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10.00.01  The  Bidder shall supply, erect terminate and test  all


         instrumentation  cables for control and  instrumentation


         equipment/ devices/systems included under bidder’s scope


         and  ensuring completeness of the control system.


10.00.02 Any   other   application   where  it   is   felt   that


         instrumentation  cables  are  required  due  to  system/


         operating   condition  requirements,  are  also  to   be 


         provided by bidder.


10.00.03 Other  type  of cables like co-axial, optical cables  for 


         system bus,  cables  for connection of  peripherals  etc.


        (under bidder’s scope) are also to  be furnished  by the




10.00.04 Bidder  shall  supply  all  cable  erection  and  laying


         hardware like cable trays, supports, flexible  conduits,


         cable  glands lugs pull boxes etc.on as  required  basis


         for all the systems covered under this specification.


10.00.05 In  addition  to  above, bidder  shall  supply  all  the 


         cables  including co-axial cables for station  wide  WAN


         interconnecting  all  the  common plant,  main  plant  &


         control system is bidder’s scope as well as the  control


         systems   supplied  by  employer  for   Electro   Static


         Precipitators, D M plant, coal handling plant, ash water


         recirculation system etc. Further, the   instrumentation


         cables  for interconnecting few Nos.information  signals


         from each of the common plant packages being supplied by


         employer and for all signals of CW pump package to DDCMIS


         are also in the scope of bidder. 




10.01.01 All   the   instrumentation  cables  i.e.  twisted   and


         shielded  multipair  cables,  compensating  cables,  pre


         fabricated  cables  etc. shall be  flame  retardant  low


         smoke (FRLS) type.  The cables shall be provided in  non


         returnable  drums.  The  drum  length  shall  be  1000 m 


         (+/-  5%) up to & including 12 pairs and 500 m  (+/-  5%)


         above 12 pairs and B-type thermocouple cables.


10.01.02 Voltage grade of the instrumentation cables  shall  be 


         600 V (peak value).


10.01.03 All instrumentation cables covered in this specification


         shall  comply with VDE 0815, VDE 0207, part 4,  part  5,


         part  6, VDE 0816, VDE 0472, SEN 4241475, ANSI MC  96.1,


         IS-8784,  IS-10810 (latest editions) and its  amendments


         read along with this specification.


10.01.04 The  conductor shall be of minimum 0.5 Sq.mm size,  high


         conductivity,  multi-stranded  copper for all  types  of


         instrumentation   cables,   except   the    thermocouple


         extension cables which shall be 1.31 mm Sq. solid  alloy




10.01.05 The   insulation  of  individual  conductor   shall   be 


         extruded PVC meeting the requirements of VDE 0207 part 4


         compound  Y  I3.  The outer  sheath  of  instrumentation


         cables  shall be extruded PVC (compound YM1)as  per  VDE


         0207  part 5 and shall be of flame retardant  low  smoke


         (FRLS)type.  The  cable shall be provided  with  marking


         including  manufacturer’s  name,  insulation   material,


         conductor  size, No.of pairs, voltage  ratings, type  of


         cable etc. Progressive sequential marking of the  length


         of  the cable at every one meter & progressive  markings


         to  read FRLS at every 5 Mtrs. shall be provided on  the


         outer   sheath of all instrumentation cables.  Pairs  of


         cables  shall be  identified by colour coding  &  colour


         banding.   The colour of outer sheath shall be sky  blue


         so that C&I cables are easily  distinguished from  other




         Fillers  in  multiple conductor cables  shall  be  flame


         retardant  and  moisture resistant.   Cable  accessories


         such  as harnessing components, markers, bedding,  cable


         jointer,  binding  tape  etc.  shall  also  have   flame


         retardant quality.


10.01.06 All  instrumentation  cables  shall  be  provided   with


         overall  shielding.  However multipair  cables  carrying


         analogue signals shall be provided with individual  pair


         shielding in addition to over all shielding.   Shielding


         shall be of Aluminium-Mylar tape with 100% coverage  and


         with   at least   20%  overlapping.   The   thickness   of


         individual  pair shield shall be 28 micron(Min)and  that


         of  over all shield shall be 55 microns(Min).   Separate 


         drain   wires   for  individual   pair   shield(wherever


         applicable)as well as over all shield shall be provided. 


         Drain  wire  shall  be of seven(7)  strand  20  AWG(0.51


         Sq.mm)tin  coated  copper  conductor.   Maximum  lay  of


         individual twisted pair shall be 50 mm. Bidder to ensure


         that  individual  core diameter shall be   suitable  for


         maxi-termi    connection.   Insulation   thickness    of


         individual  core shall be between 0.28 and 0.35  mm  for


         0.5  Sq.mm   cables and 0.35 to 0.45 mm for  1.31  Sq.mm




10.01.07 The  outer  sheath of the instrumentation  cables  shall


         meet the following minimum requirements.


     (i) An Oxygen index of not less than 29% and a Temp.index of


         not less than 250 Deg.C. as per ASTMD-2863.



    (ii) Maximum  acid gas generation by weight as per  IEC-754-I


         shall not be more than 20%.


   (iii) Smoke  Density rating shall not be more than 60%  during


         Smoke  Density Test  as per ASTMD-2843.  The results  of


         smoke   density  test  shall  be  plotted  on  a   curve


         indicating  light absorption vs time as per  ASTMD-2843. 


         The average  area under the curve(smoke density  rating)


         shall not be more than 60%.


     (iv)Complete cable assembly shall pass Swedish Chimney  test


         as per SEN-4241475 and flammability test as  per IEEE-383.


         The  thickness  of  outer sheath shall  be  as  per  the 


         guidelines given in VDE-0816. Thickness of outer  sheath


         shall  not be less than 1.8 mm in any  case.   Allowable


         tolerance  of over all diameter of the cables  shall  be


         +/- 2 mm Max.over the declared value in technical  data


         sheets.   The variation in diameter and the  ovality  at


         any cross section shall not be more than 0.1 mm.


10.01.08 All   instrumentation  cables  shall  be  suitable   for


         continuous  operation  at  85  Deg.C. except  for  high


         temp.resistant  Teflon insulated cables which  shall  be 


         suitable  for  continuous operation at  205  Deg.C.  The 


         cables  shall  be   suitable for laying in  wet  or  dry


         locations  in trays, conduits, ducts, trenches and  under


         ground buried installations.


10.01.09 The  thermocouple extension cables shall be  of  single/


         multi pair, twisted & shielded, PVC insulated, FRLS  PVC


         sheathed  and compatible for the type  of  thermocouples


         employed.   The  material of conductor shall be  as  per


         ANSI   MC-96.1.   The  material  and   requirements   of


         conductor  insulation, shielding and outer sheath  shall


         be as per Clause No.10.01.04 to 10.01.07.


10.01.10 All  cables  near  high temp.  zone  like  burner  front


         devices metal temp.thermocouples on main steam & turbine


         casing  etc.shall  be high temp.cables, which  shall  be


         terminated  at  a  junction box in  normal  temp.  zone. 


         Thermocouple  extension  cables  and  copper   conductor


         cables   for  high  temp.applications  shall   be   with


         insulation  of individual conductor and outer sheath  of


         extruded  FEP  (i.e. Teflon)as per VDE-0207 part  6  and


         ASTMD-2116. The thickness of insulation shall be  0.5 mm


         nominal (i.e.0.4 mm Min.). These cables shall be single/


         multipair, twisted & shielded.




10.01.11 Identification of the cores & pairs shall be done  with


         suitable  colour  coding & band marking as  well  as  by


         numbering of cores/ pairs as per VDE-0815.  The  details


         of  colour coding etc.shall be as  approved by  employer


         during detailed stage.


10.01.12 For analog signals individual pair shielding & over  all


         shielding and for binary signals only over all shielding


         of instrumentation cable.


10.01.13 Cable Parameters at 20 Deg.C


     a)  Mutual  capacitance at 0.8 KHz (Max) shall be 120  nF/KM


         for  type F & I, 100 nF/KM for G Type and 200 nF/KM  for


         compensating cable.


     b)  Max. Conductor resistance  shall be 73.4 ohm/KM loop.

     c)  Insulation Resistance shall be 100 M ohm/ KM.

     d)  Cross talk fig at 0.8 KHz shall be 60 db.

     e)  Characteristic impedance (Max) at 1 KHz shall be 320 ohm.

     f)  Attenuation fig at 1 KHz (Max) shall be 1.2 db/ KM.


10.01.14  Description of  various type of Cables


    i)   Type  “A”   Size 1.31 Sq.mm – 


         Two pair shielded and twisted pair T/C Extn.cable,  ANSI


         type KX, solid alloy conductor.


   ii)   Type “B”  Size  1.31 Sq.mm – 


         Two pair shielded and twisted T/C Extn.cable,  ANSI


         type SX, solid alloy conductor.


  iii)   Type “C”  Size  1.31 Sq.mm – 


         Two  pair  shielded and twisted  heat  resistant  teflon


         Insulation  & outer sheath T/C Extn.cable, ANSI type  KX,


         solid alloy conductor.


  iv)    Type “E”  Size  0.5 Sq.mm – 


         Two  pair individual pair and over all shielded  twisted


         pair instrumentation cable for both analog and   digital


         signal  to  be  used from field  mounted  instruments  to


         local junction box.


  v)     Type “F”  Size 0.5 Sq.mm


         Multipair individual pair and over all shielded  twisted


         pair  instrumentation  cable  (4/8/12  36/48  pair)  for


         analog signals with  stranded copper  conductor.


  vi)    Type “G”  Size 0.5 Sq.mm


         Multipair    over   all   shielded   &   twisted    pair


         instrumentation cable (4/8/12 24/48/64 pair) for  binary


         signals with  stranded copper  conductor.


  vii)   Type “I”  Size 0.5 Sq.mm


         Type   F cable/type G cable with heat  resistant  teflon


         insulation & outer sheath for high temp. application.


10.01.15 All instrument cables shall be Galvanized steel wire  armoured type conforming to Indian Standard (IS-3975).


10.01.16 All cables shall be Anti rodent and antitermite type.


10.01.17 Cables  for  relay based system shall be  cable  of  1.5


         Sq.mm conductor size

10.02.00 Instrumentation  Cable Interconnection  and  Termination




10.02.01  Plug in Connector(Military Standard)


        a) Valve, Damper/ drive (internal junction boxes).

        b) Transmitter, E/P Converter process actuated switches.

        c) RTD, Thermocouple

        d) Field mounted instrument


10.02.02  Cage Clamp Type


        a) Marshalling Cubicle

        b) Local Junction Box

        c) C J C Box


10.02.03  Prefab Cable


        a) System Cabinet

        b) UCP Mounted Instrument

        c) Annunciation System


10.02.04  Manufacturer’s Standard


        a) P A System

        b) Flame Scanner etc.

        e) PC, Printer


10.03.00 Internal  Panels/ Cabinets/ System Cabinets Wiring 


10.03.01 Internal  panel/  cabinet  wiring  shall  be  of   multi

stranded  copper  conductor  with  FRLS halogen free PVC  insulation without shield and outer sheath  meeting the requirements of VDE-0815 .


10.03.02 Wiring  to  door mounted devices shall be   done  by  19


         strand copper  wire provided with adequate loop  lengths


         of  hinge wire so that  multiple door opening shall  not 


         cause fatigue breaking of the conductor.


10.03.03 All  internal  wires  shall  be  provided  with  tag   &


         identification  Nos.etched on tightly fitted ferules  at


         both  ends  in  Employer’s approved  format.  All  wires


         directly   connected   to   trip   devices   shall    be


         distinguished by one additional red colour ferrule.


10.03.04 All external connection shall be made with one wire  per


         termination point. Wires shall not be tapped or  spliced


         between terminal points.


10.03.05 All  floor slots of desk/panels/cabinets used for  cable



         entrance shall be provided with removable gasket gland


         plates  and sealing material. Split type grommets  shall


         be used for prefabricated cables.


10.03.06 All the special tools as may be required for  solder less


         connections shall be provided by bidder.


10.03.07 Wire sizes to be utilized for internal wiring –


     i)  Current(4-20 mA)                  :     0.5 Sq.mm

         Low Voltage Signals(48 V)


    ii)  Ammeter/ Voltmeter Circuit,       :     1.5 Sq.mm

         control switches etc.for

         Electrical System.


    iii) Power supply and internal         :  2.5 Sq.mm Min.    

         illumination.                        (shall  ne  as  per

                                              load requirement).


10.04.00  Junction Boxes (Field Mounted)


      a) With 20% spare terminals 


      b) 3 mm thick made of Aluminium


c) Protection Class – IP-65 or better


d) The terminal Block shall be  screw less cage clamps type


e) Lockable  from front and hinge door


 f) Bidder shall submit Type Test Report confirming to


    protection Class IP-65 for review.


10.05.00  Conduits


         All  rigid conduits, couplings and enbows shall be   hot


         dipped  galvanized rigid mild steel in  accordance  with


         IS:9357 Part-I(1980) and Part-II(1981). The conduit interior 


         and exterior surfaces shall have continuous zinc coating


         with an overcoat of transparent enamel lacker or zinc


         chromate. Flexible conduit shall be heat resistant lead


         coated steel, water leak, fire and rust proof. The temp.


         rating of flexible conduit shall be  suitable for actual




10.06.00 Optical cable shall be  steel Armour, low smoke, flame

        retarded (IEEE 383).

10.07.00  Tests (Instrumentation Cable)


10.07.01  All types and sizes of cables being supplied shall be  

          Subjected to type tests routine tests and acceptance         

          test as  specified and according to relevant standards.




Finished cable shall pass the flammability test as per IEEE-383.  In addition it shall also pass flammability test as per Class F 3 of Swedish Standard SS-4241475 (1978). The cables in the installation can be of  any (or all) of the  various types specified.  However in case of failure to pass this test, the whole lot shall be subjected to rejection.


10.07.03  ROUTINE  TEST


Routine  tests shall be  carried out for each drum of cables for all types and sizes.  The following shall constitute routine as bare minimum.


a)       Conductor Resistance Measurement

b)       Insulation Resistance Measurement

c)       High Voltage Test as per D (3).




Acceptance test shall be carried out on each type and size of the instrumentation cables for acceptance of a lot.  All tests except the following tests shall constitute acceptance tests as bare minimum. Items B-3,

          4,5,6,7,8,9,11 & d(3) as mentioned above.


Further the following acceptance  test shall also be  

carried out –


1) Swedish chimney test as per SEN 4241475 and IEEE   


2) High voltage test(Water immersion test)AC & DC 

   test as per IS-5831.

3) Volume resistivity test(for sheath)as per IS-5831.

4) Check for markings and over all diameter of cables.

5) Cable length/ surface check.

6) Mutual capacitance test.

7) Attenuation test.

8) Characteristic Impedance Test.

9) Cross talk test.

 10) Visual verification of length & surface.


         10.07.05  TYPE  TEST


         Type test shall be carried out on all the type and sizes of cables.  The following shall constitute the type test

         to be  conducted as minimum. 


(A)          For Conductor (including Drain Wire)


      1.  Resistance Test    IS-5831/ IS 1554       

      2.  Diameter           IS 10810

   3.  Tin Coating Test –  IS 10810(per sulphate test)

 4.   No. of Strands     

5.          Size of each strands-

6.          Twisting Lay    


(B)   For  PVC Insulation PVC Sheath


1.     Test for thickness dia, availability

     as per spec./ approved data sheet

2.   Tensile strength & elongation – IS 10810

Test before & after aging

3.   Aging in air ovens            – IS 10810

4.   Loss of mass tests            – IS 10810  

5.   Hot Deformation test          – IS 10810

6.   Heat shock test               – IS 10810

7.   Shrinkage test                – IS 10810

8.   Cold bend/cold impact test    – IS 10810

9.   Colour fastness to water      – IS 10810

10.  Thermal stability test        – IS 10810

11.  Bleeding & blooming           – IS 10810

12.  Oxygen index test(for outer   – ASTMD-2863

     sheath and fillers)

13.  Smoke Density Test            – ASTMD-2843

     (for outer sheath and fillers)

      14.  Acid gas generation test      -(IEC-754-1)

    (for outer sheath and fillers)


(C)  For AL-Mylar Shield (Individual & over screen)


 1.  Continuity Test as per relevant IS.

       2.  Shield Thickness measurement as per approved data sheet.

       3.  Shield coverage & Overlap as per spec./ approved data 


4.       Noise Interference Test(IEEE)

5.       No.of Strands in drain wire


      (D)  For Completed cables


       1.  Dimensional checks      – IS-10810

       2.  Insulation Resistance   – IS-10810

       3.  High Voltage test       – IS-10810

          (dielectric strength and

           resistance to direct current)


       4.  Flammability test       – IEEE-383, SS4241475 

                                     Ref.No.10.06.02 below


       5.  Drain wire continuity test – As per relevant standard


       6.  Mutual Capacitance        VDE -0472

          (Wherever applicable)

       7.  Cross talk                IS-10810


8.    Noise Interference Test –



10.07.06 For these tests, the selection of cable drums shall be at random, as per the following sampling plan.



           S.No.  No.of Drums in the Lot    No.of Drums to be

                                            Taken as sample   


           1.   Up  to   50                       2

           2.   51  to  100                       5

           3.  101  to  300                      13

           4.  301  to  500                      20

           5.  501  &  above                     32  



 10.08.00 GENERAL


 10.08.01 Cable shall segregated as per IEEE-422.


 10.08.02 Cable Glands


          Cables shall be terminated using double compression type cable glands.  Cable glands shall conform to  BS: 6121 and be of robust construction  capable of clamping cable and cable armour (for armoured cables) firmly without injury to insulation. Cable glands shall be made of  heavy duty brass machine finished and nickel chrome plated.  Thickness of plating shall not be less than 10 micron.  All  washers and  hardware shall be made of  brass with nickel chrome plating Rubber components shall be of neoprene and of tested quality.


10.08.03 Cable Trays   


Cable trays, fittings and accessories shall be fabricated out of rolled mild steel sheets free from flaws such as laminations, rolling marks, pitting etc. These(including hardware)shall be  hot dip galvanized as per relevant IS.







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