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QUESTION BANK OVERHEAD LINES &TELEPHONY

CHAPTER II 1. The conductor conductor material material of drop wire used in the depart department ment is made up of ……… ……………… ……………… …………. …. 2. The pur purpose pose of ridge ridge provided provided between between the two two conduct conductors ors of drop drop wire is for ………… ………………. ……. 3. The pur purpose pose of fin provid provided ed on one side of the iinsula nsulation tion mou moulding lding of of the drop wire wire cable iis s for …………………………….. 4. Provision of protective devi devices ces at the subs. premises if the drop drop wire iis s taken from the DP is ……… ………….. ….. . The two standard diameter of bare drop wire conductor are ……………….. and…………………….  

CHAPTER :III 1! 2! 3! 4! ! +! ,! -! 0!

"ha "hatt iis s th the e purp purpos ose e of #$% #$%& & "hat is the the mai main n re' re'uir uireme ement nt of #$% & "hat are the the tw two o purp purposes oses ( which which the )ack )ack w will ill se serve& rve& *en *enti tion on the the par parts ts tthat hat a #$% cons consist ist& & "h "ha at is a $ $ac ack& k& "h "ha at is a p plu lug g& "hat are the the faci facili litie ties s of a #$%& #$%& "hat iis s the p purpos urpose e of 2.2mf 2.2mf con condense denserr on th the e #$% P/ P/ circ circuit& uit& "hat iis s the #i #ife fe Tes Testt for the the spring spring loa loaded ded shu shutter tter of of the # #$% $% &

CHAPTER IV 1. "hat are the tw two o vers version ions so off P/T P/T& & 2. "hat is the the per permitt mitted ed range range o off side tone refer reference ence e'uiv e'uivalent alent& & 3. ois oise e level level iin n the send direc direction tion is      4.    di dialed aled no no.. is stored stored automatic automaticall all w when hen the handset handset iis s replaced. replaced. . DT* DT*5 5 stand stands s for           +. 6n decadi decadic c diali dialing ng when 789 iis s dialed( dialed( there will will be    interr interruptio uptions ns in the line line current. current. ,. 6n    dialing dialing(( digit digits s are trans transmitt mitted ed as the combinati combination on of two tones. tones. -. 6n D DT*5 T*5  number of fr fre'uenc e'uencies ies are are defined defined.. 0. "hat is Pie Pie:o; :o;l lect ectric ric eff effect ect& & 18. "hat are th the e two tp tpes es of tone ringers& ringers&

 

ANSWERS (OVERHEAD LINES &TELEPHONY) CHAPTER – II  1. <ard drawn cadmium copper.  2. separating the drop wire into two full insulated conductors without in)ur to the insulation  3. identification of conductors.  4. not essential.  . 1.2mm and 8.01 mm. CHAPTER – III 1. To conne connect ct the subs. subs. instr instrument ument =v =voice oice or non voice voice termi terminal! nal! to the the telephone telephone e>change. e>change. 2. i!. reli reliable able electric electrical al conta contact ct and ii! mecha mechanical nical compati compatibili bilit t between between plug and )ack. 3. i! #$% #$%;; )ack on on which which the e>chang e>change e line directl directl termin terminates. ates. ii!e>tension #$%;the )ack used for parallel telephone connection in the subs. premises. 4. a )ack w with ith a sel self;clo f;closing sing spring spring loaded loaded s shutt hutter er and a p plug. lug. . 6t is a single moulded moulded device w where here the direct e>change line gets terminated terminated and gets connected to pi pins ns of a pl plug ug of an instrument. +. 6t is devi device ce carring carring metallic metallic co contact ntact in in the form of pins pins for the pur purpose pose of connectin connecting g a telepho telephone ne to )ack. ,. i! dir direct ect e>c e>change hange liline ne term terminati ination on and =ii! =ii! to e>tend e>tend the e>change e>change line line to instr instrument ument throug through h a plug. -. 5or e>te e>tending nding a condenser condenser cli click ck for test form th the e e>change even even when the telephone telephone is remov removed ed from the )ack )ack.. The spring;loaded shutter should sustain to life test of 2888 operations. CHAPTER IV 1! De Deca cadi dic ca and nd DT* T*5 5 2! - ? 22d/ 3! #e #ess ss than than ;+d ;+d/m /mp p 4! #ast ! Du Dual al Ton Tone e *ult *ultii 5r 5re' e'ue uenc nc  +! 18 ,! DT*5 -! 0! "hen a volt voltage age is applied applied to the opp opposite osite el electro ectrodes des a mecha mechanical nical distor distortion tion tak takes es place. 18! @ingle Tone( *ulti Tone.

 

QUESTION BANK UNDERGROUND TELECOM CABLES

Chap!" I I# $% h! 'a *%h +,%a'! *-".:: 1. The circuit between two e>changes in a local network is called …..… …….. . 2 .……………. 6s the last cable termination point from where subscriber line is connected. 3. The cable connecting Pillar and DP is called called ………………………… ………………………… 4. 6n ducted cable sstem we use ……………………….. ……………………….. cables are used . ntr of moisture into the core of cable is prevented b filling …….. ……………… ……………… in P6$5 cables. +. 66n n Teleco Telecommu mmunic nicati ation on ca cable ble netw network ork cab cables les are are ………….prevent …………. prevent damages from e>ternal sources.

re' re'uir uired ed to b be e protec protected ted from from …… ………… ………… ………… …….. ..

,. P* cables are designed with a conductor diameter of ………..mm. -. Paper 6nsulated cables are prone to more faults due to entr of ……… ………….. 0. Aver Aver la la of cond conduc ucto tors rs in a pa pair ir is do done ne du duri ring ng manu manufa fact ctur ure e of tele teleco com m cabl cable e to prev preven entt effe effect ct of ……………………….  18. B 488 pair cable consist of ……………. o of super units of ………….. ……………… si:e.

II#

INDICATE WHETHER TRUE OR $ALSE 11. The material used as conductor in local telecom under ground cables is high conductivit annealed copper . = ! 12. The sheath of a underground cable protect the conductors from damage due to entr of moisture to safe guard the insulation resistance of pairs. = ! 13. $acket is the sheathing arrangement made over armoured cable to protect the armour against corrosion and rusting. = ! 14. Paper 6nsulated cables are now being replaced with Polthene insulated $ell filled cables to improve efficienc of cable network = !

Chap!" II I# $% $% h! h! 'a 'a  *% *%h h +,% +,%a' a'! ! *-".:: *-".:: 1. 2. 3. 4. . +. ,. -.

while hile sele select ctin ing g the the rout route e for for la lai ing ng ca cabl ble e ;;;; ;;;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;; ;;;; ;;;;;; ;;;; ;;;; ;;;r ;rou oute te shou should ld se sele lect cted ed.. "hi "hile cr cros ossi sing ng pow power ca cabl bles es the tele teleco com mc cab able les ss sho houl uld d be be llai aid d at at ;;; ;;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;; ;;;;; ;;;; ;; to the the p pow ower er cabl cables es.. "hi "hile cr cros ossi sing ng road roads s iitt s sho houl uld d be be see seen n ttha hatt a an n no poin pointt ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;; ;;;;; ;;;; ;;;; ;;;; sho shoul uld dn not ot fall fall in betw betwee een n road crossing. "hi "hile lai laing ng cabl cables es ne near ar be bend nds s tthe he be bend ndin ing gs sho houl uld d be be min minim imum um of; of;;;;; ;;;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;; ;;;; ;;;;;; ;;;; ;;;; ;;;; ;;;; ttim ime e the the diameter of the cable. The The lla ain ing g of of ttel elec ecom om ca cabl bles es acro across ss rail railwa wa c cro ross ssin ing g sho shoul uld d be be llai aid d iin n ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;; ;;;;; ;;;; ;;;; ;;;; ;;pi pipe pes. s. "hi "hile pavi paving ng out out cab cable le it sh shou ould ld be se seen en that that da dama mage ges s tto o tthe he shea sheath th is to be ;;;; ;;;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;; .;;; .;;;;; ;;;; ;; 5loo 5loodi ding ng of of tthe he tre trenc nch h af afte terr fres fresh h digg diggin ing g and and lla ain ing gw wil illl help help iin n dete detect ctin ing g ;;;; ;;;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;; ;;;;; ;;;; ;;;; ;;;; ;; caus caused ed tto o the e>isting cables.

The The pr protec otecti tiv ve s sttone one s sllabs abs whi which ch are are p pllaced aced over over the cabl cables es aft after la ain ing g iin n tthe he tre renc nch ha arre cal callled ;;;;;;;;;;;;;; ;;;;;;;;;;;; ;; ;;;;;;;;;;;;;;;; and the help in preventing damages due to digging b other service utilit personnel. 0. 6ndi 6ndica cato torr k kep eptt at at 288 288 m a apa part rt in the the rrou oute te of the the cab cable le is call called ed ;;;; ;;;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;;; ;;; ;;;;; ;;;; ;;;; ;;;; ;;;; ;;; ;;;;; ;;;; ;;;; ;; . 18. 18. The The indi indica cattor ke kept pt at ever ever  )oi oint nt pl plac ace e is cal allled ;;;;; ;;;;;;; ;;;;;;;; ;;;;; ;;;;;. ;;. 11. 11. "hi "hile cr cros ossi sing ng the the pow power cab cable les s tthe he tel telec ecom om cabl cables es s sho houl uld d be la laid id in soli solid d for for a d dis isttan ance ce of ;;;; ;;;;;; ;;;; ;;;; ;;;; ;; ;;;;;;m on either

 

II#

A+* +*!" !" h! //--*% *% 0 1, 1,!+ +%%-+ %% - ! + +! !!2!# 12."rite the standard mechanical protections that are used normall. 13.6ndicate the two two important checks to be done after receivi receiving ng the cables from store depot and before laing tthe he cable. CHAPTER III I# $% $% h! h! 'a 'a  *% *%h h +,% +,%a' a'! ! *-".:: *-".:: 1.During Brea transfer the pairs from one e>change are e>tended to another e>change using ;;;;;;;;;;;;;;;;;tpe ;;;;;;;;;;;;;;;;;tpe of )ointing of the pairs. These These pairs are available to both the e>changes ti tillll the switch over of area is c completed. ompleted. 2.The )ointing of pairs of one large si:e cable to two or more smaller si:e cables is called ;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;; )ointing. 3.The )ointing of one cable to another cable of same si:e is called ;;;;;;;;;;;;;;;;;;; )ointing. )ointing. 4.onventional twist )ointing methods of conductors is used generall for the ;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;; insulated conductors and it re'uires a material called ;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;or ;;;;;or preventing the contact between the de; insulated conductors from each other. .5or )ointing 188 pair P6$5 cable conductors;;;;;;;;;;;;;;;;number conductors;;;;;;;;;;;;;;;;number of %C connectors are re'uired. +.5or )ointing conductors of bigger si:es of P6$5 cables ;;;;;;;;;;;;;;;;;;si:ed ;;;;;;;;;;;;;;;;;;si:ed module are used. ,.The B#@@ )oint is generall more used for closing the )oints of ;;;;;;;;;;;;;;;;;;;tpe of cables because of its reentr techni'ue II# A+*!" A+*!" h h! ! /--*% /--*%0 0 1, 1,!+%!+%-+ + % -! -! +! +!!2 !2!# !# -. "rite the three three cases where the necessit necessit of )oint occurs. 0."rite the three techni'ues that are in use in )ointing of cable conductors.

CHAPTER IV I# $% $% h! h! 'a 'a  *% *%h h +,% +,%a' a'! ! *-".:: *-".:: 3# THE INTRODUCTION O$ PILLAR  OR CABINET  IN A LOCAL CABLE NETWORK MAKES IT 4444444444444444444444 # 2. 6n a local cable network where there there are no ca cabinets binets and pill pillars ars then the the network iis s called ;; ;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;; ;;;;; sstem 3. 6n a loca locall cable n netwo etwork rk wher where e there there are Pil Pillars lars onl onl the then n the cable connec connected ted to DP a and nd pill pillar ar is called;;;;;;;;;;;;;;;;;;;; called;;;;;;;;;; ;;;;;;;;;; cable and the cable connected to pillar and >change *D5 is called 4. . +. ,. -. 0.

;;;;;;;;;;;;;;;;;;;;;;; cable. ;;;;;;;;;;;;;;;;;;;;;;; The si si:e :e of the modul module e used in  rone rone t tpe pe T /o /o> > term terminati ination on of undergro underground und cables cables at Pil Pillar lar or cabinet cabinet is ;;;;;;;;;;;;; . 6n kron krone e tpe  T T /o> ;;;;;;; ;;;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;; ;; tpe o off wir wiring ing is onl onl  done. o sol soldering dering(( no screwing screwing and no s strip tripping ping of insulati insulation on is re'uired re'uired ffor or terminat termination ion of cable cable pai pairs rs on a ;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;; ;;; tpe of termination points. @tri @tripping pping o off e>tra e>tra length length of insu insulated lated w wire ire is ac achiev hieved ed in kron krone e tpe T /o> b using using the ttool ool ;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;; ;;;;;;;;;; ;;;;;;;;;;;. The co contact ntact used in in krone krone T /o> /o> is an ;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;; conta contact. ct. The disc disconnect onnection ion or isol isolation ation of wires wires in a r rone one T /o> can can be achiev achieved ed b simpl simple e insert insertion ion ;;;;;;;;;;;;;;;;;;;;;

II# A+*!" A+*!" h h! ! /--*% /--*%0 0 1, 1,!+%!+%-+ + % -! -! +! +!!2 !2!# !# 18. "rite two tpes of DPs basing on the 6nstallation procedure. 11. "rite point to be kept in view while laing cable at the termination points for preparing leading in cables forimportant terminations.

 

CHAPTER V I# 1.

$% h! 'a *%h +,%a'! *-".:: Power iinduction nduction in telecom lines lines is due to ;;;;;;;;;;; ;;;;;;;;;;;;;; ;;; of power and telecommunicatio telecommunication n wires.

2. Bt the crossing of power lines( lines( telecom wires or cables should be crossed at almost ;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;; w with ith sufficient sufficient vertical separation. 3.

5or arresting induction from Eailwa traction ;;;;;;;;;;;; transformers and ;;; ;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;; ;;; ;;;;;;;;;;;;ar ;;;;;;;;;;;;are e used b railwas. railwas.

4. 6nstallation of ;;;;;;;;;;;;; ;;;;;;;;;;;;; ;;;;;;;;;;;;;; ;;;;;;;;;;;;;; ;;;;;;;;;;; at both ends of telecom line or cable involved in parallelism and at individual points along the line will protect the e'uipment and a nd personnel from dangers of electrocution. . The PT PT  clearance clearance is to be obt obtained ained iiff the length length of paral paralleli lelism sm between between telecom telecom and power power lines iis s ;;;;;;;;;;;;;;;;;;;;;; and above. ;;;;;;;;;;;;;;;;;;;;;; +. The mini minimum mum vertical vertical clearanc clearance e betwee between n power and tteleco elecom m line is ;;; ;;;;;;; ;;;;;; ;; . ,.

"hile crossing power cables the the telecom cables should be laid at right angles and should be laid in ;; ;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;. ;;;;;;;;;.

-. 5or preventing an danger of power liline ne and telecom line coming into contact and before act actual ual tripping of power line ;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;; ;;;;;;;; ;;;;;;;;;;;;;; ;;;;;;;;;;;;;; ;;;;;;;;;; are installed on top most wires of the telecommunication lines. 0. The 'ualit of telecomm telecommunication unication circuit and signals are affected b the tpe tpe of inducti induction on called ;;;;;;;;;; ;;;;;;;;;; ;; ;;;;;;;;;;;;; ;;;;;;;;;;; ;;;;;;;;;;; 18. The arrangement pr provided ovided above telecom lines or below the power lines to safe guard guard the personnel and e'ui e'uipment pment due to contact of the lines is called ;;;;;;;;;; 11. Fas discharge Tubes are of ;;;;; ;;;;;;;;;;;;;;; ;;;;;;;;;; ;;;;;;;;;; ;;;;;;;;;; restoring t tpe. pe. The come to normal position once th the e induced voltage drops down to with in limits. limits. II#

ANSWER THE $OLLOWING QUESTIONS IN ONE SENTENCE #

12."rite short notes on impact of power lines on telecom network. 13."rite two safet to be observed for cables while while handling cable at places where power iinduction nduction ma occur. 14."rite two safet measures to be observed b the staff to avoid danger of electrocution. 1."rite effect of induction on signaling circuits. CHAPTER VI I# W"%! +h-" a+*!" /-" h! /--*%0 1,!+%-+# 1."rite important cable record to be maintained. 2."rite important features of maps and diagrams to be maintained. 3."rite the details a DP card shows. 4."rite the details details a pillar card shows. ."rite importance of foot patrol.

CHAPTERVII 3#CRMS +a.+ /-" 5 6#B!!/%+ -/ CRMS 5

 

CHAPTER VIII @hort answer 'uestionsG 1. "hat is the purpose purpose of 5ault car card d position& 2. Bt what position( the the results of the testing of a fault fault telephone line are indicated on the docket docket& & 7# WHAT ARE THE CHECKS TO BE MADE BY THE TRA$$IC SECTION O$ THE E8CHANGE  OVER THE PENDING DOCKETS5 9# GIVE BRIE$ DETAILS O$ THE COMPLAINT  TO BE $ED TO THE COMPUTER IN CASE O$ COMPUTERIED  $RS# ;# WHAT ARE THE REPORTS CAN BE OBTAINED  IN A COMPUTERIED $RS5 <# MENTION THREE ADVANTAGES  O$ COMPUTERIING THE $AULT CONTROL SYSTEM# CHAPTER I8 I# $ILL THE BLANKS WITH SUITABLE WORDS# 1.

6ncom 6ncomplete plete and som sometim etimes es absence of document documentation ation and records( records( and negl negligenc igence e of prevent preventive ive as well as annual maintenance of e>ternal plant result in ;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;; .

2.

6mproper cable w works orks and lack of o;ordination with other public public uti utilit lit services services result result in cable ;;; ;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;. ;;;;;;;;;.

3.

6t is correct method to directl terminate ;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;; tpe of cables. ;;;;;;;;;;;

4.

6t is not good to provide )oints before the plinth of the pillar( instead it is better to terminate the cable cab le ;;; ;;;;;; ;;;;;; ;;;;;; ;;;;;; ;;;;;; ;;;;;; ;;;;;; ;;;on on to the T bo> bo>es. es. This This will will eli elimin minate ate cluste clusterr of )oi )oints nts sur surrou roundi nding ng cabinetsHpillars.

.

liminate )oints a att the bottom of the DP posts posts b laing sufficient length of distribution cable ;;;;;;;;;;;; ;;;;;;;;;;common branching point and it also reduces the cost of e>ternal plant. ;;;;;;;;;;common

+.

ert ertain ain uncared uncared operati operations ons in cable constructi constructions( ons( though though simple in nature( nature( ma lead to ;;;;;;;;;;;; ;;;;;;;;;;;;;; ;; ;;;;; ;;;;;;;;;; ;;;;;;; during life time of the cables.

,.

The tendenc tendenc of some some cable cable splicers splicers to develop develop ttheir heir own own theor theor of )ointing )ointing in in the abse absence nce of ful fulll comp complemen lementt of  )ointing kit should should be ;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;( ;;;( which oth otherwise erwise results iin n large number of )oint failures.

-.

6n case of P6 P6$5 $5 cable cables s ensure use use of ;;;;; ;;;;;;;;;; ;;;;;;;;; ;;;; for pr pressin essing g %C connectors connectors for ))ointi ointing ng the conductors conductors instead of ordinar pliers to avoid break faults.

0.

nsur nsure e use of ;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;; ;; in the splice to avoid an possi possibili bilit t of ingress of moisture moisture sett setting ing in to the )oint of P6$5 cables.

;;;;;;;;;;;; on *D5 b laing ;;;;;;;;;;;;; ;;;;;;;;;;;;;;;; ;;;

18. nsure sheath continuit at ;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;; ;;;;;;; and earthing at D DP P pillar and *D5. 11. B missing pol;al sheat sheath h continuit can result ;;;; ;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;due ;;;;;;;;due to power iinduction. nduction. 12. Bs far as possible a single length of drop wir wire e should be run from ;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;up ;;;;up to ma>imum length of four spans 13. limination of ;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;in ;in drop wire reduces high resistance faults. 5ollowing accessories are to be used. 14. "henev "henever er a tren trench ch is dug for lai laing ng new telephone telephone cables or some other depart department ment digs the trenc trench h for installation of their servi ces( the trench ma beisfilled in;;;;;;;;;;;;;;;;;;;;;;;;;;; with ade'uate 'uantit of water for two or three das to simulate theservices( monsoon conditions. This called ;;;;;;;;;;;;;;;;;;;;;; ;;;;; of trench. 1. 6f the water is not al allowed lowed to remain in the trench trench for ade'uate period during flooding flooding operation detection of small faults ;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;

 

1+. Fas pressur pressuri:at i:ation ion is a preventiv preventive e maintenan maintenance ce work work for ;;;;;; ;;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;; ;;;;;;. ;;. Dr air or itrogen is fed into dr core cables either b use of clinders or compressor drer units at a pressure of 8., @ either b static feed sstem or continuous feed sstem

CHAPTER 8 I# $ILL THE BLANKS WITH SUITABLE WORDS# 1.

5aul 5aultt Prone cabl cables es with low in insulat sulation ion should should be ;;;;;;;;;;;; ;;;;;;;;;;;;;; ;; ;;;;; ;;;;;;;;; ;;;;;;. ;;.

2.

Bll he heav av over head head ali alignmen gnmentt shoul should d be ;;;;;;;; ;;;;;;;;;;;; ;;;;;;;; ;;;;;;;; ;;;;b b new DP DPs. s.

3.

abinets and pillars should should be installed for for more than ;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;; ;;;;; lline ine e>changes.

4.

@ervice liline ne is the portion of the ;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;; from pole *ount DP to tthe he terminati terminating ng points.

.

@ubsc @ubscribe ribers rs ;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;; ;;;;;;;; ;;;; is tthe he loop is e'u e'ual al to the sum of resistanc resistance9s e9s of each llimb imb of subscrib subscriber9s er9s line and telephone set.

+.

6nternal DP is the cable termination Point where where underground cable is laid directl to the ;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;

,.

The 6ns 6nspecti pection on of ;;;;;;;; ;;;;;;;;;;;;; ;;;;;;;;; ;;;;;;;; ;;;;;; consi consists sts of the the inspectio inspections ns carried carried out b c checki hecking ng DPs H cabinet cabinet Pillars and subscriber lines.

-. Du Duri ring ng insp inspec ecti tion on

I ;ph ;phsi sica call in insp spec ecti tion on(( el elec ectr tric ical al para parame mete ters rs of the li line nes s an and d di dial als s are are to be

;;;;;;;;;;;;;;;;;;;;;;;;.. 0.

"hat ar are e the poi points nts to be ch checked ecked d during uring iinspec nspection tion of >ter >ternal nal pla plant. nt.

18. Points shoul should d be carried out at cabinets cabinets and pil pillars lars for & 11. Points to b be e checked of pol pole e mount mounted ed DP 188J c check heck of DP is necessar. 12. "rite th the e tests for @ubscrib @ubscribers ers Dial . 13. "rite the dis advantages of teeing of under underground ground cable. 14. write some ttest est ffor or $unction ables.

CHAPTER 8I I# $% $% h! h! 'a 'a  *% *%h h +,% +,%a' a'! ! *-".:: *-".:: 1.

"hen the insula insulation tion betw between een th the e ear earth th and the c conduc onductor tor iin n test in a c cable able becom becomes es ver ver  low the fault fault iis s called ;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;

2.

"hen th the e insul insulatio ation n between between cond conductor uctors s in the cable cable or betw between een the p pairs airs or betw between een pair and ear earth th falls falls below a prescribed limit =normall 8. meg ohm! the fault is called ;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;; ;;

3.

"hen the o onduct nductor or is cut the then n the fault is is called ;;;;;; ;;;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;

4. "hen th the e res resist istanc ance e bet betwee ween n the wires wires or betwee between n the conduc conductor tors s becomes becomes ver low even withou withoutt an loop in the circuit on the pairs the fault is called ;;;;;;;;;;;;;;;;. ;;;;;;;;;;;;;;;;. . The e>i e>iste stence nce of pot potent ential ial(( even even when when the cir circui cuitt is idl idle e or isolate isolated d from from the pote potenti ntial al of e>chan e>change ge and subscriber premises e'uipment then the fault is called ;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;; +.

hem hemical ical and and electr electro o chemical chemical acti action on which which damage damages s the outer s sheath heath an and d the condu conductor ctor of the the cable is due to ;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;

,.

@hea @heath th is effec effected ted due to mecha mechanical nical stresses stresses during constructi construction on and hence; hence;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;;; ;;;;;;;; ;;;; happen longitudinal( transverse( tensional oscillation or periodical variation of temperature or repeated overheating of the sheath

-.

/ad const construct ructional ional pra practice ctices s like in;efficie in;efficient( nt( nonst nonstandard andard and careless careless wor work;man k;man ship( ship( special speciall l during the time of laing I )ointing of cable result in ;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

 

0.

This in instrum strument ent is e>tensive e>tensivel l used in all the cable cable maintenan maintenance ce sections sections for test testing ing all t tpes pes of faults faults which on "heatstone /ridge principle is ;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;

II# II# W"% W"%! ! +h +h-" -" -! -!+ + O ::  

18. "rite different procedures adopted for fault detection.

KEY TO QUESTION BANK UNDERGRUND TELECOM CABLES# A+*!"+ - Chap!" I:: 1.

$u $unc ncti tion on circ circui uitt 2. Di Dist stri ribu buti tion on po poin intt =D =D.P .P.! .! 3. Di Dist stri ribu buti tion on cabl cable e 4.%n 4.%nar armo mour ured ed ca cabl bles es . $e $ell ll  co comp mpou ound nd +. *echanical protection. , 8.+3 mm -. moisture moisture or water 0.cross talk 18. 8 pairs. 11. True 12. True 13. true 14. True True A+*!"+ - Chap!" II 1. @hortest 2. Eight angles 3.  able able )oints 4. 1 times . F6 pipes +. avoided ,. damages -. w warning arning /ricks 0.route indicators 18. $oint indicat indicators ors 11. 08 cm 12. The st standard andard mechanical protections tthat hat are normall normall used are warning bricks over the cable. Ecc tiles( @plit pipes( and F6 pipes in concrete. 13 Phsical deformit over looked b KB( which is rare and Damages caused during loading and unloading or at stores. A+*!"+ - Chap!" III:: 1. Tee )oint 2. /ranch. 3. @traight )oint. 4. Paper insulated( sleeves . 288 numbers +. 28 pair ,. #ead sheathed -. #imited lengths availabilit availabilit(( for )ointing new cable to e>isting cable( for transferring one cable pair from one area to another area. 0. Twisting( %sing %C connectors and *odular )ointing techni'ues are the three tpes of conductor )ointing that are used in the telecom cable networks. A+*!"+ - Chap!" IV:: 1( 5le>ible cable sstem 2. Eigid cable sstem. 3. Distribution ( Primar. 4. 188 pairs . B tpe of wiring. +. rone ,. 6nsertion. 6nsertion. -. Bi Birr I Fas 0. Disconnection Disconnection plug plug or Test plug 18.The two tpes tpes of DP@ are >ternal >ternal DP and 6nternal DP =or wall DP!. 11. "hile preparing leading in cables at *D5( abinet( Pillar or at DPs the end cables laid at the termination points additional length is to be kept to directl terminate the cable pairs with out an )oint near the termination point to avoid additional )oints. A+*!"+ - Chap!" V:: 1.Parallelism 1.Parallelis m 2. 08 degrees 3 /ooster( Eeturn conductors 4.FD tubes. . -88 meters. +. 2 feet ,. @olids or pipes. -. Power contact protectors. 0. #ow fre'uenc induction. 18.personnel 11. guarding . 12.

@erious @erious ha:a ha:ards rds to 'uipment 'uipment and and personal personal of telecom telecom e'uipment e'uipment due tto o unawar unaware e ness of indu inductio ction n as the e'uipment is designed to take 8 v or less voltage. The fact that 8 L is our working voltage( which is not dangerous weighs heavil in the mind of the staff handling lines.

13.

=a!Fet =a!Fet PT PT clearance clearance the rroutes outes as as per the norms norms an and d #a cabl cables es belo below w 2 feet iin n solid or pipes at at 08 degrees to the power cable. =b! The pol;al sheath continuit should be invariabl provided continuit at all )oint places.

14.

"hile using using iinsula nsulated ted too tools ls lik like e pliers pliers and glo gloves( ves( etc. etc. proper care mu must st be tak taken en to ensu ensure re that insula insulation tion iis s ade'uate and intact.

1.

The low fre'uen fre'uenc c induct induction ion has a serious serious effec effectt on the 'ual 'ualit it of tel telecom ecom circuits circuits an and d signal signaling ing as a whol whole. e. The effect varies with the length of parallelism( distance of separation and soil receptivit.

A+*!"+ - Chap!" VI :

 

1. able records are ver effective effective tools for the maintenance of c cable able networks. The cable records ma be divided iinto nto three categories vi: =a! Plan =b! #ine diagram and =c! cards. 2. This is necessar for all e>isting e>isting >changes. 6t ma be drawn to an convenient scal scale e sa  cm to 18 cms. to a km and ma show the following detailsG; i. i...

/o /oun unda dari ries es of e>is e>isti ting ng e> e>ch chan ange ge area area defi define ned dp pre reci cise sel l

ii. ii.

Prop Propos osed ed bo boun unda dari ries es of futu future re e> e>ch chang anges es bu butt llia iabl ble e tto o alt alter erat atio ions ns..

iii.

#ocati ation of e>isting e> e>c changes

iv iv..

#o #oca cali liti ties es wh wher ere e ffut utur ure ee e>c >cha hang nges es ma ma  be be s sit itua uate ted. d.

3.These cards show the number( si:e tpe =internal or e>ternal! and location of the DP and how each terminal of the DP is unutili:ed. The also indicate the distant end terminal code corresponding to each terminal of the DP one card is re'uired for each 18 or 28 pairs DP 4.ach card shows the following particulars( number ( si:e and a nd tpe of the T. bo>( si:e of shell( location of the cabinet or pillar( circuit working. working. Ane each terminal of the T bo>( the terminal to which it is )umpered or strapped for setting up the circuit( the the distant end terminal code corresponding to each terminal of the T bo> and the codes of cable pairs connected to the terminals. .Eegular foot patrolling patrolling of cable routes are to be carried out b cable cable maintenance part. The will keep watc watch h on the cable routes( the indicators indicators and the condition of Dps. The foot patrolli patrolling ng will effectivel effectivel  reduce the damages to the cables caused b the digging of various other service utilit departments and individuals. A+*!"+ - 2hap!" VII 1.able record management sstem. 2.etralised data base( telecom assets management in a singular sstem( integration with 5E@( ease of fault locali:ation( stimates stimates for up gradationHe>pansion can be generated 'uickl. A+*!"+ - Chap!" VIII e to @hort Bnswers GG 1.Bt this position( a separate fault card is maintained for each telephone. An receipt of a fault docket( the operator make an entr of the date and time of fault reported on the fault card. The docket with the fault car card d clipped to it should be forwarded to the 6nitial testing position. 2. Bt 6nitial Testing Position 3.Detection of missing dockets( make a list of all the cases where the fault rectification has got delaed or is likel to get deleted. 4.Director number of the customer( name and address and other accessories( categor of the telephone( tpe of subscriber( *D5 termination details( Pillar and DP termination details. .Details of complaints booked( pending faults( faults cleared with nature of faults( details of dockets pending for initial testing H final testing at an instance of time( list of telephones which recorded two or more than two faults during a particular period( analsis of total complaints booked in the month( fault analsis reports( details of cable faults. <# 1.

6t handles ver huge da data ver efficientl with fa far greater accurac a an nd speed a as s co compared to m ma anual sstem.

2. 3.

5low of information from one position to another is almost instantaneous. The paper work is almost eliminated.

 

A+*!"+ - Chap!" I8 : 1. /reak down of cables 2. cable faults 3. %nderground cables ( P6$5 4. tails directl. . directl from +. cable )oint faults ,. discouraged. -. rimping pliers 0. $ell. 18. $oints 11. noise or induction.12. DP 13.$oints 14. 5looding of trench. 1. go unnoticed 1+. Dr core cables A+*!" - Chap!" 8 : 1. replaced 2. removed b erection of 3. 88 line capacit 4. @ubscriber line +. ustomer premises ,. e>ternal plant -. Tested as per norms

. loop resistance

A+*!" - 1,!+%- N-#= a. abinets and pillars. b. Pole; *ounted DP c.6nternal DP d. @ervice line. e. 6ndoor <ouse "iring g. lectric Parameters of #ine h. Dial of subscriber9s instrument 6. $unction cable A+*!" - 1,!+%- N-#3> a! The abin abinets ets Hpill Hpillars ars sho should uld be lloca ocated ted at o obst bstruc ructio tion n free free plac place e on concre concrete te b base ase and hei height ght sho should uld be above flood level. b! The The cabi cabine nett H pill pillar ars s sho shoul uld d be nu numb mber ered ed prop proper erl l c! The do doors s sh hould o op pen an and c cllos ose e ffrreel el . d! The The c cab abin inet etHp Hpil illa larr s sho houl uld d be be n nea eatt I cl clea ean n fro from m iins nsid ide. e. e! The The pill pillar ar sh shel elll sh shou ould ld be fi firm rml l fi fi>e >ed d and and bo bolt lts s shou should ld be ti tigh ght. t. f! T /o> /o> sho shoul uld db be e ffi> i>ed ed fi firm rml l to the the ffra rame me an and d all all fi fi>i >ing ng sc scre rews ws shoul should db be e ttig ight ht.. A+*!" - 1,!+%- N-#33 a! DP should should be loc locate ated d at at o obst bstruc ructio tion n free free place place and no w wa a n near ear the vi vicin cinit it of el elect ectric ric pol poles es etc etc.. b! The DP DP sh shou oulld be be p pa ainted an and n nu umbered. c! d!

*ini *i heig he ight htbe o off D DP P perl sho shoul dtted be 09f eet t =2. =post 2., ,*! fr om the the gro roun und. d. rd % ba The Thnimu e mum DPmsh shoul ould d p pro rope rl uld fi fitt ed 0 to to9fee the the po st *! b b  from me mean ans s ofg stan standa dard back ck and and s sad addl dles es.. Th The e back back o off th the e % backs should be flattered for giving good grip on the tubular posts.

A+*!" - 1,!+%- N-#36 / dialing 8.;18 6P@ GGG Bcceptable standard 18M1 6P@ A+*!" - 1,!+%- N-#37 6t has been noticed that tested for subscribers capacitance and insulation are distorted due to long length of Teed pairs. These lines ma be offered offered for BHT after Tee )oint )oint is removed. ANSWER TO QUESTION NO#39 The following information should be noted about the )unction cables a! Tpe of $n cable. b! Pl Plac aces es betw betwee een n )un unct ctio ion n ca cabl bles es is used used.. c! Total length of $unc ncttion cab ablle d! Faug auge I apac apaciit of )unc uncti tion on ca cabl ble e e! #oaded of %nloaded. A+*!"+ - Chap!" 8I : 1. arth fault. . 5oreign potential -. /reak down of network.

2. low insulation 3. /reak or high resistance. 4. #oop or short circuit. +. orrosion due to moisture. ,. 6nter crstalline sheath damages 0. *eggar

18.The procedures used for fault detection( diagnosis and location on subscriber lines are 1.@elf supervision ? is a permanent feature and fault is noticed phsicall also. 2.Performance monitoring monitoring ? Fives the indication of the the 'ualit of the service. 3.Eoutine testing ? 6ndicate the faults that are not noticed phsicall in normal course. 4.Demand testing ? Bfter detecting the side effect of fault.

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