LV WIRES AND CABLES
PART 1 - GENERAL
1.01 RELATED DOCUMENTS
A. Drawings and general provisions of Contract, including General and
Supplementary Conditions and Division 1 Specification Sections, apply to
this sections.
B. Requirements of the following Division 16 Sections apply to this section:
1. “ Basic Electrical Materials and Methods.”
1.02 SUMMARY
A. This Section includes wire
s, cables, and connectors for power, lighting
signal, control and related systems rated 600 volts and less. For special
wiring for individual systems, refer to respective section of these
specifications.
B. Extent of electrical wire and cable work is indicated by drawings and
schedules
C. Types of electrical wire, cable, and connectors specified in this section
include the following:
1. Single core copper conductor/cables
2. Multicore copper conductor/cables.
3. Fixtures wires
4. Control and signal cables.
D. Applications of electrical wire, cable, and connectors required for project
are as follows:
1. For power distribution circuits.
2. For lighting circuits.
3. For appliance and equipment circuits.
4. Foe motor-branch circuits.
5. For signal and control circuits where not specifically
required otherwise under other sections of the
specification.
E. Related Sections: The following sections contain requirements that relate
to this section:
2
1. Division 16 Section “Electrical Boxes, Cabinets and Fittings“ for
connectors for Terminating Cables in boxes and other electrical
enclosures.
2. Division 16 Section "MV Cables” for medium voltage distribution”.
3. Division 16 “Fire Alarm System: for fire alarm cables”
4. Division 16 Section "Wiring basket system” .
5. Division 16 Section "Cable Trays” .
1.03 SUBMITTALS
A. Product Data: submit manufacturer’s data on electrical wires, cables and
connectors.
B. Field Test Reports: indicating and interpreting test results relative to
compliance with performance requirements of testing standards.
C. Technical Data: submit data for approval including, but not limited to, the
following:
- Constructional details, standards to which cables comply, current
carrying capacities, derating factors for grouping and temperature.
- Manufacturer’s catalogue cuts.
- Dimensional and electrical characteristics.
- Samples of each cable and wire, if requested by the Engineer, other
accessories
D. Certificate of Origin: for each lot of cable supplies, provide a certificate of
origin issued by manufacturer stating origin, date of manufacture,
composition, standards to which it complies and test certificates.
E. Shop and Construction Drawings: submit drawings for approval including,
but not limited to, the following:
1. Exact routing layouts, sections and profiles of busducts, trays, feeder,
sub feeder cables and branch circuits, with indication of any equipment
to show and verify coordination between various trades.
2. Details, of supports and fixing for buses, trays and cables.
1. Details of connections to transformers, switchboards panelboards etc.
2. Details of terminations, splices and tapings where permitted, glands
and bushings at enclosures.
3. Number and size of conductors in conduit for all branch circuits in
accordance with final conduit routing.
F. Samples: Submit 25 cm length cables of each type and size of wires and
Cables, Manufacturer Name, insulation class and reference No. should be
indicated on the Submitted Sample.
1.04 QUALITY ASSURANCE:
3
A. Regulatory Requirements: Comply with provision of the statutory laws
having jurisdiction and local codes of practice applicable to the job site/host
country.
B. Current carrying capacities of conductors have been determined in
accordance with the Regulations for specified type of insulation and
expected conditions of installation No change will be accepted in specified
type of insulation unless warranted by special conditions and approved by
the Engineer. Check various loads and current carrying capacities and report
any discrepancies or insufficiency of size indicated to the Engineer.
C. Standards: wires and cables are to comply with IEC, BS, local codes or
other equally approved standards and are to bear the mark of identification
of the Standards to which they are manufactured. Wires and cables not
having this identification will be rejected.
D. Conform to applicable codes and regulations regarding toxicity of
combustion products of insulating materials.
E. Manufacturers: firms regularly engaged in manufacture of electrical wire
and cable products of types and sizes required, whose products have been in
satisfactory use in similar service for not less than 5 years.
1.05 DELIVERY STORAGE, AND HANDLING:
A. Deliver wire an cable properly packaged in factory-fabricated type
containers, wound on factory reels.
B. Store wire and cable in clean dry space in original containers. Protect
products from weather, damaging fumes, construction debris and traffic.
C. Handle wire and cable carefully to avoid abrasing, puncturing and tearing
wire and cable insulation and sheathing. Ensure that dielectric resistance
integrity of wires/cable is maintained.
PART 2 - PRODUCTS
2.01 MANUFACTURERS:
A. Available Manufacturers: subject to compliance with requirements,
Specifications, design drawings and regulations.
B. For approved manufacturers refer to the recommended manufacturer list.
2.02 WIRES AND CABLES
A. General: unless otherwise specified or shown on the Drawings, cables and
other feeders are to have copper conductors. Cable conductors are to be
stranded for sections 2.5 mm2 and above , based on IEC 228 Class 2. Signal
and control cables are to have solid conductors unless otherwise specified.
Flexible cords are to have finely stranded conductors. Conductors of single
4
and multi-core cables 25 mm2 and above are to be compacted. Multi-core
cables 35 mm2 and above are to be sectoral shape.
1. Conductor Sizes: are to be metric and as shown on the Drawings.
Conductors with cross-sectional area smaller than specified will not be
accepted.
2. Building Wiring Insulation: in the absence of a national code/regulation,
insulation is to be colour coded or otherwise identified as follows:
a) Neutral is to be black.
b) Protective earth is to be green or green/yellow striped.
c) Phase colour are to be selected in accordance with local regulations
and IEC standards, where not in contradiction with the local
regulations.
3. Copper conductors shall be stranded for sections 2.5mm2, and above.
Signal and control cables shall have solid conductors. Flexible cords shall
have finely stranded conductos.
4. The insulation of each conductor shall be colour coded or otherwise
identified as required by the Regulations. Colour coding shall be
maintained throughout the entire installation.
5. For each lot of cable supply a certificate of origin issued by the
manufacturer stating its origin, manufacture, constitution and standards to
which it complies with. In the absence of such documents, the Engineer
reserves the right to require that tests, at the Contractor's expense, be
performed by an official laboratory on samples taken from lots of cables
delivered to the site.
6. Cable installations whether so indicated or not shall include all joint and
their accessories at terminating ends or at tap-off points, earthing and
bonding etc. Carried to completion.
7. all cables shall be delivered to site with the manufacturer's seals, labels or
other proof of origin intact. Such labels and seals shall not be removed
until the cable is required for use, and shall be retained for inspection.
8. Unless otherwise specified herein or indicated on the drawings or in the
cable schedules all cable over sheaths shall be black.
9. Where cable sizes are not indicated on the drawings or in the cable
schedules, the contractor shall be responsible for determining the correct
size of each cable. Cable sizes shall be determined on the basis of current
rating and/or voltage drop and/or earth loop impedance, together within
allowance for grouping with other cables and the method of installation
whichever is relevant, after taking into account the type of cable, the
ambient conditions, the method of installation and the disposition of each
cable relative to other cables.
10. Wherever cables pass through walls, ceilings, partitions and the like, a
heavy gauge PVC sleeve shall be provided, of internal diameter greater by
5
at least 15mm, but no more than 25mm, than the diameter of the cable and
fire stopping Materials should be filled around cables.
11. The length of any such sleeve shall be such that each end projects by 5mm
beyond the surface of the element through which it passes, and the ends of
they bore shall be provided with an adequate radius to prevent chafing of
the cable sheath.
B. LV Wires:
1. Single Core PVC Insulated Wires: unless otherwise specified, single
conductor wires for wiring in conduit are to have annealed copper
consuctors, generally with concentric strands and insulated with flame
retardant, moisture and heat resistant PVC/D to IEC 227 (type 1 to BS
6746), suitable for wet locations and for conductor temperature of 70 deg
C. wires are to be 450/750 V grade.
C. LV Cables:
1. Multi-core PVC Insulated Cables (0.6/1 kV): to have annealed, copper
conductors, insulated with PVC/D to IEC 227 (type 1 to BS 6746), flame
retardant, moisture and heat resistant, suitable for wet locations and
conductor temperatures of 70 deg. C, laid up, bedded with suitable filler
and sheathed with PVC. Armour cables are to have single layer of
galvanized steel wire armour with PVC over sheath. Cables are to comply
with IEC 502 and IEC 540.
2. Multicore XLPE Insulated Feeder Cables (0.6/1 kV): single core annealed
copper conductors, XLPE insulated, for conductor temperature of 90 deg.
C, laid up and bedded with suitable non-hygroscopic material compatible
are to have single layer of galvanized steel wire applied helically over
extruded PVC bedding (which may be an integral part of filling) and over
sheathed with PVC, colour black. PVC oversheaths are to be type ST2 to
IEC 502.
3. Flexible Cable for Connection to Appliances, Window Fans, Pendants etc:
is to be 300/500 V grade to BS 6500, three or four core, with tinned finely
stranded copper wires, EPR insulated, twisted and sheathed with
chlorosulphonated polyethylene (CSP compound) and with strengthening
cord.
4. High Temperature Cable (similar to Perilli FP-200 Gold or equal): solid or
stranded plain annealed copper conductors to BS 6360(in sizes up to 4
mm2), extruded silicon rubber insulation to BS 6889 (0.6 mm radial
thickness), aluminum/PVC laminate and PVC composite sheath with
tinned earth continuity conductor/drain wire. Cable is to be rated 300/500
V, capable of accepting voltage surges up to 5 kV, to operate continuously
at 150deg C. and for short durations at 200 deg. C. It is to be certified to
have passed IEC 331 and IEC 332 flame resistance and fire retardant tests.
6
5. High Temperature Cable (similar to Perilli FP-400 or equal): plain copper
stranded circular conductor complying with BS 6360, Mica/Glass Fire
resistant tape covered by extruded cross-linked insulation comply with BS
7655 operating temperature 90OC, cables is to be rated 600/1000V. It is to
be certified to have passed IEC 331, BS 6387 categories CWZ, and IEC
332-1 flame resistance and fire retardant test. Cables are to be used to feed
the fire pumps. and other loads as shown on the drawings.
D. Control and Signal Cables
1. Multicore PVC Insulated Control Cables: 0.6/1 kV rating, solid 1.5mm2,
2.5 mm2 or stranded 4 mm2 plain circular copper conductors, with heat
resistive PVC/D to IEC 227(PVC type to BS 6747), rated for 70 deg. C, of
7, 12, 19, 24, 30 or 37 cores are to be laid up together and filled with nonhygroscopic
material, PVC over sheathed, to form compact and circular
cable for use in switchgear, control gear and generally for control of power
and lighting systems. Armoured cable is to have extruded PVC bedding
which may be an integral part of the filling, galvanized steel wire
armouring, and over sheath of PVC type ST2 to IEC 502, colour black.
Core identification is to be white printed numbers 1,2,3 etc. over black
insulation.
2. PE Insulated Control and Signal Cables: for use on instrumentation or data
systems, are to be generally 300 V rating, polyethylene insulated, colour
coded, tinned copper conductors(0.6 mm diameter), twisted together into
pairs Multi-pair core assembly is to be covered with binder tape, spirally
wound 0.075 mm bare copper shielding tape and provided with drain wire
and overall PVC sheath.
3. Control and Signal Cables, enclosed in conduit and raceways with power
cables, are to be insulated for same voltage grade. Cables used for
controlling equipment related to the life safety are to be of the fire
resistance type.
E. Connectors (LV Power)
1. Connector – Type A-1: pressure indent type, for terminating or making Ttaps
and splices on conductors 10 mm2 and smaller. Connector is to be
non-ferrous copper alloy applied to conductor by mechanical crimping
pressure, with vinyl insulating sleeves or phenolic insulating covers.
2. Connector – Type-A –2 bolted pressure split type for terminating or
making t-taps and splices on conductors 16 mm2 and large. Connector is
to be cast non-ferrous copper alloy applied to conductor by clamping with
minimum of two screws and provided with phenolic insulating cover.
3. Connector – Type B-1 : pre-insulated spring type, for branch circuit and
fixture wiring. Connector is to be steel encased spring with shell,
insulated with vinyl cap and skirt, type Scotchlok brand, as manufactured
by Minnesota Mining & Mfg. Co. or other equal and approved.
7
2.03 IDENTIFICATION OF CABLES AND WIRES
1. Except in the case where it is terminated in full view onto a clearly labeled
switch, starter, distribution board or similar piece of apparatus, or onto a
motor or other item of equipment the function of which is evident, each
and every cable end shall be provided with an approved means of
identification. In particular, this requirement shall apply to all cables
terminating on the back or in the base, of cubicle type or similar
switchboard or control panel and in any other case where the function of
the cable is not immediately obvious.
2. The means of identification shall be one or other of the following:-
i. An engraved brass label securely fixed to the cable sealing box.
ii. A stamped brass label securely tied to the cable with tinned copper
binding wire.
3. Self-adhesive embossed plastic labels will not be accepted as means of
identification.
4. The means of identification shall give the cable size, number of cores, and
function together with the cable reference number if one has been
allocated.
5. All cables run above ground shall be identified by means of engraved or
stamped brass label at intervals not exceeding 30 meters. The labels shall
bear details of the cable size, number of cores, function and reference
number (if any) and shall be securely attached to the cables with tinned
copper binding wires.
PART 3 - EXECUTION
3.01 INSTALLATION OF WIRES AND CABLES:
A. General: install electrical cables, wires and wiring connectors as indicated,
in compliance with applicable requirements of the Regulations/codes
applicable, and IEC, BS and in accordance with recognized industry
practices. Building wires and cables are to be installed in conduit, trunking
or ducts indoors and in conduit and ducts outdoors, unless shown otherwise
on the drawings.
B. Co-ordinate: wire/cable installation work including electrical raceway and
equipment installation work, as necessary to properly interface installation
of wires/cable with other work.
C. Run d.c. wiring in separate conduits than a.c. wiring.
D. Run: emergency lighting and power circuits in separate conduits from
normal wiring.
8
E. Use pulling compound or lubricant, where necessary, compound or
lubricant used must not deteriorate conductor or insulation and must be
approved by the Engineer.
F. Use pulling means including, fish tape, cable, rope and basket weave
wire/cable grips which will not damage cables or raceway.
G. Maintain colour coding throughout installation. Phase-conductors for which
outer jacket is not colour coded are to have engraved alphanumeric mark
(L1, L2, L3) or colour coded heat-shrinkable sleeves.
H. Buried Cables: cables buried directly in the ground are to be armoured type,
unless otherwise indicated in particular sections of the specification or on
the Drawings.
I. Install exposed cable, parallel and perpendicular to surfaces, or exposed
structural members, and follow surface contours, where possible.
J. Keep conductor splices to minimum. In case of splices, these are to be
inside splice boxes, pull or junction boxes.
K. Install splices and tapes which possess equivalent-or better mechanical
strength and insulation ratings than conductors being spliced.
L. Use splice and tap connectors which are compatible with conductor
material.
M. Tighten electrical connectors and terminals, including screws and bolts, in
accordance with manufacturer’s published torque tightening values. Where
manufacturer’s torquing requirements are not indicated, tighten connectors
and terminals to comply with tightening torques specified in recognized
standards.
N. Pull cables simultaneously where more than one cable is being installed in
the same raceway.
O. Branching of wires in raceways is to be in accordance with raceway filling
factors permitted by the Regulations.
P. Control cables may be fixes to racks, installed directly on cable trays or
pulled in conduit and trunking indoors, and in underground ducts or in
conduit outdoors.
Q. Bunching of wires in conduits check that inside of conduit (and raceway in
general) is free of burrs and is dry and clean.
R. Before: pulling wires in conduits check that inside of conduit (and raceway
in general) is free of burrs and is dry and clean.
9
S. Support: cables and wires pulled inside very high conduit risers are to be
supported at upper end of risers and at intermediate points by split rubber
grommets to relieve any stresses on conductors, where required.
T. Extra Length: at every branch circuit outlet and pull-box, every cable
passing through is to be left to allow inspection and for connections to be
made. Cables terminating in outlet boxes are to be left with at least 250mm
extra length for terminations.
U. Joints or taps in wires and cables, if permitted, are to be permanently
accessible or made only in boxes or cabinet gutters.
V. Connectors for terminating or making T-taps and splices are to be Type A-1
on conductors 10mm2 or smaller, Type A-2 for conductors 16mm2 and
larger, and Type B-1 for branch circuit and fixture wiring.
W. Insulating covers are to be applied to prevent exposure of bare cable
connections.
X. Switch legs for local wall, switches are to have distinctive colour, selected
as complementary to cable colour coding used in the project.
Y. Terminations: conductors of wires and cables up to 16 mm2 .are to be
tightly twisted and where possible doubled back before being clamped with
set screws. Where two or more wires are looped into same terminal these
conductors are to be tightly twisted together before inserting into terminals.
In no case is bare conductor to be allowed to project beyond any insulated
shrouding or mounting of a line terminal. Cables sizes 16mm2 and larger
are to terminate in tunnel lugs with set-screw, or by using bolted or sweated
compression connectors.
Z. Tagging: tag main and feeder cables in pull-boxes, wireways and wiring
gutters of panel boards or distribution cabinets. Tags are to identify cable or
circuit number and conductor size in accordance with the schedules.
AA. Tagging: where two or more circuits are run to or through a control device,
outlet box or ceiling junction box, each circuit is to be tagged as a guide in
making connections.
BB. Do not install thermoplastic wires in computer area raised floors.
3.02 FEEDER AND SUB-FEEDER CABLE INSTALLATION
A. Cables generally are to be run through duct-banks, shafts or special
recesses, clamped to steel racks or cable trays.
B. Fixing: single cables above suspended ceilings or in concealed spaces are to
be fixed directly to walls or ceilings but must be accessible. Where two or
more cables are run in parallel, they are to be fixed on galvanized steel
perforated trays or on other approved special cable supporting and
protecting arrangement.
10
C. Clamps: where cables are fixed to steel trays or supporting structures,
approved galvanized cast steel clamps (or moulded plastic or die cast
Aluminum clamps for single core cables) are to be used at distances not
exceeding 20 diameters. Cables shall be laid parallel in one plane, with the
exception of single core cables in “trefoil” formation, with a spacing
between cables equal to the larger of the two adjacent cables.
D. Joints or splices will not be accepted on main and sub-feeders. Cables are to
be supplied in lengths sufficient for straight-through unjointed termination
to termination pull.
E. Cables laid direct in the ground shall be at a minimum depth of 750 mm
below finished level A 100 mm tamped bedding and 100 mm tamped
covering of sifted soil or sand is to be provided with a tile cover all along
the route of the cables for protection. Surface cable markers shall be
provided on every change of direction and at 50 m intervals when in a
straight line. A tape marker shall be embedded at 100mm below ground
level, all along the cable trench.
F. Where cables are installed in underground ducts the ducts shall be laid with
a minimum covering of 700mm to finished level. The ends of the ducts
shall be sealed immediately after any cable installation. The ends of any
unused ducts shall be plugged and sealed.
1. Draw wires are to be left in all unused ducts.
2. Just before pulling cables in, ducts shall be cleared with a mandrel 13 mm
(1/2 inch) smaller than the internal diameter of the duct and followed by a
circular wire brush 13mm (1/2 inch) larger in diameter than the duct.
G. Directly buried cables crossing under roads, pipe banks or other services,
are to be drawn in heavy duty PVC duct banks. IN no case are cables to be
directly buried in concrete, in masonry or in floor finishing’s.
H. Buried cables liable to mechanical damage are to be drawn through PVC
conduit or asbestos cement pipe. If steel conduit is used, all three phase
conductors, neutral and protective earth circuits are to be in the same
conduit.
I. Where multiple runs occur the cables shall be installed such that crossovers
are avoided wherever practicable, if unavoidable, suitable separators for at
least 1m each side from the cross-point must be provided according to
approved details.
J. Where cables are run on ladder rack and cable tray, the size and routes of
the rack and tray shall be carefully selected taking into account other
services. In addition to these routes the Contractor shall include for any
vertical drops of cable tray and supporting brackets where cables drop from
the main runs to switchgear and equipment.
K. In situations where individual cables pass through walls, the cables shall be
sleeved and suitably sealed. Fire barriers are to be provide as necessary by
the safety Code applicable.
L. Cables rising from ground level up walls or stanchions shall be protected by
a substantial steel frame to a height of 1.5 meters Such framework shall be
approved by the Engineer prior to the commencement of work.
11
M. Exposure To Heat: route wires and cables to prevent exposure to excessive
heat or to corrosive agents. If such condition is unavoidable, cables are to
be type designed for particular condition.
N. Insulating covers are to be applied to prevent exposure of bare cable
connections. Insulating cover is to be purpose made and is to provide
minimum insulation level equal to that of conductor insulation.
O. Glands and cable boxes for various single-core and multicore cables are to
be purpose made and suitable for rigid mounting to equipment enclosure.
P. Cables shall be identified at regular intervals and terminations with
approved cable markers.
3.03 FEEDER CABLE JOINTING AND TERMINATING
A. Though joints will not be allowed in feeder cables where adequate
manufacturer’s lengths are available. Where a joint is necessary, it has to be
made inside boxes, handholds or manholes.
B. Recommendations: through Joints and terminations are to be carried out
strictly in accordance with cable manufacturer’s recommendations, and
made with correct specified materials, boxes, tapes, compounds or
mixtures, glands and bonds as applicable.
C. Jointing skilled operatives are to be employed for jointing of cables.
Qualifications of operatives are to be submitted to the Engineer prior to
work commencing on site joints are to be filled with epoxy resin after
taping unless commencing on site. Joints are to be filled with epoxy resin
after taping unless contrary to cable manufacturer’s recommendations.
Samples site constructed cable terminations and through-joints are to be
submitted to the Engineer prior to commencing work on site. Samples are
to be constructed in the presence of the Engineer and are to be available to
the Engineer for test and inspection in accordance with manufacturer’s
recommendations.
D. Cutting tools for jointing and terminating cables are to be purpose made, to
prevent damage to insulation in general, and to cable sheathing.
E. Cleaning of lacquer on conductors is to be by use of “Sponge and white
spirit or equal approved.
3.04 FIELD QUALITY CONTROL
A. Cable tests are to be carried out in accordance with the requirements of the
Regulations and Standards.
B. Test Equipment: provide megger testers of various ranges as applicable, and
HV test equipment as necessary for testing MV installations. Use 500V
Megger on installations with nominal voltage up to 500V, 1000 V megger
on installations with nominal voltage over 500V up to 1000V.
C. Insulation resistance tests for LV power and lighting installations is to be
measured in accordance with IEE Regulations 613-5 through 613-8 and
713-04.
12
D. Insulation resistance for control and signal cables is to be minimum 10000
Megohm-km for PVC insulated cables, all measured core-core and coreearth,
in accordance with the Regulations.
E. Prior to energize of circuitry, check installed wires and cables with megohm
meter to determine insulation resistance levels to ensure requirements are
fulfilled.
F. Prior to energize, test wires and cables for electrical continuity and for
short-circuits.
G. Subsequent to wire and cable hook-ups, energize circuitry and demonstrate
functioning in accordance with requirements. Where necessary, correct
malfunctioning units, and then retest to demonstrate compliance.
H. Perform tests prior to connecting equipment and in presence of authorized
representatives.
I. Submit written reports of test results.
END OF SECTION 16120
PART 1 - GENERAL
1.01 RELATED DOCUMENTS
A. Drawings and general provisions of Contract, including General and
Supplementary Conditions and Division 1 Specification Sections, apply to
this sections.
B. Requirements of the following Division 16 Sections apply to this section:
1. “ Basic Electrical Materials and Methods.”
1.02 SUMMARY
A. This Section includes wire
s, cables, and connectors for power, lighting
signal, control and related systems rated 600 volts and less. For special
wiring for individual systems, refer to respective section of these
specifications.
B. Extent of electrical wire and cable work is indicated by drawings and
schedules
C. Types of electrical wire, cable, and connectors specified in this section
include the following:
1. Single core copper conductor/cables
2. Multicore copper conductor/cables.
3. Fixtures wires
4. Control and signal cables.
D. Applications of electrical wire, cable, and connectors required for project
are as follows:
1. For power distribution circuits.
2. For lighting circuits.
3. For appliance and equipment circuits.
4. Foe motor-branch circuits.
5. For signal and control circuits where not specifically
required otherwise under other sections of the
specification.
E. Related Sections: The following sections contain requirements that relate
to this section:
2
1. Division 16 Section “Electrical Boxes, Cabinets and Fittings“ for
connectors for Terminating Cables in boxes and other electrical
enclosures.
2. Division 16 Section "MV Cables” for medium voltage distribution”.
3. Division 16 “Fire Alarm System: for fire alarm cables”
4. Division 16 Section "Wiring basket system” .
5. Division 16 Section "Cable Trays” .
1.03 SUBMITTALS
A. Product Data: submit manufacturer’s data on electrical wires, cables and
connectors.
B. Field Test Reports: indicating and interpreting test results relative to
compliance with performance requirements of testing standards.
C. Technical Data: submit data for approval including, but not limited to, the
following:
- Constructional details, standards to which cables comply, current
carrying capacities, derating factors for grouping and temperature.
- Manufacturer’s catalogue cuts.
- Dimensional and electrical characteristics.
- Samples of each cable and wire, if requested by the Engineer, other
accessories
D. Certificate of Origin: for each lot of cable supplies, provide a certificate of
origin issued by manufacturer stating origin, date of manufacture,
composition, standards to which it complies and test certificates.
E. Shop and Construction Drawings: submit drawings for approval including,
but not limited to, the following:
1. Exact routing layouts, sections and profiles of busducts, trays, feeder,
sub feeder cables and branch circuits, with indication of any equipment
to show and verify coordination between various trades.
2. Details, of supports and fixing for buses, trays and cables.
1. Details of connections to transformers, switchboards panelboards etc.
2. Details of terminations, splices and tapings where permitted, glands
and bushings at enclosures.
3. Number and size of conductors in conduit for all branch circuits in
accordance with final conduit routing.
F. Samples: Submit 25 cm length cables of each type and size of wires and
Cables, Manufacturer Name, insulation class and reference No. should be
indicated on the Submitted Sample.
1.04 QUALITY ASSURANCE:
3
A. Regulatory Requirements: Comply with provision of the statutory laws
having jurisdiction and local codes of practice applicable to the job site/host
country.
B. Current carrying capacities of conductors have been determined in
accordance with the Regulations for specified type of insulation and
expected conditions of installation No change will be accepted in specified
type of insulation unless warranted by special conditions and approved by
the Engineer. Check various loads and current carrying capacities and report
any discrepancies or insufficiency of size indicated to the Engineer.
C. Standards: wires and cables are to comply with IEC, BS, local codes or
other equally approved standards and are to bear the mark of identification
of the Standards to which they are manufactured. Wires and cables not
having this identification will be rejected.
D. Conform to applicable codes and regulations regarding toxicity of
combustion products of insulating materials.
E. Manufacturers: firms regularly engaged in manufacture of electrical wire
and cable products of types and sizes required, whose products have been in
satisfactory use in similar service for not less than 5 years.
1.05 DELIVERY STORAGE, AND HANDLING:
A. Deliver wire an cable properly packaged in factory-fabricated type
containers, wound on factory reels.
B. Store wire and cable in clean dry space in original containers. Protect
products from weather, damaging fumes, construction debris and traffic.
C. Handle wire and cable carefully to avoid abrasing, puncturing and tearing
wire and cable insulation and sheathing. Ensure that dielectric resistance
integrity of wires/cable is maintained.
PART 2 - PRODUCTS
2.01 MANUFACTURERS:
A. Available Manufacturers: subject to compliance with requirements,
Specifications, design drawings and regulations.
B. For approved manufacturers refer to the recommended manufacturer list.
2.02 WIRES AND CABLES
A. General: unless otherwise specified or shown on the Drawings, cables and
other feeders are to have copper conductors. Cable conductors are to be
stranded for sections 2.5 mm2 and above , based on IEC 228 Class 2. Signal
and control cables are to have solid conductors unless otherwise specified.
Flexible cords are to have finely stranded conductors. Conductors of single
4
and multi-core cables 25 mm2 and above are to be compacted. Multi-core
cables 35 mm2 and above are to be sectoral shape.
1. Conductor Sizes: are to be metric and as shown on the Drawings.
Conductors with cross-sectional area smaller than specified will not be
accepted.
2. Building Wiring Insulation: in the absence of a national code/regulation,
insulation is to be colour coded or otherwise identified as follows:
a) Neutral is to be black.
b) Protective earth is to be green or green/yellow striped.
c) Phase colour are to be selected in accordance with local regulations
and IEC standards, where not in contradiction with the local
regulations.
3. Copper conductors shall be stranded for sections 2.5mm2, and above.
Signal and control cables shall have solid conductors. Flexible cords shall
have finely stranded conductos.
4. The insulation of each conductor shall be colour coded or otherwise
identified as required by the Regulations. Colour coding shall be
maintained throughout the entire installation.
5. For each lot of cable supply a certificate of origin issued by the
manufacturer stating its origin, manufacture, constitution and standards to
which it complies with. In the absence of such documents, the Engineer
reserves the right to require that tests, at the Contractor's expense, be
performed by an official laboratory on samples taken from lots of cables
delivered to the site.
6. Cable installations whether so indicated or not shall include all joint and
their accessories at terminating ends or at tap-off points, earthing and
bonding etc. Carried to completion.
7. all cables shall be delivered to site with the manufacturer's seals, labels or
other proof of origin intact. Such labels and seals shall not be removed
until the cable is required for use, and shall be retained for inspection.
8. Unless otherwise specified herein or indicated on the drawings or in the
cable schedules all cable over sheaths shall be black.
9. Where cable sizes are not indicated on the drawings or in the cable
schedules, the contractor shall be responsible for determining the correct
size of each cable. Cable sizes shall be determined on the basis of current
rating and/or voltage drop and/or earth loop impedance, together within
allowance for grouping with other cables and the method of installation
whichever is relevant, after taking into account the type of cable, the
ambient conditions, the method of installation and the disposition of each
cable relative to other cables.
10. Wherever cables pass through walls, ceilings, partitions and the like, a
heavy gauge PVC sleeve shall be provided, of internal diameter greater by
5
at least 15mm, but no more than 25mm, than the diameter of the cable and
fire stopping Materials should be filled around cables.
11. The length of any such sleeve shall be such that each end projects by 5mm
beyond the surface of the element through which it passes, and the ends of
they bore shall be provided with an adequate radius to prevent chafing of
the cable sheath.
B. LV Wires:
1. Single Core PVC Insulated Wires: unless otherwise specified, single
conductor wires for wiring in conduit are to have annealed copper
consuctors, generally with concentric strands and insulated with flame
retardant, moisture and heat resistant PVC/D to IEC 227 (type 1 to BS
6746), suitable for wet locations and for conductor temperature of 70 deg
C. wires are to be 450/750 V grade.
C. LV Cables:
1. Multi-core PVC Insulated Cables (0.6/1 kV): to have annealed, copper
conductors, insulated with PVC/D to IEC 227 (type 1 to BS 6746), flame
retardant, moisture and heat resistant, suitable for wet locations and
conductor temperatures of 70 deg. C, laid up, bedded with suitable filler
and sheathed with PVC. Armour cables are to have single layer of
galvanized steel wire armour with PVC over sheath. Cables are to comply
with IEC 502 and IEC 540.
2. Multicore XLPE Insulated Feeder Cables (0.6/1 kV): single core annealed
copper conductors, XLPE insulated, for conductor temperature of 90 deg.
C, laid up and bedded with suitable non-hygroscopic material compatible
are to have single layer of galvanized steel wire applied helically over
extruded PVC bedding (which may be an integral part of filling) and over
sheathed with PVC, colour black. PVC oversheaths are to be type ST2 to
IEC 502.
3. Flexible Cable for Connection to Appliances, Window Fans, Pendants etc:
is to be 300/500 V grade to BS 6500, three or four core, with tinned finely
stranded copper wires, EPR insulated, twisted and sheathed with
chlorosulphonated polyethylene (CSP compound) and with strengthening
cord.
4. High Temperature Cable (similar to Perilli FP-200 Gold or equal): solid or
stranded plain annealed copper conductors to BS 6360(in sizes up to 4
mm2), extruded silicon rubber insulation to BS 6889 (0.6 mm radial
thickness), aluminum/PVC laminate and PVC composite sheath with
tinned earth continuity conductor/drain wire. Cable is to be rated 300/500
V, capable of accepting voltage surges up to 5 kV, to operate continuously
at 150deg C. and for short durations at 200 deg. C. It is to be certified to
have passed IEC 331 and IEC 332 flame resistance and fire retardant tests.
6
5. High Temperature Cable (similar to Perilli FP-400 or equal): plain copper
stranded circular conductor complying with BS 6360, Mica/Glass Fire
resistant tape covered by extruded cross-linked insulation comply with BS
7655 operating temperature 90OC, cables is to be rated 600/1000V. It is to
be certified to have passed IEC 331, BS 6387 categories CWZ, and IEC
332-1 flame resistance and fire retardant test. Cables are to be used to feed
the fire pumps. and other loads as shown on the drawings.
D. Control and Signal Cables
1. Multicore PVC Insulated Control Cables: 0.6/1 kV rating, solid 1.5mm2,
2.5 mm2 or stranded 4 mm2 plain circular copper conductors, with heat
resistive PVC/D to IEC 227(PVC type to BS 6747), rated for 70 deg. C, of
7, 12, 19, 24, 30 or 37 cores are to be laid up together and filled with nonhygroscopic
material, PVC over sheathed, to form compact and circular
cable for use in switchgear, control gear and generally for control of power
and lighting systems. Armoured cable is to have extruded PVC bedding
which may be an integral part of the filling, galvanized steel wire
armouring, and over sheath of PVC type ST2 to IEC 502, colour black.
Core identification is to be white printed numbers 1,2,3 etc. over black
insulation.
2. PE Insulated Control and Signal Cables: for use on instrumentation or data
systems, are to be generally 300 V rating, polyethylene insulated, colour
coded, tinned copper conductors(0.6 mm diameter), twisted together into
pairs Multi-pair core assembly is to be covered with binder tape, spirally
wound 0.075 mm bare copper shielding tape and provided with drain wire
and overall PVC sheath.
3. Control and Signal Cables, enclosed in conduit and raceways with power
cables, are to be insulated for same voltage grade. Cables used for
controlling equipment related to the life safety are to be of the fire
resistance type.
E. Connectors (LV Power)
1. Connector – Type A-1: pressure indent type, for terminating or making Ttaps
and splices on conductors 10 mm2 and smaller. Connector is to be
non-ferrous copper alloy applied to conductor by mechanical crimping
pressure, with vinyl insulating sleeves or phenolic insulating covers.
2. Connector – Type-A –2 bolted pressure split type for terminating or
making t-taps and splices on conductors 16 mm2 and large. Connector is
to be cast non-ferrous copper alloy applied to conductor by clamping with
minimum of two screws and provided with phenolic insulating cover.
3. Connector – Type B-1 : pre-insulated spring type, for branch circuit and
fixture wiring. Connector is to be steel encased spring with shell,
insulated with vinyl cap and skirt, type Scotchlok brand, as manufactured
by Minnesota Mining & Mfg. Co. or other equal and approved.
7
2.03 IDENTIFICATION OF CABLES AND WIRES
1. Except in the case where it is terminated in full view onto a clearly labeled
switch, starter, distribution board or similar piece of apparatus, or onto a
motor or other item of equipment the function of which is evident, each
and every cable end shall be provided with an approved means of
identification. In particular, this requirement shall apply to all cables
terminating on the back or in the base, of cubicle type or similar
switchboard or control panel and in any other case where the function of
the cable is not immediately obvious.
2. The means of identification shall be one or other of the following:-
i. An engraved brass label securely fixed to the cable sealing box.
ii. A stamped brass label securely tied to the cable with tinned copper
binding wire.
3. Self-adhesive embossed plastic labels will not be accepted as means of
identification.
4. The means of identification shall give the cable size, number of cores, and
function together with the cable reference number if one has been
allocated.
5. All cables run above ground shall be identified by means of engraved or
stamped brass label at intervals not exceeding 30 meters. The labels shall
bear details of the cable size, number of cores, function and reference
number (if any) and shall be securely attached to the cables with tinned
copper binding wires.
PART 3 - EXECUTION
3.01 INSTALLATION OF WIRES AND CABLES:
A. General: install electrical cables, wires and wiring connectors as indicated,
in compliance with applicable requirements of the Regulations/codes
applicable, and IEC, BS and in accordance with recognized industry
practices. Building wires and cables are to be installed in conduit, trunking
or ducts indoors and in conduit and ducts outdoors, unless shown otherwise
on the drawings.
B. Co-ordinate: wire/cable installation work including electrical raceway and
equipment installation work, as necessary to properly interface installation
of wires/cable with other work.
C. Run d.c. wiring in separate conduits than a.c. wiring.
D. Run: emergency lighting and power circuits in separate conduits from
normal wiring.
8
E. Use pulling compound or lubricant, where necessary, compound or
lubricant used must not deteriorate conductor or insulation and must be
approved by the Engineer.
F. Use pulling means including, fish tape, cable, rope and basket weave
wire/cable grips which will not damage cables or raceway.
G. Maintain colour coding throughout installation. Phase-conductors for which
outer jacket is not colour coded are to have engraved alphanumeric mark
(L1, L2, L3) or colour coded heat-shrinkable sleeves.
H. Buried Cables: cables buried directly in the ground are to be armoured type,
unless otherwise indicated in particular sections of the specification or on
the Drawings.
I. Install exposed cable, parallel and perpendicular to surfaces, or exposed
structural members, and follow surface contours, where possible.
J. Keep conductor splices to minimum. In case of splices, these are to be
inside splice boxes, pull or junction boxes.
K. Install splices and tapes which possess equivalent-or better mechanical
strength and insulation ratings than conductors being spliced.
L. Use splice and tap connectors which are compatible with conductor
material.
M. Tighten electrical connectors and terminals, including screws and bolts, in
accordance with manufacturer’s published torque tightening values. Where
manufacturer’s torquing requirements are not indicated, tighten connectors
and terminals to comply with tightening torques specified in recognized
standards.
N. Pull cables simultaneously where more than one cable is being installed in
the same raceway.
O. Branching of wires in raceways is to be in accordance with raceway filling
factors permitted by the Regulations.
P. Control cables may be fixes to racks, installed directly on cable trays or
pulled in conduit and trunking indoors, and in underground ducts or in
conduit outdoors.
Q. Bunching of wires in conduits check that inside of conduit (and raceway in
general) is free of burrs and is dry and clean.
R. Before: pulling wires in conduits check that inside of conduit (and raceway
in general) is free of burrs and is dry and clean.
9
S. Support: cables and wires pulled inside very high conduit risers are to be
supported at upper end of risers and at intermediate points by split rubber
grommets to relieve any stresses on conductors, where required.
T. Extra Length: at every branch circuit outlet and pull-box, every cable
passing through is to be left to allow inspection and for connections to be
made. Cables terminating in outlet boxes are to be left with at least 250mm
extra length for terminations.
U. Joints or taps in wires and cables, if permitted, are to be permanently
accessible or made only in boxes or cabinet gutters.
V. Connectors for terminating or making T-taps and splices are to be Type A-1
on conductors 10mm2 or smaller, Type A-2 for conductors 16mm2 and
larger, and Type B-1 for branch circuit and fixture wiring.
W. Insulating covers are to be applied to prevent exposure of bare cable
connections.
X. Switch legs for local wall, switches are to have distinctive colour, selected
as complementary to cable colour coding used in the project.
Y. Terminations: conductors of wires and cables up to 16 mm2 .are to be
tightly twisted and where possible doubled back before being clamped with
set screws. Where two or more wires are looped into same terminal these
conductors are to be tightly twisted together before inserting into terminals.
In no case is bare conductor to be allowed to project beyond any insulated
shrouding or mounting of a line terminal. Cables sizes 16mm2 and larger
are to terminate in tunnel lugs with set-screw, or by using bolted or sweated
compression connectors.
Z. Tagging: tag main and feeder cables in pull-boxes, wireways and wiring
gutters of panel boards or distribution cabinets. Tags are to identify cable or
circuit number and conductor size in accordance with the schedules.
AA. Tagging: where two or more circuits are run to or through a control device,
outlet box or ceiling junction box, each circuit is to be tagged as a guide in
making connections.
BB. Do not install thermoplastic wires in computer area raised floors.
3.02 FEEDER AND SUB-FEEDER CABLE INSTALLATION
A. Cables generally are to be run through duct-banks, shafts or special
recesses, clamped to steel racks or cable trays.
B. Fixing: single cables above suspended ceilings or in concealed spaces are to
be fixed directly to walls or ceilings but must be accessible. Where two or
more cables are run in parallel, they are to be fixed on galvanized steel
perforated trays or on other approved special cable supporting and
protecting arrangement.
10
C. Clamps: where cables are fixed to steel trays or supporting structures,
approved galvanized cast steel clamps (or moulded plastic or die cast
Aluminum clamps for single core cables) are to be used at distances not
exceeding 20 diameters. Cables shall be laid parallel in one plane, with the
exception of single core cables in “trefoil” formation, with a spacing
between cables equal to the larger of the two adjacent cables.
D. Joints or splices will not be accepted on main and sub-feeders. Cables are to
be supplied in lengths sufficient for straight-through unjointed termination
to termination pull.
E. Cables laid direct in the ground shall be at a minimum depth of 750 mm
below finished level A 100 mm tamped bedding and 100 mm tamped
covering of sifted soil or sand is to be provided with a tile cover all along
the route of the cables for protection. Surface cable markers shall be
provided on every change of direction and at 50 m intervals when in a
straight line. A tape marker shall be embedded at 100mm below ground
level, all along the cable trench.
F. Where cables are installed in underground ducts the ducts shall be laid with
a minimum covering of 700mm to finished level. The ends of the ducts
shall be sealed immediately after any cable installation. The ends of any
unused ducts shall be plugged and sealed.
1. Draw wires are to be left in all unused ducts.
2. Just before pulling cables in, ducts shall be cleared with a mandrel 13 mm
(1/2 inch) smaller than the internal diameter of the duct and followed by a
circular wire brush 13mm (1/2 inch) larger in diameter than the duct.
G. Directly buried cables crossing under roads, pipe banks or other services,
are to be drawn in heavy duty PVC duct banks. IN no case are cables to be
directly buried in concrete, in masonry or in floor finishing’s.
H. Buried cables liable to mechanical damage are to be drawn through PVC
conduit or asbestos cement pipe. If steel conduit is used, all three phase
conductors, neutral and protective earth circuits are to be in the same
conduit.
I. Where multiple runs occur the cables shall be installed such that crossovers
are avoided wherever practicable, if unavoidable, suitable separators for at
least 1m each side from the cross-point must be provided according to
approved details.
J. Where cables are run on ladder rack and cable tray, the size and routes of
the rack and tray shall be carefully selected taking into account other
services. In addition to these routes the Contractor shall include for any
vertical drops of cable tray and supporting brackets where cables drop from
the main runs to switchgear and equipment.
K. In situations where individual cables pass through walls, the cables shall be
sleeved and suitably sealed. Fire barriers are to be provide as necessary by
the safety Code applicable.
L. Cables rising from ground level up walls or stanchions shall be protected by
a substantial steel frame to a height of 1.5 meters Such framework shall be
approved by the Engineer prior to the commencement of work.
11
M. Exposure To Heat: route wires and cables to prevent exposure to excessive
heat or to corrosive agents. If such condition is unavoidable, cables are to
be type designed for particular condition.
N. Insulating covers are to be applied to prevent exposure of bare cable
connections. Insulating cover is to be purpose made and is to provide
minimum insulation level equal to that of conductor insulation.
O. Glands and cable boxes for various single-core and multicore cables are to
be purpose made and suitable for rigid mounting to equipment enclosure.
P. Cables shall be identified at regular intervals and terminations with
approved cable markers.
3.03 FEEDER CABLE JOINTING AND TERMINATING
A. Though joints will not be allowed in feeder cables where adequate
manufacturer’s lengths are available. Where a joint is necessary, it has to be
made inside boxes, handholds or manholes.
B. Recommendations: through Joints and terminations are to be carried out
strictly in accordance with cable manufacturer’s recommendations, and
made with correct specified materials, boxes, tapes, compounds or
mixtures, glands and bonds as applicable.
C. Jointing skilled operatives are to be employed for jointing of cables.
Qualifications of operatives are to be submitted to the Engineer prior to
work commencing on site joints are to be filled with epoxy resin after
taping unless commencing on site. Joints are to be filled with epoxy resin
after taping unless contrary to cable manufacturer’s recommendations.
Samples site constructed cable terminations and through-joints are to be
submitted to the Engineer prior to commencing work on site. Samples are
to be constructed in the presence of the Engineer and are to be available to
the Engineer for test and inspection in accordance with manufacturer’s
recommendations.
D. Cutting tools for jointing and terminating cables are to be purpose made, to
prevent damage to insulation in general, and to cable sheathing.
E. Cleaning of lacquer on conductors is to be by use of “Sponge and white
spirit or equal approved.
3.04 FIELD QUALITY CONTROL
A. Cable tests are to be carried out in accordance with the requirements of the
Regulations and Standards.
B. Test Equipment: provide megger testers of various ranges as applicable, and
HV test equipment as necessary for testing MV installations. Use 500V
Megger on installations with nominal voltage up to 500V, 1000 V megger
on installations with nominal voltage over 500V up to 1000V.
C. Insulation resistance tests for LV power and lighting installations is to be
measured in accordance with IEE Regulations 613-5 through 613-8 and
713-04.
12
D. Insulation resistance for control and signal cables is to be minimum 10000
Megohm-km for PVC insulated cables, all measured core-core and coreearth,
in accordance with the Regulations.
E. Prior to energize of circuitry, check installed wires and cables with megohm
meter to determine insulation resistance levels to ensure requirements are
fulfilled.
F. Prior to energize, test wires and cables for electrical continuity and for
short-circuits.
G. Subsequent to wire and cable hook-ups, energize circuitry and demonstrate
functioning in accordance with requirements. Where necessary, correct
malfunctioning units, and then retest to demonstrate compliance.
H. Perform tests prior to connecting equipment and in presence of authorized
representatives.
I. Submit written reports of test results.
END OF SECTION 16120
No comments:
Post a Comment