8.5.1 CEE and Electrical Inspector to the Government for the Railway may nominate at his discretion one of his officers preferably Sr. DEE (TrD) for joint check and tests of the section proposed to be energized. For such joint check by Dy. CEE(OHE)/ RE will associate from RE side. Alternately he may authorize Dy. CEE(OHE)/RE to conduct checks and tests before energisation. The following checks and tests shall normally be carried out.
8.6 Checks
1. That clearance between live and earthed structures is in accordance with the provisions of Schedule of Dimensions.
2. That earthing and bonding of the OHE have been carried out as per Bonding and Earthing code with exception for station area as specified in para 2.1.2 above.
3. That height of contact wire at level crossings is proper and that height gauges have been provided.
4. That protective screens have been provided in FOBs, ROBs and signalling structures.
5. That the earthing and isolation of overhead equipment adjacent to the section to be energized has been carried out properly.
6. ac immunized track relays have been provided.
7. Overhead P&T as well as Rly crossings have been cabled and wire removed.
Over Head Equipments Page 152 8.7 Tests
1. Megger tests for continuity and insulation of the OHE.
2. With the above checks and tests and after it is certified either jointly by Sr. DEE(TrD) and Dy. CEE(OHE) / RE or by Dy. CEE (OHE)/RE that the section can be energized at 2.2kV for test purpose, the following fault tests shall be conducted on the section energized at 2.2kV.
a) By creating earth fault at the farthest end of energized OHE through discharge rod.
b) By creating earth fault at the farthest end of energized OHE touching only ballast.
c) By creating earth fault at the farthest end of energized OHE touching only rail.
In all these cases of earth fault, it should be ensured that fuse provided at the supply point is blown.
8.8 Immediately on the successful completion of the checks and tests of the OHE, OHE can be energized provided that:
a) All the certificates as mentioned in paras 8.3.2/3 above are obtained.
b) DOT’s clearance and EIG’s sanction are obtained.
8.9 Immediately after energisation, a notification to that effect may be issued as normally done for 25 kV energisation.
Over Head Equipments Page 153 PANTOGRAPH ENTANGLEMENT
9.0 INTRODUCTION
Electric locomotive gets power from overhead contact wire through pantograph. For smooth operation of locomotive, the movement of pantograph should be even and unobstructed on the contact wire, when any part of pantograph comes in between overhead wires or vice versa, panto entanglement takes place.
Panto entanglement causes damage to pantograph and overhead equipment resulting in dislocation of Electric Traction traffic.
Pantograph entanglement occurs due to following reasons.
1. OHE detects.
2. Pantograph defects.
3. External detects 9.1 OHE DEFECTS
Damaged OHE components such as insulators, cantilever tubes, jumpers, droppers etc may foul with the movement of the pantograph and result in entanglement. To avoid them :-
Check insulators, droppers and other OHE component periodically for any cracks.
Ensure provision of C jumpers to avoid dropper failure.
Ensure provision of double PG clamps on G jumpers and feeder wire locations.
9.1.1 Turnout And Crossovers
It has been observed that about 43% of the total OHE failures are due to improper adjustment at turnout and crossover.
Improper adjustment of stagger and height at turnout or cross over results in pantograph getting entangled with overhead wire while moving on the main line. To avoid this, it should be ensured that he height of turnout/crossover contact wire is kept 5 cm above the main line contact wire at obligatory locations.
Ensure that panto is not touching the turnout and crossover contact wire while going on main line.
The height and stagger should be strictly as per RDSO Drgs.
9.1.2 Procedure For Adjustment Of Turn Out And Cross Over.
Before adjustment of Turn-out and Cross-over at any location. ATDs of both main and Loop lines shall be checked for its free movement.
1. Measure the implantation of obligatory Mast from L/L & M/L tracks, track separation and adjust the turn-out as per SED at obligatory point.
Over Head Equipments Page 154 2. ‘C’ Jumpers should be provided at 5.6 and 3.0 m distance from obligatory
mast for cross-over and turn-out points respectively towards parallel run side.
3. Height of turn out contact wire should be 5 cm more than that of M/L contact wire at Cantilever location of obligatory mast.
4. Adjust A&B droppers as per schedules & their distances from obligatory mast for M/L & turn out OHE both.
5. Hogging on M/L contact wire be removed by increasing the length of ‘B’ and adjoining droppers upto a distance of 10 m from obligatory mast towards turn out side on M/L OHE contact wire.
6. Adjust the height of Contact wire on L/L one mast before obligatory taking into account the track level diff. of M/L & L/L
7. At a distance of 10 mts. Towards turn out side, adjust the loop line contact wire height +3cms. (loop line B and adjoining droppers may be adjusted for this purpose) as compared to main line contact wire height.
8. At obligatory mast, contact wire height diff. of M/L & L/L OHE should not be less than 5 cms.
9. Now, while running the tower wagon on M/L, panto should not touch the L/L cross over contact wire.
10. Take the tower wagon to turn out track and M/L contact wire should take in / take off panto pan at about 65 + /- 2 cms. From centre of panto of Tower Wagon.
11. On cross type turn out, height diff. should be +1.5 cms at obligatory, 5 mtrs and 10 mts from mast & panto should not touch turn out contact wire while tower running on M/L for this A&B dropper can be adjusted if required.