Metro Rail Advantages of AFTC
1. Jointless Track Circuits except in point zone.
2. Immune to AC/DC Traction interference.
3. Suitable for Non-RE Section.
4. More Length.
5. Less Depends on R B Integrity (presence) of both rails are ensured in the circuit.
6. Both Rails are available for Traction Return Current.
7. Less maintenance, less staff more reliable.
8. Sensitive TR with a high % of release is not required.
TI-21 Can be arranged
1. End Feed arrangement(Continuous)
2. Center Feed Arrangement (Continuous) C
3. A.F.T.C. Ending with other type Track Circuit.
4. A.F.T.C. Ending with Non-Track Circuited
TECHNICAL SPECIFICATION OF
COMPONENTS FOR END FEED A.F.T.C.
1. POWER SUPPLY UNIT (PSU) 2 Nos.
2. TRANSMITTER UNITS (Tx ) 1 Nos.
3. RECEIVER UNITS ( Rx ) 1 Nos.
4. TUNING UNITS (T U-Tx & TU- Rx ) 2 Nos.
5. LINE RELAY (QN1) (50 V,1350 Ω ) 1 Nos.
6. CABLES 1) Tx, Rx TO T.U. 2 Set.
2) T.U. TO TRACK 2 Set.
BLOCK DIAGRAM OF TI-21 END FEED AFTC
BLOCK DIAGRAM OF TI-21 CENTER FEED AFTC
AFTC END FEED WITH NO TRACK CIRCUIT ZONE
Gain Setting In T1 Type AFTC
• 6 System Characteristics and Technical Data
• Range of applications Station and open- line tracks, points, and crossings
• Joints Electrical separation joints with S. terminal and shunt bonds
• Traction current return Two-rail
• Interference Frequency-modulated transmission provides immunity to interference
• Cable faults Protection by coded transmission and inter-core short-circuit supervision
• Component failures Safety measures dual-channel design of receive equipment parallel movement (synchronism) of track circuit relays: error detection by the divergent condition of the two relays
• Shock-hazard voltages Electrical isolation between outdoor and indoor equipment
• Rated operating frequencies
• FTG S 46: 4.75 kHz, 5.25 kHz, 5.75 kHz, 6.25 kHz FTG S 917: 9.5 kHz, 10.5 kHz, 11.5 kHz, 12.5 kHz, 13.5 kHz, 14.5 kHz, 15.5 kHz, 16.5 kHz
• Modulation Frequency modulation (shift keying)
• Bit pattern for coding 15 different bit patterns
• Transmission speed For the transmission of time-multiplex bit patterns: VD = max. 200 bit/s
• Operating reliability MTBF: 5 years
• Pick-up delay of track circuit: approx. 0.6 s (in special cases 1.3 s)
• Drop-out delay of track circuit TDR: approx. 0.25 s (in special cases 0.17 s)
• Power supply Operating voltage:
• U = 230 V AC +10 %/—15 %, 50Hz + 2%
• System Description
• VT 1 P 64
• Siemens code no:
• FTG S Track Circuit
• without Data Transmission
• Notice no: K75/D62/V
BLOCK DIAGRAM SEAMAN’S AFTC
Maximum Effective Length Of Track Circuit.
TRACK VACANCY DETECTION
Modulation And Coding
Trackside Connection box
Modulation Frame FTGS917
Modulation Frame FOR POINT T.C.
Modulation Frame FOR X- ING T.C.
Modulation Frame FTG S 46 T.C.
Modulation Frame FTG S 46 – M T.C.
Filter & Amplifier Board
Receiver – I Board
Receiver – II Board
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