Page 458 - IRSEM_Main Book

(h) Miscellaneous Circuits:

(i) Miscellaneous arrangements like effectiveness of Station Master’s key,
cascading of signals on the route, Red lamp protection on the route etc.
shall be thoroughly tested for the independent signal/routes.

(ii) The protection arrangements like Lightning arrestors, Surge protection
devices and its associated Fuse/Earthing arrangements shall be
regularly tested and Maintained.

(iii) The relay contacts shall be paralleled, if spare contacts are available.

19.8.12 Precautions during Testing

Following precautions shall be taken during testing and checking so that

(a) No signal taken 'OFF' for a train movement is thrown to 'ON' in the face of
the train.

(b) No signal which will create a conflicting or unsafe movement is taken ‘OFF’.

(c) No point and isolation in a route set for a train movement is disturbed.

(d) No track relay of an occupied track circuit is energised.

(e) No voltage higher than permissible levels is applied to the equipment.

(f) There should be no risk of electric shock to testing or operating personnel.

Section 9: Maintenance of Outdoor Signalling

19.9.1 Insulation tests on Cables shall done as per Chapter 15 of SEM.

19.9.2 Maintenance of Colour Light Signals

(a) Cleanliness of LED Lenses

(i) Polycarbonate Lenses of LED lamp shall be kept clean. A dry soft cloth
free from lint and abrasives shall be used for cleaning.

(ii) Housing shall be kept clean and opening in inclement or stormy
weather avoided. The condition of the gasket shall be checked to
ensure that rain water does not have access to the interior of lamp unit.

(b) Replacement

(i) Defective LED lamps must be replaced immediately.

(ii) The LED lamps shall be replaced as per prescribed codal life.

(c) New lamp shall be pre-tested as per approved instructions before putting
into use.

Chapter 19: Installation, Testing & Maintenance of Signalling Equipment Page 406 of 535