HVI Track Circuits. Withdrawn Document Uncontrolled When Printed. Railway Group Approved Code of Practice GK/RC0756 Issue Two Date December 1998

Transcription

1 Synopsis This Approved Code of Practice details the planning, installation, testing, maintenance and fault finding procedures to ensure that the integrity of is maintained at all times. Approved by Keith Turner Standards Project Manager Authorised by Richard Spoors Controller, Railway Group Standards This document is the property of Railtrack PLC. It shall not be reproduced in whole or in part without the written permission of the Controller, Railway Group Standards, Railtrack PLC. Published by Safety & Standards Directorate, Railtrack PLC, Floor DP01, Railtrack House, Euston Square, London NW1 2EE Copyright 1998 Railtrack PLC

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3 Contents Page 1 of 2 Section Description Page Part A Issue record Distribution Health and Safety Responsibilities Supply A1 A1 A1 A1 Part B 1 Purpose B1 2 Scope B1 3 Glossary B1 4 Limitations B1 5 Introduction B1 6 Features B1 7 Principle of Operation B2 Part C Planning and Design 1 Introduction C1 2 Uses and Limitations C1 3 Different Forms of HVI Track Circuit C2 4 Design Principles C6 5 Arrangements for a Network of Track Circuits C10 Part D Components and Installation 1 Introduction D1 2 Bonding D2 3 Installation D2 Part E Instrumentation Description and Use 1 Introduction E1 2 Test Equipment E1 Part F Testing and Commissioning 1 Introduction F1 2 Cable Tests F1 3 Track Circuit Energisation F2 4 Drop Shunt Requirements F2 5 Limit Test F2 6 Electrical Stagger F2 7 Interference Tests F2 8 Table of Tests F2 1

4 Page 2 of 2 Withdrawn Document Section Description Page Part G Maintenance 1 Introduction G1 2 Service B Tests G1 3 Track Circuit Maintenence Record Card G3 Part H Fault Finding 1 Introduction H1 2 Sequential Testing H1 References Ref1 2

5 Page 1 of 1 Issue Record Part A This Approved Code of Practice will be updated when necessary by distribution of a replacement Part A and such other parts as are amended. Amended or additional parts of revised pages will be marked by a vertical black line in the adjacent margin. Part Issue Date Comments Part A One August 1994 Original document Part B One August 1994 Original document Part C One August 1994 Original document Part D One August 1994 Original document Part E One August 1994 Original document Part F One August 1994 Original document Part G One August 1994 Original document Part H One August 1994 Original document References One August 1994 Original document Part Issue Date Comments Part A Two October 1998 Revised document. Part B Two October 1998 Revised document. Part C Two October 1998 Revised document. Part D Two October 1998 Revised document. Part E Two October 1998 Revised document. Part F Two October 1998 Revised document. Part G Two October 1998 Revised document. Part H Two October 1998 Revised document. References Two October 1998 Revised document. Distribution Health and Safety Responsibilities Supply Controlled copies of this Approved Code of Practice should be made available to all personnel who are responsible for the design, installation, testing, maintenance and faulting of. In issuing this Approved Code of Practice, Railtrack PLC makes no warranties, express or implied, that compliance with all or any Railway Group Standards or Codes of Practice is sufficient on its own to ensure safe systems of work or operation. Each user is reminded of its own responsibilities to ensure health and safety at work and its individual duties under health and safety legislation. Controlled and uncontrolled copies of this Approved Code of Practice may be obtained from the Industry Safety Liaison Dept, Safety and Standards Directorate, Railtrack PLC, Railtrack House DP01, Euston Square, London, NW1 2EE. B1

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7 Page B1 of 4 1 Purpose 2 Scope 3 Glossary 4 Limitations Part B This Approved Code of Practice gives details of best practice in respect of GEC Alsthom High Voltage Impulse track circuits in order to achieve the requirements of GK/RT The contents of this Approved Code of Practice apply to all GEC Alsthom High Voltage Impulse track circuits and is to be read in conjunction with GK/RC0752. The definitions of terms used by Signal Engineers vary depending on the location in which they were trained. A full list of terms is given in GK/RC0752, Part B. Where job titles are used within this Approved Code of Practice to reflect the anticipated functional splits of responsibility relevant to technical competence, they should not be interpreted as actual job titles. The specific split of responsibility will be governed by a contractual framework, to which reference should be made. Catalogue Numbers shown within this document are not directly controlled by Railtrack and as such, will not be maintained and kept up to date. Although every effort has been made to ensure that these were correct at the time of publication, it is therefore recommended that your supplier is contacted and a check is made with regard to the accuracy of these catalogue numbers prior to use. Where references are made to other documents, a comprehensive list of these will be contained within the Ref section of this document. The information appertaining to these references was correct as of Issue 13 of the Railtrack Catalogue of Railway Group Standards 5 Introduction 6 Features The GEC Alsthom High Voltage Impulse (HVI track circuit is significantly different from other types of track circuit. It has features that are very beneficial in its application under certain operating requirements. Its design is based on the continental practice of centralised equipment rooms with remote lineside transmission. The HVI track circuit can only be used as a jointed track circuit and, dependent on the bonding configuration, can be used on electrified or non electrified lines. The track circuit requires a power supply for the transmitter, but a power supply is not required at the receiver/track relay. The high peak voltage used in the operation of the track circuit will break through railhead contamination and enable the track circuit to be satisfactorily shunted by vehicles. The HVI track circuit is immune to a.c., d.c., train borne electrical systems and external electrical systems. The performance of the track circuit can be affected by neighbouring HVI track circuits. This mutual interference is prevented in the design process by the provision of electrical stagger between adjoining track circuits. The track circuit settings are calculated during design, and are shown in the wiring diagrams. After the initial setting up, no further adjustments are required. Inherent in its operation, the HVI track circuit has a very long drop-away time and is categorised as Category C, requiring two slow-to-pick TPRs, or extra B1

8 Page B2 of 4 Withdrawn Document delay data in SSI. Reference should be made to GK/RC0752 Part D for interfacing details between adjacent track circuits. 7 Principle of Operation 7.1 Rail Voltage Waveform The HVI track circuit operates by applying a short high voltage impulse to the rails at relatively long intervals. The asymmetric operating waveform has the shape of a high peak voltage (termed the positive polarity. A proportion of this is reflected back as a reverse voltage of much lesser amplitude (termed the negative polarity. The amplitude ratio of the polarities is typically 7:1, a typical feed end rail voltage waveform is shown in Figure B1. 330ms 1.5ms 8ms 7X X Figure B1 7.2 Feed End A basic representation of how the equipment is arranged is shown in Figure B2. The waveform is generated by charging a capacitor to a high voltage and then discharging it through a thyristor and matching transformer into the track. The inductance of the feed and relay end transformers, together with that of the rails, causes the positive pulse to be followed by a negative undershoot. The transmitter is fed from a Power Supply Unit (PSU, which requires a 110V 50W a.c. power supply, from which the current is constant whether the track circuit is occupied or not. The design of the transmitter ensures that the waveform is not reflected back to the power supply. 7.3 Track Equipment The operating waveform requires connection to the rails through a track transformer. On electrified lines, the track transformer requires a protective resistance in series with the track winding to prevent the traction current saturating or damaging the winding. This resistance has scope for adjustment, but in the British application, adjustment is not required. 7.4 Receiver/Relay End At the receiver/relay end, the energy from the track transformer is rectified and directly drives the track relay, hence a power supply is not required at the relay end. The positive and negative parts of the waveform are rectified separately and applied to different windings on the relay. The relay has a magnetic circuit which ensures that it can only pickup if the applied voltages are in the correct ratio (ie. the track waveform is correct. B2

9 Page B3 of 4 PSU Track Transformers TR Transmitter Receiver Figure B2 7.5 Traction Immunity HVI track circuits can only be applied in jointed form, and cannot be used successfully with impedance bonds currently installed on Railtrack s infrastructure, as they do not operate at a single frequency to which the impedance bond can be set to resonate. Therefore, where they are used in d.c., a.c. or dual electrified areas, they are installed as single rail track circuits. Note: Double rail HVI track circuits are currently under development and may be available for installation on Railtrack s infrastructure in the future. Parallel tracks are cross-bonded at regular intervals, so that the traction return current from an individual train will have a number of different parallel paths back to the source (substation or feeder station. This minimises the impedance to the traction supply and hence the volt drop, whilst it also limits the amount of current which can flow through an individual track circuit. However, under some circumstances, the vast majority of current from an individual train will pass through a single track circuit. Where traction return current flows through a single rail HVI track circuit, the majority of the current will flow in the traction rail, resulting in a voltage drop along its length. This voltage drop is proportional to the current, the track circuit length and the impedance of the rail. With a train shunt applied toward the feed end of the track circuit, this voltage drop can be presented across the signal rail and receiver end track transformer in series. Given the relatively low impedance of the signal rail then the great majority of this voltage will be applied across the track transformer, creating corresponding currents in the relay coils. Both transmitter and receiver are transformer coupled to the rails and the equipment is therefore isolated from d.c. traction currents in the track, or any d.c. interference offset. Very high levels of d.c. current can however lead to saturation of the track transformers and this therefore leads to a restriction on length. As described above (clause 7.1, the HVI track feed provides a series of asymmetric pulses. At the receiver, the positive polarity and negative polarity voltages are rectified separately and fed to different relay coils. A particular ratio of these rectified currents is required to energise the relay. If the receiver is subjected to a.c. interference of sinusoidal form, the currents rectified into each coil match each other, and the correct ratio will not be achieved. The HVI track circuit is therefore inherently immune to a.c. traction currents. However, large asymmetric transients within the traction current (from either a.c. or d.c. supplies, can occasionally create the correct ratio of currents in the relay B3

10 Page B4 of 4 Withdrawn Document coils, leading to false energisation of the relay. In practice, the operate delay (800 ms minimum, due to the use of two slow-to-pick TPRs (to BR933 or extra delay SSI data, is sufficient to cope with transient interference, and wrong side failure of the track circuit is avoided. However, it is imperative that the length restrictions and interface requirements contained within this Approved Code of Practice are applied. These limits and time delays may require reassessment for the introduction of new types of rolling stock. Note: Tests have shown that NCO.RVT.600 receivers can be susceptible to high frequency (above 4 khz ringing of the a.c. electrification supply that is caused by phase angle control systems used by some types of rolling stock (eg. Class 373/2. A temporary modification to fit a 1µF capacitor across the receiver inputs has been made to HVI track circuits on (and within 500m of affected a.c. electrified lines, to provide protection until such time that a modification is made within the receiver unit itself. On fitting modified receivers, the external capacitor will be removed. To maintain satisfactory performance, the temporary modification requires two changes to the track circuit: the receiver tapping should be changed to 3 ; the maximum permissible drop shunt is increased to 3.2Ω. For details of the modification, see Special Inspection Notice GK/RT Electrical Stagger Since the waveform is considered to have positive and negative peaks, protection against IRJ failure can be obtained by ensuring that abutting track circuits have opposite polarities. B4

11 Page C1 of 11 1 Introduction Part C Planning and Design This Part describes the planning and design constraints that apply to HVI track circuits. This Part should be read in conjunction with GK/RC0752, Part D, which describes general planning and design criteria for track circuits. 2 Uses and Limitations The HVI track circuit is a jointed track circuit and can be used in S&C as well as on plain line. It is immune from d.c. and a.c. traction currents, although length restrictions and interface delay constraints need to be applied to avoid wrong side failures due to large traction transients. The high peak voltage of the track circuit waveform, means that the HVI track circuit can be used with advantage on track with poor rail surfaces. On a.c., d.c. and dual electrified lines, the HVI track circuit can only be used with bonding configuration SR, whereas on non-electrified lines, the track circuit may be used with bonding configuration DRDS, DRSS or CR (see GK/RT0252 and GK/RC0752, Part D. Where required for electric traction purposes, common rail through S&C can be considered as an acceptable cross bond between adjacent tracks. Note: The length restrictions and interface delay constraints currently applied, may require reassessment for the introduction of new types of rolling stock. Special considerations must be given to the installation of HVI track circuits when used with SSI equipment to avoid interference (see Clause 4.1. HVI track circuit components are relatively expensive (eg. when compared to say d.c. track circuits and its use has therefore been restricted to applications where its functional capabilities are of benefit (eg. S&C areas in dual electrified areas and where poor rail surfaces exist. 2.1 Track Circuit Lengths Line Maximum Minimum Dual electrified lines 200m 18.3m d.c. electrified lines 200m 18.3m a.c. electrified lines 300m 18.3m Non electrified lines (CR bonding 1200m 18.3m Non electrified lines (DRDS or DRSS bonding 300m 18.3m Minimum track circuit length must be increased to 30m for line speeds over 75 mph. 2.2 Track Circuit Interrupters Track circuit interrupters shoud not be directly wired in series with HVI track circuits. Refer to GK/RT0252 and GK/RC0752. C1

12 Page C 2 of 11 Withdrawn Document 3 Different Forms of HVI Track Circuit There are three different forms of the HVI track circuit, all of which use the common equipment/circuitry as listed: HVI track circuit for d.c. electrified lines; HVI track circuit for a.c. or dual electrified lines.; HVI track circuit for non electrified lines. C2

13 Page C3 of 11 BX110 3A AA PSU AN NCO EAT.115CA P2 D2 S2 AP P1 D1 S1 HVI Track Circuit on D.C. Electrified Lines Rails NX110 AP1 P1 D1 S1 P2 D2 S2 AP2 NCO EGT.600P AA TX C+ 1 TO 6 C- 1.15mm 2 Type A1 (1 (2 2c 2.5mm 2 (f Type C2 Maximum 500m AA FEED TRACK TRANSFORMER (1 ( A V+ TV.TH1 (2 R ( B C V- HVI Trackside Housing 2.5mm 2 (f Type C1 ER2.2 Resistor Maximum 80m AATR Relay NCO CV.TH2.404 V2+ V2- V1+ V1- V1+ V V AA RX Receiver NCO RVT.600 C+ C1- C2- Maximum 500m 1.15mm 2 Type A1 (1 (2 2c 2.5mm 2 (f Type C2 Maximum 500m (1 (2 ( ( AA Relay Track Transformer A B C V+ R TV.TH1 V- HVI Trackside Housing 2.5mm 2 (f Type C1 ER2.2 Resistor Maximum 80m a Power supply NCO EAT.115CA b Transmitter NCO.EGT.600P. c Track transformers TV.TH1. d Resistors ER2.2. e Receiver NCO RVT.600 f Relay NCO CV.TH2.404 Figure C1 C3

14 Page C 4 of 11 Withdrawn Document 3.2 HVI Track Circuit on A.C. and Dual Electrified Lines BX110 AA PSU 3A AN NCO EAT.115CA P2 D2 S2 AP P1 D1 S1 Rails NX110 AP1 P1 D1 S1 P2 D2 S2 AP2 NCO EGT.600 AA TX C+ 1 TO 6 C- 1.15mm 2 Type A1 (1 (2 2c 2.5mm 2 (f Type C2 Maximum 500m (1 ( A (2 ( AA Feed Track Transformer B C V+ TV.TH1 R V- HVI Trackside Housing 2.5mm 2 (f Type C1 ER2.2 Resistor Maximum 80m AATR Relay NCO CV.TH2.404 V2+ V2- V1+ V1- V1+ V V AA RX Receiver NCO RVT.600 C+ C1- C2- Maximum 500m 1.15mm 2 Type A1 (1 (2 2c 2.5mm 2 (f Type C2 Maximum 500m (1 (2 ( ( AA Relay Track Transformer A V+ B R C TV.TH1 V- HVI Trackside Housing 2.5mm 2 (f Type C1 ER2.2 Resistor Maximum 80m a Power supply NCO EAT.115CA b Track transformers TV.TH1. c Resistors ER2.2. d Receiver NCO RVT.600 e Relay NCO CV.TH2.404 Figure C2 C4

15 Page C5 of 11 BX110 3A AA PSU AN NCO EAT.115CA P2 D2 S2 AP P1 D1 S1 3.3 HVI Track Circuit on Non electrified Lines Rails NX110 AP1 P1 D1 S1 P2 D2 S2 AP2 NCO EGT.600 AA TX C+ 1 TO 6 C- 1.15mm 2 Type A1 2c 2.5mm 2 (f Type C2 (1 (2 (1 (2 Maximum 500m AA Feed Track Transformer ( A VA 40 ohms RESISTOR TV.TH.D2 RK.40 ( C VC HVI Trackside Housing 2.5mm 2 (f Type C1 Maximum 80m AATR Relay NCO CV.TH2.404 V2+ V2- V1+ V1- V1+ V V AA RX Receiver NCO RVT.600 C+ C1- C2- Maximum 500m 1.15mm 2 Type A1 (1 (2 2c 2.5mm 2 (f Type C2 Maximum 500m (1 (2 ( ( AA Receiver Track Transformer A B VA C TV.TH.D2 VB HVI Trackside Housing 2.5mm 2 (f Type C1 Maximum 80m a Power supply NCO EAT.115CA b Transmitter CO.EGT.600. c Track transformers TV.TH.D2 d Resistors ER2.2. e Receiver NCO RVT.600 f Relay NCO CV.TH2.404 Figure C3 C5

16 Page C 6 of 11 Withdrawn Document 4 Design Principles 4.1 Housing of Equipment It is preferable that the track relay is installed at or about eye level, to assist in the observation of its operating position. To minimise interference, the HVI track circuit equipment should be placed on the same side of the lineside apparatus housing as its track links. See Figure C4 for a suggested arrangement. HVI Receiver TC HVI TC Links Figure C4 The transmitter, receiver and relay units are mounted on plugboards fixed to mounting plates, which are rail mounted in standard lineside apparatus housing or equipment buildings. The mounting plates are two relays wide and 370mm long and it is recommended that a maximum of five mounting plates are installed side by side. The track transformers and, where required, resistors are mounted adjacent to their corresponding rail connection. They should be mounted in a trackside transformer housing or, for several local transformers, in a standard lineside apparatus housing. Where track transformers and resistors are mounted in HVI trackside housings, shielding of the terminals is not required. If they are housed in a standard lineside apparatus housing or equipment building then special shielding arrangements are required. This can take the form of a transparent Perspex sheet, which is removable for maintenance purposes. The nature of the oscillation produced by the HVI track circuit equipment is capable of interfering with SSI equipment by means of radiated electromagnetic interference or by capacitive coupling between the cables. The potential for causing right side failures exists thus reducing the reliability of the SSI data link. It is therefore recommended that: C6 a HVI track circuit transmitters, feed transformers, or cables connecting the transmitter equipment should not be housed in the same lineside apparatus housing as Mark 1, or Mark 11 SSI Trackside Functional Modules.

17 Page C7 of 11 b Where Mark III (or later SSI Trackside Functional Modules are housed in the same lineside apparatus housing as HVI track circuit transmitters, feed transformers, or cables connecting the transmitter equipment, then arrangements must be put in place to prohibit their substitution by Mark I or Mark II equipment. c SSI Interlockings and HVI track circuit equipment should not be installed in close proximity to each other. 4.2 Lineside Apparatus Housing/Equipment Building Wiring HVI track circuit internal wiring should be run separately from other equipment wiring. This should be specified on the appropriate wiring diagrams. All lineside apparatus housing wiring should be in standard 0.75mm² Type A cable, except the connections from the receiver and transmitter to their associated links which should be 1.15mm² Type A cable. 4.3 Track Cables The track transformers are connected to the rails by track cables. So that the resistance of 0.7Ω is not exceeded, the maximum cable length is 80m. The standard arrangement is four single core, 2.5mm²(f cables to GS/ES0872 specification, terminated as shown in Figure C Tail Cables The power supply, transmitter, receiver and track relay are connected to the track transformers by tail cables. The maximum length of tail cable is 500m. Each receiver should have its own tail cable, but, where advantageous, multiple transmitter feeds may be operated over a 2.5mm²(f, 2.5mm² or 1.5mm² multicore cable. Any multicore cable used for HVI track circuit transmission should not be used for any other purpose. The terminations are as shown in 4.5. C7

18 Page C 8 of 11 Withdrawn Document 4.5 Cable Terminations Transmitter End Electrified Lines Transmitter Terminal Transformer Input Transformer Output Rail C+ C- A B V+ V- +ve -ve Figure C5 Transmitter Terminal C+ C- Non electrified Lines Transformer Input A (via RK C Transformer Output VA VC Rail +ve -ve Figure C Receiver End Receiver Terminal C+ C1- Transformer Input A C Electrified Lines Transformer Output V+ V- Rail +ve -ve Figure C7 Non electrified Lines TC Length Receiver Terminal Transformer Input Transformer Output Rail <600m C+ VA B +ve C1- VB C -ve >600m C+ VA A +ve C1- VB B -ve Figure C8 C8

19 Page C9 of Transmitter Settings Designers should know the distance between the transmitter and the track transformer to an accuracy of 25m. This information is required to set the loop resistance of the tail cables and transmitter to approximately 20Ω using the adjustment terminals of the transmitter. These settings are calculated at the design stage, and are shown in Figure C9. Tail Cable Length (m Cable Resistances 2.5mm² 2.5mm² (f 2.0Ω 3.6Ω 5.4Ω 7.6Ω 2.0Ω 4.0Ω 6.0Ω 8.2Ω 1.5mm² 3.0Ω 6.0Ω 8.8Ω 12.2Ω Transmitter Terminal Straps C+ to 6 C+ to 5 C+ to 5 & 2 to 3 C+ to 6 & 3 to 4 Figure C9 Note: The transmitter terminal straps are not intended for on site adjustment. 4.7 Receiver Settings For track circuits on electrified lines the receiver should have terminals V and 2 linked together after initial resetting. For track circuits on non electrified lines, the receiver should have terminals V and 1 linked together. 4.8 Unit Wiring The wiring diagrams should show all inter unit connections as shown in Figure C1, Figure C2 or Figure C Fuses, Surge Arresters and Earthing The power supply for the transmitter should be fused with a 3A fuse to BS 714 or Def. Stan size 0. For all mains power calculations, the maximum power consumption is 50W at 110V a.c. The track circuit equipment is isolated from the rails by the track transformers as shown in Figure C1, Figure C2 and Figure C3. Since the track transformer can withstand any traction interference apart from a full traction short circuit current and as there is no viable fuse available which will break this current in time to protect the equipment, fuses are not fitted in the track leads. Any damage will, therefore, be limited to the track transformer. Because of the high voltages present, the track cable disconnection links in lineside apparatus housing/equipment buildings should be enclosed fuse holders fitted with links in place of fuses. Surge arresters are not required. The high voltages on the HVI track circuit can cause a reflexive shock, but do not directly endanger health. Therefore, earthing arrangements are not required. C9

20 Page C 10 of 11 Withdrawn Document 5 Arrangements for a Network of Track Circuits 5.1 Electrical Stagger The HVI track circuit should be arranged in order to provide a change of polarity across IRJs abutting adjacent HVI track circuits, the intent being that IRJ failure will prevent false operation with the track circuit occupied. The only permitted exception to this rule is at IRJs where two feed ends abut. 5.2 Mutual Interference On common rail networks (which include single rail traction return sections on electrified lines, to prevent a residual polarity building up on the common rail, there should be, as near as possible, an equal number of +ve and -ve feeds to the common rail. Although this should generally occur due to the electrical stagger, it should be checked. 5.3 Adjoining Other Types of Track Circuit The HVI track circuit has the potential to falsely energise d.c. track circuits (including diode track circuits, but not a.c. immune types or non-frequency selective a.c. track circuits (e.g. quick release track circuits. Therefore, the only permissible interface with non a.c. immune d.c. track circuits or non-frequency selective a.c. track circuits is at their feed end. As the relay of the diode track circuit is at its feed end, then the permitted interface is at the diode end only. Since this condition precludes intermediate interfaces between HVI track circuits and these types of track circuits, interfaces in S&C layouts are not permitted. 5.4 Operating Categories The HVI track circuit is category C (see GK/RC0752, Part D. C10

21 Page C11 of Contact Usage The contacts used in the track relay type NCO CV.TH2.404 are shown in Figure C10. M V1- V1+ V2- V2+ T1 T3 T5 T7 M1 M2 M3 M4 M5 M6 M7 M8 R2 R4 R6 R8 Track Relay (Rear View TR B N T1 M3 TR M1 T3 FRONT BACK CONTACTS CONTACTS M1 T1 M2 R2 M3 T3 M4 R4 M5 T5 M6 R6 M7 T7 M8 R8 Figure C10 C11

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23 Page D1 of 4 1 Introduction Part D Components and Installation The following is a list of all equipment and catalogue numbers. Unless otherwise stated, one of each item is required for each track circuit. The installation guidelines are outlined in this Part: Note: The Catalogue Numbers shown within this document are not directly controlled by Railtrack and as such, will not be maintained and kept up to date. Although every effort has been made to ensure that these were correct at the time of publication, it is therefore recommended that your supplier is contacted and a check is made with regard to the accuracy of these catalogue numbers prior to use. Description Catalogue No. PSU/transmitter end mounting plate, with : 86/43597 package of screws and contact labels (BRS-SM 440 T2 Relay/receiver end mounting plate, with : 86/43598 package of screws and contact labels (BRS-SM 440 T3 Plugboard type NS1.PFC12 for use with : 86/43909 NS1 style racking (7 per track circuit. Crimped Connectors - Faston type 110, : 86/43912 gold plated, bag of 1000 Crimp Tool, AMP part No : 39/08126 Key, occupation/securing : 88/23324 Power supply unit (NCO.EAT.115.CA : 86/43900 Transmitter for d.c. electrified lines only : 86/43907 (NCO.EGT.600P Transmitter for electrified or : 86/43921 non electrified lines (NCO.EGT.600 Receiver (NCO.RVT.600 : 86/43901 Track Relay (NCO.CV.TH : 86/43902 Track transformer for non electrified lines : 86/43903 (TV.TH.D2 (2 per track circuit Track transformer for electrified lines : 86/43904 (TV.TH1 (2 per track circuit Resistor for electrified lines : 86/43905 (ER-2.2 (2 per track circuit Resistor for non electrified lines : 86/43920 (RK (2 per track circuit Holder, Fuse 32A 660V : 86/13053 front connecting (4 per track circuit Link, Solid copper for Fuse Holder 86/13053 : 86/13065 (4 per track circuit Transformer box : 86/43922 (c/w mounting brackets D1

24 Page D 2 of 4 Withdrawn Document 2 Bonding 3 Installation The bonding arrangements for the HVI track circuit are detailed in GK/RT0252 and GK/RC0752, Part E. 3.1 Mounting Plates The plugboards are installed on vertical mounting plates, as shown in Figure D1. The mounting plates attach directly to the standard racking to BRS-SM 440 sheet G1. The standard racking should be placed 342mm apart (at variance with BRS-SM 440 to accommodate the mounting plates. Transmitter Label Track Relay Label Power Supply Label Receiver Label Transmitter Plate Receiver Plate Figure D1 D2

25 Page D3 of Equipment Mounting The equipment units are installed on plugboards, which aid replacement of defective units without wiring disconnection. Coding pins, similar to those used on BR 930 style relays, are used to ensure that the correct units are installed. The equipment units are secured by a lug which is turned from the front with the triangular key. The equipment will not operate correctly unless the locking mechanism is fully turned. In equipment buildings and lineside apparatus housings, cables to and from transmitters, receivers and relays should not be run parallel to cables carrying circuits for other electronic equipment, such as reed, TI.21 and SSI. This restriction does not apply to the power supply cables of the transmitter PSU. 3.3 Plugboards and Connectors The plugboards used are different from standard miniature relay plugboards. Up to three are used with some plug in units. The wiring does not connect directly to the contact springs but is attached using miniature automobile Faston connectors. Each connector takes one wire but each contact position can accommodate two connectors. The connectors are used with 1.15mm² and 0.75mm² Type A cable and should be crimped with the correct tool. 3.4 Transformer Equipment and Housings The track transformers should be positioned within 80m of their rail termination to avoid excessive circuit resistance. They are usually mounted in small trackside housings, the intended layout of equipment is shown in Figure D2. If mounted in standard lineside apparatus housings, special terminal shielding arrangements are required for safety. With reference to Part F, the trackside transformer housing constitutes a disconnection point and no other lineside disconnection point is required. There should be two trackside housings per track circuit, but each one can be shared with an adjacent HVI track circuit. In the trackside housing, it is good practice to install the type ER2.2 resistor upside down to aid wiring and to avoid excessive strain on the wires. It is not critical which way around the blue and brown wires are connected to terminals R and V- of the transformer. It is important to insulate the uncut green wire, as this is unused. Transformer TV. TH1 Transformer TV. TH1 Transformer TV.TH.02 Resistor RK Resistor RK Transformer TV.TH.02 Twin Resistor Block ER 2.2 Figure D2 D3

26 Page D 4 of 4 Withdrawn Document 3.5 Track Cables The track transformers are connected to the rails by track cables. So that the resistance of 0.7Ω is not exceeded, the maximum cable length from the transformer to the rails is 80m. The standard arrangement is four single core, 2.5mm 2 (f Type C1 cables to specification GS/ES The track cables are installed and terminated as indicated on the wiring diagrams. 3.6 Tail Cables The tail cables should not exceed 500m in length. Formal design changes will be required if the installed length is not as shown in the lineside apparatus housing wiring diagrams to a tolerance of ±25m. The transmitter and receiver wiring is connected to the tail cables on shrouded terminals. The tail cables may be run in the same external cable route as other signalling circuits. Note: As there are high voltages on the tail cable circuits, there should be no bare terminals on these circuits in equipment buildings or lineside apparatus housings. Therefore, the wiring from the outgoing/incoming links to the transmitter/receiver should be unbroken by terminal strips. If an intermediate termination is required, it should have shrouded terminals, as above, and a high voltage warning label. The tail cables are installed and terminated as indicated on the wiring diagrams. 3.7 Safety Labelling Due to the high voltage impulses present on HVI track circuits, it is necessary to install warning labels inside the lineside apparatus housing/equipment building for the purposes of staff safety. The warning labels depict a yellow triangle with lightning flash, as described in GK/RC0752, Part E, and are installed on: lineside apparatus housing / equipment building rack. Transmitter end racking; Power supply unit Transmitter; Outgoing links; Track transformer housing; Track transformer; Incoming links Receiver; Track relay; Receiver end racking; Shrouded terminals in lineside apparatus housings. D4

27 Page E1 of 1 1 Introduction 2 Test Equipment Part E Instrumentation Description and Use This Part describes the instrument particular to HVI track circuits. Details of more general test equipment are contained in GK/RT0752. An adaptor integrator is required for the measurement of the transmitted pulses. It uses capacitors to store the peak voltages of one polarity only and converts the waveform into a voltage level which may be measured by a digital volt meter (DVM on the d.c. auto range. To measure the opposite polarity, the test probes should be reversed. It is connected as shown in Figure E1. Description Catalogue No. Adaptor Integrator (French Design : 86/ High impedance voltmeter with shrouded probes : 40/ DVM dc auto Optional 2M2 Shunt For Faster Meter Discharge ITE No Other Terminals To Be Used Adaptor Integrator Rails Figure E1 E1

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29 Page F1 of 3 1 Introduction Part F Testing and Commissioning This part should be read in conjunction with the general information in GK/RC0752 Part G. Only special instructions for HVI track circuits are covered in this Part. The table of tests (Figure F1 should be referred to for the application of the tests and the results required. The test results should be recorded on the Track Circuit Maintenance Record Card (Part G. The Track Circuit Test Certificate should also be completed. There are some operations which are not required for the HVI track circuit; a dash should be put next to these tests. Note: Transmitters and power supply units should not be plugged in or unplugged, or straps changed whilst they are powered up. 2 Cable Tests The standard cable tests, as stated in GK/RH0730,GK/RH0740 and GK/RC0241, are now carried out. It should be noted that the HVI track circuit tail cables are not exempt from these tests, whereas the track cables are exempt. All cable problems should be found by the cable tests. However, if they are not found, the subsequent testing will highlight the faults, examples of which are shown below. 2.1 Crossed Connections between Transmitter and Receiver If any of the cables between the transmitter and receiver ends are crossed, the relay will not operate correctly. On energisation, the relay may pick up briefly but would then drop. The effect of such a cross is a reduction in the rail voltage (Test T4 when all links are inserted, however Test T5 will not show this fault condition. Typically, with track circuits of up to 600m a reduction in voltage of 25% at the feed end and 50% at the relay end will be found. Note: Without the receiver in circuit, this voltage will still be as expected. If the cross is at the feed end, the rail polarity will be the wrong way round. The voltage on the relay will also be reversed, with the higher voltage now on coil V1. Due to impedance mismatching at the relay coils, the lower voltage, now on V2, may be significantly reduced from that expected. 2.2 Crossed Connections between Receiver and Relay If the wires between the receiver and the relay are crossed, the relay will not operate correctly. On energisation, the relay may pick up briefly but would then drop. The higher voltage would again be on V1, with the same symptoms as above. If the wiring to one winding is crossed, the voltages (Test T3 will appear as expected, but reversed, and the relay will not operate correctly. The rail voltages (Test T4 should not be impaired. F1

30 Page F2 of 3 Withdrawn Document 3 Track Circuit Energisation Insert relay end, then the feed end links. Insert BX supply fuse to energise the transmitter. Check that the relay energises. Verify correct polarities to rail and confirm with the bonding plan. Verify the +ve polarity is connected to V+ or VA of both transformers. Measure:- The supply voltage & current (Test T6; The transmitter power (Test T7; The feed end voltage (Test T8; The pulse rate (Test T9; The relay voltage (Test T3; The relay end voltage (Test T4; The load capability (Test T5; 4 Drop Shunt Requirements For the general drop shunt (0.5Ω procedures see GK/RC0752 Part F. The drop shunt tolerances are given in Tests T1 and T2. The track relay will pulse before it drops away. It will then remain moving on its back contacts until the track circuit is shunted. Measure the drop shunt at the relay end track transformer (Test T1. Measure the drop shunt at the rails at the relay end (Test T2. 5 Limit Test 6 Electrical Stagger 7 Interference Tests The minimum drop shunt should be applied to the extremities of the track circuit. Details are contained in GK/RC0753 Part G. Where electrical stagger is required, verify the polarities of the rail voltages on either side of the IRJ, using the adaptor integrator. The only source of external interference will come from other HVI track circuit equipment. The interference tests require the track circuit under test to be de energised and all adjacent track circuits to be energised. Measure the unshunted interference (Test T10. Measure the shunted interference (Test T11. 8 Table of Tests The Figure F1 lists details of all tests specific to HVI track circuits. F2

31 Page F3 of 3 Test Description Electrified Lines T1 Drop Shunt Test at relay end track transformer track terminals. Min 1Ω Max 3Ω T2 Drop Shunt Test at relay end rails. Min 1Ω Max 3Ω T3 Relay Voltage Test at track relay plugboard contacts, using DVM on d.c. manual range. There will be a fluctuation in the reading. V1+ to V1- Min 20V Max 50V Non electrified Lines Min 0.5Ω Max 2.5Ω Min 0.5Ω Max 2.5Ω V1+ to V1- Min 20V Max 50V V2+ to V2- Min 30V Max 100V V2+ to V2- Min 30V Max 100V T4 Relay Voltage Test at track relay end track transformer track terminals, using adaptor integrator with DVM on auto range. The ratio of the +ve to -ve polarity should be in the range: V+ to V- Min 50V Max 150V VA to VB Min 20V Max 120V T5 Min 5 : 1 Max 10 : 1 Load Test at relay end track transformer track terminals with 0.5Ω shunt across the track terminals, using adaptor integrator. Min Max 8V 22V V+ to V- Min 10V T6 Supply Test voltage and current of mains, under full working load. Min 95V Max 121V Min Max 2V 12V VA to VB Min 6V Min Max 95V 121V Min 0.3A Max 0.5A Min 0.3A Max 0.5A T7 Test to be completed within 2 minutes T8 Transmitter Power Test between terminals 1 (+ve & 3 (-ve of the transmitter, with a short circuit between terminals C- and 6 of the transmitter. If any terminals 1 to 6 are strapped together, temporarily disconnect at one end. If any terminal other than 6 is connected to the outgoing links, remove the links. Use adaptor integrator. Feed End Voltage Test at the feed end track transformer track terminals, using integrator adaptor. The ratio of the +ve to -ve polarity should be in the range: Min 120V Min 120V V+ to V- VA to VC Min 50V Min 20V Max 150V Max 120V T9 T10 T11 Min 5 : 1 Max 10 : 1 Min Max Pulse Rate Test measured by touching the rear casing of feed end track transformer. Number of pulses in 7 seconds: Min 15 Max 30 Unshunted External Interference Test measured by disconnecting the PSU fuses. Voltage at track relay terminals, using a DVM on d.c. manual range. Shunted External Interference Test measured by disconnecting the PSU fuses and connecting a short circuit across the feed end transformer V+ V-. Voltage at track relay terminals, using a DVM on d.c. manual range. 8V 22V V2+ to V2- Max 10V V2+ to V2- Max 7V Min Max 2V 12V Min 15 Max 30 V2+ to V2- Max 6V V2+ to V2- Max 7V Figure F1 F3

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33 Page G1 of 4 1 Introduction Part G Maintenance This Part details the requirements for maintenance of HVI track circuit equipment. The general physical examination of the track circuit is the same as for other types of track circuit and can be found in GK/RC0752 Part H. No adjustments can be made to the HVI track circuit during maintenance visits. It does, however, have components whose performance can be expected to change. The performance of these components is tested during periodic maintenance to ensure that they remain within levels which will avoid failure of the track circuit. This section gives more details of the maintenance requirements of the HVI track circuit, how measurements are made and what conclusions may be drawn from the results. The conclusions may be used to take immediate remedial action to prevent a developing failure. The values should be noted on the Track Circuit Maintenance Record Card, an example of which is shown in Figure G1 and Figure G2. Note: Transmitters and power supply units must not be plugged in or unplugged, or straps changed whilst they are powered up. 2 Service B Tests Service B comprises the following tests (see Part F and GK/RC0752, Part H: T1 Drop Shunt Test; T3 Track Relay Voltage; T4 Relay End Track Transformer Voltage; T5 Current at Relay End Track Transformer; See Figure F1 for maximum and minimum values of tests. 2.1 Test T1: Drop Shunt Test The drop shunt test is taken on the relay end track transformer track terminals. 2.2 Test T3: Track Relay Voltage The track relay voltages V1 and V2 will indicate the correct functioning of the receiver, and will vary inversely proportional to the drop shunt value (ie. as the track voltage rises the drop shunt will fall. Track relay voltages which are near the minimum, while the drop shunt remains low, would indicate a developing fault of the receiver. It is recommended that the receiver is changed to see if this will bring the track relay voltage and drop shunt back into correspondence. Track relay voltages which are near the maximum, while the drop shunt remains high, would indicate the transmitter not producing the required waveform. It is recommended that the transmitter is changed to see if this will bring the track relay voltage and drop shunt back into correspondence. G1

34 Page G 2 of 4 Withdrawn Document 2.3 Test T4: Relay End Voltage The rail voltage is a measure of the energisation level of the track circuit. It will change inversely proportional to the drop shunt value and will be affected by the same factors. Values of the relay end voltage towards the maximum should be accompanied by higher limit values of track relay voltage (T3 and lower limit values of drop shunt (T1. Values of the relay end voltage towards the minimum should be accompanied by lower limit values of track relay voltage (T3 and higher limit values of drop shunt (T1. If the rail voltage is high and the drop shunt is high, it indicates that the transmitter is providing an unsatisfactory waveform. It is recommended that the transmitter is changed to re establish the inverse correspondence between the rail voltage and the drop shunt value. 2.4 Test T5: Current Provided by Equipment The ability of the transmitter to provide power to the track circuit may be checked by measuring the current at the relay end. As the instrument for measuring the waveform will only measure voltages, it is necessary to pass the current through a 0.5Ω resistor to measure a representative voltage. The value of this voltage is individual to each track circuit, being affected by length, the length of its tail cables and the complexity of S & C work. Therefore, the measurement is important as a basis for comparison rather than as an absolute value. The voltage measured at the maintenance visit should not differ by ±3V from the commissioning result. If the test voltage is satisfactory, but the rail and track relay voltages are low, then it is likely that the track circuit is being shunted by poor ballast or debris, and it should be examined. If the test voltage is low, but the rail voltage is satisfactory, it is likely that the track circuit bonding or tail cables are becoming defective and they should be examined. G2

35 Page G3 of 4 3 Track Circuit Maintenance Record Card Figure G1 G3

36 Page G 4 of 4 Withdrawn Document Figure G2 (Reverse of Figure G1 G4

37 Page H1 of 7 1 Introduction Part H Fault Finding This Part deals with the diagnosis and repair of failures on HVI track circuits. It should be read in conjunction with GK/RC0752 Part J, which explains how to define types of failure present. Staff who are not experienced with HVI track circuits, should familiarise themselves with the tests (Figure F1 and sequential testing before commencing actual fault finding. 2 Sequential Testing This fault finding procedure is based on sequentially testing the equipment and wiring to isolate the location of the fault in a manner which minimises movement from one test location to another. There is no standard order in which to isolate the fault, each case must be dealt with on its own merits. In each case, if one test cannot reveal the failure then another test must be undertaken as directed. It will be instructive to consult the Track Circuit Maintenance Record Card to see which readings have dramatically changed, thus giving an indication as to the source of the failure. As the HVI track circuit has proved to be very reliable in service, only common items (eg. fuses, resistors and bonding equipment need to be taken on site. It is recommended that a minimum of a transmitter, track transformer and a relay are close to hand. Using the Table of Tests (see Figure F1 and the Test Diagrams 1 to 4 (Figure H1, Figure H2, Figure H3 and Figure H4; it should be possible to locate the fault with the aid of the following instructions. 2.1 Relay Voltage Test : Test T3 This test is to check whether the track relay is faulty: Result (a: Both voltages are within specified limits. Action: Replace Track Relay. Result(b: One or both voltages are low or absent. Action: Proceed to (Test T3a: Receiver Output Voltage Test. 2.2 Receiver Output Voltage Test : Test 3a (See Figure H1 This test is measured at the output of the receiver on V1+ to V and V2+ to V respectively. The expected results are identical to Test T3 above: Result (a: Voltage is within specified limits. Action: Check wiring between receiver and track relay for disconnection or high resistance. Result (b: Voltage low or absent. Action: Proceed to (Test T4 Relay End Voltage Test. H1

38 Page H 2 of 7 Withdrawn Document 2.3 Relay End Voltage Test : Test T4 This test is to check whether the failure is at the feed end or the relay end of the track circuit. Result (a: Voltage within specified limits. Action: Replace track transformer/resistor.if failure remains, replace receiver; if failure still remains, check wiring/cabling. Result (b: Voltage absent. Action: Check bonding/cabling: Possible bonding disconnection. Result (c: Voltage is below specified limits. Action: Further test required; disconnect resistor from R terminal of track transformer If voltage remains low, it is possible there is a short circuit on the track. If the voltage increases, it indicates that the fault is within the relay end equipment. Result (d: One or both polarities remain below specified limits Action: Proceed to (Test T5 Load Test. 2.4 Load Test : Test T5 This test is to check the voltage at the relay end while the track is under load. This will prove the electrical integrity of the track circuit bonding. Result (a: Voltage is below specified limits or greatly below previous readings. Action: Proceed to (Test T6 Supply tests. Result (b: Voltage is within specified limits. Action: Check insulations in the track circuit. 2.5 Supply Tests : Test T6 This test is to check that the supply voltage is correct, the supply fuse is intact and the equipment is drawing the correct load current. Result(a: Voltage is incorrect. Action: Inform Supervisor, as further tests unrelated to track circuit fault finding will be required. Result(b: Supply current not between 0.3A and 0.5A. Action: Proceed to (Test T7 Transmitter Power Test. Result(c: Current is between specified limits. Action: Proceed to (Test T9 Pulse Rate Test. H2

39 Page H3 of Transmitter Power Test : Test T7 This test is to see whether the track circuit is being shunted. For electrified lines, disconnect resistor from terminal R of the track transformer. For non electrified lines, the track connections should be removed from terminal VA of the track transformer. Measure voltages as described for Test T7. Minimum voltage in all cases is 120V. Result (a: Voltages above specified minimum. Action: Inspect track circuit for poor insulation. Result (b: Voltages at or below specified minimum. Action: Proceed to (Test T8 Feed End Voltage Test. Note: Reconnect wire to track transformer terminal. 2.7 Feed End Voltage Test : Test T8 This test is to check whether the voltage on the output side of the transformer is within limits. Result (a: Voltage is below specified limits. Action: Replace transmitter Note: Damage may result if the mains supply is not disconnected. If failure remains, replace power supply unit. Result (b: Voltage is within specified limits. Action: Inspect track circuit bonding and rails. Result (c: Voltage is below specified limits. Action: Test for track circuit being shunted by insulation failure. Result (d: Voltage absent. Action: Check track transformer/resistor. 2.8 Pulse Rate Test : Test T9 This test is to check whether the pulse rate is within limits. Result (a: Number of pulses not within specified limits. Action: Replace transmitter and/or power supply unit. Note: Damage may result if the mains supply is not disconnected. Result (b: Number of pulses within specified limits. Action: Proceed to (Test T8 Feed End Voltage Test. H3