Page 448 - IRSEM_Main Book

Section 5: Installation of Electrical Point Detector (EPD)

19.5.1 Electrical point detector of approved type shall be used. Normally it shall be
installed beside the close switch leading to high-speed movement, clear of all
infringements as per approved plan and drawing.

(a) Detectors shall be mounted either on the left or on the right-hand side of a
point layout clear of infringements.

(b) The detectors shall be mounted on extended sleepers or as per any other
approved arrangement.

(c) Contacts shall be adjusted so that they make or break at the same time.
Shunt contacts shall be adjusted so that they do not make before the
detector contacts break. In AC traction area shunt contact shall not be
used. Care shall be exercised to check that the detection contacts flex a
little after they are closed.

(d) All nuts and screws shall be tightened. Check nuts with spring washer shall
be provided.

(e) After installation before connecting the detector slide, the slides shall be
pulled by hand to check for free movement. Binding, if any shall be
attended to.

(f) The lock slide shall be pulled and it shall be checked that as soon as the
roller is lifted above the slot in the lock slide, the normal or reverse
contacts are open and the shunt contacts are made. The electrical detector
must be so adjusted that with 3.25 mm thick test piece obstruction placed
between the switch and the stock rail at 150 mm from toe of the switch -
The electrical detector contacts shall not make.
(g) To keep the slides in correct position the locating marks on the switch and
lock slides shall be made use of.

19.5.2 Circuit Controller: These shall not be newly installed normally (except in few
Installations like LC Gates) and the existing one to be replaced in phased
manner. Railways still having these equipments may please refer the earlier
version of SEM Part-II, September 2001.

Section 6: Signalling Relays

For information on Signalling Relays, Refer to Annexure: 21-A1.

19.6.1 Relays – General Requirements: Refer to para 21.2.1

19.6.2 Installation of Relays: Refer to para: 21.2.2

19.6.3 Sealing of Plug-in Relays: Refer to para 21.2.3

19.6.4 Maintenance of Relays: Refer to para 21.2.4

19.6.5 Periodical Inspection of Relays: Refer to para 21.2.5

19.6.6 Replacement of Relays: Refer to para 21.2.6

Chapter 19: Installation, Testing & Maintenance of Signalling Equipment Page 396 of 535