Notes On Diado Block Instrument

CAMTECH/99/S/DAIDO/1.0

1

SINGLE LINE, HANDLE TYPE TOKEN LESS BLOCK INSTRUMENT (FM CODED) 1.

INTRODUCTION This Hand book covers the general requirements of, Single line, Handle type Token less Block Instrument for use in RE & Non-RE sections. A pair of Block Instruments is connected electrically through overhead or cable to control the movement of trains on single line Block Section in either direction. The Instrument is designed to work on Frequency Modulation (Carrier frequency 1800 Hz or 2700 Hz and modulating frequency 65 Hz and 85 Hz).

1.1

Advantages over Token Block Instrument : 1. 2. 3. 4. 5. 6. 7.

Less operating time. No Token exchange. Less physical strain. Problems like token missing, token balancing, census of token, recoupment of lost token or damaged token etc. are not encountered. Avoidable detention is minimized. Increase section capacity Maintaining normal polarity/Reverse Polarity of Block instrument is not required.

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2.

3

SYSTEM COMPOSITION The Block instrument is compact & robust in construction and fit to stand for rough handling. It is easy to maintain. Removal/ replacement of any part or sub-assembly does not disturb the adjoining parts/ sub-assemblies. The following components are provided within the Block Instrument: Bell

Galvo Block phone

Time Release 1

COUNTER

Train On Line Indicator

2 PB2

2

PB1

LINE CLOSED S1

N

S2

SM SH

S/ Line Tokenless B/Instrument

TGT

Block Handle TCF

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2.1

5

Block Handle : A mechanically operated rotary type handle, called Block Handle is located in the front on the lower part of the Block instrument. Different contact positions of the handle are shown in figure given below:

X

N

Y

XI

YI

B L

D

A

R

VARIOUS POSITION OF BLOCK HANDLE L AB

X1

X

N

Y

Y1

D

LOCK PAWL

FORCED DROP PROJECTION

FORCED DROP PROJECTION

FORCE DROP LOCKING ARRANGEMENT S/ Line Tokenless B/Instrument (DEVELOPED VIEW) December’ 1999

R

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2.1.1 The handle is free to be turned between X and Y, R and D and also between L and B. Movement of the handle to Train Coming From, Train Going To and back to Normal position from Train Coming From and Train Going To is controlled by an electric lock and this lock is required to be energized at Y position for turning handle to Train Coming From and at D or B position for turning from Train Coming From or Train Going To to Normal. For turning to Train Going To, the lock is initially energised at X position but gets forced dropped before X and is actuated at X position for further movement to Train Going To. The locking effective at X is termed as check locking and is provided to ensure the conscious cooperation of the operator at the other end. This locking is however not effective while turning the handle from Train Going To normal even though the lock is forced dropped. It is because of the beveled edge of the concerned notch on which the lock just slides over and does not cause an obstruction to the movement of the handle. The block handle assembly consists of 24 sets of spring contacts (circuit controller), actuated during the course of handle of operation. 2.1.2 Need for Forced Drop Arrangement When the lock gets energised then the handle is free to move from Normal to Train Coming S/ Line Tokenless B/Instrument

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From/Train Going To position depending upon the code that is received. Due to residual magnetism there is a possibility of lock armature to stick up, then the operator can normalise the block handle from Train Coming From/Train Going To. To avoid such type of irregular movement there is a need to lock the handle in respective position. The projection on the locking bracket ensure the forced drop of the lock coil so that the operator can not normalise the block handle, once it is turned to Train Coming From/Train Going To, with out cooperation of other operator. 2.2

Galvo Indicates incoming and outgoing DC current. The resistance of the coil is 18.2 ohms, working current is 110 mA and working voltage is 2 volt.

2.3

Time release Indication It is an electromagnetic indicator to indicate the maturity of Time Element Relay during cancellation of a line clear. The coil resistance is 200 ohms. Normally it shows white indication with words LOCKED and when operated it shows green indication with words FREE.

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2.4

9

TOL Indicator It is an electromagnetic indicator(magnetic latch type). It operates on entry of train in to block section at either of station. When the Block section is clear, it displays white indication and when the train enters into the Block Section on a line clear it changes to Red indication with writing “Train On Line” and it holds magnetically. The indicator again changes to white when block handle is turned from any position to line closed.

2.5

Switch S1 with counter Switch Sl is a two position switch. when operated to reverse it initiates the cancellation of line clear. The counter is used to register cancellation operation.

2.6

Switch S2 with counter Switch S2 is a two position switch. when operated to reverse it is used for normalising the instrument during a push-back operation of a train to the starting station. Push Back operation is performed immediately after reversing S2. The counter is used to register Push Back operation.

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2.7.

10

Push Button PB1 It transmits DC current for exchanging bell codes. When PB1 is pressed alone it transmit 1. DC (-ve) on Line 1 for Bell. 2. DC (+ve) on L1 for TOL acknowledgment. 3. The same button, when pressed along with PB2, is used for sending of operational code.

2.8

Push Button PB2 It is used in conjection with PB1 to transmit operational codes to permit the operation of block handle at other station. The code sent is frequency modulated code along with a DC (+ve) code. PB2 is pressed always along with PB1 to pickup PBPR, which in turn sends ; i) Frequency modulated code by switching on the Transmitter. ii) DC (+ve) on L1.

2.9

Single Stroke Bell It is mounted on the top of the instrument and is used for exchanging bell code signals i.e. It provides to receive bell code. The bell coil is

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wound to a resistance of 310 ohms and requires about 70 mA for operation. It sounds when BLR or NR picks up and used for exchanging Bell Code. 2.10

Buzzer Two electronic buzzers (BZ1 & BZ2) are provided in side the Block instrument. BZ1 - It is a dual tone buzzer & sounds at both stations when the train enters into the block section and stops after acknowledgment by the pressing PB1 at the train receiving station. BZ2 - It Sounds at the Receiving station on train arrival on proper reception signals and sequence. It stops by normalizing the Home Signal SM’s slide/lever.

2.11

SM’s Key To avoid unauthorised operation in the absence of SM. When this key is taken out the block instrument becomes inoperative for all functions except for: i) Reception of Bell Code. ii) Reception or transmission of TOL Code.

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2.12

12

Shunting Key This key is used as a shunting authority to shunt in any direction beyond Last stop signal up to first stop signal of the station. It is normally kept inserted in the Block instrument. It can be taken out only when the block handle is in Line Closed or Train Going To position, and when taken out, the Block handle is locked mechanically in last position. The insertion and extraction of key can be done only when SM’s key is inserted and turned ON.

2.13

Transmitter It transmits a frequency modulated output (1800 or 2700 with 65 or 85 Hz) when the DC feed is connected to it by different selections. The modulated frequency is selected by the transmitter by an external loop completed through the relevant selection according to the condition of the block instrument.

2.14

Receiver

This receives the frequency modulated signals transmitted from the other end and gives DC output for energising either CR1 or CR2 depending on the modulating frequency of the code received. The S/ Line Tokenless B/Instrument

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receiver is switched on when the DC feed is connected through the relevant selections. 2.15

The block instruments are designed to work either on 1800 Hz or 2700 Hz carrier frequencies. The modulating frequencies are 85 Hz and 65 Hz and these are common for all the instruments.

The codes used in the Block Instrument are 2.15.1

1800 Hz or 2700 Hz modulated by 85 Hz with DC positive : To permit operation of block handle from line closed to Train Coming From, Train Coming From to line closed and Train Going To to line closed.

2.15.2

1800 Hz or 2700 Hz modulated by 65 Hz with DC positive : To permit operation of block handle from line closed to Train Going To.

2.15.3

1800 Hz or 2700 Hz modulated by 65 Hz : To set the other end’s Block instrument to “Train On Line”.

2.15.4

DC negative : For exchanging bell code signals. NOTE :

• DC positive refers to line battery positive connected to line 1 and negative to line 2.

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• 3. 3.1

14

DC negative refers to line battery negative connected to line 1 and positive to line 2. RELAYS NOMENCLATURES BLR It is a biased Relay and picks up when (+ve) on L2 and (-ve) on L1 is received from the line and the single stroke Bell sounds through the pickup contacts of BLR.

3.2

NR It is also a biased Relay and pickup when (+ve) on L1 and (-ve) on L2 is received from the line, Single stroke Bell sounds and lock magnet energised through its pickup contact.

3.3

PBPR Picks up when PB1 & PB2 are pressed simultaneously or only PB1 with TOLR pickup condition during TOL code transmission. It connects DC (+ve) on L1 and (-ve) on L2 and transmitter to the local Battery.

3.4

CR1 :

Coding Relay

3.5

CR2 :

Coding Relay

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3.6

TRSR :

3.7

1R

15

Train sending Relay

It proves the normal condition of reception signal’s and Last stop signal’s levers and SM’s slide. 3.8

1TPR This is a repeater of FVT Track Relay (ASTR).

3.9

TOLR : Train on line relay

3.10

2R Picks up after the complete arrival of the train with proper sequence.

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3.11

3R :

16

Cancellation Relay

When S1 is turned for normal cancellation, after a specified time (120 sec.) delay it picks up and the ‘FREE’ indicator energised through its pick up. 3.12

TEPR Once S1 is turned for normal cancellation the electronic timer relay gives output of 24 v after a specified time delay (120 sec.) which in turns picks up the TEPR.

3.13

Timer Relay It is an electronic Type Relay used for pickup of TEPR relay after 120 sec. time delay in case of normal cancellation.

3.14

TELR Telephone Relay of resistance 70 ohms, picks up when switch of hand micro telephone is pressed and in turns it connects the telephone on line and also disconnect the TX & RX from the frequency line.

3.15 3.15.1

External Relays : ASR : Advance Starter Relay

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3.15.2

HSR : Home Signal Control relay.

3.15.3

TAR : Train Arrival Relay SNR : Signal Normal Relay

3.15.4 4.

POWER SUPPLY Three sets of batteries are required : 4.1.

Line Battery Line battery is normally of dry cells. The voltage is varying from 24 V depending on the length of the block section in order to get a working current of 100 mA on line. This battery is connected on line whenever the DC is required to be sent either foe exchanging the bell signals or as a part of the operational code.

4.2.

Local Battery Local battery is of 24 Volt and is used for giving the supply to the transmitter and receiver and also operating relays, indicators, local magnets etc. of the instruments. Since the current drain on the battery is high, secondary cells are generally used. 4.3

Location/External Battery

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It is used for external circuits to repeat the external conditions to the instruments according to the requirements of the circuits. Picking up of PBPR, connects +ve to L1 & -ve to L2 and also switches on the DC feed for the transmitter. Since the block handle is in normal position, the loop circuit is connected for the modulated output is connected to the line. 5. 5.1

SPECIAL FEATURES Special features of Daido Tokenless Block Instrument are given below:

5.1.1 To ensure that the relays “NR” and “BLR” are not picked up simultaneously back contact of NR relay is proved in BLR circuit. Similarly in the PBPR circuit back contact of CR1 and CR2 relays have been provided to ensure that PBPR relay will not be energized. While receiving modulated frequencies. 5.1.2 Front contact of PBPR Relay has been proved in the DC feed circuit of transmitter, whereas back contact has been proved to the receiver circuit to guard against receiving its own F.M. output modulated frequency transmitted similarly, back contact of CR2 and CR2 relays have been proved in the DC feed circuit for transmitted to ensure S/ Line Tokenless B/Instrument

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that no code except the code of bell signals can be generated unless the code relays are de-energised. 5.1.3 Since TOL code has to be transmitted automatically as soon as a train occupies FVT, Front contact of PBPR Relay is not proved in DC feed circuit to the transmitter but the same is taken in TOLR Front contact NR Relay back contact with the block handle at L position. 5.1.4 Similarly for the receiver to be in readiness. To receive the TOL code, the DC feed circuit is taken via 2R Relay back contact with the block handle “R” position. 5.1.5 Pressed contact of the PB2 button in the DC feed circuit of the transmitter, proves the positive action taken to energise PBPR Relay for transmitting modulated frequency along with DC. 5.1.6 Block handle contacts (BX) and (DY) are included in the DC feed circuit to the receiver so that the DC feed to the receiver is switched on only. When the Block handle operation is initiated. Thus minimising battery consumption. 5.1.7 SM’s key contact has not been provided in the DC feed circuit of Transmitter for transmitting and receiving of automatic TOL code to ensure that the TOL indicator will display, immediately the block sections occupied irrespective of the position of the SM’s key. S/ Line Tokenless B/Instrument

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5.1.8 To ensure that the relay CR1 and CR2 are not be energised one at a time, back contact of CR1 relay is proved to energise CR2 relay and similarly back contact of CR2 relay is proved to energise CR1 relay. 5.1.9 Cross protection to the lock Magnet is given through the CR1 and CR2 back contacts.

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5.1.10 “Transmitter” and “Receiver” are connected to line through the back contact of TELR relay is ensure that during conversation on telephone, no code is transmitted or received by the transmitter and receiver respectively at either end. Similarly the telephone set is connected to the lines through the front contact of TELR Relay and TELR Relay feed is taken through the back contact of CR1 and CR2 relays to ensure that during Transmission and reception of Code the telephone is disconnected the back contact of TOLR is included in the TELR PICK UP circuit to ensure that the telephone circuit is disconnected the moment TOLR picks up to transmit TOL Code. 5.1.11 TOLR relay is made slow to release since its energising circuit is through the front contact of TRSR released stick circuit as through the back contact of TRSR relay. 5.2

POSITION OF RELAYS IN RELAY RACK TEPR PBPR TOLR IR

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CR1 BLR TRSR 2R

CR2 NR ITPR 3R

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5.3

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DIFFERENT COLOUR CODE FOR INTERNAL WIRING

COLOUR RED BLUE BLACK BROWN YELLOW GREEN WHITE

DESCRIPTION -

Local Source (+) Local Source (-) Block Line Circuit Relays circuit for Reverser Control Transmitter and Receiver circuit Relays and Lock magnet circuit Other circuit

6.

CIRCUIT DESCRIPTIONS

6.1

NORMAL POSITION : Normally, the Block handle is in center upright position, i.e. ‘Line Closed’ position. The SM Key is IN, shunting (SH) key is IN, cancellation switch (S1) and push back switch (S2) are in normal position. The TOL and time release indicator are white and the Galvo indicator indicates zero current position. In this case, all the relays except for ITPR and 1R are dropping away, with no current flowing in the block line and the concerned signals and levers are in normal position (Fig. 1).

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B1 24 V

10TPPR

5

15 1+

2- 55 45

10TPPR

BTPR 2

10NBPR 3 4 10 10LCC 1

N

N

N1 24V

2

1TPR

1 B1 24V

23

N

6

1+ 2- 56 46

N1 24V

1R

16

FIGURE 1 6.2

When a train is leaving A Station to B Station.

6.2.1 Turning the SM key to ON position at Station A completes a circuit. Push Button PB1 is pressed to give CALL ATTENTION Bell code signal to B station. A DC (-ve) current flows to B station in Line 1, to pick up the BLR at B station as per fig. 2 and fig. 3. B2

2 12

67 68

CHI

PPB1

SM

NR PBPR

• 1

N2 3 13 PBPR

1 R2 2

20 OHM/2W

2

2 PB1 2

3

PB2

6A 5A 6D 2/5D

35 25 L1 (-)

3

36 26 4 UF/160V

L2 (+) OUTGOING

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CIRCUIT AT A December’ 1999

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24

4 UF/160V

35 25

2

1

L1 PBPR

4/7B 8B

PB2

PB1

3

2

2-

1+ D2 26 PB1 NR PBPR

36 26

3

BLR BH-126

4

L2

6A 5A 6D 2/5D

INCOMMING CIRCUIT AT B

FIGURE 3

Now with the BLR picking up, a current flows to ring the BELL as per fig. 4.

B24V 61 62 224V 555858 24V

48 58

BEL L

BLR 2A 1A

21 N24 V

1

2 31 LOCAL CIRCUIT AT B

FIGURE 4 6.2.2

Upon receipt of a call attention at B station, SM inserts & turns SM key to IN. SM presses to

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acknowledge call attention signal from Stn. A. The circuit is same as described in Fig. 4 above. 6.2.3 Verbal communication for grant of Line Clear takes place between SM of Stn. A and Stn. B over block telephone. 6.2.4 Push Button PB1 and PB2 are pressed simultaneously at Stn. A to send the IS LINE CLEAR code. PBPR relay picks up as per fig. 5. B24V

61

62

SM CR1 PB1 PB2 CR2 1R

7D 8D 2B 1B

1

NR

PBPR

N24V LOCAL CIRCUIT AT ‘A’ 8B 4/7B

2

FIGURE 5 6.2.5 With the PBPR picking up at A the NR picks up at B station through the line circuit as per fig. 6 & 8. B2

2 12

67 68

CH1

PBPR

35 25

L1

N2

3

13

1 R2 2

OUTGOING CIRCUIT AT ‘A’ 36 26

PPBPR

L2 20 OHM/2W

1D 2/5D

FIGURE S/ Line Tokenless B/Instrument

6

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TX B 24 V

61 62

48

SM

1R PBPR PB2 TOLR CR1

3 4A 3A 4/7 D 3D 6A 2/5A 5D 6D 5D

58

1

6D

1 N

7

NR

+1

D1

18

8

31 34

1 2

37 TO ISOLATION TRANSFORMER LINE SIDE

FIGURE 7

-2

N24 3

4

5 6

21

PBPR

35 25

L1

BY-126

8B 4/7 B

R3 / 470 ohm 2 watt

PBPR

XY LB RD

6D

36 26 2/5 D

FIGURE 8

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6.2.6 An FM code is generated due to picking up of PBPR at ‘A’, which connects power to TX as per circuit in Fig. 7. The modulating frequency F1(85 Hz) is selected over terminal TX-5 & TX6 & modulated current flows to terminals 34, 37 to the line side isolation transformer ( in this case the input circuit to RX of same station is isolated by PBPR back contacts. 6.2.7 CR1 picks up at Stn. B on receipt of modulated current as per fig. 9. TX B24 V 42

61 62

48

SM

21

1R PBPR TOLR 41 BX DY

58

1

4A 3A 4/7 D 8D 5D 6D

3

N24

4

7

31

CR2 1+ 2+

TELR

CR1

5

1 2

PBPR

CR2

7A 8A 5B 6B

FIGURE 9

TO ISOLATE TRANSFORMER (LINE SIDE)

6.2.8 On getting the Bell & Galvo deflection at Stn. B, SM turns the block handle as far as Y point, S/ Line Tokenless B/Instrument

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Lock magnet picks up to releases the Block Handle, which can be turned to right position (Train Coming From position), as per fig. 11.

BELL B 24V 61 62

48 58

21

NR 4A 3A

1

2

48

SM

58

S1 N1 S2 CR1

N1 TEPR

R2

R1 21

NR N 24V

31

LOCAL CIRCUIT AT ‘B’

FIGURE 10

B 24V 61 62

N24 V

4/7B 3B

TRSRT

5D 6D 4/7B 8B 1A 8/5A 2

1

M

BX DY

31

CR1

2/5A 6A

FIGURE S/ Line Tokenless B/Instrument

11

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6.2.9 While the block handle is being turned from one to another position, the circuit controller contact (XY-RD-LB) of the handle in line circuit, in series with the relay NR is opened between the Y&D points.

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6.2.10

31

On opening of circuit controller contact in Line circuit, a resistance R3 to be added in series to line circuit with a resultant reduction in the volume of line current ( which remains substantially greater than the drop away current of NR). This cause a click on Galvo needle at both stations, making it possible for SM of button pressing station to know that the block handle has been turned. Then PB1 and PB2 at station A may be released (The same procedure is followed in operating the handle as subsequently to be described).

R3 (470 Ohm)

XY LB RD

6.2.11

PBPR 6D

•

2/5 D

After confirming that the Galvo needle has returned to zero position (indicating that A station has stopped sending a code of signal), PB1 and PB2 are now simultaneously pressed down at B station to send a code of signal to A station (Fig. II). PBPR relay picks up as per fig. 5. With the PBPR picking up at A the NR

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picks up at B station through the line circuit as per fig. 6 & 8. 6.2.12

An FM code is generated due to picking up of PBPR at ‘A’, which connects power to TX as per circuit in Fig. 7. The modulating frequency F2(65 Hz) is selected over terminal TX-5 & TX7 & modulated current flows to terminals 34, 37 to the line side isolation transformer Local and outgoing circuit at ‘A’ (Fig. 12,13 & 14) local and incoming circuit at ‘B’ (Fig. 15 to 16).

LOCAL AND OUTGOING CIRCUITS AT B

B24V

61

62

SM K CR1 PB1 PB2 CR2 1R

7D 8D 1B

1

2B

PBPR

8B 4/7B

N 24 V

2

FIGURE 12

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NR

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B2

2 12

67 68

CH1

33

PBPR

35 25

L1 +

3B 4/7B

N2

3

13

R2

PPBPR

36 26 L2 -

20 OHM/2W

1D 2/5D

FIGURE 13

TX B24 V CR2

61 62

48

21

SM k 1R PBPR PB2 TOLR CR1

3 4A 3A 4/7 D 3D 6A 2/5A 5D 6D 5D

58

1

6D

1

5

6 R

FIGURE 14 S/ Line Tokenless B/Instrument

2R

31

5 6 7

N24

4 TELR 1 2

34 4

1

37

2/5D 6D TO LINE SIDE TRANS

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LOCAL AND INCOMING CIRCUITS AT `A’ RX B 24 V

61 62

48

SM k

1R PBPR TOLR 41

42 BX DY

58

3

4A 3A 4/7 D 8D 5D 6D

21

31

7 8 CR2 1+ 2CR2

7B 8B

5

6

N24

4

34

TELR

2

4

1

PBPR

CR

37

7A 8A 5B 6B

TO LINE SIDE I.TRANS

FIGURE 15

18 NR

‘X’

BY-126

8

1

35 25

L1

8B 4/7 B

470 OHM/2W R3

PBPR

XY LB RD

6D

36 26

L2

2/5 D

FIGURE 16 61 62 61 6248 48 58 58 B 24V B 24V

NR NR

4A 4A 3A 3A S/ Line Tokenless B/Instrument

FIGURE FIGURE 17 17

BELL BELL 21 21

N24 N24 V V

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6.2.13

35

On getting the Bell & Galvo deflection at Stn. B, SM turns the block handle from N point to as far as the X point. At X point TRSR picks up & releases the lock on block handle by picking up lock magnet as per fig. 17 & 18. TRSR remains UP till X/ and later on sticks through its own front contact in LX/ position of Block handle. The lock magnet is once again required to be in picked up condition to release the block handle at check lock position at X/as per fig. 18 &19. R1

61 62

48

58 3R

CR2 NR ITPR 39

21

40 1+

XX/

B24

C1 1000 UF/60V

2-

N24

TRSR

7B 8B

31 TRSR ITPR

B 24V

48

37

38

LX

2/5 D 1D 2/5A SM 1R 2A S1 S2 TRSR 2R 3R

/

CR1 9

FIGURE 18 58

2A 1A

10 1 XX

2

M

N 5D 6D 4/7B 5B 6B 7A 8A 1A 2/5A

FIGURE 19

3B 4B

CR 2

6A 2/5A

S/ Line Tokenless B/Instrument

NR

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N24

31

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6.2.14

36

When Block handle is in Train Going To position, i.e., Line clear is granted, Last stop signal can be taken OFF by reversing the necessary controls like SM control on signal, Lever/ switch/ push button operation etc. Reversing of any of above control causes 1R to drop. An external relay ASR (Advance starter control relay) picks up as per fig. 20. With ASR picking up, it possible to take OFF the Last Stop signal.

B3 24V 65 66

1R

2R TRSR S1

17 N3

7D 6D

18

53 43 8B 4/7 B

HSR ASR

R3

FIGURE 20 6.2.15 Now the train can be sent into block section. On entry of train into block section, FVT track relay drops causing 1TPR to drop, thus releasing the stick circuit of TRSR to drop. Dropping of the S/ Line Tokenless B/Instrument

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TRSR causes the ASR to drop and replace the Last Stop signal to ON automatically. 6.2.16 With the 1TPR drop, the circuit of TRSR breaks , which drops with a time lag, but before its dropping, TOLR picks up as per fig. 21 through Path 1.

B24

61 62

6.2.17

When TRSR drops after the time lag, TOLR sticks through Path 2. the indicator TOLK and buzzer BZ1 are actuated through a branch of a contact LB, indicating a train departure (TOL). An additional Path 3 is provided to prevent the premature dropping of TOLR during transition, when other station is transmitting TGT code & CR2time NR TOLR 23 24picks up. It ensures that at the same D3 BY-126 TOLR will not drop LBbefore transmission of TOL 2B 1B 2/5B 1B code. Path3 A Normal contact of S2 switch is provided in 48 the stick stop the of TOL21 TRSR toITPR 13 transmission 14 3R circuit 1+ 2code, during a failure of its transmission or Path1 TOLR acknowledgment to silenceLBthe departure buzzer.N24 7B 8B 31

58

At this time the advance starter lever is restored to normal position. TRSR NR

TOLR S2

2/5 D 6D 7D 8D 4B 3B

Path2

N3 R3

BZ1

5

TOLK

S/ Line Tokenless B/Instrument XX’ YY’

December’ 1999

FIGURE 21

CAMTECH/99/S/DAIDO/1.0

B24 V 61 62

48

38

SM

TX 44 NR TOLR CR1

L

58 43

CR2

3 2/5D 6D 1A 2/ 5A 5D 6D 5D 6D 3R

TOLR

6D 5D 3A 4/7

4 L

N24

31

3

5 (c) 6 1 7

FIGURE 22

21 4

2

TELR 31

34

4 1

37

LINE SIDE I. TRANS

6.2.18

An FM code is generated due to picking up of TOLR at ‘A’, which connects power to TX as per circuit in Fig. 22. The modulating frequency F2(65 Hz) is selected over terminal TX-5 & TX-7 & modulated current flows to terminals 34, 37 to the line side isolation transformer ( in this case the input circuit to RX of same station is isolated by TOLR back contacts.

6.2.19

CR2 picks up at Stn. B on receipt of modulated code F2. The power to RX is connected through B24-fuse (61-62)- Terminals (48-58)-2R(B)-R. TOLR picks up as per fig. 24. With the TOLK

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39

and BZ1 operating through the same circuit as in A station to give an indication of train departure. Local and incoming circuit at ‘B’ (Fig. 23).

S/ Line Tokenless B/Instrument

December’ 1999

CAMTECH/99/S/DAIDO/1.0

B 24 V 61 62

40

RX

48

2R

45

21

46 3

58

7A 8A

R

7

CR1

7B 8B

6 CR2

34

31

8 5

N24 V

4

TELR

2

4

PBPR

1

CR2

37

7A 8A 5B 6B

TO LINE - SIDE I.TANS

FIGURE 23 6.2.20

SM of Stn. B, on getting TOL buzzer, presses push button PB1 to acknowledge the TOL code. PBPR at picks up as per fig. 5.

6.2.21

With the PBPR picking up, the NR picks up at Stn. B station through the line circuit as per fig. 6 & 8. Picking up of NR causes TOLR to drop & stop the buzzer. As the TOLK is a magnetic stick type, it maintains its TOL indication. (Refer Path 2 in fig. 21)

6.2.22

Dropping of TOLR at Stn. A, stops TOL code transmission by disconnecting power to TX. As the TOLK is a magnetic stick type, it maintains its TOL indication.

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6.2.23

41

CR2 drops at Stn. B & stops the buzzer .

48 B24 61 62 58

CR2

3R

NR

11

1+

R D

2B 1B 2/5B 6B

7B 8B

12

21

2TOLR

N24

31

D3 BY-126 .01 UF/100 V TOLR S2

TRSR NR

2/5 D 6D 7D 8D 4B 3B

BZ1 N3 R3

1

2

7A 8A 470 OHM/2W

47

R5

48

XX’ YY’

TOLR

220 OHM/2W

FIGURE 24 61 62 42

SM

B24 61 62

CR1 7D 8D

PB1 1

PB2

2

1

PBPR 2A 1A TOLR

19

20 PBPR

RD

21 B24

S/ Line Tokenless B/Instrument

FIGURE 25

NR

6B

4/7B December’ 1999 31

CAMTECH/99/S/DAIDO/1.0

42

6.2.24

A bell code for train departure is issued from A station and a answering signal is issued from B station. After departure of train bell code is exchanged.

6.2.25

At Stn. B, Reception signals are taken OFF. As soon as any of the control pertaining to reception signal is disturbed from its Normal position, 1R drops. Where SM’s control is not provided on reception signals, 1R back contact, in HSR and ASR circuit, is looped in instrument. The HSR picks up (Fig. 26). The home operates in the same way as advance starter.

B3 12V 65 66

1R

2R TRSR S1 N4

35

36 54

44

XY RD 7D 6D

7D 8D 4/7D 8D

R4 LA

ASR N3 12

HSR

2

FIGURE 26

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CAMTECH/99/S/DAIDO/1.0

6.2.26

On arrival of train at Stn. B, AT & BT tracks operate & sense the direction of travel of train. 2R picks up (Fig. 27) & sticks over LX/-RY. With the relay 2R picking up the HSR drops away and the home signal is automatically restored to normal position. At the same time a Buzzer BZ2 sounds to announce the train arrival. The buzzer can be stopped by restoring the SM slide or Home signal controls to their Normal position as per fig. 27.

R

R

B24

61 62

43

48 52

4

OUTER 2

TAR

R

7 17 TAR

2R

15

16

21

XX’ Y’

N24

2R 31

2B 1B

HOME SM SLIDE

R

3

4

BZ2

FIGURE 27 S/ Line Tokenless B/Instrument

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B 24

44

6.2.27

Stn. B verifies the e complete arrival of train & sends Train Out Of Section signal to Stn. A. who in turn replies to Stn. B by similar signal. Stn. B presses PB1 and PB2 simultaneously to transmit Line closed code (F1). PBPR picks up at ‘B’ station. ( see Fig. 5).

6.2.28

An FM code is generated due to picking up of PBPR at Stn. B, which connects power to TX as per circuit in Fig. 7. The modulating frequency F1(85 Hz) is selected over terminal TX-5 & TX-6 & modulated current flows to terminals 34, 37 to the line side isolation transformer.

6.2.29

With the PBPR picking up at Stn. B the NR picks up at Stn. A through the line circuit as per fig. 6 & 8. CR1 picks up at Stn. A on receipt of modulated current as per fig. 9.

42

1R

SM

1

3

3A 4A

4

TX 44 NR TOLR CR1 CR2

S/ Line Tokenless B/Instrument 43

5 (c)

2/5D 6D 1A 2/ 5A 5D 6D 5D 6D 6 R

2R FIGURE

28

2

21 December’ 34 1999 31

TELR 1 4

N24 TO

37

I. TRANS

CAMTECH/99/S/DAIDO/1.0

45

2/5D 6D

24 V

61 62

48

SM

1R

PBPR

TOLR BX DY

58

4A 3A 4

42

2D 5D 6D 41

1 RX 41 3

4

31 48

B 24V 61 62

58

SM 1R

7 1CR1 TELR S1 N1 S2 N2 TEPR TRSR 7 4 2 NR B

CR2 2A 1A 7B AB

DY

2

8

2 NR 21

CR2

M

N 5D 6D 4/7B 5B 6B 7A 8A 1A 2/5A

8

CR1

FIGURE 29

CR1

FIGURE 30

6A

TOLR

5B 4/7B

TO TRANS

5B 6B 21

47

XX’ YY’

48 1 R5 2

S/ Line Tokenless B/Instrument 220 OHM/2W

N24 TOLK

FIGURE 31

31

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46

With the NR and CR1 picking up Lock magnet is energised at B point of block handle as per fig. 30, making it possible to restore the handle to Line Closed position. TOLK release coil is energised to restore it Normal as per fig. 31. 6.2.30

SM at Stn. A presses PB1 and PB2 simultaneously to transmit Line closed code (F1). PBPR picks up at Stn. A as per fig. 5.

6.2.31

An FM code is generated due to picking up of PBPR at Stn. A, which connects power to TX as per circuit in Fig. 7. The modulating frequency F1(85 Hz) is selected over terminal TX-5 & TX-6 & modulated current flows to terminals 34, 37 to the line side isolation transformer.

6.2.32

With the PBPR picking up at Stn. A, NR picks up at Stn. B through the line circuit as per fig. 6 & 8. CR1 picks up at Stn. B on receipt of modulated current as per fig. 9. With the NR and CR1 picking up Lock magnet is energised at B point of block handle as per fig. 30, making it possible to restore the handle to Line Closed position. TOLK release coil is energised to restore it Normal as per fig. 31. The same procedure is followed when a train leaves B station from A station.

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December’ 1999

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S/ Line Tokenless B/Instrument

47

December’ 1999

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6.3

48

CANCELLATION OF “LINE CLEAR” BEFORE A TRAIN ENTERS THE BLOCK SECTION :

6.3.1 When a line clear has been taken by Stn. A, i.e., Block Handle in Train Going To, & it becomes necessary to cancel the Line Clear, the cancellation switch S1 is put to reverse position at Stn. The following sequence is observed: • External relay ASR drops • S1 counter increments to next higher number. • All controls are to be replaced to Normal so as to pick up 1R • Timer relay times up as per fig. 32 • On expiry of 120 seconds TEPR picks up • TEK appears Green with wording “FREE” • 3R picks up. An advice for cancellation of Line clear is sent By SM at Stn. A to SM of Stn. B 6.3.2 SM at Stn. A presses PB1 and PB2 simultaneously to transmit Line closed code (F1). PBPR picks up at Stn. A as per fig. 5. 6.3.3 An FM code is generated due to picking up of PBPR at Stn. A, which connects power to TX as S/ Line Tokenless B/Instrument

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49

per circuit in Fig. 7. The modulating frequency F1(85 Hz) is selected over terminal TX-5 & TX-6 & modulated current flows to terminals 34, 37 to the line side isolation transformer. 6.3.4 With the PBPR picking up at Stn. A, NR picks up at Stn. B through the line circuit as per fig. 6 & 8. CR1 picks up at Stn. B on receipt of modulated current as per fig. 9. With the NR and CR1 picking up Lock magnet is energised at D point of block handle as per fig. 30, making it possible to restore the handle to Line Closed position. 6.3.5 Similarly Stn. B takes action to bring the instrument of Stn. A to Line Closed. SM at Stn. B presses PB1 and PB2 simultaneously to transmit Line closed code (F1). PBPR picks up at Stn. B as per fig. 5. An FM code is generated due to picking up of PBPR at Stn. B, which connects power to TX as per circuit in Fig. 7. The modulating frequency F1(85 Hz) is selected over terminal TX-5 & TX-6 & modulated current flows to terminals 34, 37 to the line side isolation transformer. 6.3.6 With the PBPR picking up at Stn. B, NR picks up at Stn. A through the line circuit as per fig. 6 & 8.

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CR1 picks up at Stn. A on receipt of modulated current as per fig. 9. With the NR and CR1 picking up Lock magnet is energised at B point of block handle as per fig. 30, making it possible to restore the handle to Line Closed position. When Stn A turns block handle to Line Closed, TEK changes to White.

INPUT

SM 1R S1

B 24V 61 62

58

2A 1A

N2

TIMER 1 S1 2

TRSR 3R 2A 1A 7D 8D

1

R1 3R

N24

COUNTER

TER

S1

OUTPUT

COM

2A 1A

TEPR

TEPR

29

4A 4B 3R

2B 1B

30

3R

1

LX

2 TEK

48 38

FIGURE 32

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51

TX 43 SM

B 24V 61 62

58

IR

PBPR PB2 TOLR CR1

4A 3A 4/7D 3D 1 6A 2/ 5A 5D 6D

21 3

4

31

N24

TELR 5 (c) TOLR 3R L 4/7A 8A 2/5A 1A

6 2

34

4 1

37

FIGURE 33

6.4

PUSH BACK OPERATION : When a train sent from Stn. A to Stn. B has entered the Block section, but due to unavoidable circumstances, it has to be pushed back to departure Stn. A, it is called PUSH BACK OPERATION .

6.4.1 The block handle at Stn. A and Stn. B are in left position (Train Going To) and right position (Train Coming From) respectively. TOL indicator indicates that train in to block section. 6.4.2

SM at Stn. A push back switch S2 to reverse position, actuates the counter S2 as per fig. 34. Reception signals are taken OFF. As soon as any of the control pertaining to reception signal is disturbed from its Normal position, 1R drops. HSR picks up as per fig. 26.

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TO I. TRANS

CAMTECH/99/S/DAIDO/1.0

52

6.4.3 On arrival of train at Stn. B, AT & BT tracks operate & sense the direction of travel of train. 2R picks up (Fig. 27) & sticks over LX/-RY. With the relay 2R picking up the HSR drops away and the home signal is automatically restored to normal position. At the same time a Buzzer BZ2 sounds to announce the train arrival. The buzzer can be stopped by restoring the SM slide or Home signal controls to their Normal position as per fig. 27. 6.4.4 Stn. A verifies the complete arrival of train. An advice for push back operation is sent By SM at Stn. A to SM of Stn. B 6.4.5 SM at Stn. A presses PB1 and PB2 simultaneously to transmit Line closed code (F1). PBPR picks up at Stn. A as per fig. 5. 6.4.6 An FM code is generated due to picking up of PBPR at Stn. A, which connects power to TX as per circuit in Fig. 7. The modulating frequency F1(85 Hz) is selected over terminal TX-5 & TX-6 & modulated current flows to terminals 34, 37 to the line side isolation transformer. 6.4.7 With the PBPR picking up at Stn. A, NR picks up at Stn. B through the line circuit as per fig. 6 & 8. CR1 picks up at Stn. B on receipt of modulated current as per fig. 9. S/ Line Tokenless B/Instrument

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53

With the NR and CR1 picking up Lock magnet is energised at D point of block handle as per fig. 30, making it possible to restore the handle to Line Closed position. TOL indicator changes to White during turning of handle from Train Coming From to Line Closed. 6.4.8 Similarly Stn. B takes action to bring the instrument of Stn. A to Line Closed. SM at Stn. B presses PB1 and PB2 simultaneously to transmit Line closed code (F1). PBPR picks up at Stn. B as per fig. 5. An FM code is generated due to picking up of PBPR at Stn. B, which connects power to TX as per circuit in Fig. 7. The modulating frequency F1(85 Hz) is selected over terminal TX-5 & TX-6 & modulated current flows to terminals 34, 37 to the line side isolation transformer. 6.4.9 With the PBPR picking up at Stn. B, NR picks up at Stn. A through the line circuit as per fig. 6 & 8. CR1 picks up at Stn. A on receipt of modulated current as per fig. 9. With the NR and CR1 picking up Lock magnet is energised at B point of block handle as per fig. 30, making it possible to restore the handle to Line Closed position. TOL indicator changes to White

S/ Line Tokenless B/Instrument

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54

during turning of handle from Train Coming From to Line Closed.

48

SM

S2 N2

B24 61 62

58

C2

1

R2 1

S2

2 29

COUNTER

30

21

N24

LX’

31

FIGURE 34

48 SM

B 24V 61 62

58

IR

PBPR

PB2

4A 3A 4/7D 3D 1

1

TX TOLR CR1 CR2

21 3

4

6A 2/3A 5D 6D 5D 6D

31

N24

TELR 5 (c) TOLR 3R 2R

S/ Line Tokenless

L B/Instrument 4/7A 8A 2/5A 6A 1A 2A

FIGURE 35

6 2

34

4 1

37 December’ 1999 TO I. TRANS

CAMTECH/99/S/DAIDO/1.0

(D) WHEN A TRAIN STATION)

55

SHUNTING

(AT

‘A’

The Block handles are in Line Closed position at both stations ‘A’ & ‘B’, or Stn. A in Train Going To & Stn. B in Train Coming From. A station calls ‘B’ station to obtain authorization over the telephone. SM at Stn. A inserts SM key & turns IN. SHUNT key is taken out & handed over to the driver of a shunting train. The Block handle is locked at the time. The SM key is taken out. On completion of shunting operation, Shunt key is taken back from driver of train. SM inserts SM key & turns to IN, thereafter inserts SHUNT key and turns IN. The advice is sent to Stn. B over the telephone to that effect.

S/ Line Tokenless B/Instrument

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CAMTECH/99/S/DAIDO/1.0

(E)

56

TELEPHONE CIRCUIT : While modulated current F1 to F2 is being transmitted or received, telephone circuit is isolated from power line. While telephone is used, transmitter and receiver are isolated from line. To explain in detail telephone relay TELR is inserted in series connection with relay. CR1 (B) CR2(B) and TOLR (B) in the circuit fig. 36. Also TELR(F) is connected in series in the telephone circuit, Thus telephone circuit is isolated from signal circuit. Where modulated current is transmitted and received by TELR which is inserted between signal circuit and Transmitter/Receiver, Transmitter/Receiver is isolated form signal line which telephone is used.

7.

TRANSMITTER AND RECEIVER

7.1

Operating Parameters

Transmitter S/ Line Tokenless B/Instrument

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57

Item

Rating

Transmitting frequency Transmitting output

1800 Hz or 2700 Hz 1 mW, 3 mW, 5 mW, adjustable 600 Ohms, 1120 Ohms adjustable Frequency modulation 65 Hz or 85 Hz 1.2 watts or less 24 V DC 160 Hz

Output impedance Modulation system Modulation frequency Power consumption Input power supply Shift frequency

Tolerance + 2% +10%, -5% + 2% + 1.5 Hz at 24 V DC + 20% + 15%

Receiver Rating

Tolerance

Receiving frequency Level range

Item

1800 Hz or 2700 Hz 0 to 28 dB

Max. noise allowance Input impedance

-44 dBm 600 ohms, 1120 ohms adjustable 24V DC or above 8 watt or less 24V DC less than - 29 dBm More than - 38 dBm

+2% In step of 2 dB or less + 2%

Relay output voltage Power consumption Input power supply Sense level for receiving No Sense level for receiving Shift frequency

7.2

160 Hz.

21V min. at 24 V DC + 20%

+ 15 %

Connection Terminals & Test Blocks

S/ Line Tokenless B/Instrument

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58

7.2.1 Transmitter Connection Terminals It have 8 fixed terminals. Serial Nos. and connections are as below: Terminal Nos. 1&2 3 4 5 6 7 8

Connections Out put Positive DC input Negative DC input Common 85 Hz. 65 Hz. Spare

Test Blocks Test blocks are provided at the back side of the transmitter with a cover and seating arrangements. 1. 2. 3. 4. 5.

24V DC supply Regulated voltage Modulated frequency 65 Hz & 85 Hz Carrier frequency 1800 Hz. or 2700 Hz. TX output

S/ Line Tokenless B/Instrument

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7.2.2

59

Receiver Connection Terminals It have 8 fixed terminals. Serial Nos. and connections are as below: Terminals 1&2 3 4 5&6 7&8

Connections Input Positive DC input Negative DC input Output for CR2 relay Output for CR1 relay

Test Blocks Test blocks are provided at the back side of the receiver with a cover and seating arrangements. 1. 2. 3. 4. 5. 6.

24V DC supply Regulated DC supply Input Demodulated Signal Input to CR1 Input to CR2

S/ Line Tokenless B/Instrument

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CAMTECH/99/S/DAIDO/1.0

7.3 Sr. 1.

2

60

Trouble Shooting Method for Transmitter & Receiver SYMPTOM ACTION TO BE TAKEN No output from Check if the supply is OK by pressing receiver. push to make switch in transmitter and receiver. If power ON indicators are glowing with red LED it means power supply is OK. If the red LED does not glow, check the fuse. If the fuses are missing/blown, replace it. Power OK, Press the PTM switch which is on the LEDs OK but front panel and see if the level relay does not indicator green LED glows or not. If pick up. glows that means relay driving signal is OK & the problem is with respective relay, so replace it and get the desired result. If the level indicator Amber LED glows: The relay driving signal is missing, check the following: Input to the RX between 5&6 (+10V to +13V PP) between 7&8 (+1.5V to + 2.5V PP), between 9&10 or 11&12 (+21.6V to +26V PP).

S/ Line Tokenless B/Instrument

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61

If the above voltage signals are not regular/proper, open the cabinet and follow the signal flow and check the voltages. 8.

EARTHING A separate earth should be provided for each block instrument. The resistance of earth shall not exceed 10 Ohm. The earth shall be located on lower level soft ground far from underground cable, water and gas pipes.

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S/ Line Tokenless B/Instrument

62

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63

9.

SAFETY CHECK

•

Ensure that double lock is provided and seal is intact.

•

Try to operate the instrument without cooperation i.e. without receipt of functional code, it shall not be possible to turn the block handle from Line Closed to Train Going To or Train Coming From position.

•

On receipt of TGT code, turn block handle from Line Closed towards Train Going to & stop midway. Disconnect Line & try to turn the handle further. It shall lock in check lock position. Ensure armature of electric lock on block handle is force dropped in check lock notch and the block handle can not be turned to Train Going to position.

•

With a train in Block Section, try to bring the block handle to Line closed with & without cooperation from other station, it shall not be possible to turn the block handle to line closed position. The Block handle should remain locked in last operated position.

S/ Line Tokenless B/Instrument

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64

For Last Stop Signal : • Try to take OFF the Last Stop Signal without taking line clear (“L” position of block handle), the signal should not clear. • Shunt the FVT track, the Last Stop Signal shall go back to danger automatically. • It is not possible to take OFF the Last Stop Signal again unless a fresh line clear is obtained. SUGGESTION : a) Removal of Filter unit & X, Y relays in RE area. b)Disconnect the two condensers of the Block Filter unit c) The rare gas lightning arrestor should be replaced with MOVR.

S/ Line Tokenless B/Instrument

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10.

65

MAINTENANCE

10.1 Periodicity of Overhauling A thorough periodical overhauling in Workshop is necessary and the period shall not exceed 7 years. 10.2

Maintenance

The following points are to be kept in mind while doing maintenance for reliable working of block instrument. • The local battery voltage at the instrument terminals on load should not be below 24 volts. Secondary cells of sufficient capacity may be used as the maximum working current per instrument is about 2 Amps ( when thermal time element relay is used) & 0.6 Amp (when Electronic time element relay is used) • The upper limit of local battery on load should not exceed 29 V as it may affect the Zener diode working.

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66

• The line battery shall be capable of circulate 110 mA in Line circuit measured at code receiving station. • The line current shall be measured both at the transmitting end and the receiving end. There shall not be an appreciable variation. • Separate battery or DC-DC converter shall be provided for line circuit of each block instrument. Whenever the line battery/ DC-DC converter is changed, the line current should be checked. •

??Whenever old type condenser units are changed ( with 4 BA fixing screw ), ensure that the other interconnected instrument condenser unit is also changed to the same type since the values are different. • Care shall be taken to ensure that the relay jack boards and relays are clean and dust free. • During the periodical Maintenance/ Inspection, the charger shall be switched “OFF ” and the working of the relays shall be observed for few operations. The terminal voltage should be monitored during the code transmission in order to ensure the condition of the battery. • Whenever the instrument fails, interchanging of relays and units shall not be restored to, without

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67

ascertaining the actual cause and this change may be effected only if it is warranted. • While plugging in relays/ units, excessive force should not be exerted as it may affect the jack board clips. 11.

TROUBLE SHOOTING

Sr. Fault Cause/ Rectification no. Condition 1. Bell beats 1. Line battery low or disconnection at failed from station ‘A’. Stn. ’A’ to 2. PB1 push button contact develops Stn. B disconnection at Stn A. 3. Line is open/short circuit or offering high resistance. 4. PB1 button contact develops disconnection at Stn. B. 5. Local battery disconnection or weak at Stn. B. It shall be 24 V. 6. BLR relay not picking up at Stn. ‘B’ when PB1 pressed at Stn. A due to some fault. 7. Diode, in series with BLR/ NR punctured. 8. Relay contacts NR, BLR, PBPR offering high resistance at Stn. A & Stn. B. 9. When PB1 is pressed at Stn. A, BLR S/ Line Tokenless B/Instrument

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shall pick up at Stn. B. Suppose BLR is not picking up, check up the incoming line voltage at Stn. B across L1 & L2(Terminal No. 25 & 26 working voltage 24 Volt. If voltage is available and relay is not picking up, check for working current ( 110 mA.).

S/ Line Tokenless B/Instrument

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CAMTECH/99/S/DAIDO/1.0

Sr. Fault no. Condition 2. Failure of Lock Magnet.

69

Cause/ Rectification Ensure the following: 1. SM’s key ‘ON’ contact is making. 2. Relay 1R front contact is making (checking up the slides/ levers/ block signals ‘ON’). 3. TER cold contact in TER. 4. Switch S1 & switch S2 in ‘N’. 5. Back contact of relay 2R & relay 3R is making. 6. Relay TRSR front contact is making in case of turning the block handle from ‘N’ to ‘L’ including check lock. 7. Relay TRSR back contact is making in case of turning the block handle from ‘N’ to ‘R’, ‘T’ to ‘N’, ‘L’ to ‘N’. 8. Block handle contact XX/, in case of turning block handle from ‘N’ to ‘L’. 9. Block handle contact BDY, in case of turning block handle from ‘N’ to ‘R’, ‘R’ to ‘N’, ‘L’ to ‘N’ respectively.. 10. Front contact of relay NR is making. 11. Front contact of relay CR2 is making for turning the Block handle from ‘N’ to ‘L’. 12. Front contact of relay CR1 is making for turning the Block handle from ‘N’ to ‘R’, ‘R’ to ‘N’, ‘L’ to ‘N’. 13. Local battery voltage 24 Volts.

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14. Ensure cross protection contact viz. CR1 & CR2 breaking during the respective operations.

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Sr. Fault Cause/ Rectification no. Condition 3. Failure of 1. Ensure voltage of location battery relay 1R 24 Volt. 2. All block signals at ‘ON’ concerned levers/slides normal. 4. Failure of Ensure relay 2R a. TAR pickup while train arrives. If TAR is not pickup, check TAR circuit. b. TAR front contact making properly. c. Stick circuit is taken through block handle contact LB/RD, check the block handle contacts. 4. Failure of Check TER circuit, SM’s key contact, relay 3R. Switch S1, ‘R’ contact, TER hot contact, TEPR circuit, TER cold contact, Block handle LX contact. 5. Failure of Check the PB1 & PB2 contact of push PBPR relay. button, 1R front contacts. When Block handle is in (RD) check up Block handle contact, TOLR front contact, check SM’s key contacts. 6. Failure of 1. Check for CR2 front contacts NR front relay TRSR contacts, 1 TPR front contacts. at train 2. Block handle contracts XX/, LX. sending 3. Local voltage 24V(Including fuses end ‘A’ etc.) 4. 3R back contacts. 5. If stick feed is not available, check TRSR front contacts, make before S/ Line Tokenless B/Instrument

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break contacts of XX//LX/. 6. Check the condenser across TRSR.

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Sr. Fault Cause/ Rectification no. Condition 7. Failure of A. Pickup circuit for TOLR. TOLR at ‘A’ i) Ensure TRSR show to release feature (condenser)-(slow to release) ii) Ensure TRSR front contact making. iii) Ensure ITPR back contact making. iv) Ensure Block handle contacts LB making. v) Ensure 3R back contacts making. B. Ensure stick feed to TOLR.

8.

9.

i) Ensure S2 normal contacts making. ii) Ensure TOLR front contacts making. iii) NR back contacts making. iv) TRSR back contacts making. v) 3R back contacts making. Failure of i) Ensure CR2 front contacts making. TOLR at ii) Ensure NR back contact making. Stn. ‘B’. iii) Ensure block handle RD contact making. iv) Ensure local voltage 24 Volt. Failure of Ensure at code receiving end. CR1/ CR2 If CR1 & CR2 are picking up. Check at the receiver test terminals for (a) 24V DC input to receiver (b) FM input. If DC input is absent check the block handle contact XY/LB/RD. If FM input is present

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Sr. Fault no. Condition

74

checkup the level. If the level is OK, adjust the attenuator. If the level is low at the TX, check the level low/high/medium. Cause/ Rectification

If the level is OK, check the frequency for CR1 carrier frequency 1800/2700 Hz./ Modulated frequency 85 Hz, for CR2 carrier frequency 1800/2700 Hz./ Modulated frequency 65 Hz. If the level and frequency OK check the FM input path in to RX. At the TX end check DC input, TX freq. Loop circuit for FM, which includes block handle contacts N, R & L. 10. Failure of Check for ASR:- TRSR front contacts, S1 Last Stop normal contact, LA contact of block Signal handle, 1R back contacts. circuit. 11 Failure of Check for HSR circuit:S1 normal Home contacts & RY/ LB contact or ( S2 reverse Signal contacts & L of block handle for push back operation). 12 Premature Stick feed to TRSR cut off due to ITPR TOL momentarily dropped due to unknown reason before train enters into section. Check the TPR circuit, if OK, check track circuit & block handle’s LX/ contact . 13 Normal TRSR dropped due to momentary cancellation dropping of 1 TPR or 3R circuit. LX/ not contact not making. Check S1 switch R S/ Line Tokenless B/Instrument

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possible.

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contacts in TER circuit and 3R circuit are making properly. Check 1R front contact and SM’s key contact. 

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