Page 388 - IRSEM_Main Book

Min. Max.
Sl. RE/ Section Ballast TSR Length of Type of Track Relay to

No. Non-RE Sleeper (Yard/ Resistance in Track be used
Block) in Ohm per Ohms Circuit in
Km meters

1 Non-RE *Wooden/PSC Block 4 0.5 1000 QT type 9 ohm
2 Non-RE *Wooden/PSC Yard 2 0.5 670 -do-

3 RE *Wooden Block 4 0.5 450 QT 9 ohms AC immune

4 RE *Wooden Yard 2 0.5 450 -do-

5 RE PSC Block 4 0.5 450 -do-

6 RE PSC Yard 2 0.5 350 -do-

7 RE PSC Yard 2 0.5 750 QBAT in conjunction
with QSPA1 with B type
choke at relay end

(* where existing)
17.2.10 Track Feed

(a) Approved type of secondary cells shall be used for feeding track circuits.

(b) Secondary cell(s) shall be used along with battery charger/solar panel of
adequate capacity.

(c) Separate feed shall be provided for each track circuit.

Section 3: Maintenance of DC Track Circuits

17.3.1 General: Track circuits shall be so maintained that:

(a) There is always a good connection between power feed and track, Relay
and track and also between adjoining rails, through jumpers and rail bonds.

(b) The ballast resistance always remains high and does not fall below
prescribed minimum values.

(c) The limiting resistance shall be as high as possible.

(d) The insulating joints are of high resistance.

(e) The surface of rail is clean and is free of dust, sand and foreign materials.

(f) The circuit is properly energised during wet weather on minimum ballast
resistance conditions and during dry weather on maximum ballast
resistance conditions. The track circuit shall not be over-energised to such
an extent that the shunting value drops below 0.5 ohms for all types of
track circuits. These values shall be obtained irrespective of whether the
track is provided with concrete sleepers or wooden sleepers.

(g) The connection of DC track relay shall be quarterly interchanged to prevent
permanent magnetisation.

Chapter 17: Train Detection Track Circuits & Axle Counters Page 336 of 535