Ch.22: 25KV Electrified Area Signalling PDF

22125kV General Factor Affecting signals due to AC Electrified Area i of signals due to OHE Structure visibility Lii Electrical clearance of signals due to line OHE closeby iii Traction Return Current in Electrostatic Inductio...

22125kV General Factor Affecting signals due to AC Electrified Area i of signals due to OHE Structure visibility Lii Electrical clearance of signals due to line OHE closeby iii Traction Return Current in Electrostatic Induction and Electro magneticInduction layout plan of ONE shall be based on Approved SIP Protective wire mesh screen Shall be provided of approved 2 meter toom ONE Li Life One Bonds shall be provided by electrical structural dept ci ii longitudinal Iiii cross band Induced voltage depends on various factors Lengthof parallistism b w the Cable Conductor and electrified trade Sail conductivity Screening efficiency of the cable Return Current through the rail and return conductor Mutual inductance b w catenary and the Cable conductor Separation b w catenary and cable Current Carried the by catenary If The normal hight of a contact wire 5.60 mtr The normal height of Catenary wire a 7.05 mtr In tunnel bridges Contact wire Height 4.58 Mtr ftp.t catenary wire  contact wire Clearance for If safetya signal its fitting where any portion of have to post or work falls within 2 Mtr signalling staff live conductor or metal part of a 25kV any electrically connected to this such portionconductor shall protected by an iron screening It for any reason it is not practicable to provide the protective iron screening as mentioned above A Caution Board Shall be provided on the Signal post at a height of 3 meters above the sail level to Cautiontresignalstaff Take power Block during working signal with tools that come near 2 mar live Conductor of Location of Mentral section mental section after a stop signal 1600 mtr away with gradient up to in 3 co Mentral section before a stop signal 2500 mtr with higher gradient up to in200 VF The PTFE Polytetra Fluso ethylene type short neutral section shall be located on level target track at least how mtr after the stop signal Intefore the stop fiened Final decision will be CEE of Erection of signals in RE Area In case the traction mast is Located in tent of the signal p the dis b w I sackers was signal post should not less than 30 meter No traction mast is Located in advance of the signal Part at a distance less than 10 meter to to meter Reduction 30 mar of signal distance PCSTES PCEE given by on tangent tracks it is desirable that the signal should located within the OHE Structure be i e the implantation of signal foam are track Centre shall be less than an implantation ofthe ONE most from the toach centre On Curved track or in areas where other obstruction such as building trees etc enist the site should be individually examined signal sighting committee by the Signals without Junction Indicators outside trad The signal units Shall be so tired that height of the centre line of the red signal shall be Approvimently 3.65 mtr above saill level No part of signal without a routeIndicator Shall normally be higher than 5.2 meters above cail level Signals without Junction Indicators b w Tracks Is signals are located b w tracks no ONE structure shall be provided in the same track space for at least 600 meters in rear of the signals i same for portal arm for mtr Signals with junction Indicator outside tradst Signals with Junction Indicator bw Tracks Note It at stage the official feels that the any is not visibility adequate he shall impose Suitable speed restriction Signalling Circuits in RE area As a rule no aerial Circuits Shall be retained in the electrified zone In case the length of Parallelism and every the distance of Black wires foam the nearest electrified traell Shall be checked to ensure that the manimum induced voltage does not exceed tlmit prescribed by CCITT case in Blaw wire length of Parallish Gova It in case other cut 400 volt signalling Barring block instrument Circuits no other earth return Circuit Shall be permittedinn  Int c my PVC Insulated wire IRS 5 76 Polarized Relay Using Permanent magnet shall no be used in internal Circuit any Permanent causing Loosing magnet properties The Relays which release interlocking shall an be slow so that the interlocking is acting released not inadvertently by voltage variation short duration Time of 0.6 to 0.8 second delay Outdoor Signalling Circuits in RE area Maximumlengthofparalklism. Q The Length of any signalling line Circuit must be limited to ensure that the induced voltage toom the traction system does not enceed 400 volts under normal condition Induced voltage in the Underground Unscreend Cable for S L 116 volt km 800 Amp D 2 95 volt km 1000 Dup Immunity shall not less than hoor If The length of D1 Circuit on line Relays With Unscreened Cable Shall be Type of Relay A immunity 51L DIL WE ANAI ANNAI ONAIK 1000 21m 2.81m Maximum Permissible induced voltage is restricted I 1 safety factor of safety 1.5 Signal Feeding Distance For 1100 feeds system Unscreend Cable single Double Trade 4 220 mtr Point operation Detection AC immunity SIL Typeof D L Machine level v apple.my gg yog factor 1.5 of safety Insulated Rod Joints for RE It the distance between the two insulators at either end is greater than 300 meters additional insulator shall be provided on each rod when a sod crosses the track the top of thethe sod shall not be less than 40 mm from bottom of the sail when steel or C I Sleepers are used the distance b w the sod and sleeper shall be also not than 40 mm Similarly the distance b w any ONE mast and the point sods shall not be less than 40 mm Note with RED If Cable is Heavy induced voltage Paint it Any 2.2 kV Changing as An Anti Measure Theft No portion signal post or its of 700mm shall fittings be less than from the line conductor