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8/11/2019 PIJF Cables Ukb
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Armoured PIJF Cable
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Unarmoured PIJF Cable
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Cross section
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Cable Layering
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2400 Pair
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Conductor: Solid annealed copperith conductor sizes of 0.4 & 0.6mm.
Insulation: Colored high molecular weight solid High Density Polyethylene.
Color Coding: Cables are fully color coded in accordance with PIC even count color code.
Twining/pairing: Two colored insulated conductors are uniformly twisted together to form apair. Varying lay length is designed to minimize the cross talk and capacitance unbalance.
Stranding / Cabling: Twisted pairs are assembled into unit of 25 pairs. When desired for lay-upreason, the units are divided into two or more sub-units, which are bind with durably coloredpolyethylene tapes to form a compact and circular cable.
Filling Compound: The water resistant filling compound is applied to the air space within thecable core.
Core Covering: A non-hygroscopic and dielectric Polyester Tape and Water Blocking Tape areapplied helically having a suitable overlap.
Flooding Compound: Sufficient flooding compound is applied between the core wrap andshield.
Moisture Barrier Inner Sheath: An aluminum tape with co-polymer coating is applied over thecable core and then sheathed with black polyethylene compound.
Jacket: Black High Molecular weight low density polyethylene compound. Identification: A plastic tape, duly marked with the manufacturers name, year of manufacture
and cable size, if required, is placed under the core covering. Alternatively, thesse details maybe printed on the outer jacket of cable.
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CONDUCTOR
Pairing and Overlay
Unit Formation
Core wrappings
Filling compound SCREEN
SHEATH
ARMOURING
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Pairing and Overlay
Two insulated conductors shall be twisted
together with uniform lay to form a pair.
The length of the lay of any pair shall be
different from that of adjacent pairs. Thelay of various pairs shall be so chosen as
to satisfy the capacitance unbalance
requirements and cross-task requirement.
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SCREEN
An aluminum tape coated with
polythene / copolymer on both sides
shall be applied over the cable core
with a minimum overlap of 6 mm for allsizes of cables
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CODE FOR WIRE
IDENTIFICATION
Primary colors For 1st wire in a pair
White
RedBlack
Yellow
S d l F 2 d i i
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Secondary colors For 2nd wire in
a pair and binder tape of unit in
50pr/100pr unit Blue
Orange
Green
Brown
Slate/Gray
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CODE FOR TAPE OR BINDER
FOR UNIT IDENTIFICATION
Unit Colour
1 Blue
2 Orange 3 Green
4 Brown
5 Slate/Gray
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Super Units
200 & 400 pair cable su of 50 paiirs
Above 400 pairs su of 100 pairs
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Identification of super units
Position of the layer Colour
First (Marker) Red
Itermediate White
Last (Reference) Black
The numbering of the units will be clockwise
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CABLE LAYING
Receipt, storage, handling andtransport of cable
Surveying and selection of routes,
trenching and layingJointing of cables and termination
Preparation of cable plan, cablediagram and other relevant records
Acceptance testing
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SURVEYING THE SELECTION OF
ROUTE : The routes should be as short as practicable provided other requirements
viz., future requirements and expansion of other services are take in toconsideration. Normally the cable should be laid along road and railwaytracks.
(b) Corrosive soil should be avoided. If unavoidable measures likecovering
the cable with sand or drawing the cable through non-reactive duct shouldbe adopted.
(c) Opening of expensive pavements and roads should be avoided.
(d) The consideration should be given to the existence, alternation and
growth of other services.
(e) While surveying along a new road under construction or newly
developed area, proper coordination should be maintained with otherunderground services like water, electricity, sewage, gas etc.
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DEPENDING UPON THE ROUTESELECTED, PERMISSION FOR
DIGGING TRENCHES ARE TO BE
TAKEN FROM THE RELEVANTAUTHORITIES
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AT THE TIME OF TRENCHING
OPERATION CO-ORDINATION
WITH THE FOLLOWING AUTHORITIES
ARE TO BE MAINTAINED:-
(1)Electric supply.
(2) Water supple.
(3) Gas pipeline.
(4) Sewage system.
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TRENCHING :
Trenching should be such that the top of thecable should not be less than
60 cms. from the soil surface.
(b) The alignment should be straight at least 50m at a stretch.
(c) It should be at least 0.3m away from theboundary walls.
(d) The depth of the trench should be 1.2 m. (e) The width of the trench should be between
30 cm and 40 cm minimum
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(i) A separation of 0.6 m (relaxable upto 0.2m)should be maintained while cable laid parallel toelectric cables.
(ii) Parallelism exceeding 0.8 km with 11KV andabove should be referred to PTCC
(iii) At the crossing with electric cables, thetelephone cable should be laid solid in between
for 90 cm on either side. Cross-trenches (trialpits are to be made if records for existingservices
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The min. bending diameter for armouredcables should be 15 times of the
diameter of the cable
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ROAD CROSSING
Cable should be laid through G.I. pipes ofsuitable sizes.
(b) The depth of the pipe from the surface
of the road should be 1m and with a slightslope to pass away water.
(c) The number of pipes laid at a time
should be sufficient to cater to therequirements for 20 years.
(d) No jointing in the middle of the road
GUIDELINES FOR LAYING OF
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GUIDELINES FOR LAYING OF
CABLES ALONG NATIONAL
HIGH WAYS Permission from the Chief Engineer PWD is to be taken.
(b) The cables should be laid at distance not less than457 cm from the Centerline of the road on formation.
(c) The depth of the cable from the soil surface shouldnot be less than 120 cm.
(d) While laying along grove or avenue, dueconsideration to save the cable from the clutches of theroots are envisaged
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Along over bridges culverts &
Flyover
A culvert should be paid by a concrete
channel of 12 depth below the bed of the
culvert to correspond to the footpath
alignment so that all the cables can bedrawn through this opening
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In order to lay the cable across small
bridges with piers the piers should be
extended beyond the width of the road so
that pipe for cables may be securelyclamped on the piers
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In case of long bridges and fly over in
cities, liaison should be kept with proper
authorities to ensure that suitable
arrangements are provided for layingcables. the present practice is to have a
concrete channel 20 to 30 cm in depth 90
cm in width along the footpath withremovable covers
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ALONG RAILWAYS
Side of the track will be selected by DET inconsultation with proper Railway authority e.g.either Divisional Operating superintendent ordistrict Engineer, if the alignment falls within 3
to 5.5 meters from the centre line of anyRailway Track.
Excavation and reinstatement for anyunderground cable within 3 meters of thecentre of any Railway track or any attachmentto any Railway structure should be attended bythe Railway staff at the cost of DOT.
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RAILWAY CROSSING
Railway track should be crossed by G.I. pipes
of 75 mm dia.
Minimum depth of the GI pipe from below the
rail level should be 1.25 meters. The length of the pipe should be sufficiently
long so that work on telecom alignment can be
carried out without any hindrance to the
railway traffic. This should extend at least 4.5
meters from the center of the last track.
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LAYING METHOD OF THE
CABLE
Laying direct in the
ground
laying solid drawing through
duct or duct laying
Digging the trench as perstandard The digging may bedone manually or be thrustboring or by other mechanical
means. Preparation of a bedding 5 cm
high of soft soil (sieved earth)free from stones and corrosive
elements. Thorough checking of cablewhich is to be laid.
Paying out the cable in thetrench
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LAYING METHOD OF THE
CABLE
Laying direct in the
ground
laying solid drawing through
duct or duct laying
As a protective measure a row
of bricks
(length wise or width wise
depending upon the number ofcables) or stone slabs are to be
placed along with cable
alignment. The modern practice
is to lay a plastic tape with name
of the Department printed on it
at about 30 cms above and
along with cable alignment
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LAYING METHOD OF THE
CABLE
Laying direct in the
ground
laying solid drawing through
duct or duct laying
As a protective measure a row
of bricks
(length wise or width wise
depending upon the number ofcables) or stone slabs are to be
placed along with cable
alignment. The modern practice
is to lay a plastic tape with name
of the Department printed on it
at about 30 cms above and
along with cable alignment
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DIRECT LAYING
Digging the trench as per standard Thedigging may be done manually or be thrustboring or by other mechanical means.
Preparation of a bedding 5 cm high ofsoft soil (sieved earth) free from stonesand corrosive elements.
Thorough checking of cable which is tobe laid.
Paying out the cable in the trench
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Precautions at the time of paying
There should not be any twist in the cable and
there should not be heavy strain (specially in
the case of un armoured cable)
Laying should be as far as practicablestraight and along one side of the bed of the
trench .
If more than one cable are to be laid at a
time, there must not be any criss-cross of the
cables.
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Warning Bricks or tapes
As a protective measure a row of bricks
(length wise or width wise depending upon
the number of cables) or stone slabs are
to be placed along with cable alignment.
The modern practice is to lay a plastic
tape with name of the Department printed
on it at about 30 cms above and alongwith cable alignment
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Preparation of diagrams &
records
All the diagrams relating to the cable
alignment viz. line diagram for primary
secondary and distribution side, cable
plan for primary secondary and distributionside, records for Pillars and DPs etc. are
to be prepared.
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JOINTING ACTIVITY
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Some Common Wrong Practices
and Their Remedies.
Crossing Water Pipes
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Crossing Culverts
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Crossing 11KV Electric Cables
In respect of parallelism, it is advisable to take
the telecom cable with maximum horizontal
clearance as far as practicable but not less than
0.6 meters Absence of sheath continuity and armour
continuity in Telecom cable and its improper
earthing in the vicinity of power cable will result
in AC induction and consequent impairment ofthe telecom circuits
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. In case of crossings, care should be taken see
that telecom cable crosses at right angles and at
a vertical clearance preferably of 0.6 meters but
not less than 0.3 meters at any point. When thespecified clearances cannot be maintained, it is
preferable to lay the telecom cable through
cement concrete pipes for a length of 1 meter on
either side of power cable at the crossing andseal the mouths at both ends.
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CABLE JOINTING
STRAIGHT JOINT
BRANCH JOINT
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ARRANGEMENTS TO BE MADE
BEFORE THE START OF JOINTING
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DIFFERENT JOINTING
PROCEDURES IN TELECOM
CABLES
LEAD SLEEVE JOINTS
AUXILIARY LEAD SLEEVE SEAL(ALSS) JOINT.
JOINTING OF JELLY FILLED CABLES
USINGT THERMOSHRINKINGTECHNIQUE
PROCEDURE FOR JOINTING J.F.
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PROCEDURE FOR JOINTING J.F.CABLE USING XAGA
TECHNIQUE Cable Marking
Armour removing
Conductor Jointing
Filling of Compound
Metal Canister
Cable Preparation
Thermo shrinking
Armour Continuity Completed
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Kit Selection
TSF 1 10/6.5, 20/6.5
TSF2 50/6.5
TSF3 100/6.5
TSF4 200,300, 400/6.5
TSF5 600, 800/6.5
TSF 6 1000 ,1200/6.5
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When cables to be jointed are of same
pair found on both sides, use the kit
indicated in the kit selection chart
b)When one cable is larger in pair count
than the other, the kit indicated against
the smaller one is to be used, e.g. to join a
100 pair cable to a 20 pair cable, TST1 is to be used.
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. The sum of the diameters of all the cables on
the branch side plus the thickness of branch
clips should not exceed the maximum splice
bundle diameter indicated in the kit selectionchart.
Condition 2. If any side contains only one
cable, the diameter of the single cable should
not fall below the minimum cable diameterindicated in the kit selection chart.
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Kit Selection
TSF 1 TSF2
TSF4
TSF5
TSF 6
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Kit Selection
TSF 1 TSF2
TSF4
TSF5
TSF 6
10/6.5, 20/6.5
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Kit Selection
TSF 1 TSF2
TSF4
TSF5
TSF 6
18/6.5, 28/6.5
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Kit Selection
TSF 1 TSF2
TSF4
TSF5
TSF 6
10/6.5, 20/6.5
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Kit Selection
TSF 1 TSF2
TSF4
TSF5
TSF 6
10/6.5, 20/6.5
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Kit Selection
TSF 1 TSF2
TSF4
TSF5
TSF 6
10/6.5, 20/6.5