

BREAKERCONFIGURATION

Table 1: Bus Transfer Directions.



3.1.4 Bus Transfer Initiation

The need of a bus transfer can be motivated by a variety of reasons. Depending on these, the means of initiating a bus transfer can be further classified as manual, protective and auto transfer. Manual transfers are planned transfers, while protective transfers are actuated by protective relaying elements. BTS 2000 can also be configured for intelligent auto transfers based on continuous system monitoring algorithms.

3.1.4.1 Manual Transfer

Manual transfer is used for a planned transfer during normal operation of the power station. This is useful during a startup, shutdown or certain kinds of maintenance work of the system. The choice of transfer direction among the available transfer directions is automatically selected by BTS 2000 based on current breaker configuration. Therefore, if UNIT I/C is ON and UNIT TIE breaker is OFF, then BTS 2000 automatically selects unit-to-station transfer. Similarly, if UNIT TIE breaker is ON and UNIT I/C breaker is OFF, then BTS 2000 automatically selects station-to-unit transfer, provided other conditions for readiness are met. The transfer can be manually actuated using the HMI on the front panel of BTS 2000 or through a dedicated local computer or a remote central computer with SCADA, using the ModBus protocol to communicate with BTS 2000 on the RS-485/ RS-232 port. Manual transfers are possible in various transfer directions as shown in Table 1. The Fast mode is recommended for a manual transfer, although other choices including the momentary paralleling mode have also been provided.

3.1.4.2 Protective Transfer

Protective transfer initiation is done for unit source failure conditions only in unit to station transfer direction. For unit source failure, the initiating signals are derived from generator trip, unit trip, reverse power, winding temperature and oil temperature high trip. The choice of transfer mode for unit source failure is selected in the protective transfer settings, wherein the Fast-In Phase-Slow mode is recommended.

3.1.4.3 Auto Transfer

BTS 2000 has the ability to do intelligent auto transfers in unit-to-station direction based on continuous system monitoring algorithms. These algorithms can initiate a transfer on sustained conditions of bus under-voltage, bus under-frequency or a high bus |df/dt| with respect to their individual settings. This can be used to ensure a healthy source to the motor bus at all times without the need of additional protection elements for transfer initiation. The Fast-In Phase-Slow mode is recommended for auto transfers.

3.1.5 Bus Transfer Modes

BTS 2000 can do bus transfers between the old source and the new source in different modes such as fast, in-phase, slow and momentary paralleling depending on the choice of transfer mode(s) and the dynamic system conditions.



3.1.5.1 Fast Transfer

Fast transfer is a supervised open circuit “break before make” transfer, where the old source breaker trips before the new source breaker closes. It minimizes the interruption of power to the bus, while avoiding a potentially unsafe parallel operation. In the fast transfer mode, the decision to transfer is done on the basis of comparing the phase angle and voltage magnitude of the bus with that of the new source. The following factors are taken into consideration:

Phase difference prediction

Usually the instantaneous phase difference between the new source and bus is compared with the specified fast transfer phase window setting. However, a prediction of the phase difference between the new source and the bus at the instant of the closing of the new source breaker may be compared with the specified fast transfer phase window setting instead of the instantaneous phase difference, for a better estimate of the dynamic conditions. The choice of a first order prediction (based on the first rate of change of phase difference) as well as a second order prediction (based on the use of both the first and second rate of change of phase difference) is available. The new source breaker closing time setting is used for this prediction.

Bus condition

i) The bus voltage magnitude is verified to be greater than a specified minimum bus voltage magnitude for fast bus transfer setting.

ii) Other dynamic criteria as described in section 3.1.7 .

Simultaneous and sequential transfer

A simultaneous transfer, which is typically used, sends simultaneous tripping and closing command to the old source breaker and new source breaker respectively. Since tripping times are lower than the closing times, this automatically achieves an open circuit transfer. Additionally, the option of adding an additional time delay in the closing of the new source breaker is also provided. A sequential transfer does not send a closing command to the new source breaker unless it ascertains that the old source breaker is tripped. The option of using the early ‘b’ tripping contact of the breaker is also provided.

3.1.5.2 In Phase Transfer

The main advantage of the in-phase transfer mode is the ability to safely transfer the bus to the new source, even if the fast transfer is blocked, without necessarily having to trip the motors. It is an open circuit transfer with longer bus dead times, depending on the bus spin-down characteristics. An in-phase transfer takes place by intelligently sending a closing command to the new source breaker such that the breaker power contacts close when the drifting bus voltage vector synchronizes with the new source voltage vector. The following factors are taken into consideration:




A prediction of the phase difference between the new source and the bus at the instant of the closing of the new source breaker is compared with the specified in-phase transfer phase window setting. The choice of a first order prediction (based on the first rate of change of phase difference) as well as a second order prediction (based on the use of both the first and second rate of change of phase difference) is available. The second order prediction is recommended for a more accurate prediction of the bus spin-down characteristics. The new source breaker closing time setting is used for this prediction.

Bus condition

i) A tripping command is sent to the old source breaker on the initiation of an in-phase transfer. The closing of the new source breaker in an in-phase transfer is permissible only when the old source breaker is tripped.

ii) The bus voltage magnitude is verified to be greater than a specified minimum bus voltage magnitude for in-phase bus transfer setting.

iii) The magnitude of the difference between the bus frequency and the new source frequency should be within its specified maximum limit setting.

iv) The magnitude of the difference between the new source (df/dt) and the bus (df/dt) should be within its specified maximum limit setting.

v) Other dynamic criteria as described in section 3.1.7 . However, at the instant at which an in-phase transfer decision is justified, the dynamic criteria might not be satisfied due to the instantaneous bus drift. Hence, the use of the dynamic criteria for supervising in-phase transfer is optional.

3.1.5.3 Slow Transfer or Residual Voltage Transfer

The slow transfer or residual voltage transfer method is the slowest transfer of the motor bus to the new source. After tripping the old source breaker, the motor bus voltage magnitude is allowed to decay to acceptable levels before closing the new source breaker. Since simultaneous re-acceleration is not possible, the auxiliary motors are optionally tripped as per custom-built logic. The following factors are taken into consideration:

Bus condition

i) The closing command is sent to the new source breaker only after the bus voltage magnitude goes below the residual transfer voltage setting.

ii) The optional tripping command can be sent to various motor auxiliaries of the transfer bus on a prioritized basis. The priority of the motor tripping can be pre-decided or be decided dynamically, by using custom-built logic. For instance, the minimum bus voltage magnitude setting(s) for the tripping of individual motors can be individually assigned. The CT inputs from the important motors can also be used for deciding the custom-logic for motor tripping.

iii) Other dynamic criteria as described in section 3.1.7 .

3.1.5.4 Momentary Paralleling Transfer or Parallel Transfer

The momentary paralleling transfer or parallel transfer is a supervised “make before break” transfer where the new source breaker is closed followed by the opening of the



old source breaker. This mode is not recommended for unplanned transfers as it violates interrupt ratings of the breakers and short-term withstand ratings of the power transformers. Steady state voltage/phase differences between the normal and new source or electrical faults and other abnormal conditions will also preclude the use of a momentary paralleling transfer. The following criteria are taken into consideration:


Usually the instantaneous phase difference between the new source and bus is compared with the specified parallel transfer phase window setting. However, a prediction of the phase difference between the new source and the bus at the instant of the closing of the new source breaker may be compared with the specified parallel transfer phase window setting instead of the instantaneous phase difference, for a better estimate of the dynamic conditions. The choice of a first order prediction (based on the first rate of change of phase difference) as well as a second order prediction (based on the use of both the first and second rate of change of phase difference) is available. The new source breaker closing time setting is used for this prediction.

Bus condition

i) The bus voltage magnitude is verified to be greater than a specified minimum bus voltage magnitude for parallel bus transfer setting.

ii) Other dynamic criteria as described in section 3.1.7 .

3.1.6 Bus Transfer Mode Combinations

BTS 2000 provides a choice of different bus transfer mode combinations that can be selected for each bus transfer initiation method. The settings for selecting bus transfer mode combinations are thus available for manual transfer, protective transfer (unit-to-station) and auto transfer (unit-to-station). The following bus transfer mode combinations are available:

3.1.6.1 Fast-In Phase-Slow

This is the recommended bus transfer mode combination for all transfers. The transfer modes that are attempted in order of priority are fast, backed up with in-phase, backed up with slow transfer. It offers the advantage of a fast and safe open circuit bus transfer whenever possible, with an attempt to transfer in-phase on the failure of a fast transfer and prevent motor tripping. As a last resort, the slow transfer is executed wherein the motors are tripped.

3.1.6.2 Fast-Slow

This bus transfer mode combination can be used in place of the Fast-In Phase-Slow combination, when the in-phase mode is to be disabled. The transfer modes that are attempted in order of priority are fast, backed up with slow transfer. It offers the advantage of a fast and safe open circuit bus transfer whenever possible. On the non-availability of the fast transfer mode, the slow transfer is executed wherein the motors are tripped.



3.1.6.3 Fast

This bus transfer mode combination has been provided for use in planned transfers. Since the fast transfer is the only mode that is made available, a bus transfer takes place only if the fast transfer criteria are satisfied. However for protective transfers and auto transfers, such a mode is not recommended, since no backup mode is provided.

3.1.6.4 Slow

This bus transfer mode combination has been provided for situations where a slow transfer is to be affected. It is not generally recommended for transfer operations, since the fast and in-phase modes are not available and the motors are tripped.

3.1.6.5 Momentary Paralleling

A momentary paralleling bus transfer mode differs from all other modes in that it is not an open circuit based transfer. Its use is generally not recommended, but if desired, is usually restricted to manual transfers.

3.1.7 Dynamic Bus Transfer Criteria

The dynamic bus transfer criteria can be optionally used to supervise the bus transfer modes according to specified motor bus transfer recommendations.

3.1.7.1 ANSI C50.41 (1982) and NEMA MG-1 (1982) Criterion

This widely followed criterion states that the vectorial difference between the motor bus and the incoming source volts per hertz should not exceed 1.33 p.u. in magnitude. The closing of the new source breaker can be supervised by this criterion for different transfer modes.

3.1.7.2 Maximum New Source – Bus Healthiness Criterion

This criterion can be used to supervise the healthiness of the vectorial difference of voltage, frequency and/or |df/dt| between the motor bus and the incoming source, as per the analog input settings. The closing of the new source breaker can be supervised by this criterion for different transfer modes.

3.1.8 System Readiness Conditions

BTS 2000 continuously performs several system checks to determine whether the bus transfer system is ready. If any of these readiness conditions are not met, it does not allow a transfer to be initiated. The following readiness checks are continuously performed:

3.1.8.1 BTS Service Selection

The BTS service selection toggle switch is used to select the BTS in an IN or OUT state. The BTS needs to be selected in the IN state as a necessary condition for system readiness.



3.1.8.2 BTS Blocking

Several events can put the BTS in a blocked condition. These are described in section 3.1.9 . When any such event takes place, the blocked condition of the BTS also puts the bus transfer system into non-readiness.

3.1.8.3 Breaker Configuration

The normally open (NO) contact and normally closed (NC) contact of each breaker are both used by BTS 2000 to determine the status of the breaker. A closed NO contact and an open NC contact indicates a closed status of the breaker. Similarly, an open NO contact and a closed NC contact indicates a tripped status of the breaker. If the status of the NO and NC contact of the breaker are not consistent with each other for more than a certain breaker consistency check timer setting, a breaker status error condition is detected. A breaker status error for any of the breakers in the system configuration will put the bus transfer system into non-readiness. A breaker configuration in which the bus is paralleled by both the sources is an invalid configuration. Such a configuration also puts the bus transfer system into non-readiness.

3.1.8.4 Breaker Trip/Close Circuit Monitoring

BTS 2000 continuously monitors the DC voltage across the tripping and closing contacts for the UNIT I/C, UNIT TIE breakers. A DC voltage across the tripping contact of a closed breaker and the closing contact of a tripped breaker indicate the electrical continuity of their respective circuits. In the event of the non-compliance of any of the above contact monitoring measures, the bus transfer system is put into non-readiness. Due to certain switchgear configurations and connections, it is possible that the tripping circuit cannot be monitored when the breaker is open, and the closing circuit cannot be monitored when the breaker is closed. In such cases, a conditional trip/close circuit monitoring may be optionally selected, wherein only the tripping circuits of closed breakers and the closing circuits of open breakers are monitored.

3.1.8.5 New Source Healthiness

BTS 2000 continuously monitors the healthiness of the new source for Under/Over voltage/frequency and/or |df/dt| conditions as per the respective analog input settings for the PT voltage inputs. The identity of the new source and the old source is ascertained by the current breaker configuration. By the choice of this optional feature, the bus transfer system is put into non-readiness if the new source is unhealthy.

3.1.8.6 Station Tie Breaker ON

BTS 2000 continuously monitors the NO contact of the STATION TIE breaker and incase the breaker is OFF, it puts the bus transfer system into non-readiness

3.1.8.7 Unit Bus PT Fuse Healthy

BTS 2000 continuously monitors status of Unit Bus PT Fuse for healthiness. If Unit Bus PT Fuse is unhealthy, the bus transfer system is put into non-readiness.



3.1.8.8 External Permissives OK

Several permissive conditions are connected in series to form an external permissives OK input. These include:-

1. Permissives on BTS 2000 front panel HMI a. BTS readiness disable fuse healthy. b. Breaker Main Lockout 86: UNIT I/C, UNIT TIE breaker c. Breakers in service 75S: UNIT I/C, UNIT TIE breakers. d. PT fuse healthy 98: UNIT I/C line, UNIT TIE line PTs. e. PT in service 75S: UNIT bus.

3.1.9 System Blocking Conditions

BTS 2000 puts the bus transfer system into a blocked condition on the occurrence of certain events. These events demand operator attention, and hence, only a manual reset can return the bus transfer system to readiness. The HMI is useful in such a case to diagnose the reason of the blocked condition and take appropriate measures. The following are the events that create a blocked condition:

3.1.9.1 Protective / Auto Transfer

After executing a protective transfer (unit source failure), BTS 2000 puts the bus transfer system into a blocked condition. Thus the operator is required to acknowledge the event, and is recommended to observe the bus transfer operation.

3.1.9.2 Self Test Failure

BTS 2000 continuously performs self-tests and in the event of a failure of any of these tests, the bus transfer system is put into a lockout condition. The following events define a self test failure: 1. Power supply failure 2. RAM test failure 3. ROM test failure

3.1.9.3 Breaker Failure

A breaker failure is an event when a breaker does not respond to a valid breaker command. On having detected such an event, BTS 2000 takes certain corrective actions, which are described in greater detail in section 3.1.10 . After having completed these actions, BTS 2000 puts the bus transfer into a blocked condition.

3.1.9.4 Transfer Failure

A transfer failure occurs when a bus transfer request does not result in the desired bus transfer operation. This can occur due to many reasons such as system non-readiness, non availability of selected transfer mode(s) or breaker failure. On such a transfer failure, BTS 2000 puts the bus transfer system into a blocked condition.



3.1.10 Breaker Failure Detection and Corrective Action

BTS 2000 detects the failure of a breaker operation when the breaker NO and NC contacts do not respond to the issuance of a breaker command through the bus transfer system. The maximum response time used for this decision making is based on the sum of the operation time (tripping time / closing time) setting of the breaker and an additional operation time margin (tripping time margin / closing time margin) setting. Breaker failure can lead to several different bus transfer scenarios. During a transfer, which can be initiated by manual, protective as well as auto means, the old source breaker is tripped and the new source breaker is closed according to the appropriate mode available for transfer. For a protective transfer, the old source breaker usually receives a trip command from sources other than the bus transfer system as well. The following breaker failure scenarios can emerge:

1. Old source breaker fails to trip and the new source breaker closes - This results in a permanent paralleling situation. On detecting the tripping failure of the old source breaker, a tripping command is given to the new source breaker. If the new source breaker also does not trip – a tripping command is given to the NC station tie breaker.

2. Old source breaker fails to trip and the new source breaker fails to close - No bus transfer takes place.

3. Old source breaker trips and the new source breaker fails to close - This results in an open circuit of the bus resulting in a bus dead condition.

3.1.11 Closing Supply Control

As discussed in 3.1.8.4 above, BTS 2000 monitors the tripping and closing circuits of the breakers. The closing circuit of a breaker has an anti pumping relay provision which prevents continuous command to the closing coil of the breaker. The anti pumping relay typically has a low dropout voltage and thus may not dropout even after the closing command is over due to the close circuit monitoring; which may cause breaker operation malfunction later on. The closing supply control thus momentarily disconnects all the breaker closing circuits at the end of the transfer cycle to enable dropout of the anti pumping relay.

3.1.12 Online Testing

On the selection of the test mode using the HMI, BTS2000 inserts a high resistance in the path of the control supplies of the tripping and closing circuit of the breakers and also checks interlocks to ascertain this operation. If the interlocks are not satisfied, BTS 2000 automatically deselects the test mode. On actuation of a test transfer using the HMI, the tripping and closing contacts are asserted by BTS2000 as per actual system conditions, but they do not actually trigger a transfer. Fictitious displays of breaker statuses are temporarily indicated on the LED targets corresponding to the tripping and closing contacts asserted by BTS2000. The online testing gets automatically deselected on the occurrence of an auto or protective transfer.



3.1.13 Transfer Analysis

BTS2000 records every transfer event, which can be uploaded to the PC using the BTS2000 software scheme in the ProView environment. These events can be replayed step-by-step to analyze the scheme logics and oscillographic plots in fine detail. A few pertinent system quantities are also logged and displayed using the panel meters and HMI. These system quantities are the phase difference between the new source and the bus, magnitude of the vectorial difference between the new source and the bus voltage, PT voltage magnitude and frequency measurements, all at the instance of closure of the new source breaker; and breaker tripping and closing timings.

3.2 Scheme Description

Reference: Block Logic Diagram and Schematic Diagram The BTS panel block logic and schematic diagram are detailed as follows:-

3.2.1 Single Line Diagrams (SLD)

In Sheet: Single Line Diagram shows the detailed SLD of the system relevant to the BTS panels. The interface of the BTS 2000 bus transfer schemes with various system components is also shown here.

3.2.2 Bus Transfer Details

In Sheet Bus Transfer Detail: shows the scheme-wise designations of the various breakers, switchboards, PTs and bus transfer details related to each such bus transfer scheme.

3.2.3 Block Logic Diagram

In Sheet Block Logic Diagram: provide a detailed block logic diagram of the scheme. The notes section on Sheet No. 5 provides a brief summary of the scheme logic blocks and is reproduced for quick reference below:- NOTES: 1. BTS Ready: Checks all permissive conditions for BTS readiness. 2. Transfer Direction Selection: Selects the transfer direction based on the current breaker

configuration. a. Manual transfer: Transfer direction is selected by operator using BTS 2000 HMI

interface. Depending on the current breaker configuration, appropriate transfer directions are made available to the operator for choice.

b. Protective transfer / auto transfer: Transfer direction is automatically determined by BTS 2000 from pre-fed software settings as per breaker configuration, type of fault and type of bus transfer initiation (protective / auto).



3. Transfer Mode Combination: Selects the combination of transfer modes (fast / in phase / slow / momentary paralleling) for bus transfer.

a. Manual transfer: Transfer mode combination is selected by operator using BTS 2000 HMI interface.

b. Protective transfer / auto transfer: Transfer mode combination is automatically determined by BTS 2000 from pre-fed software settings as per type of fault (UAT / STN) and type of bus transfer initiation (protective / auto).

4. Transfer Command: Command a bus transfer operation. a. Manual transfer: Transfer command is issued by operator using BTS 2000 HMI

interface. b. Protective transfer: Transfer command is automatically issued by BTS 2000 from

pre-fed software settings as per breaker configuration and verification of protective transfer initiation command.

c. Auto transfer: Transfer command is automatically issued by BTS 2000 on sensing time delayed bus unhealthiness (under / over) (voltage / frequency / |df/dt|) as per pre-fed software settings, breaker configuration and type of fault.

5. Transfer Initiate: Upon initiation, a transfer is permitted as per the transfer cycle time window (3.0 s). If transfer does not take place during this period, BTS 2000 is automatically blocked on a transfer failure condition.

6. Transfer Processing: Processes the transfer initiation request based on the choice of the transfer mode combination to generate and sequence breaker operation commands.

7. Breaker Failure Detection and Corrective Action: Detect the failure of breaker operation (if any) and take feasible backup corrective action.

The detailed settings that govern the logics of each block are described in section 3.4.

3.2.4 BTS 2000 Main Module TB Interface

In this Sheet - Block Logic Diagram & Schematic Drawing describes the terminal block interface of the rear panel of BTS 2000 Main Module, which are pre-fixed with the letter “M”. There are 5 terminal blocks M-TB1, M-TB2, M-TB3, M-TB4 and M-TB5 in BTS 2000 apart from a RS-232, RS-485 and IRIG-B port. These terminal blocks interface the external circuits to the internal 220VDC power supply, 17 contact inputs (CI), 4 trip rated electromechanical contact outputs (CO), 9 trip rated solid state contact outputs (SS), 3 current inputs [5A] (IA, IB, IC) and 4 voltage inputs [110VAC] (VA, VB, VC, VS). The RS-232 port J1 is a 9-pin male D-sub connector configured as a RS-232 DTE. The recommended cable is a 1-1 male-female cable for modem connection; and a null modem female-female cable for PC connection. The IRIG-B port J2 is a 5V demodulated time code input female BNC connector. An IRIG-B demodulated TTL signal is required for time synchronisation. The RS-485 port J3 is a 2-wire 9-pin female D-sub connector. A twisted pair with 3rd conductor for signal ground is recommended for the RS-485 looped connection.

3.2.5 A.C. Circuit: Supply, Protection and Distribution

In this Sheet :Describes the A.C distribution circuit of the panel. The 240 VAC single phase A.C. circuit has the following sub-circuits: 1. AC supply switching and protection circuit

o 2 pole MCB 6A/240VAC



2. Switch socket circuit (S1-SKT1) 3. Lighting circuit

o Illumination lamp (14W) (IL1) operates if switch S2 is ON and the door switch DS1 operates.

4. Heater circuit o Space heaters (60W) (HTR1) operates by switch S3 and thermostat control

(TH1).

3.2.6 D.C. Circuit: Supply, Protection and Distribution

Sheet No. 8 describes the D.C distribution circuit of the panel. The 220VDC circuit has the following sub-circuits: 1. D.C. Supply switching and protection circuit

o DC supply can be selected from one of two sources, by operation of 2-pole, 2-way center off switch S4 (16A).

o The main DC supply is protected by 10A fuses F1 (+ve) and F2 (-ve). o The panel DC supply is protected by 4A fuses F3 (+ve) and F4 (-ve).

2. BTS 2000 power supply circuit

o The main scheme circuit provides power supply to the BTS 2000 main module power supply circuit through 2A fuses F5(+ve) and F6(-ve)

3. Scheme control circuit o The main scheme circuit provides power supply to the scheme control

circuit through 2A fuses F7 (+ve) and F8 (-ve).

3.2.7 Control Interface

Sheet No. 9 describes the control interface of the BTS panel, and consists of the following sub-circuits:-

3.2.7.1 BTS 2000 Power Supply

The 220VDC power supply for BTS 2000 main module is derived from the scheme main circuit as described in section 3.2.6.

3.2.7.2 BTS IN/OUT Selection

When the BTS service selection toggle switch is in IN position and the BTS readiness disable fuse is healthy, BTS IN/OUT relays R1, R1A are energised. The NO contacts of the auxiliary relays are used to connect the BTS 2000 breaker tripping and closing circuits to the switchgear as described in section 3.2.12 and permit motor tripping as well. The NC contacts of the auxiliary relays are used as in interlock for the switchgear closing circuits. Thus, BTS 2000 trip/close operations will operate the switchgear only if BTS is in IN condition.

3.2.7.3 Closing Supply Control

The operation of the BTS main module closing supply control contact M-CO4 energizes relay R2. The NC contact of this relay is used to temporarily disconnect the breaker closing circuits at the end of the transfer cycle to enable dropout of the anti pumping relay.



3.2.7.4 BTS 2000 Test Transfer / Manual Transfer Interface

The ‘BTS Ready to Transfer’ contact output M-CO3 closes when the bus transfer direction is manually selected, and all system conditions, including permissive interlocks are OK. When the test mode is not selected, contact output M-CO1a is open and M-CO1b is closed, a ‘Ready for Manual Transfer’ condition is indicated by the RED lamp-pushbutton which is also monitored by contact input M-CI16. A manual transfer gets initiated on pressing this RED ‘TRANSFER’ pushbutton. When the test mode is selected, contact output M-CO1a closes and M-CO1b opens. This energizes the test mode auxiliary relays R3 and R4 and their pickup is also ascertained for indicating the ‘Ready for Test Transfer’ condition by the GREEN lamp-pushbutton, which is also monitored by contact input M-CI15. R3 and R4 introduce a high impedance in the breaker tripping / closing circuits and motor tripping circuits (refer section 3.2.12) thus ensuring that they will not operate during a test transfer. A test transfer gets initiated on pressing this GREEN ‘TEST’ pushbutton. A test transfer checks all system conditions and conducts a fictitious bus transfer to provide the operator a feedback of the anticipated operations of the bus transfer system if a manual bus transfer is conducted for the selected transfer direction and transfer mode combination under the current system conditions.

3.2.8 Unit Bus PT Fuse Failure

In this Sheet i.e Control Interface: shows the unit bus PT fuse failure input to M-CI11 of the BTS 2000 main module, which is an essential condition for readiness.

3.2.9 Protective Transfer

In this Sheet i.e Control Interface: shows the protective transfer inputs to the BTS 2000 main module. Protective transfer in unit-to-station direction on unit source failure is monitored using unit source failure condition provided to M-CI12.

3.2.10 Permissive Interlocks

In this Sheet i.e Control Interface: describes all the external connected permissive interlocks required for BTS readiness, and has the following sub-circuits:-

1. UNIT I/C breaker permissive interlocks a. UNIT I/C breaker in service b. UNIT I/C line PT fuse healthy c. UNIT I/C breaker lockout reset

2. UNIT TIE breaker permissive interlocks a. UNIT TIE breaker in service b. UNIT TIE line PT fuse healthy c. UNIT TIE breaker lockout reset

3. UNIT bus PT permissive interlocks a. UNIT bus PT in service



The inputs mentioned above are connected in series to provide an integrated permissive interlocks OK feedback to the BTS 2000 main module through contact M-CI1.

3.2.11 Breaker NO/NC Contacts

Sheet No. 11 describes the interface of the Normally Open (NO) and Normally Closed (NC) contacts of the UNIT I/C and UNIT TIE breakers with M-CI6-M-CI9 contact inputs of BTS 2000. The breaker NO/NC contacts are monitored for evaluating the status of the breaker operations. The trip/close operation timings and breaker failure detection of the breakers are ascertained by monitoring the time difference between the breaker operation signal (trip/close) and the respective change in the status of the breaker contacts. Normally Open (NO) contact of STATION TIE breaker is monitored for closed condition of the breaker as required for readiness with M-CI10.

3.2.12 BTS OUT Interlock for Closing Circuit

In Sheet describes provision of NC contacts of R1A relay for BTS OUT condition which may be interfaced with UNIT I/C & UNIT TIE closing circuits for permitting remote close operation only under BTS OUT condition.

3.2.13 Breaker Trip/Close Circuits

In this Sheet i.e. Breaker Trip/Close Circuit describes the interface of the trip and close contacts for the UNIT I/C, UNIT TIE and STATION TIE (Trip Only without Circuit Monitoring) breakers with the ,SS3-SS7 solid state contact outputs of BTS 2000. The circuits have the following properties:- 1. Breaker trip circuits utilize switchgear DC supply for trip and close operations. 2. All breaker trip/close circuits and motor trip circuits get disconnected from BTS

2000 trip/close commands when BTS is in OUT condition by the BTS IN/OUT selection relays R1, as described in section 3.2.7.2.

3. On pickup, the test mode relays R3 and R4 introduce a high impedance in the breaker tripping / closing circuits and motor trip circuit, thus ensuring that they will not operate during a test transfer, as described in section 3.2.7.4.

4. The breaker close circuit +ve DC supply get momentarily disconnected by the closing supply control contacts of the relay R2 at the end of each transfer cycle. This enables the dropout of the anti pumping relays with low dropout characteristics, as described in section 3.1.11.

5. The close and trip circuit voltages are 220VDC (-20%, +10%). 6. The breaker trip/close contact of BTS 2000 is monitored by trip/close circuit

monitoring contact inputs – CI2, C13, CI4, CI5.

3.2.14 Motor Trip Contacts

In this Sheet describes the motor trip contacts provided for unit bus motor trip from BTS 2000 through contact multiplication relay R5. The motor trip circuit get disconnected from BTS 2000 unit bus motor trip command when BTS is in OUT condition by the BTS IN/OUT selection relays R1, as described in section 3.2.7.2. On pickup, the test mode relays R3 introduces a high impedance in the breaker tripping /



closing circuits and motor trip circuit, thus ensuring that the circuit will not operate during a test transfer, as described in section 3.2.7.4.

3.2.15 PT Inputs

In this Sheet i.e. PT Inputs/Annunciation describes the 110VAC R-Y phase-phase PT inputs from the UNIT I/C LINE PT, UNIT BUS PT and UNIT TIE LINE PT to the M-VA, M-VB & M-VC voltage inputs of BTS 2000. These PT inputs are internally processed by BTS 2000 to derive the various system characteristics required for monitoring bus transfer operations.

3.2.16 External Annunciation / Alarm

In this Sheet i.e. PT Inputs/Annunciation describes the following external annunciation / alarms provided to the control room from BTS 2000: 1. BTS not ready 2. Auto/Fast Transfer Successful 3. BTS IN 4. Fast Transfer Failure 5. Alarm Contact 6. Bus Transfer Failure 7. Transfer Cycle Over

3.2.17 X-CTB, X-TB1, X-TB2 Interface

In Sheet: Terminal Block Interface describes the terminal interface for X-CTB, X-TB1 and X-TB2 terminal blocks. X-CTB and X-TB1 are located on the left hand side and X-TB2 is located on the right hand side of the panel (as seen from the rear side) respectively. X-CTB relates to AC supply and DC supply terminals.X-TB1 incorporates control inputs (unit source failure protective transfer input), breaker-wise terminal interface for Protective Transfer Input, UNIT I/C, UNIT TIE, STATION TIE breakers, UNIT BUS PT input, PT-wise terminal interface for UNIT I/C LINE PT, UNIT BUS PT, STATION BUS PT, Unit Board Motor Trip and alarm/annunciation in DCS terminals.



3.3 Panel Description

Reference: General Arrangement, Foundation Plan and Bill of Material

3.3.1 General Arrangement (External View)

Sheet No. 3 describes the external front, side, rear and top views of the general arrangement of the bus transfer system panel. Overall dimensions are: 2355mm (H) x 800mm (W) x 800mm (D) including base frame of 140mm (H) and industrial rubber anti-vibration pad of 15mm (H). The bus transfer system panel is an independent, free standing, floor mounting, bottom cable entry type sheet metal enclosed panel with front glass door and suitable for 19” rack mounting. The panel has a 100mm base frame along with anti vibration pads – with foundation plan as shown in the drawing. The bus transfer system panel has an independent bus transfer scheme and is based on Aartech’s BTS 2000 bus transfer system.

3.3.2 Labels

1. Sheet No. 3 shows the description details of the various main labels used in the panel. All labels are 1 mm thick anodised aluminium - black background / white inscriptions except graphic labels which are made by screen printing process / embossing / paper label printing process.

3.3.3 Internal Construction

Sheet No. 4 describes the internal construction of the panel. The salient features of the internal construction are described as follows:-

3.3.3.1 Construction

1. BTS panel is an independent, free standing, floor mounting, bottom cable entry type, CRCA sheet steel enclosed panel.

2. Overall dimensions are: 2355mm (H) x 800mm (W) x 800mm (D) including base frame of 140mm (H) and industrial rubber anti-vibration pad of 15mm (H).

3. Front door of acrylic material / 1.5mm sheet steel thickness frame with full size 3mm toughened viewing glass is provided.

4. 3mm thick removable undrilled gland plates are provided for cable entry. 5. Front and rear doors are provided with internal hinges. 6. Paint shade: IS5:631 light grey, powder coated, texture finish. Base: black. Paint

thickness: 40 micron & above. 7. Lifting: 4 nos. Eye bolts are provided on the roof of the panel for lifting. 8. Net weight of panel is 300 kgs. Approximately (500 kgs. Including packing) 9. Panel degree of protection is IP-40, suitable for installation in air conditioned

plant control room.



3.3.3.2 Panel standard equipments

1. Front and rear doors are provided with flush type handle with lock facility. 2. 1 no. 19" component shelf - withdrawable tray is provided for laptop use. 3. Lighting: 1 no. Compact flourescent tubelight (240VAC, 14W) with door operated

switch is provided. 4. Space heating: 1 no. 230VAC 60W space heater with 30-85 deg c thermostat

control is provided. 5. Socket: 1 no. 230VAC 5A 3 pin power socket with switch is provided.

3.3.3.3 Wiring and termination

1. Wiring: 1.5 sq. mm. (except earth & PT connection: 2.5 sq.mm.) 660V grade, single core, stranded copper conductor wires with PVC insulation duly laid in PVC wiring troughs with detachable covers.

2. Colour of wires: ac circuits-red/black, dc circuit-red/black/grey, earth circuit-green, as per IS-375, PT circuits – red/yellow/blue.

3. Terminations: solderless crimping type of tinned copper lugs with insulated sleeves and tightly fitting engraved core identification plastic ferrules.

4. Terminal blocks: PT & output circuits-disconnecting type CDTTS, others-standard type CSTSB4.

3.3.3.4 Protection

1. A.C. Circuit: input 240VAC supply is controlled by 2 pole MCB. 2. D.C. Circuit: input 220VDC supply is selected from 2 sources using 2 pole, 2 way

with centre off dc source supply selector switch. The selected dc supply is protected with 10A HRC fuses.

3.3.3.5 Labels

1. All labels are 1 mm thick anodised aluminium - black background / white inscriptions except graphic labels which are made by screen printing / embossing / paper label printing process.

3.3.3.6 Earthing

1. Earth bar of size 25 x 3 sq.mm. or equivalent, copper is provided. Metal cases are connected to earth bus individually without looping.

3.3.3.7 Panel mounting

1. Minimum clearance of 1000 mm is required at the front and the rear end of the panel.

2. Minimum clearance of 200 mm is requred at the left and the right side of the panel

3.3.3.8 Operation

1. Bus transfer system panel is suitable for operation upto max. Ambient temperature of 50 deg. C.

3.3.4 Bill of Material (BOM)

The detailed BOM including item description, make and quantities is provided on Sheet No. 4 and is reproduced here as follows:-



S.No. ITEM DESCRIPTION MAKE QTY

1 19” RACK PANEL WITH FRONT TRANSPERENT DOOR AND STANDARD PANEL ACCESSORIES PYROTECH 1 No.

2 BTS 2000 BUS TRANSFER SYSTEM MAIN MODULE

TWO BREAKER UNIT-TO-STATION BUS TRANSFER SCHEMES

AARTECH 2 No.

3 19” COMPONENT SHELF WITH WITHDRAWABLE TRAY SAME AS (1) ABOVE 1 No.

4 EARTH BUS BAR 25 x 3 sq.mm OR EQ. WITH M10 NUT AT BOTH SIDES OF PANEL AARTECH 1 No.

5 MCB (2 POLE / 6A / 240VAC) SIEMENS / MDS 1 No.

6 CONTROL FUSE : NS TYPE HRC FUSE LINK WITH BASE (10A (F1,F2), 4A(F3,F4), 2A (F5,F6,F7,F8), ) SIEMENS 10A(2),4A(2),

2A(8)

7 ON/OFF SWITCH (5A/240VAC) / SOCKET ISI MARKED 3+1

8

AUXILIARY RELAY 3TH30 TYPE SICONT PLUS CONTACTOR RELAY WITH NO/NC AUX. CONTACTS

COIL VOLTAGE 220VDC CONTACT CONFIGURATION: 4NO/2NO+2NC

SIEMENS AS Reqd

9 TERMINAL BLOCKS: STANDARD TB - CSTSB4 PT & OUTPUT CKTS - DISCONNECTING TEST TYPE CDTTS

CONNECTWELL As Reqd

10 ROTARY SWITCH ( 16A / 250V AC/DC) WITH

75 x 75 mm INDICATING PLATE & WING TYPE KNOB S4: 2 POLE 2 WAY WITH CENTRE OFF

SWITRON 1 No.

11 SPACE HEATER (75W/230V AC 50Hz) PRAVEEN/GIRISH 1 No.

12 ENCLOSURE LIGHT (14W/230VAC 50 Hz) PHILLIPS / EQ. 1 No.

13 DOOR OPERATED SWITCH SIEMENS 1 No.

14 THERMOSTAT (30-85 DEG C) GIRISH/ NOOTAN 1 No.

15 PCB MODULE AARTECH 2 Nos.

Table 2: Bill of Material (BOM)

3.3.5 BTS 2000 Main Module Front Panel

Sheet No. 5 describes the front panel of BTS 2000 Main Module. Aartech’s BTS 2000 Main Module is based on the Edison Idea Plus platform of M/s Cooper Power Systems USA. Edison Idea Plus is a programmable 32 bit microprocessor based relay platform. BTS 2000 Main Module front panel interface provides access to status information by means of LED indications, illuminated pushbuttons and LCD menu interface. Front RS-232 dataport is used to access data for digital communication and various software enabled analysis. BTS 2000 Main Module front panel interface provides all necessary control functions such as menu navigation, BTS IN/OUT service toggle, BTS readiness disable fuse, transfer direction selection, transfer mode selection, test and manual transfer commands. Hot-key operations enable direct access to the commonly accessed HMI menus.

3.3.5.1 LED Indications

BTS 2000 Main Module front panel interface has 5 columns of LED indications, each having 5 LED indications each, programmed for the following functions:-



COL-UMN ROW COL-

OUR LEGEND DESCRIPTION HOT-KEY: FOR FURTHER INFO.

1 Green BTS READY BTS readiness conditions satisfied

2 Red BTS NOT READY BTS readiness conditions not satisfied HOT-KEY: BTS NOT READY

3 Red BTS BLOCKED BTS blocked. HOT-KEY: BTS BLOCKED

4 Red BTS TXFR FAIL Bus transfer failure. HOT-KEY: PREV. TXFR LOG

1

5 Red AUX. TRIPPED Slow transfer occurred – transfer bus motor

tripping on undervoltage likely. HOT-KEY: PREV. TXFR LOG

1 Red UNIT HEALTHY UNIT line PT healthy. HOT-KEY: METERING

2 Red UNIT I/C ON UNIT I/C breaker

indication

Steady ON : Breaker ON Blink: Breaker NO/NC

inconsistent Steady OFF: Breaker OFF

HOT-KEY: BTS NOT READY => BREAKER

CONFIGURATION

3 Red UNIT TIE ON

UNIT TIE

breaker indication

Steady ON : Breaker ON Blink: Breaker NO/NC

inconsistent Steady OFF: Breaker OFF

HOT-KEY: BTS NOT READY => BREAKER

CONFIGURATION

4 Red STN TIE ON STN TIE breaker

indication

Steady ON: Breaker ON Steady OFF: Breaker OFF

2

5 Red STN HEALTHY STN Bus PT healthy. HOT-KEY: METERING

1 Red FAST TXFR. CONDITIONS OK

BTS ready, transfer direction selected and fast transfer conditions satisfied. HOT-KEY: METERING

2 Red FAST TXFR BUS HEALTHY

Transfer direction selected and transfer bus is healthy for fast transfer

HOT-KEY: METERING

3 Red NEW SOURCE – BUS OK

Transfer direction selected and phase difference between new source and transfer bus is

healthy for fast transfer HOT-KEY: METERING

4 Red NEW SOURCE – BUS V OK

Transfer direction selected and magnitude of vectorial voltage difference V between new

source and transfer bus is healthy for fast transfer HOT-KEY: METERING

3

5 Red ANSI C50.41 CRIT. (V/F) OK

ANSI C50.41 criteria satisfied. magnitude of vectorial voltage difference

divided by frequency (V/F) between new source and transfer bus is less than 1.33 p.u.

1 Red BUS PT FUSE FAIL UNIT Bus PT Fuse failure HOT-KEY: BTS NOT READY

2 Red UNIT I/C NOT READY UNIT I/C breaker not ready. Trip/close circuit

monitoring failure. HOT-KEY: BTS NOT READY

3 Red UNIT TIE NOT READY UNIT TIE breaker not ready. Trip/close circuit

monitoring failure. HOT-KEY: BTS NOT READY

4

4 Red BKR. MON. FAIL Trip/close circuit monitoring failure for one or

more breakers HOT-KEY: BTS NOT READY



5 Red BKR.OPERN. FAIL Breaker operation failure during bus transfer for

one or more breakers HOT-KEY: PREV. TXFR LOG

1 Green PREV. TXFR OK Previous bus transfer OK. Bus transfer took

place as per transfer mode combination. HOT-KEY: PREV. TXFR LOG

2 Red UNIT => STATION Previous transfer occurred in

UNIT => STATION transfer direction HOT-KEY: PREV. TXFR LOG

3 Red STATION => UNIT Previous transfer occurred in

STATION => UNIT transfer direction HOT-KEY: PREV. TXFR LOG

4 Red PROT’VE/ AUTO TXFR Previous transfer occurred due to

Protective / Auto Transfer Initiation HOT-KEY: PREV. TXFR LOG

5

5 Red MANUAL TRANSFER Previous transfer occurred due to

Manual Transfer Initiation HOT-KEY: PREV. TXFR LOG

Table 3: LED Indications

3.3.5.2 LCD Menu Interface

The LCD menu interface consists of the following elements:-

1. A 4-line by 20-character backlit LCD display 2. A set of 4 context sensitive function keys F1 through F4 located directly

below the LCD. 3. Four menu navigation buttons (‘MENU’, ‘ENTER’, ‘+’ and ‘-’) 4. Four cursor movement arrow buttons (, , , ) 5. 8 hot-keys – white membrane pushbuttons arranged in two vertical groups on

the outside edges.

The information and controls viewable via the LCD are arranged in a hierarchical menu structure, which is navigated using the menu navigation and cursor movement pushbuttons. The hierarchical menu structure has cascading menus, such that when an item is selected from a menu list, a new list appears in which selected information is displayed, or from which additional selections can be made. The context sensitive function keys are only active in certain menus, and their function change from menu to menu. When these keys are active, their functions are indicated in the lowest line of the 4x20 LCD display. When the keys are not specifically activated by the menu systems, pressing any of the function keys has no effect. The menu navigation and cursor movement buttons have the following functions:- MENU: Pressing the MENU button ascends one hierarchical level HIGHER through the menu structure than the present level, until the top hierarchical level of the menu structure is reached. The MENU button can be used to abort a currently displayed control feature in a menu, simply pressing it to exit the menu item. Adjusting LCD Contrast: The contrast of the LCD can be changed by pressing and holding the blue MENU button along with the red ‘+’ or ‘-’ buttons to increase or decrease contrast respectively.



: Pressing the button moves the cursor (a “greater-than” sign “>”, on the left-hand side of the 4x20 display) UPWARD within a given hierarchical menu list. This continues until the button is released, or when the cursor reaches the top of the list. The cursor indicates the specific menu item upon which the ENTER key will operate if it is pressed. : Pressing the button moves the cursor DOWNWARD within a given hierarchical menu list. This continues until the list is released, or when the cursor reaches the bottom of the list. ENTER: Pressing the ENTER button descends one hierarchical level LOWER through the menu structure than the present level, until the bottom hierarchical level of the menu branch is reached. The ENTER button is not used to activate a control feature, but rather is only employed to either display information or enter another hierarchical menu level. When control functions are accessed through the LCD menu interface, the ENTER button simply allows the operator to enter the necessary control menu, wherein the context sensitive function keys are temporarily configured for the explicit control functions. HOTKEYS: The hot-keys provide direct access to various commonly accessed menus. This saves the operator from having to navigate to the menu of interest. The hot-keys have the following functions:- HOT-KEY MENU ITEM DESCRIPTION OF MENU ITEM ACCESSED BY HOT-KEY

OPERATOR INTERFACE

All operator related primary displays and controls. This enables the operator to see the snapshot status of the bus transfer system, reset a BTS blocked condition, select / deselect the test mode, conduct test transfers as well as live transfers and provide feedback of bus transfer operation success / failure during transfer.

ALARM Displays status of Alarms latched in BTS – Unaccepted/Persisting Alarms are in Blinking State Cleared and Accepted Alarms are in Static State - until Alarm Reset

BTS NOT READY Displays all the conditions for BTS readiness. All the conditions resulting in BTS non-readiness blink continuously. This enables the operator to quickly identify the cause of non-readiness

BTS BLOCKED Displays all the conditions for BTS blocking. All the conditions resulting in BTS blocking blink continuously. This enables the operator to quickly identify the cause of blocking.

TRANSFER DIRECTION

Displays the various transfer directions for the bus transfer system. Depending on the current breaker configuration, scheme settings and automatic selection logic based on system conditions, each bus transfer direction is marked by one of three flags - ‘0’, ‘1’, ‘*’. ‘0’ implies that the transfer direction is available, but not selected by the operator for manual transfer. ‘1’ implies that the transfer direction is available and selected by the operator for manual transfer ‘*’ implies that the transfer direction is not available to the operator for manual transfer. The fixed function pushbuttons with LED indications also indicate the selected / available transfer directions.

TRANSFER MODE

Displays the transfer mode combinations for conducting manual transfers for the bus transfer system. Depending on scheme settings each transfer mode combination is marked by one of three flags – - ‘0’, ‘1’, ‘*’. ‘0’ implies that the transfer mode combination is available, but not selected by the operator for manual transfer.



‘1’ implies that the transfer mode combination is available and selected by the operator for manual transfer. ‘*’ implies that the transfer mode combination is not available to the operator for manual transfer. The operator can use this menu to select the transfer mode combination if available. Alternately, the same can be done from the fixed function pushbuttons with LED indications.

METERING Displays the voltage magnitude and frequency values of the PT inputs and the vectorial voltage difference magnitude V and phase angle across all the breakers.

PREVIOUS TXFR LOG Displays the detailed log of the previous bus transfer operation. This log includes the detailed description of the transfer, system conditions at the instant of transfer and breaker operation timings.

Table 4: Hot-Key Functions

HMI PARENT MENU OVERVIEW: The HMI is comprehensively built around a descriptive hierarchical menu structure to simplify and ease operator use and understanding, by providing easy-to-follow textual instructions and relevant diagnostic information, activity logs and testing features.

HMI PARENT MENU HMI PARENT MENU ITEM FUNCTION OPERATOR INTERFACE METERING

[HOT-KEY SELECTABLE] See Hot-Key Description Above.

SELECT : -BTS [IN/OUT]- BTS IN OUT Status with operation instructions EXTERNAL ALARMS BTS [READY/NOT READY] BTS [BLOCKED/NOT BLOCKED] TRANSFER DIRECTION SELECT: TXFR MODE PREV. TRANSFER LOG

[HOT-KEY SELECTABLE] See Hot-Key Description Above.

TEST MODE Choice of Test Mode Selection, LAMP Test Display the Test Mode Interlock Log.

SCHEME IDENTIFICATION Display the Details of the BTS Scheme Installation. SOE VIEW Sequence of Events View CONTACT INS FOR FACTORY ACCESS ONLY CONTACT OUTS FOR FACTORY ACCESS ONLY TIME Display the Current Time of the Internal Clock

Table 5: HMI Parent Menu Overview

The contents of the menus are self-explanatory.

3.3.5.3 RS-232 Data Port

The BTS 2000 Main Module front panel has a 9-pin female D-Sub configured connector as an RS-232 DCE. A 1-1 male-female cable is required for PC connection.

3.3.5.4 Fixed Function Pushbuttons with LED Indications

BTS 2000 Main Module has 3 rows of 3 each fixed function pushbuttons with integral LED indications and are used for selection of the transfer mode combination and the transfer direction. The integral LED indications give visual feedback and guidance to the operator for the respective selections. Their functions are as follows:- COL-UMN ROW LEGEND PUSHBUTTON

FUNCTION LED INDICATION

TRANSFER MODE COMBINATION SELECTION 1 1 FAST MODE Selects respective o Blinks on selection of



1 2 SLOWMODE

1 3 MOMENTARY PARALLELING

2 1 FAST-SLOW MODE

3 1 FAST-INPHASE-SLOW MODE

transfer mode combination if

permitted by scheme settings

respective transfer mode combination until written in non-volatile memory.

o Steadily ON thereafter. o Automatically turns OFF

when another transfer mode combination is selected.

TRANSFER DIRECTION SELECTION

2 2

SELECT DIRECTION

-------------------------- UNIT=> STATION

2 3

SELECT DIRECTION

-------------------------- STATION => UNIT

Automatically selects respective transfer

direction if permitted by scheme settings and

current breaker configuration, as

indicated by its integral LED indication.

o Blinks when respective transfer direction is selected for manual transfer. Also blinks during protective / auto transfer in the respective transfer direction

o Automatically turns OFF when transfer direction is not permitted.

3 2 ALARM ACCEPT Accept Alarms o Blinks when alarms are

latched and unaccepted.

3 3 ALARM RESET Reset Alarms

o Remains steady incase alarms are latched until reset.

Table 6: Fixed Function Pushbuttons with LED Indications

3.3.5.5 Test and Transfer Illuminated Pushbuttons

The test pushbutton (GREEN) is used by the operator to conduct a test transfer. It is illuminated when BTS is ready, the operator selects a transfer direction and selects the test mode from the operator interface menu. On depressing the test pushbutton BTS 2000 conducts a fictitious bus transfer, which is indicated in the breaker status LEDs in Column 2. The transfer pushbutton (RED) is used by the operator to conduct a live manual transfer. It is illuminated when BTS is ready, the operator selects a transfer direction and the test mode is not selected from the operator interface menu. On depressing the transfer pushbutton BTS 2000 conducts a live manual bus transfer operation for the selected transfer direction.

Instruction Manual

3.4 Software Description

Section 3.4 illenvironment in which the ProView. The viewfeatures of ProView provide interface. The various settings of the bus transfer system are also enumerated here. There software scheme file for the BTS 2000 Main Module is BTSand needs to be loaded into Proview for emodule.

Instruction Manual

3.4.2 Loading the Program

Double clicking on the icon for the scheme fiProView and load the respective scheme. Alternately, ProView may be launched independently, and the concerned scheme file (*.ipe) can be specifically selected.



Click on the CONNECT button seen in ProView’s menu bar. This will bring up the Select Connections dialog box. Select the desir cycle to enable dropout of the anti pumping relay.ed connection method and press “OK”. For eg. if BTS 2000 is connected to the COM1 port of the PC, select the “Connect using Com 1” option. The CONNECT button’s appearance will change into a connection dialog box whose appearance will depend on the phase of connection ProView is in. In order to disconnect, simply click on the connection dialog box.

Incase a serial DB9 COM port is not available in the PC/Laptop – a USB-RS232 converter may be used. Some USB-RS232 converters may not be compatible to the timing requirements of ProView. Please check with Aartech for recommendation / compatibility of USB-RS232 converter incase of any connectivity problems.

After successfully connecting to the relay, ProView compares the contents of the RAM and the EEPROM of the connected relay to the version of the scheme currently loaded on the PC. This process can take upto 5 minutes, and its status is indicated by a progress indicator bar. The COMPARE button’s appearance is that of a comparison status indicator, and when clicked, provides the details of the ‘Same’ and ‘Different’ features of the two. A message dialog box indicates the result of the comparison. If the BTS 2000 scheme and the scheme file loaded on the PC match exactly, the operator is ready for using all the software tools. If the BTS 2000 scheme and the scheme file loaded on the PC differ, the operator may choose to download the scheme file loaded on the PC to BTS 2000. The same applies to the software settings as well. CAUTION: Download of scheme structure / settings will erase all event records and Sequence of Events (SOE) data, and will reset all accumulators and counters. Please insure that all event data is retrieved and that accumulator and counter values are recorded before downloading scheme. CAUTION: Do not download scheme structure / settings with BTS 2000 in service. Always disable critical trip/close connections before downloading. For further assistance in operating ProView, consult the Help section in the software menu. Refer to the ProView Help section menu option for a detailed ProView guide.

3.4.4 Software Operation Modes

3.4.4.1 Online Viewing

View Online is a special operating mode that links the BTS 2000 software scheme in the ProView software environment and the BTS 2000 hardware in nearly real-time communications. This allows the operator to observe the values of data being measured or calculated within the software scheme. After establishing communications with BTS 2000, and confirming that the BTS 2000 scheme and the scheme file loaded on the PC match exactly, click on the GO ONLINE button. The logics and the status of all the elements can now be viewed in the View-Online mode.

Instruction Manual

3.4.4.2

Bus transfer events are automatically recorded in manually uploaded to the PC using the software environment. These events can be replayed stepobserve the values of data being measured or calculated within the software scheme during the event. The effect of a change in settings can also be analysed during the event replay. After establishing communications with 2000 scheme and the scheme file loaded on the PC match exactly, click on the Manage > Oscillographic Events menu option. The top portion of the Event Manager is titled PC EVENTS, and provides the ability to load any event record previously been saved to disk, or of any event records as created in the Virtual Test Set (VTS) within ProView. The lower portion of the window titled DEVICE

Instruction Manual

The Virtual Test Settings are accessed using the The simulation settings can also be stored on disk and restored from disk by clicking on the MANAGE SIMULATION FILES After setting the simulation inputs, click on the Simulation Control Panel allows a stepwith breakpoints on the virtual test set timing setti

3.4.5 Software Tools : Display Menu

The Display menu provides the operator access to several useful software tools which give information regarding the scheme operation in the various operating modes discussed above.

Instruction Manual

Instruction Manual

The Display > to monitoring a bus transfer system, such as PT input voltage magnitudes, frequencies, phase difference across breakers etc., at regular intervals. The time period, duration and interval ofconfigurable in software. This data profile can also be written to a file for record. The data profiler offers an illustrative historical characteristic description of the various system quantities perti

Instruction Manual

3.4.5.9

The Display > Contact outputs. This offers a means to monitor the status of the control commands sent by BTS 2000 to the system in a viewtest set analysis.

Instruction Manual

3.4.6.1

The Settings > BTS 2000 settings files. Factory default settings for the scheme are stored in “Scheme_BTS

Instruction Manual

The simulation settings can also be storedon the MANAGE SIMULATION FILES

3.4.6.3

The Settings > ratings, voltage and deltafor the PT inputs.

Instruction Manual

3.4.6.5

The Settings > controller of specified here.

Instruction Manual



4 Installation Instructions On receiving the BTS panel, you are advised to install the same as per procedure prescribed. This will ensure that the panels will render the trouble free service they have been designed to offer.

4.1 Receiving, Handling and Storage

The panels must be inspected upon receipt even if they are not to be erected immediately. The panels are wrapped in corrugated sheet and waterproof plastic cover and packed in a plywood case. The front glass door is provided with a thermocol sheet for additional protection. A canopy is provided at the top for additional protection against rainfall. Immediately on receipt follow the procedure mentioned below: 1. Remove the plywood packing by removing the M.S. brackets provided at the

corners. Exercise caution while removing the plywood packing as the front of the panel has a glass door.

2. Remove the plastic cover, corrugated sheet & thermocol, and then open the panel. 3. Inspect the panel. 4. Report any loss or damage in transit to the carrier; lodge a claim if necessary and

inform us. 5. Replace all protective covering until erection work is started. 6. Cranes should be used for lifting and shifting. Lifting lugs are provided on top of

the panel for this purpose. 7. If the panel can not be installed in position soon after receipt, repack the panel. 8. Store all equipment indoor in a clean, dry and well ventilated place where

condensation can not occur. Storage out doors even when protected by tarpaulin is not recommended, since this could result in corrosion and malfunction of equipment when installed.

9. If there are any scratches on panel they must be touched up immediately to prevent rusting.

4.2 Floor Preparation and Erection

The panels must be mounted on flat level surface. An uneven foundation may cause misalignment of sections and hinged doors. The panels have an integral base frame of 140mm height, bolted to the structure to facilitate erection. The foundation plan is shown in the G.A. drawings of the panel and must be referred to before constructing any foundation for the panel.



4.3 Instructions before Energizing

1. Inspect the panel for tool, conductors and other foreign material and remove all such articles.

2. Use a vacuum cleaner to remove dust, small particles etc. Do not used air hoses which may contain oil, moisture on scale and result in redistributing the dust on other surfaces.

3. Wipe the insides, particularly the insulation surface, with clean cloth, do not use cotton waste.

4. Check all control circuit connections at terminal blocks, cable terminals, contactor, relay terminals. This is especially important after long period of storage.

5. Check all terminals for loosening of wire terminations due to vibrations during transit.

6. Plug all cable/wire entries and other unused entries. 7. Operate mechanism and make sure that the switch functions correctly. 8. Use a 500V DC megger to check for shorts and grounds. Do not used 1000VDC

megger. Disconnect any devices, such as electronic devices, solid state relays etc., which may be damage by megger voltages. Make sure that all shorting wires if used are removed. If the measured insulation resistance of the panel is less than 2 mega ohms, heat the panel by switching on the space heater, and/or illumination lamp in the panel. It will be found that at the beginning of drying processes the insulation resistance decreases due to moisture re-distribution and increases [after stabilizing at a minimum value for some time) to a maximum value.

9. When the maximum value of the insulation resistance has been reached it is safe to put the panel into service (Recommended minimum value of insulation resistance is 10 Mega ohms).

10. The individual components as well as completely assembled panel are subjected to High Voltage (HV) tests at different stages of manufacture/ assembly. Once megger results are satisfactory, repetition of HV test at site is not considered necessary. Repeated application of HV may cause deterioration of insulation properties. However if the test must be conducted it should be as per IS 8623 (85% of test voltage as specified in relevant IS specification should be applied). The voltage at moment of application must not exceed 50% of the final value. It must then be gradually raised to the final value. Ensure that the electronic devices and solid state relays are disconnected before commencement of HV test.

11. Ensure that the cable bends with in the panel have adequate bending radii to avoid excessive force on terminals. Vertical cable runs should be adequately supported to avoid stress on terminals due to weight of the cables.

12. Check that fuses are fitted in main and auxiliary circuits and the ratings are appropriate to the circuit.

13. Ensure that wires are not allowed to hang loose. Anchor them firmly preferably with plastic clamps.

14. Temporary connections made during testing should be removed. 15. A thorough check of protection scheme is essential before commissioning.



5 Commissioning Instructions

5.1 Pre-Commissioning Checks

1. Check for the tightness of all terminals inside the panel. 2. Check connections of the panel as per wiring diagram. 3. Check cable connections between panels as per interconnection diagram. 4. Check availability of AC supply, DC supply & PT Supplies. 5. Check fuse ratings as per designated values. 6. Check megger value after heater has been kept on for 4-6 hours particularly

during rainy season. Minimum megger value should be above 10 mega ohms. 7. Check operation of switch socket, door switch and illumination lamp. 8. Check thermostat operation by varying temperature on thermostat set at 40 deg C. 9. Check free operation of rotary switches.

5.2 Commissioning Procedure

Commissioning of the auto transfer panel is broadly divided into the following activities:-

5.2.1 Cold Trials

The cold trials are conducted with no loads connected to the bus. This procedure is carried out by simulating one or more PT inputs (from the available source PT inputs) and simulating all interlocks necessary to enable BTS readiness. The trials are carried out by verifying breaker operations on simulated bus transfer initiation by external protective relays.

5.2.2 Spin Down Trials

It is advisable to conduct a spin down characteristics trial of the typical motor load on a bus prior to a hot trial. This is usually done when the bus is scheduled to have a planned shutdown. A spin down characteristic is obtained by blocking the closing operation of the new source breaker, which results in the spin down of all the motors connected to the bus. The resulting voltage magnitude and phase decay characteristics of the bus due to the motor spin down reflects upon the nature of the motor loads. These are useful to decide on the most appropriate settings for the various modes of bus transfer.

5.2.3 Hot Trials

The hot trial conditions are conducted under live system conditions and is the final commissioning procedure. The trials are carried out by verifying breaker operations

Instruction Manual

on bus transfer initiation by external protective relays. The bus load during the hot trial should reflect the typical cunsuccessful hot trial may result in a bus dead condition, unit tripping and loss of generation.

5.2.4 Trial Procedure

The procedure for carrying out the trials is as follows: 1. Ensure necessary permits from oper2. Disconnect the test/disconnect terminals of all outgoing breaker trip/close contacts

to avoid system disturbance due to any mal3. Switch DC supply selector switch S4 to Source I / Source II as per source

availability. Verify that the



upload the event record from BTS 2000 and store in the events folder with unique filename for further analysis. Spin down trials: This operation will result in a dead bus condition and BTS 2000 will alarm breaker failure. Upload the event record and analyse the spin down characteristics of the bus. Reset BTS 2000 and abort further steps.

g) Repeat test and manual transfer for transfer direction STATION=>UNIT. h) Operate the external protective relay(s) for Unit Source Failure. Automatic

UNIT=>STATION bus transfer must take place between UNIT I/C and UNIT TIE. Upload the event record from BTS 2000. Analyse the transfer operation using the PREV. TRANSFER LOG hot-key.

i) A protective / auto transfer results in a BTS BLOCKED condition. Reset the BTS Blocked condition. Refer section 6.1.1 “Operator Interface – BTS Blocked Condition” for more details.

j) Conduct a manual transfer for transfer direction STATION=>UNIT. k) The scheme is now tested for all transfer directions. Conduct similar tests with

different transfer mode combinations. l) Conduct similar tests by simulating breaker operation failure condition for

different breakers in the system. Disconnecting a breaker trip/close connection will result in BTS non-readiness since the same is monitored. This can by bypassed for simulation purposes by connecting it to a dummy 220VDC auxiliary relay coil, with its negative terminal connected to switchgear DC –ve.



OPERATOR INTERFACE ----BTS BLOCKED----- RESET

F1 F2 F3 F4

OPERATOR INTERFACE ---BTS NOT READY---

F1 F2 F3

OPERATOR INTERFACE FAST-IN-PHASE-SLOW

F1 F2 F3 F4

6 Operating Instructions

6.1 Operating Procedure

The BTS panel is designed for automatic operation in case of Unit source failure conditions. However, the operator can use BTS 2000 to operate, analyse and review various conditions related to bus transfer using the rich and user friendly HMI. Press OPERATOR INTERFACE hot-key to go to the OPERATOR INTERFACE menu, designed to provide a simple utility interface to the bus transfer operations.

6.1.1 Operator Interface – BTS Blocked Condition

This indicates that BTS is blocked (eg. after auto transfer). Press BTS BLOCKED hot-key to go to BTS BLOCKED menu in order to investigate this condition. Press F3 to reset the BTS blocked condition. If the BTS blocked condition is present, this display overrides all other displays in the operator interface menu.

6.1.2 Operator Interface – BTS Not Ready Condition

This indicates that BTS is not ready. Press BTS NOT READY hot-key to go to BTS NOT READY menu in order to investigate this condition. If the BTS not ready condition is present, this display overrides all displays mentioned below in the operator interface menu.

6.1.3 Operator Interface – Transfer Mode Combination

The transfer mode combination selected for manual transfer operation is displayed here. The transfer mode combination can be selected from the various transfer mode combination selection pushbuttons with LED indications (bottom right). The LED for the selected transfer mode combination is ON. On selection

of another transfer mode combination, the respective LED starts blinking briefly before stabilising. The transfer mode combination is stored in non-volatile memory.



OPERATOR INTERFACE UNIT => STATION

TEST MODE LIVE IN OUT TXFR

F1 F2 F3 F4



F1 F2 F3 F4

OPERATOR INTERFACE UNIT=>STATION

TEST MODE TEST IN OUT TXFR

F1 F2 F3

6.1.4 Operator Interface – Selecting a Transfer Direction

A 2 breaker bus transfer scheme has only two possible transfer directions: UNIT=>STATION and STATION=> UNIT. BTS 2000 automatically selects the transfer direction based on current breaker configuration and system healthiness. In such a case, the respective transfer direction LED starts blinking and the direction is indicated in the operator interface menu. For eg. if the UNIT I/C is ON and the UNIT TIE is OFF, then the transfer directions UNIT=>STATION is available. If BTS is ready and tie line PT is healthy then UNIT=>STATION transfer direction is automatically selected and the display will be

as shown here. BTS 2000 is now ready to conduct a live manual transfer or a test transfer. The red illuminated pushbutton TRANSFER will turn ON. The transfer mode combination and transfer direction displays as described above toggle periodically to enable the operator to note both selections. The selection of the transfer

direction enables BTS 2000 to identify the transfer bus and the new source. The Column 3 LED indicate the corresponding sync check conditions. Ensure that the FAST TXFR CONDITIONS OK LED is ON, which confirms that fast transfer conditions are available. Troubleshooting: If a transfer direction selection gets reset automatically on selection, check the healthiness of the PT input of the new source. On selection of transfer direction, BTS 2000 checks the new source healthiness for BTS readiness. If the new source is unhealthy, this immediately results in a BTS not ready condition and resets the earlier selected transfer direction.

6.1.5 Operator Interface – Test Transfer

After automatic selection of the transfer direction, say, UNIT=>STATION, the operator interface display will be as shown. This display enables the operator to conduct a live manual transfer or a test transfer. The red illuminated pushbutton TRANSFER will turn ON.

To conduct a test transfer, first press F1 (TEST MODE IN). The display will now indicate TEST TXFR instead of LIVE TXFR. The BTS READY LED indication (Column 1) will start blinking. The red illuminated pushbutton TRANSFER will turn OFF and the green illuminated pushbutton TEST will turn ON.

Troubleshooting: If the test mode cannot be selected, check the operation of test mode relays R3 and R4 NC contacts of these relays open the path of the breaker trip/close circuits and insert resistances RES1-RES6 (PCB1). A breaker trip/close circuit monitoring failure, will result in a BTS not ready condition and reset the selected transfer direction as well. The TEST MODE Menu provides additional information for diagnosing this condition.



OPERATOR INTERFACE TEST TRANSFER OK!


F1 F2 F3 F4



F1 F2 F3 F4



F1 F2 F3 F4

OPERATOR INTERFACE LIVE TRANSFER OK!


F1 F2 F3 F4

Press the TEST pushbutton OR F4 (TEST TXFR) pushbutton. A fictitious transfer is indicated in the breaker status LED indications in Column 2. For a successful test transfer, the display will indicate TEST TRANSFER OK message. The previous transfer log hot-key can also be used to analyse the transfer log.

Troubleshooting: A test transfer failure will result in a BTS blocked condition. Press BTS BLOCKED hot-key to go to BTS BLOCKED menu in order to investigate this condition. Note that if ‘fast transfer / momentary paralleling’ transfer mode combination is selected and the required fast transfer / momentary paralleling system conditions are not present, a transfer failure will result and BTS will get blocked.

To deselect the test mode, press F2 (TEST MODE OUT). The display will now indicate LIVE TXFR instead of TEST TXFR. The BTS READY LED indication (Column 1) will stop blinking. The green illuminated pushbutton TEST will turn OFF and the red illuminated pushbutton TRANSFER will turn ON.

CAUTION:

BTS 2000 is now ready for live transfer !!!

6.1.6 Operator Interface – Live Transfer

After automatic selection of the transfer direction, say, UNIT=>STATION, the operator interface display will be as shown. This display enables the operator to conduct a actual manual transfer or a test transfer. The red illuminated pushbutton TRANSFER will turn ON.

CAUTION:

BTS 2000 is now ready for live transfer !!! Press the TRANSFER pushbutton OR F4 (LIVE TXFR) pushbutton. Verify the breaker status LED indications in Column 2 for bus transfer. For a successful transfer, the display will indicate LIVE TRANSFER OK message.

The previous transfer log hot-key can also be used to analyse the transfer log. The transfer direction automatically resets after a live manual transfer operation. Troubleshooting: A live transfer failure will result in a BTS blocked condition. Press BTS BLOCKED hot-key to go to BTS BLOCKED menu in order to investigate this condition. Note that if ‘fast transfer / momentary paralleling’ transfer mode combination is selected and the required fast transfer / momentary paralleling system conditions are not present, a transfer failure will result and BTS will get blocked. Also a breaker operation failure, such as trip failure of old source, close failure of new source will result in a BTS blocked condition.



6.2 Safety Precautions

1. Measure voltage to make sure that circuit breakers & switches are open. 2. Ensure that only qualified personnel are instructed and permitted to work at

energized panel. 3. Disconnect all critical connections by opening the test/disconnect type terminals

as a precautionary measure.

6.3 Maintenance Instructions

It is recommended that the maintenance instructions listed below be carried out regularly. 1. Check all terminations for tightness within three months of commissioning and at

least once every year. 2. Inspect all wiring for wear & cuts, replace if necessary. 3. Inspect all devices periodically to ensure that equipment is in working order. 4. Look for indications of over heating, arcing of insulation break down and replace

defective parts. 5. Ensure that all glands & doors are securely tightened to eliminate ingress of dust

and vermin. Inspect door gasket. Replace the door gaskets where necessary. Block all unnecessary gland cutouts.

6. Check the rating & sizes of protective fuses. 7. Ensure that earth wires are connected to main earth bar. 8. Ensure no tools or loose materials are left in side the panel. 9. Ensure periodic cleaning of the panel. 10. When the panel is not in use, it is advisable to use space heaters to prevent

moisture condensation in the panel. 11. Do not wire HRC link type fuses. Wire cannot sustain high faults and are liable to

explode or arc causing fire and failure. 12. Test all relays periodically for permissive / blocking conditions with reference to

the designated set points.

6.4 Troubleshooting Guide

6.4.1 ‘BTS 2000 reports a BTS NOT READY condition’

The BTS NOT READY hot-key on the HMI provides direct access to the readiness status menu. Any non-readiness condition is indicated by continuous blinking of the respective condition. Refer section 3.1.8 for more details. The BTS NOT READY conditions can be diagnosed and rectified as follows:- 1. BTS Status OUT: Ensure BTS service select toggle switch is in IN position. 2. Permissive I/L Fail: Refer Sheet No. 10. The series logics from UNIT I/C, UNIT

TIE and UNIT BUS PT and STATION BUS PT should be satisfied for permissive interlocks checking by BTS 2000. Accordingly, check proper feedback of all the



field readiness inputs on the respective terminal blocks for the scheme for diagnosing the permissive interlock failure condition.

3. Breaker Config. Not OK: Verify Breaker NO/NC contacts (Sheet No. 14) and LED target status indications for the breakers (Column 2). If NO/NC contacts are not consistent with respect to each other, the breaker status indications blinks.

4. New Source NOT OK: This is applicable if transfer direction is selected and new source is unhealthy.

5. BTS Blocked: Verify BTS blocked condition – Press BTS BLOCKED hot-key for more information.

6. Trip/Close Ckts Fail: Check status of “UNIT I/C /UNIT TIE Not Ready” LED indications and also identify exact trip/close circuit fail condition from HMI. Verify that all interlocks in the respective switchgear circuits are satisfied for continuous circuit monitoring.

7. Bus PT Fuse Fail: Verify if UNIT Bus PT fuse failure have operated.

6.4.2 ‘BTS 2000 reports a BTS BLOCKED condition’

The BTS BLOCKED hot-key on the HMI provides direct access to the blocking status menu. Any blocking condition is indicated by continuous blinking of the respective condition. After due observations, go to the OPERATOR INTERFACE menu and RESET the BTS blocked condition. Refer section 3.1.9 for more details. The BTS BLOCKED conditions can be diagnosed and rectified as follows:- 1. Protective / Auto Transfer: A protective (Unit Source Failure) / auto transfer has

occurred. Review the transfer using the PREVIOUS TXFR LOG hot-key. 2. Self Test Failure: Use the BTS BLOCKED menu to find the nature of the self test

failure – viz. power supply failure, RAM test failure, ROM test failure. Immediately contact TECH SUPPORT on occurrence of this condition.

3. Breaker Failure: A breaker failed to operate during a bus transfer operation. Note the identity of the breaker and nature of breaker operation failure (trip/close). Verify the healthiness of the breaker, its associated trip/close circuitry and operation timings at the earliest possible opportunity.

4. Transfer Failure: The last transfer request did not result in a successful bus transfer. This can occur due to many reasons such as system non-readiness, non availability of selected transfer mode(s) or breaker failure. Upload the event from BTS 2000 and do a detailed event analysis with reference to system observations.



7 Recommended Spares S.

NO. ITEM DESCRIPTION MAKE QTY

1

BTS 2000 BUS TRANSFER SYSTEM MAIN MODULE

TWO BREAKER UNIT-TO-STATION BUS TRANSFER SCHEME EDISON IDEA PLUS PLATFORM OF COOPER POWER SYSTEMS, USA

WITH HARDWARE MODIFICATION / CUSTOMISATION AND SOFTWARE ENGINEERING BY AARTECH

AARTECH 1

2 ONLINE TEST MODE PCB MODULE AARTECH 1

3 AUXILIARY RELAY 3TH30 TYPE

SICONT PLUS CONTACTOR RELAY COIL: 220VDC CONTACT CONFIGURATION: 2NO+2NC

SIEMENS 2

4 AUXILIARY RELAY 3TH30 TYPE

SICONT PLUS CONTACTOR RELAY COIL: 220VDC CONTACT CONFIGURATION: 4NO

SIEMENS 4

auto bus transfer scheme in power plants

Documents

bus transfer details

transfer analysis

bts inout selection

accompanying data

india telfax

control interface

power supply

closing supply control