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10.CONTROL AND INSTRUMENTATION CABLE October 16, 2008

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10.00.00  CONTROL AND INSTRUMENTATION CABLE

 

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

 

         bidder.

 

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. 

 

10.01.00 INSTRUMENTATION CABLE SPECIFICATIONS

 

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

 

         type.

 

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

 

         cables.

 

         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

 

         cables.

 

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

       

         Philosophy.

 

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

 

         application.

 

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.

 

10.07.02  FLAMMABILITY  TEST

 

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).

 

10.07.04   FACTORY ACCEPTANCE  TEST

 

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   

   383.

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 

           sheet.

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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