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
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
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
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
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
iii) Power supply and internal : 2.5 Sq.mm Min.
illumination. (shall ne as per
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.
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.
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
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
5. Drain wire continuity test – As per relevant standard
6. Mutual Capacitance – VDE -0472
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
10.08.01 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.