Page 505 - IRSEM_Main Book

Para no: 21.1.21 Timers in Various circuits – Table-1
S.No Description Delay in Conditions/Remarks
seconds
10 Opening of LC gate (Gate 60 1) Timer shall start on putting back the Gate signal.
signal at 180 m from LC) 2) If two track circuits are provided to prove that train has passed beyond LC gate, such sequential
proving is adequate to open LC gate immediately with out waiting for completion of 60 seconds.

11 Opening of LC gate (Gate 120 1) Timer shall start on putting back the Gate signal.
signal at more than 180 m 2) If two track circuits are provided to prove that train has passed beyond, LC gate, such sequential
from LC) proving is adequate to open LC gate without waiting for completion of 120 seconds.
12 Opening LC Gate (Traffic 120 When route/sub route is locked, LC gate opening control can be given after 120 sec time delay by
Gate) applying cancellation, duly putting back the signals taken OFF.
13 Opening of LC gate in 120 When approach track circuits of an automatic signal protecting LC gate have failed.
automatic section
14 Crank handle/LC gate key 120 To extract keys when Electronic Interlocking/VDU has failed.
Extraction
15 Point failure alarm 15 Alarm to SM that point has failed to operate.
16 Point Operation timer 10 Point contactor relay to de-energise and cut off power to Point Machine to protect it.
17 Signal blank buzzer 10 Alarm to SM if any signal goes blank by proving that all ECRs are de-energised
18 Panel Button struck up alarm 10 Alarm to SM, whenever any button is struck up in button type panels
(Button type panels)
19 HR Relay de-energisation 5 Slow to drop for HR relay of starter where starter is placed at 3 meters from controlling Track Circuit
glued joint/Detection Point, to avoid confusion to Loco pilot
20 Holding HR relay energised 3 To prevent signal bobbing, in case of intermittent failures of Track circuit`s/Point detection due to
loose packing.
21 HR control timer de- 5 For HR control timer de-energisation, if read back is not received from Concerned signal as per
energisation command given by Electronic Interlocking
22 Power failure Alarm 5 Alarm to SM, if all power supplies fail

Note:Above timers where not yet existing, may be provided for new works and major alterations.
Chapter 21: Relay & Electronic Interlocking Page 448 of 535