Page 540 - IRSEM_Main Book

22.7.5 (a) Please refer to SEM Chapter 16 for details of Power supply arrangements.

(b) Please refer to SEM Chapter 17 for details of Track Circuits, AFTC in RE area,
Axle counter.

(c) Please refer to SEM Chapter 18, section 2 for details of Block working in
RE area.

(d) Please refer to SEM Chapter 19, section 11 for details of Earthing.

Section 8: Rules for Protection of Staff working on Signal &

Telecommunication Installation

22.8.1 Protection for Staff

Railway personnel working on Signal & Telecommunication equipment on
sections provided with 25 KV A.C traction are required to take suitable
precautions on account of the following:-

(a) Proximity to live conductors.

(b) Presence of returns currents in the rails.

(c) Induction in all metallic bodies situated near the overhead equipment.

22.8.2 Proximity of a Live Conductor: Any contact direct or indirect, with the 25 KV
conductors is dangerous and shall be strictly avoided.

22.8.3 Pressure of Return Current in Rail

The flow of return current in the rails will give rise to a potential difference.

(a) Between adjacent rails at an insulated joint of a track circuit or at an
ordinary joint in case the fish plates and bonding are broken.

(b) Between the ends of a fractured rail at the fracture.

(c) Between an insulated rail and the non-insulated rail used for the traction
return current.

(d) Between the rail and the surrounding mass of earth.

22.8.4 Wherever staff has to work on installations, which are in direct or indirect
contact with the rails, they shall:

(a) Insulated tools must be usedin accordance with approved instructions.

(b) Observe provisions of Section 'J' of permanent way manual (extract given
at Annexure: 22-A2).

Chapter 22: Requirements Of Signalling in 25 KV AC Electrified Area Page 483 of 535